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From b654564713dfdba38ccd82d72b129b58d06a85d0 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Stefan=20Br=C3=BCns?= <stefan.bruens@rwth-aachen.de>
Date: Mon, 15 Jul 2019 20:04:01 +0200
Subject: [PATCH] Fix OpenMP 4.0 issues with GCC9

Backport of pull request #2550.
---
 CMakeLists.txt                  | 72 ++++++++----------------
 ConfigureChecks.cmake           | 30 ++++++++++
 DefineOptions.cmake             | 44 +++++++++++++++
 src/CMakeLists.txt              |  2 -
 src/chart/cairo.c               |  5 +-
 src/chart/main.c                | 16 ++++--
 src/common/bilateral.c          | 18 ++++--
 src/common/color_picker.c       |  9 ++-
 src/common/darktable.h          | 24 ++++++--
 src/common/dwt.c                | 20 +++++--
 src/common/focus.h              | 10 +++-
 src/common/gaussian.c           | 22 ++++++--
 src/common/heal.c               | 22 ++++++--
 src/common/histogram.c          | 10 +++-
 src/common/imageio.c            | 34 ++++++++---
 src/common/imageio_rawspeed.cc  | 10 +++-
 src/common/interpolation.c      | 16 ++++--
 src/common/locallaplacian.c     | 99 ++++++++++++++++++++++++++-------
 src/common/opencl.c             |  8 ++-
 src/config.cmake.h              |  2 +
 src/control/jobs/control_jobs.c |  5 +-
 src/develop/blend.c             | 36 ++++++++----
 src/develop/imageop_math.c      | 55 ++++++++++++++----
 src/develop/imageop_math.h      |  5 +-
 src/develop/masks/circle.c      | 12 +++-
 src/develop/masks/ellipse.c     | 12 +++-
 src/develop/masks/gradient.c    | 24 ++++++--
 src/develop/masks/group.c       | 24 ++++++--
 src/develop/pixelpipe_hb.c      | 15 ++++-
 src/develop/tiling.c            | 35 +++++++++---
 src/gui/draw.h                  | 11 +++-
 src/iop/ashift.c                | 50 +++++++++++++----
 src/iop/atrous.c                | 33 ++++++++---
 src/iop/basecurve.c             | 48 ++++++++++++----
 src/iop/bilateral.cc            |  6 +-
 src/iop/bloom.c                 | 20 +++++--
 src/iop/channelmixer.c          |  5 +-
 src/iop/clahe.c                 | 11 +++-
 src/iop/clipping.c              | 11 +++-
 src/iop/colisa.c                | 15 ++++-
 src/iop/colorbalance.c          | 39 +++++++++++--
 src/iop/colorchecker.c          |  5 +-
 src/iop/colorcontrast.c         | 14 ++++-
 src/iop/colorin.c               | 50 +++++++++++++----
 src/iop/colorize.c              |  5 +-
 src/iop/colormapping.c          | 15 ++++-
 src/iop/colorout.c              | 16 ++++--
 src/iop/colorreconstruction.c   | 11 +++-
 src/iop/colortransfer.c         | 15 ++++-
 src/iop/colorzones.c            |  5 +-
 src/iop/defringe.c              | 14 +++--
 src/iop/demosaic.c              | 71 ++++++++++++++++++-----
 src/iop/denoiseprofile.c        | 64 ++++++++++++++++-----
 src/iop/dither.c                | 12 +++-
 src/iop/equalizer_eaw.h         | 22 ++++++--
 src/iop/exposure.c              |  8 ++-
 src/iop/filmic.c                | 16 +++++-
 src/iop/gamma.c                 | 16 ++++--
 src/iop/globaltonemap.c         | 15 ++++-
 src/iop/graduatednd.c           | 20 +++++--
 src/iop/grain.c                 |  5 +-
 src/iop/hazeremoval.c           | 41 ++++++++++----
 src/iop/highlights.c            | 44 +++++++++++----
 src/iop/highpass.c              | 10 +++-
 src/iop/hotpixels.c             | 13 ++++-
 src/iop/invert.c                | 27 +++++++--
 src/iop/lens.c                  | 46 ++++++++++++---
 src/iop/levels.c                |  4 +-
 src/iop/liquify.c               |  4 +-
 src/iop/lowlight.c              |  5 +-
 src/iop/lowpass.c               | 15 ++++-
 src/iop/monochrome.c            | 10 +++-
 src/iop/nlmeans.c               | 22 ++++++--
 src/iop/overexposed.c           |  5 +-
 src/iop/profile_gamma.c         | 20 +++++--
 src/iop/rawdenoise.c            | 48 ++++++++++++----
 src/iop/rawoverexposed.c        | 12 +++-
 src/iop/rawprepare.c            | 26 +++++++--
 src/iop/relight.c               |  5 +-
 src/iop/retouch.c               | 65 +++++++++++++++++-----
 src/iop/rotatepixels.c          |  5 +-
 src/iop/scalepixels.c           |  5 +-
 src/iop/shadhi.c                | 13 ++++-
 src/iop/sharpen.c               | 41 ++++++++++----
 src/iop/soften.c                | 38 ++++++++++---
 src/iop/splittoning.c           |  6 +-
 src/iop/spots.c                 |  4 +-
 src/iop/temperature.c           | 30 ++++++++--
 src/iop/tonecurve.c             |  6 +-
 src/iop/velvia.c                |  9 ++-
 src/iop/vibrance.c              |  5 +-
 src/iop/vignette.c              |  6 +-
 src/iop/zonesystem.c            | 29 ++++++++--
 93 files changed, 1519 insertions(+), 444 deletions(-)
 create mode 100644 ConfigureChecks.cmake
 create mode 100644 DefineOptions.cmake

diff --git a/CMakeLists.txt b/CMakeLists.txt
index 5b783d1..ce4047b 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -33,15 +33,7 @@ IF(DEFINED DT_FORCE_CXX_COMPILER)
   set(CMAKE_CXX_COMPILER ${DT_FORCE_CXX_COMPILER})
 endif()
 
-include(CheckCCompilerFlag)
-include(TestBigEndian)
-
-# Check if this is source package build
-if(NOT IS_DIRECTORY ${CMAKE_SOURCE_DIR}/.git)
-  set(SOURCE_PACKAGE 1)
-else()
-  set(SOURCE_PACKAGE 0)
-endif()
+include(DefineOptions.cmake)
 
 # Include GNUInstallDirs, which sets sensible defaults for install directories.
 # See https://cmake.org/cmake/help/v3.0/module/GNUInstallDirs.html for further information.
@@ -50,41 +42,31 @@ endif()
 
 include(GNUInstallDirs)
 
-option(USE_CAMERA_SUPPORT "Detect and use camera support if available." ON)
-option(USE_NLS "Build Native Language Support (using gettext)" ON)
-option(USE_COLORD "Enable colord support" ON)
-option(USE_MAP "Build Map View parts" ON)
-option(USE_LUA "Build lua scripting support" ON)
-option(DONT_USE_INTERNAL_LUA "Never fall back to the intree copy of lua" ON)
-option(USE_FLICKR "Enable Flickr support" ON)
-option(USE_KWALLET "Build kwallet password storage back-end" ON)
-option(USE_LIBSECRET "Build libsecret password storage back-end" ON)
-option(USE_UNITY "Use libunity to report progress in the launcher" OFF)
-option(USE_OPENMP "Use openmp threading support." ON)
-option(USE_OPENCL "Use OpenCL support." ON)
-option(USE_GRAPHICSMAGICK "Use GraphicsMagick library for image import." ON)
-option(USE_DARKTABLE_PROFILING OFF)
-option(CUSTOM_CFLAGS "Don't override compiler optimization flags." OFF)
-option(BUILD_USERMANUAL "Build all the versions of the usermanual." OFF)
-option(BINARY_PACKAGE_BUILD "Sets march optimization to generic" OFF)
-option(USE_XMLLINT "Run xmllint to test if darktableconfig.xml is valid" ON)
-option(USE_OPENJPEG "Enable JPEG 2000 support" ON)
-option(USE_WEBP "Enable WebP export support" ON)
-option(BUILD_CMSTEST "Build a test program to check your system's color management setup" ON)
-option(USE_OPENEXR "Enable OpenEXR support" ON)
-option(BUILD_PRINT "Build the print module" ON)
-option(BUILD_RS_IDENTIFY "Build the darktable-rs-identify debug aid" ON)
-option(BUILD_SSE2_CODEPATHS "(EXPERIMENTAL OPTION, DO NOT DISABLE) Building SSE2-optimized codepaths" ON)
-option(VALIDATE_APPDATA_FILE "Use appstream-util (if found) to validate the .appdata file" OFF)
-option(BUILD_TESTS "Build tests in src/tests/, runnable from the build/ directory" OFF)
-option(BUILD_BATTERY_INDICATOR "Add an icon to the top toolbar showing the state of a laptop battery" OFF)
-option(BUILD_MSYS2_INSTALL "Build an MSYS2 version of the install, aka for Windows platform, but without dependency installs" OFF)
-option(BUILD_NOISE_TOOLS "Build tools for generating noise proifles" OFF)
+if (USE_OPENMP)
+    if (CMAKE_CXX_COMPILER_ID STREQUAL "Clang" OR
+        CMAKE_CXX_COMPILER_ID STREQUAL "AppleClang")
 
-if(USE_OPENCL)
-  option(TESTBUILD_OPENCL_PROGRAMS "Test-compile opencl programs (needs llvm and clang 3.9+)" ON)
+        # Clang has an option to specify the OpenMP standard to use. Specify it.
+        # FIXME: Implement this in FindOpenMP.cmake
+        set(OPENMP_VERSION_SPECIFIER "-fopenmp-version=40")
+
+        set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} ${OPENMP_VERSION_SPECIFIER}")
+        set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} ${OPENMP_VERSION_SPECIFIER}")
+    endif()
+
+    find_package(OpenMP 4.0 REQUIRED)
+endif()
+
+include(ConfigureChecks.cmake)
+
+include(CheckCCompilerFlag)
+include(TestBigEndian)
+
+# Check if this is source package build
+if(NOT IS_DIRECTORY ${CMAKE_SOURCE_DIR}/.git)
+  set(SOURCE_PACKAGE 1)
 else()
-  set(TESTBUILD_OPENCL_PROGRAMS OFF)
+  set(SOURCE_PACKAGE 0)
 endif()
 
 if(BUILD_SSE2_CODEPATHS)
@@ -122,12 +104,6 @@ MESSAGE(STATUS "Is the target platform supported: ${IS_SUPPORTED_PLATFORM}")
 set(CMAKE_REQUIRED_INCLUDES "${CMAKE_REQUIRED_INCLUDES_OLD}")
 unset(CMAKE_REQUIRED_INCLUDES_OLD)
 
-if(APPLE)
-	option(USE_MAC_INTEGRATION "Enable OS X integration" ON)
-else(APPLE)
-	set(USE_MAC_INTEGRATION OFF)
-endif(APPLE)
-
 # When cross compiling, CMAKE_INSTALL_PREFIX will point to something like "/opt/darktable", but that's not useful when using the path to load
 # modules on runtime. Then we need something like "C:\Program Files\darktable". Doesn't need to be set when doing regular compiles.
 if(NOT DEFINED RUNTIME_INSTALL_PREFIX)
diff --git a/DefineOptions.cmake b/DefineOptions.cmake
new file mode 100644
index 0000000..b49c21b
--- /dev/null
+++ b/DefineOptions.cmake
@@ -0,0 +1,44 @@
+option(USE_CAMERA_SUPPORT "Detect and use camera support if available." ON)
+option(USE_NLS "Build Native Language Support (using gettext)" ON)
+option(USE_COLORD "Enable colord support" ON)
+option(USE_MAP "Build Map View parts" ON)
+option(USE_LUA "Build lua scripting support" ON)
+option(DONT_USE_INTERNAL_LUA "Never fall back to the intree copy of lua" ON)
+option(USE_FLICKR "Enable Flickr support" ON)
+option(USE_KWALLET "Build kwallet password storage back-end" ON)
+option(USE_LIBSECRET "Build libsecret password storage back-end" ON)
+option(USE_UNITY "Use libunity to report progress in the launcher" OFF)
+option(USE_OPENMP "Use openmp threading support." ON)
+option(USE_OPENCL "Use OpenCL support." ON)
+option(USE_GRAPHICSMAGICK "Use GraphicsMagick library for image import." ON)
+option(USE_DARKTABLE_PROFILING OFF)
+option(CUSTOM_CFLAGS "Don't override compiler optimization flags." OFF)
+option(BUILD_USERMANUAL "Build all the versions of the usermanual." OFF)
+option(BINARY_PACKAGE_BUILD "Sets march optimization to generic" OFF)
+option(USE_XMLLINT "Run xmllint to test if darktableconfig.xml is valid" ON)
+option(USE_OPENJPEG "Enable JPEG 2000 support" ON)
+option(USE_WEBP "Enable WebP export support" ON)
+option(BUILD_CMSTEST "Build a test program to check your system's color management setup" ON)
+option(USE_OPENEXR "Enable OpenEXR support" ON)
+option(BUILD_PRINT "Build the print module" ON)
+option(BUILD_RS_IDENTIFY "Build the darktable-rs-identify debug aid" ON)
+option(BUILD_SSE2_CODEPATHS "(EXPERIMENTAL OPTION, DO NOT DISABLE) Building SSE2-optimized codepaths" ON)
+option(VALIDATE_APPDATA_FILE "Use appstream-util (if found) to validate the .appdata file" OFF)
+option(BUILD_TESTS "Build tests in src/tests/, runnable from the build/ directory" OFF)
+option(BUILD_BATTERY_INDICATOR "Add an icon to the top toolbar showing the state of a laptop battery" OFF)
+option(BUILD_MSYS2_INSTALL "Build an MSYS2 version of the install, aka for Windows platform, but without dependency installs" OFF)
+option(BUILD_NOISE_TOOLS "Build tools for generating noise proifles" OFF)
+option(BUILD_CURVE_TOOLS "Build tools for generating base and tone curves" OFF)
+option(USE_LENSFUN "Enable LensFun support" ON)
+
+if (USE_OPENCL)
+    option(TESTBUILD_OPENCL_PROGRAMS "Test-compile opencl programs (needs llvm and clang 3.9+)" ON)
+else ()
+    set(TESTBUILD_OPENCL_PROGRAMS OFF)
+endif ()
+
+if(APPLE)
+    option(USE_MAC_INTEGRATION "Enable OS X integration" ON)
+else(APPLE)
+    set(USE_MAC_INTEGRATION OFF)
+endif(APPLE)
diff --git a/src/CMakeLists.txt b/src/CMakeLists.txt
index 0ed087d..d01dc6b 100644
--- a/src/CMakeLists.txt
+++ b/src/CMakeLists.txt
@@ -225,8 +225,6 @@ list(APPEND LIBS "${CMAKE_THREAD_LIBS_INIT}")
 # Need to explicitly link against math library.
 list(APPEND LIBS "-lm")
 
-# Check for openmp
-find_package(OpenMP)
 if(USE_OPENMP)
   if(OpenMP_C_FLAGS)
     set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} ${OpenMP_C_FLAGS}")
diff --git a/ConfigureChecks.cmake b/ConfigureChecks.cmake
new file mode 100644
index 0000000..58d229a
--- /dev/null
+++ b/ConfigureChecks.cmake
@@ -0,0 +1,30 @@
+include(CheckCSourceCompiles)
+
+if (OpenMP_FOUND)
+
+set(CMAKE_REQUIRED_FLAGS ${OpenMP_C_FLAGS})
+set(CMAKE_REQUIRED_LIBRARIES ${OpenMP_C_LIBRARIES})
+check_c_source_compiles("
+#include <omp.h>
+
+static void sink(const int x, int a[])
+{
+#pragma omp parallel for default(none) firstprivate(x) shared(a)
+    for(int i = 0; i < 3; i++) {
+        a[i] = x + i;
+    }
+}
+
+int main(void)
+{
+    int x = 42;
+    int a[3] = {0};
+
+    sink(x, a);
+
+    return 0;
+}" HAVE_OMP_FIRSTPRIVATE_WITH_CONST)
+
+set(CMAKE_REQUIRED_FLAGS)
+set(CMAKE_REQUIRED_LIBRARIES)
+endif()
diff --git a/src/config.cmake.h b/src/config.cmake.h
index 715ea48..bdd72c9 100644
--- a/src/config.cmake.h
+++ b/src/config.cmake.h
@@ -66,6 +66,8 @@ static const char *dt_supported_extensions[] __attribute__((unused)) = {"@DT_SUP
 #define ASAN_UNPOISON_MEMORY_REGION(addr, size) ((void)(addr), (void)(size))
 #endif
 
+#cmakedefine HAVE_OMP_FIRSTPRIVATE_WITH_CONST 1
+
 // modelines: These editor modelines have been set for all relevant files by tools/update_modelines.sh
 // vim: shiftwidth=2 expandtab tabstop=2 cindent
 // kate: tab-indents: off; indent-width 2; replace-tabs on; indent-mode cstyle; remove-trailing-spaces modified;
diff --git a/src/common/darktable.h b/src/common/darktable.h
index 25e8d46..5bdcbf8 100644
--- a/src/common/darktable.h
+++ b/src/common/darktable.h
@@ -75,11 +75,23 @@ typedef unsigned int u_int;
 #endif
 
 #ifdef _OPENMP
-#include <omp.h>
-#else
-#define omp_get_max_threads() 1
-#define omp_get_thread_num() 0
-#endif
+# include <omp.h>
+
+/* See https://redmine.darktable.org/issues/12568#note-14 */
+# ifdef HAVE_OMP_FIRSTPRIVATE_WITH_CONST
+   /* If the compiler correctly supports firstprivate, use it. */
+#  define dt_omp_firstprivate(...) firstprivate(__VA_ARGS__)
+# else /* HAVE_OMP_FIRSTPRIVATE_WITH_CONST */
+   /* This is needed for clang < 7.0 */
+#  define dt_omp_firstprivate(...)
+# endif/* HAVE_OMP_FIRSTPRIVATE_WITH_CONST */
+
+#else /* _OPENMP */
+
+# define omp_get_max_threads() 1
+# define omp_get_thread_num() 0
+
+#endif /* _OPENMP */
 
 #ifndef _RELEASE
 #include "common/poison.h"
@@ -542,7 +554,7 @@ int dt_load_from_string(const gchar *image_to_load, gboolean open_image_in_dr, g
 
 #define dt_unreachable_codepath_with_desc(D)                                                                 \
   dt_unreachable_codepath_with_caller(D, __FILE__, __LINE__, __FUNCTION__)
-#define dt_unreachable_codepath() dt_unreachable_codepath_with_caller(NULL, __FILE__, __LINE__, __FUNCTION__)
+#define dt_unreachable_codepath() dt_unreachable_codepath_with_caller("unreachable", __FILE__, __LINE__, __FUNCTION__)
 static inline void dt_unreachable_codepath_with_caller(const char *description, const char *file,
                                                        const int line, const char *function)
 {
diff --git a/src/common/bilateral.c b/src/common/bilateral.c
index 2708eea..ac67210 100644
--- a/src/common/bilateral.c
+++ b/src/common/bilateral.c
@@ -127,7 +127,7 @@ void dt_bilateral_splat(dt_bilateral_t *b, const float *const in)
   const int oz = b->size_y * b->size_x;
 // splat into downsampled grid
 #ifdef _OPENMP
-#pragma omp parallel for default(none) shared(b)
+#pragma omp parallel for default(none) dt_omp_firstprivate(in, oy, oz) shared(b)
 #endif
   for(int j = 0; j < b->height; j++)
   {
@@ -170,7 +170,9 @@ static void blur_line_z(float *buf, const int offset1, const int offset2, const
   const float w1 = 4.f / 16.f;
   const float w2 = 2.f / 16.f;
 #ifdef _OPENMP
-#pragma omp parallel for default(none) shared(buf)
+#pragma omp parallel for default(none) \
+    dt_omp_firstprivate(size1, size2, size3, offset1, offset2, offset3) \
+    shared(buf)
 #endif
   for(int k = 0; k < size1; k++)
   {
@@ -208,7 +210,9 @@ static void blur_line(float *buf, const int offset1, const int offset2, const in
   const float w1 = 4.f / 16.f;
   const float w2 = 1.f / 16.f;
 #ifdef _OPENMP
-#pragma omp parallel for default(none) shared(buf)
+#pragma omp parallel for default(none) \
+    dt_omp_firstprivate(size1, size2, size3, offset1, offset2, offset3) \
+    shared(buf)
 #endif
   for(int k = 0; k < size1; k++)
   {
@@ -260,7 +264,9 @@ void dt_bilateral_slice(const dt_bilateral_t *const b, const float *const in, fl
   const int oy = b->size_x;
   const int oz = b->size_y * b->size_x;
 #ifdef _OPENMP
-#pragma omp parallel for default(none) shared(out)
+#pragma omp parallel for default(none) \
+    dt_omp_firstprivate(b, in, norm, oy, oz) \
+    shared(out)
 #endif
   for(int j = 0; j < b->height; j++)
   {
@@ -306,7 +312,9 @@ void dt_bilateral_slice_to_output(const dt_bilateral_t *const b, const float *co
   const int oy = b->size_x;
   const int oz = b->size_y * b->size_x;
 #ifdef _OPENMP
-#pragma omp parallel for default(none) shared(out)
+#pragma omp parallel for default(none) \
+    dt_omp_firstprivate(b, in, norm, oy, oz) \
+    shared(out)
 #endif
   for(int j = 0; j < b->height; j++)
   {
diff --git a/src/common/color_picker.c b/src/common/color_picker.c
index 76875d4..45c49a2 100644
--- a/src/common/color_picker.c
+++ b/src/common/color_picker.c
@@ -79,7 +79,8 @@ static void color_picker_helper_4ch_parallel(const dt_iop_buffer_dsc_t *dsc, con
   }
 
 #ifdef _OPENMP
-#pragma omp parallel default(none)
+#pragma omp parallel default(none) \
+  dt_omp_firstprivate(w, pixel, width, box, mean, mmin, mmax)
 #endif
   {
     const int tnum = dt_get_thread_num();
@@ -199,7 +200,8 @@ static void color_picker_helper_bayer_parallel(const dt_iop_buffer_dsc_t *const
   }
 
 #ifdef _OPENMP
-#pragma omp parallel default(none)
+#pragma omp parallel default(none) \
+  dt_omp_firstprivate(pixel, width, roi, filters, box, msum, mmin, mmax, cnt)
 #endif
   {
     const int tnum = dt_get_thread_num();
@@ -326,7 +328,8 @@ static void color_picker_helper_xtrans_parallel(const dt_iop_buffer_dsc_t *const
   }
 
 #ifdef _OPENMP
-#pragma omp parallel default(none)
+#pragma omp parallel default(none) \
+  dt_omp_firstprivate(pixel, width, roi, xtrans, box, cnt, msum, mmin, mmax)
 #endif
   {
     const int tnum = dt_get_thread_num();
diff --git a/src/common/dwt.c b/src/common/dwt.c
index eb37224..0fedbe8 100644
--- a/src/common/dwt.c
+++ b/src/common/dwt.c
@@ -194,7 +194,10 @@ static void dwt_add_layer_sse(float *const img, float *layers, dwt_params_t *con
   const int i_size = p->width * p->height * 4;
 
 #ifdef _OPENMP
-#pragma omp parallel for default(none) shared(layers) schedule(static)
+#pragma omp parallel for default(none) \
+  dt_omp_firstprivate(img, i_size) \
+  shared(layers) \
+  schedule(static)
 #endif
   for(int i = 0; i < i_size; i += 4)
   {
@@ -216,7 +219,10 @@ static void dwt_add_layer(float *const img, float *layers, dwt_params_t *const p
   const int i_size = p->width * p->height * p->ch;
 
 #ifdef _OPENMP
-#pragma omp parallel for default(none) shared(layers) schedule(static)
+#pragma omp parallel for default(none) \
+  dt_omp_firstprivate(img, i_size) \
+  shared(layers) \
+  schedule(static)
 #endif
   for(int i = 0; i < i_size; i++) layers[i] += img[i];
 }
@@ -233,7 +239,10 @@ static void dwt_subtract_layer_sse(float *bl, float *bh, dwt_params_t *const p)
   const int size = p->width * p->height * 4;
 
 #ifdef _OPENMP
-#pragma omp parallel for default(none) shared(bl, bh) schedule(static)
+#pragma omp parallel for default(none) \
+  dt_omp_firstprivate(v4_lpass_mult, size) \
+  shared(bl, bh) \
+  schedule(static)
 #endif
   for(int i = 0; i < size; i += 4)
   {
@@ -258,7 +267,10 @@ static void dwt_subtract_layer(float *bl, float *bh, dwt_params_t *const p)
   const int size = p->width * p->height * p->ch;
 
 #ifdef _OPENMP
-#pragma omp parallel for default(none) shared(bl, bh) schedule(static)
+#pragma omp parallel for default(none) \
+  dt_omp_firstprivate(size) \
+  shared(bl, bh) \
+  schedule(static)
 #endif
   for(int i = 0; i < size; i++)
   {
diff --git a/src/common/gaussian.c b/src/common/gaussian.c
index 545377e..0798060 100644
--- a/src/common/gaussian.c
+++ b/src/common/gaussian.c
@@ -173,8 +173,10 @@ void dt_gaussian_blur(dt_gaussian_t *g, const float *const in, float *const out)
 
 // vertical blur column by column
 #ifdef _OPENMP
-#pragma omp parallel for default(none) shared(temp, Labmin, Labmax, a0, a1, a2, a3, b1, b2, coefp,           \
-                                              coefn) schedule(static)
+#pragma omp parallel for default(none) \
+  dt_omp_firstprivate(in, width, height, ch) \
+  shared(temp, Labmin, Labmax, a0, a1, a2, a3, b1, b2, coefp, coefn) \
+  schedule(static)
 #endif
   for(int i = 0; i < width; i++)
   {
@@ -245,8 +247,10 @@ void dt_gaussian_blur(dt_gaussian_t *g, const float *const in, float *const out)
 
 // horizontal blur line by line
 #ifdef _OPENMP
-#pragma omp parallel for default(none) shared(temp, Labmin, Labmax, a0, a1, a2, a3, b1, b2, coefp,           \
-                                              coefn) schedule(static)
+#pragma omp parallel for default(none) \
+  dt_omp_firstprivate(out, ch, width, height) \
+  shared(temp, Labmin, Labmax, a0, a1, a2, a3, b1, b2, coefp, coefn) \
+  schedule(static)
 #endif
   for(int j = 0; j < height; j++)
   {
@@ -340,7 +344,10 @@ static void dt_gaussian_blur_4c_sse(dt_gaussian_t *g, const float *const in, flo
 
 // vertical blur column by column
 #ifdef _OPENMP
-#pragma omp parallel for default(none) shared(temp, a0, a1, a2, a3, b1, b2, coefp, coefn) schedule(static)
+#pragma omp parallel for default(none) \
+  dt_omp_firstprivate(in, Labmin, Labmax, width, height) \
+  shared(temp, a0, a1, a2, a3, b1, b2, coefp, coefn) \
+  schedule(static)
 #endif
   for(int i = 0; i < width; i++)
   {
@@ -408,7 +415,10 @@ static void dt_gaussian_blur_4c_sse(dt_gaussian_t *g, const float *const in, flo
 
 // horizontal blur line by line
 #ifdef _OPENMP
-#pragma omp parallel for default(none) shared(temp, a0, a1, a2, a3, b1, b2, coefp, coefn) schedule(static)
+#pragma omp parallel for default(none) \
+  dt_omp_firstprivate(out, Labmin, Labmax, width, height) \
+  shared(temp, a0, a1, a2, a3, b1, b2, coefp, coefn) \
+  schedule(static)
 #endif
   for(size_t j = 0; j < height; j++)
   {
diff --git a/src/common/heal.c b/src/common/heal.c
index 37e53eb..56ae231 100644
--- a/src/common/heal.c
+++ b/src/common/heal.c
@@ -54,7 +54,10 @@ static void dt_heal_sub(const float *const top_buffer, const float *const bottom
   const int i_size = width * height * ch;
 
 #ifdef _OPENMP
-#pragma omp parallel for default(none) shared(result_buffer) schedule(static)
+#pragma omp parallel for default(none) \
+  dt_omp_firstprivate(top_buffer, bottom_buffer, i_size) \
+  shared(result_buffer) \
+  schedule(static)
 #endif
   for(int i = 0; i < i_size; i++) result_buffer[i] = top_buffer[i] - bottom_buffer[i];
 }
@@ -66,7 +69,10 @@ static void dt_heal_add(const float *const first_buffer, const float *const seco
   const int i_size = width * height * ch;
 
 #ifdef _OPENMP
-#pragma omp parallel for default(none) shared(result_buffer) schedule(static)
+#pragma omp parallel for default(none) \
+  dt_omp_firstprivate(first_buffer, second_buffer, i_size) \
+  shared(result_buffer) \
+  schedule(static)
 #endif
   for(int i = 0; i < i_size; i++) result_buffer[i] = first_buffer[i] + second_buffer[i];
 }
@@ -78,7 +84,11 @@ static float dt_heal_laplace_iteration_sse(float *pixels, const float *const Adi
   float err = 0.f;
 
 #ifdef _OPENMP
-#pragma omp parallel for default(none) shared(pixels) schedule(static) reduction(+ : err)
+#pragma omp parallel for default(none) \
+  dt_omp_firstprivate(Adiag, Aidx, w, nmask_from, nmask_to) \
+  shared(pixels) \
+  schedule(static) \
+  reduction(+ : err)
 #endif
   for(int i = nmask_from; i < nmask_to; i++)
   {
@@ -135,7 +145,11 @@ static float dt_heal_laplace_iteration(float *pixels, const float *const Adiag,
   const int ch1 = (ch == 4) ? ch - 1 : ch;
 
 #ifdef _OPENMP
-#pragma omp parallel for default(none) shared(pixels) schedule(static) reduction(+ : err)
+#pragma omp parallel for default(none) \
+  dt_omp_firstprivate(Adiag, Aidx, w, nmask_from, nmask_to, ch1) \
+  shared(pixels) \
+  schedule(static) \
+  reduction(+ : err)
 #endif
   for(int i = nmask_from; i < nmask_to; i++)
   {
diff --git a/src/common/histogram.c b/src/common/histogram.c
index 2fccdd3..b7bbfd7 100644
--- a/src/common/histogram.c
+++ b/src/common/histogram.c
@@ -217,7 +217,10 @@ void dt_histogram_worker(dt_dev_histogram_collection_params_t *const histogram_p
   const dt_histogram_roi_t *const roi = histogram_params->roi;
 
 #ifdef _OPENMP
-#pragma omp parallel for schedule(static) default(none) shared(partial_hists)
+#pragma omp parallel for default(none) \
+  dt_omp_firstprivate(histogram_params, pixel, Worker, bins_total, roi) \
+  shared(partial_hists) \
+  schedule(static)
 #endif
   for(int j = roi->crop_y; j < roi->height - roi->crop_height; j++)
   {
@@ -230,7 +233,10 @@ void dt_histogram_worker(dt_dev_histogram_collection_params_t *const histogram_p
   memset(*histogram, 0, buf_size);
   uint32_t *hist = *histogram;
 
-#pragma omp parallel for schedule(static) default(none) shared(hist, partial_hists)
+#pragma omp parallel for default(none) \
+  dt_omp_firstprivate(nthreads, bins_total) \
+  shared(hist, partial_hists) \
+  schedule(static)
   for(size_t k = 0; k < bins_total; k++)
   {
     for(size_t n = 0; n < nthreads; n++)
diff --git a/src/common/imageio.c b/src/common/imageio.c
index c82cdb5..f1ac149 100644
--- a/src/common/imageio.c
+++ b/src/common/imageio.c
@@ -182,7 +182,10 @@ void dt_imageio_flip_buffers(char *out, const char *in, const size_t bpp, const
   if(!orientation)
   {
 #ifdef _OPENMP
-#pragma omp parallel for schedule(static) default(none) shared(in, out)
+#pragma omp parallel for default(none) \
+    dt_omp_firstprivate(ht, wd, bpp, stride) \
+    shared(in, out) \
+    schedule(static)
 #endif
     for(int j = 0; j < ht; j++) memcpy(out + (size_t)j * bpp * wd, in + (size_t)j * stride, bpp * wd);
     return;
@@ -205,7 +208,10 @@ void dt_imageio_flip_buffers(char *out, const char *in, const size_t bpp, const
     si = -si;
   }
 #ifdef _OPENMP
-#pragma omp parallel for schedule(static) default(none) shared(in, out, jj, ii, sj, si)
+#pragma omp parallel for default(none) \
+  dt_omp_firstprivate(wd, bpp, ht, stride) \
+  shared(in, out, jj, ii, sj, si) \
+  schedule(static)
 #endif
   for(int j = 0; j < ht; j++)
   {
@@ -229,7 +235,10 @@ void dt_imageio_flip_buffers_ui16_to_float(float *out, const uint16_t *in, const
   if(!orientation)
   {
 #ifdef _OPENMP
-#pragma omp parallel for schedule(static) default(none) shared(in, out)
+#pragma omp parallel for default(none) \
+    dt_omp_firstprivate(wd, ch, scale, stride, black, ht) \
+    shared(in, out) \
+    schedule(static)
 #endif
     for(int j = 0; j < ht; j++)
       for(int i = 0; i < wd; i++)
@@ -255,7 +264,10 @@ void dt_imageio_flip_buffers_ui16_to_float(float *out, const uint16_t *in, const
     si = -si;
   }
 #ifdef _OPENMP
-#pragma omp parallel for schedule(static) default(none) shared(in, out, jj, ii, sj, si)
+#pragma omp parallel for default(none) \
+  dt_omp_firstprivate(wd, ch, black, scale, stride, ht) \
+  shared(in, out, jj, ii, sj, si) \
+  schedule(static)
 #endif
   for(int j = 0; j < ht; j++)
   {
@@ -279,7 +291,10 @@ void dt_imageio_flip_buffers_ui8_to_float(float *out, const uint8_t *in, const f
   if(!orientation)
   {
 #ifdef _OPENMP
-#pragma omp parallel for schedule(static) default(none) shared(in, out)
+#pragma omp parallel for default(none) \
+    dt_omp_firstprivate(wd, scale, black, ht, ch, stride) \
+    shared(in, out) \
+    schedule(static)
 #endif
     for(int j = 0; j < ht; j++)
       for(int i = 0; i < wd; i++)
@@ -305,7 +320,10 @@ void dt_imageio_flip_buffers_ui8_to_float(float *out, const uint8_t *in, const f
     si = -si;
   }
 #ifdef _OPENMP
-#pragma omp parallel for schedule(static) default(none) shared(in, out, jj, ii, sj, si)
+#pragma omp parallel for default(none) \
+  dt_omp_firstprivate(wd, ch, scale, black, stride, ht) \
+  shared(in, out, jj, ii, sj, si) \
+  schedule(static)
 #endif
   for(int j = 0; j < ht; j++)
   {
@@ -865,7 +883,9 @@ int dt_imageio_export_with_flags(const uint32_t imgid, const char *filename,
       { // !display_byteorder, need to swap:
         uint8_t *const buf8 = pipe.backbuf;
 #ifdef _OPENMP
-#pragma omp parallel for default(none) schedule(static)
+#pragma omp parallel for default(none) \
+  dt_omp_firstprivate(processed_width, processed_height, buf8) \
+  schedule(static)
 #endif
         // just flip byte order
         for(size_t k = 0; k < (size_t)processed_width * processed_height; k++)
diff --git a/src/common/imageio_rawspeed.cc b/src/common/imageio_rawspeed.cc
index 0dcdc81..a6fc74d 100644
--- a/src/common/imageio_rawspeed.cc
+++ b/src/common/imageio_rawspeed.cc
@@ -383,7 +383,10 @@ dt_imageio_retval_t dt_imageio_open_rawspeed_sraw(dt_image_t *img, RawImage r, d
  */
 
 #ifdef _OPENMP
-#pragma omp parallel for default(none) schedule(static) shared(r, img, buf)
+#pragma omp parallel for default(none) \
+    schedule(static) \
+    dt_omp_firstprivate(cpp) \
+    shared(r, img, buf)
 #endif
     for(int j = 0; j < img->height; j++)
     {
@@ -407,7 +410,10 @@ dt_imageio_retval_t dt_imageio_open_rawspeed_sraw(dt_image_t *img, RawImage r, d
  */
 
 #ifdef _OPENMP
-#pragma omp parallel for default(none) schedule(static) shared(r, img, buf)
+#pragma omp parallel for default(none) \
+    schedule(static) \
+    dt_omp_firstprivate(cpp) \
+    shared(r, img, buf)
 #endif
     for(int j = 0; j < img->height; j++)
     {
diff --git a/src/common/interpolation.c b/src/common/interpolation.c
index f627d0d..154715a 100644
--- a/src/common/interpolation.c
+++ b/src/common/interpolation.c
@@ -1378,7 +1378,9 @@ static void dt_interpolation_resample_plain(const struct dt_interpolation *itor,
     int64_t ts_resampling = getts();
 #endif
 #ifdef _OPENMP
-#pragma omp parallel for default(none) shared(out)
+#pragma omp parallel for default(none) \
+    dt_omp_firstprivate(in, in_stride, out_stride, roi_out, x0, l) \
+    shared(out)
 #endif
     for(int y = 0; y < roi_out->height; y++)
     {
@@ -1424,7 +1426,9 @@ static void dt_interpolation_resample_plain(const struct dt_interpolation *itor,
 
 // Process each output line
 #ifdef _OPENMP
-#pragma omp parallel for default(none) shared(out, hindex, hlength, hkernel, vindex, vlength, vkernel, vmeta)
+#pragma omp parallel for default(none) \
+  dt_omp_firstprivate(in, in_stride, out_stride, roi_out) \
+  shared(out, hindex, hlength, hkernel, vindex, vlength, vkernel, vmeta)
 #endif
   for(int oy = 0; oy < roi_out->height; oy++)
   {
@@ -1536,7 +1540,9 @@ static void dt_interpolation_resample_sse(const struct dt_interpolation *itor, f
     int64_t ts_resampling = getts();
 #endif
 #ifdef _OPENMP
-#pragma omp parallel for default(none) shared(out)
+#pragma omp parallel for default(none) \
+    dt_omp_firstprivate(in, in_stride, out_stride, roi_out, x0, l) \
+    shared(out)
 #endif
     for(int y = 0; y < roi_out->height; y++)
     {
@@ -1582,7 +1588,9 @@ static void dt_interpolation_resample_sse(const struct dt_interpolation *itor, f
 
 // Process each output line
 #ifdef _OPENMP
-#pragma omp parallel for default(none) shared(out, hindex, hlength, hkernel, vindex, vlength, vkernel, vmeta)
+#pragma omp parallel for default(none) \
+  dt_omp_firstprivate(in, in_stride, out_stride, roi_out) \
+  shared(out, hindex, hlength, hkernel, vindex, vlength, vkernel, vmeta)
 #endif
   for(int oy = 0; oy < roi_out->height; oy++)
   {
diff --git a/src/common/locallaplacian.c b/src/common/locallaplacian.c
index 5deb3c1..bfe7f4c 100644
--- a/src/common/locallaplacian.c
+++ b/src/common/locallaplacian.c
@@ -114,7 +114,10 @@ static inline void gauss_expand(
     const int ht)
 {
 #ifdef _OPENMP
-#pragma omp parallel for default(none) schedule(static) collapse(2)
+#pragma omp parallel for default(none) \
+  dt_omp_firstprivate(fine, input, wd, ht) \
+  schedule(static) \
+  collapse(2)
 #endif
   for(int j=1;j<((ht-1)&~1);j++)  // even ht: two px boundary. odd ht: one px.
     for(int i=1;i<((wd-1)&~1);i++)
@@ -151,7 +154,9 @@ static inline void gauss_reduce_sse2(
       float *const row = ringbuf + (rowj % 5)*stride;
       const float *const in = input + rowj*wd;
 #ifdef _OPENMP
-#pragma omp parallel for schedule(static) default(none)
+#pragma omp parallel for default(none) \
+      dt_omp_firstprivate(cw, in, row) \
+      schedule(static)
 #endif
       for(int i=1;i<cw-1;i++)
         row[i] = 6*in[2*i] + 4*(in[2*i-1]+in[2*i+1]) + in[2*i-2] + in[2*i+2];
@@ -169,7 +174,9 @@ static inline void gauss_reduce_sse2(
                 *const row2 = rows[2], *const row3 = rows[3], *const row4 = rows[4];
     const __m128 four = _mm_set1_ps(4.f), scale = _mm_set1_ps(1.f/256.f);
 #ifdef _OPENMP
-#pragma omp parallel for schedule(static) default(none)
+#pragma omp parallel for default(none) \
+    dt_omp_firstprivate(cw, out, scale, four, row0, row1, row2, row3, row4) \
+    schedule(static)
 #endif
     for(int i=0;i<=cw-8;i+=8)
     {
@@ -224,7 +231,10 @@ static inline void gauss_reduce(
   memset(coarse, 0, sizeof(float)*cw*ch);
   // direct 5x5 stencil only on required pixels:
 #ifdef _OPENMP
-#pragma omp parallel for schedule(static) default(none) collapse(2)
+#pragma omp parallel for default(none) \
+  dt_omp_firstprivate(coarse, cw, ch, input, w, wd) \
+  schedule(static) \
+  collapse(2)
 #endif
   for(int j=1;j<ch-1;j++) for(int i=1;i<cw-1;i++)
     for(int jj=-2;jj<=2;jj++) for(int ii=-2;ii<=2;ii++)
@@ -251,7 +261,11 @@ static inline float *ll_pad_input(
   if(b && b->mode == 2)
   { // pad by preview buffer
 #ifdef _OPENMP
-#pragma omp parallel for schedule(dynamic) default(none) shared(wd2, ht2) collapse(2)
+#pragma omp parallel for default(none) \
+    dt_omp_firstprivate(ht, input, max_supp, out, wd) \
+    shared(wd2, ht2) \
+    schedule(dynamic) \
+    collapse(2)
 #endif // fill regular pixels:
     for(int j=0;j<ht;j++) for(int i=0;i<wd;i++)
       out[(j+max_supp)**wd2+i+max_supp] = input[stride*(wd*j+i)] * 0.01f; // L -> [0,1]
@@ -276,22 +290,38 @@ static inline float *ll_pad_input(
       out[*wd2*j+i] = b->pad0[b->pwd*py+px];\
     } } while(0)
 #ifdef _OPENMP
-#pragma omp parallel for schedule(dynamic) default(none) shared(wd2, ht2, b) collapse(2)
+#pragma omp parallel for default(none) \
+    dt_omp_firstprivate(input, max_supp, out, wd) \
+    shared(wd2, ht2, b) \
+    schedule(dynamic) \
+    collapse(2)
 #endif // left border
     for(int j=max_supp;j<*ht2-max_supp;j++) for(int i=0;i<max_supp;i++)
       LL_FILL(input[stride*wd*(j-max_supp)]* 0.01f);
 #ifdef _OPENMP
-#pragma omp parallel for schedule(dynamic) default(none) shared(wd2, ht2, b) collapse(2)
+#pragma omp parallel for default(none) \
+    dt_omp_firstprivate(input, max_supp, out, stride, wd) \
+    shared(wd2, ht2, b) \
+    schedule(dynamic) \
+    collapse(2)
 #endif // right border
     for(int j=max_supp;j<*ht2-max_supp;j++) for(int i=wd+max_supp;i<*wd2;i++)
       LL_FILL(input[stride*((j-max_supp)*wd+wd-1)] * 0.01f);
 #ifdef _OPENMP
-#pragma omp parallel for schedule(dynamic) default(none) shared(wd2, ht2, b) collapse(2)
+#pragma omp parallel for default(none) \
+    dt_omp_firstprivate(max_supp, out) \
+    shared(wd2, ht2, b) \
+    schedule(dynamic) \
+    collapse(2)
 #endif // top border
     for(int j=0;j<max_supp;j++) for(int i=0;i<*wd2;i++)
       LL_FILL(out[*wd2*max_supp+i]);
 #ifdef _OPENMP
-#pragma omp parallel for schedule(dynamic) default(none) shared(wd2, ht2, b) collapse(2)
+#pragma omp parallel for default(none) \
+    dt_omp_firstprivate(ht, max_supp, out) \
+    shared(wd2, ht2, b) \
+    schedule(dynamic) \
+    collapse(2)
 #endif // bottom border
     for(int j=max_supp+ht;j<*ht2;j++) for(int i=0;i<*wd2;i++)
       LL_FILL(out[*wd2*(max_supp+ht-1)+i]);
@@ -300,7 +330,10 @@ static inline float *ll_pad_input(
   else
   { // pad by replication:
 #ifdef _OPENMP
-#pragma omp parallel for schedule(dynamic) default(none) shared(wd2, ht2)
+#pragma omp parallel for default(none) \
+    dt_omp_firstprivate(input, ht, max_supp, out, wd) \
+    shared(wd2, ht2) \
+    schedule(dynamic)
 #endif
     for(int j=0;j<ht;j++)
     {
@@ -312,12 +345,18 @@ static inline float *ll_pad_input(
         out[(j+max_supp)**wd2+i] = input[stride*(j*wd+wd-1)] * 0.01f; // L -> [0,1]
     }
 #ifdef _OPENMP
-#pragma omp parallel for schedule(dynamic) default(none) shared(wd2, ht2)
+#pragma omp parallel for default(none) \
+    dt_omp_firstprivate(max_supp, out) \
+    shared(wd2, ht2) \
+    schedule(dynamic)
 #endif
     for(int j=0;j<max_supp;j++)
       memcpy(out + *wd2*j, out+max_supp**wd2, sizeof(float)**wd2);
 #ifdef _OPENMP
-#pragma omp parallel for schedule(dynamic) default(none) shared(wd2, ht2)
+#pragma omp parallel for default(none) \
+    schedule(dynamic) \
+    dt_omp_firstprivate(ht, max_supp, out) \
+    shared(wd2, ht2)
 #endif
     for(int j=max_supp+ht;j<*ht2;j++)
       memcpy(out + *wd2*j, out + *wd2*(max_supp+ht-1), sizeof(float)**wd2);
@@ -452,7 +491,9 @@ void apply_curve_sse2(
 {
   // TODO: do all this in avx2 8-wide (should be straight forward):
 #ifdef _OPENMP
-#pragma omp parallel for default(none) schedule(dynamic)
+#pragma omp parallel for default(none) \
+  dt_omp_firstprivate(clarity, g, h, highlights, in, out, padding, shadows, sigma, w) \
+  schedule(dynamic)
 #endif
   for(uint32_t j=padding;j<h-padding;j++)
   {
@@ -478,11 +519,15 @@ void apply_curve_sse2(
     for(int i=w-padding;i<w;i++) out2[i] = out2[w-padding-1];
   }
 #ifdef _OPENMP
-#pragma omp parallel for default(none) schedule(dynamic)
+#pragma omp parallel for default(none) \
+  dt_omp_firstprivate(out, padding, w) \
+  schedule(dynamic)
 #endif
   for(int j=0;j<padding;j++) memcpy(out + w*j, out+padding*w, sizeof(float)*w);
 #ifdef _OPENMP
-#pragma omp parallel for default(none) schedule(dynamic)
+#pragma omp parallel for default(none) \
+  dt_omp_firstprivate(h, out, padding, w) \
+  schedule(dynamic)
 #endif
   for(int j=h-padding;j<h;j++) memcpy(out + w*j, out+w*(h-padding-1), sizeof(float)*w);
 }
@@ -502,7 +547,9 @@ void apply_curve(
     const float clarity)
 {
 #ifdef _OPENMP
-#pragma omp parallel for default(none) schedule(dynamic)
+#pragma omp parallel for default(none) \
+  dt_omp_firstprivate(clarity, g, h, highlights, in, out, padding, sigma, shadows, w) \
+  schedule(dynamic)
 #endif
   for(uint32_t j=padding;j<h-padding;j++)
   {
@@ -515,11 +562,15 @@ void apply_curve(
     for(int i=w-padding;i<w;i++) out2[i] = out2[w-padding-1];
   }
 #ifdef _OPENMP
-#pragma omp parallel for default(none) schedule(dynamic)
+#pragma omp parallel for default(none) \
+  dt_omp_firstprivate(out, padding, w) \
+  schedule(dynamic)
 #endif
   for(int j=0;j<padding;j++) memcpy(out + w*j, out+padding*w, sizeof(float)*w);
 #ifdef _OPENMP
-#pragma omp parallel for default(none) schedule(dynamic)
+#pragma omp parallel for default(none) \
+  dt_omp_firstprivate(h, out, padding, w) \
+  schedule(dynamic)
 #endif
   for(int j=h-padding;j<h;j++) memcpy(out + w*j, out+w*(h-padding-1), sizeof(float)*w);
 }
@@ -704,7 +755,11 @@ void local_laplacian_internal(
     gauss_expand(output[l+1], output[l], pw, ph);
     // go through all coefficients in the upsampled gauss buffer:
 #ifdef _OPENMP
-#pragma omp parallel for default(none) schedule(static) collapse(2) shared(w,h,buf,output,l,gamma,padded)
+#pragma omp parallel for default(none) \
+    dt_omp_firstprivate(ph, pw) \
+    shared(w,h,buf,output,l,gamma,padded) \
+    schedule(static) \
+    collapse(2)
 #endif
     for(int j=0;j<ph;j++) for(int i=0;i<pw;i++)
     {
@@ -724,7 +779,11 @@ void local_laplacian_internal(
     }
   }
 #ifdef _OPENMP
-#pragma omp parallel for default(none) schedule(dynamic) collapse(2) shared(w,output,buf)
+#pragma omp parallel for default(none) \
+  dt_omp_firstprivate(ht, input, max_supp, out, wd) \
+  shared(w,output,buf) \
+  schedule(dynamic) \
+  collapse(2)
 #endif
   for(int j=0;j<ht;j++) for(int i=0;i<wd;i++)
   {
diff --git a/src/common/opencl.c b/src/common/opencl.c
index e426f39..5160e13 100644
--- a/src/common/opencl.c
+++ b/src/common/opencl.c
@@ -950,7 +950,9 @@ static float dt_opencl_benchmark_gpu(const int devid, const size_t width, const
   if(buf == NULL) goto error;
 
 #ifdef _OPENMP
-#pragma omp parallel for default(none) shared(buf)
+#pragma omp parallel for default(none) \
+  dt_omp_firstprivate(height, tea_states, width) \
+  shared(buf)
 #endif
   for(size_t j = 0; j < height; j++)
   {
@@ -1023,7 +1025,9 @@ static float dt_opencl_benchmark_cpu(const size_t width, const size_t height, co
   if(buf == NULL) goto error;
 
 #ifdef _OPENMP
-#pragma omp parallel for default(none) shared(buf)
+#pragma omp parallel for default(none) \
+  dt_omp_firstprivate(height, width, tea_states) \
+  shared(buf)
 #endif
   for(size_t j = 0; j < height; j++)
   {
diff --git a/src/common/focus.h b/src/common/focus.h
index efbfca5..a887686 100644
--- a/src/common/focus.h
+++ b/src/common/focus.h
@@ -46,7 +46,10 @@ static inline void _dt_focus_cdf22_wtf(uint8_t *buf, const int l, const int widt
   const int st = step / 2;
 
 #ifdef _OPENMP
-#pragma omp parallel for default(none) shared(buf) schedule(static)
+#pragma omp parallel for default(none) \
+  dt_omp_firstprivate(height, st, step, width) \
+  shared(buf) \
+  schedule(static)
 #endif
   for(int j = 0; j < height; j++)
   {
@@ -66,7 +69,10 @@ static inline void _dt_focus_cdf22_wtf(uint8_t *buf, const int l, const int widt
       gbuf(buf, i, j) += _from_uint8(gbuf(buf, i - st, j)) / 2;
   }
 #ifdef _OPENMP
-#pragma omp parallel for default(none) shared(buf) schedule(static)
+#pragma omp parallel for default(none) \
+  dt_omp_firstprivate(height, st, step, width) \
+  shared(buf) \
+  schedule(static)
 #endif
   for(int i = 0; i < width; i++)
   {
diff --git a/src/control/jobs/control_jobs.c b/src/control/jobs/control_jobs.c
index 2fc03e9..df88fb9 100644
--- a/src/control/jobs/control_jobs.c
+++ b/src/control/jobs/control_jobs.c
@@ -356,7 +356,10 @@ static int dt_control_merge_hdr_process(dt_imageio_module_data_t *datai, const c
   float saturation = 1.0f;
   d->whitelevel = fmaxf(d->whitelevel, saturation * cal);
 #ifdef _OPENMP
-#pragma omp parallel for schedule(static) default(none) shared(d, saturation)
+#pragma omp parallel for default(none) \
+  dt_omp_firstprivate(ivoid, cal, photoncnt) \
+  shared(d, saturation) \
+  schedule(static)
 #endif
   for(int y = 0; y < d->ht; y++)
     for(int x = 0; x < d->wd; x++)
diff --git a/src/develop/blend.c b/src/develop/blend.c
index 044880b..ad24cb5 100644
--- a/src/develop/blend.c
+++ b/src/develop/blend.c
@@ -2901,7 +2901,8 @@ void dt_develop_blend_process(struct dt_iop_module_t *self, struct dt_dev_pixelp
     // blend uniformly (no drawn or parametric mask)
 
 #ifdef _OPENMP
-#pragma omp parallel for default(none)
+#pragma omp parallel for default(none) \
+    dt_omp_firstprivate(buffsize, mask, opacity)
 #endif
     for(size_t i = 0; i < buffsize; i++) mask[i] = opacity;
   }
@@ -2920,7 +2921,8 @@ void dt_develop_blend_process(struct dt_iop_module_t *self, struct dt_dev_pixelp
       {
         // if we have a mask and this flag is set -> invert the mask
 #ifdef _OPENMP
-#pragma omp parallel for default(none)
+  #pragma omp parallel for default(none) \
+        dt_omp_firstprivate(buffsize, mask)
 #endif
         for(size_t i = 0; i < buffsize; i++) mask[i] = 1.0f - mask[i];
       }
@@ -2931,7 +2933,8 @@ void dt_develop_blend_process(struct dt_iop_module_t *self, struct dt_dev_pixelp
       // we fill the buffer with 1.0f or 0.0f depending on mask_combine
       const float fill = (d->mask_combine & DEVELOP_COMBINE_MASKS_POS) ? 0.0f : 1.0f;
 #ifdef _OPENMP
-#pragma omp parallel for default(none)
+  #pragma omp parallel for default(none) \
+      dt_omp_firstprivate(buffsize, mask, fill)
 #endif
       for(size_t i = 0; i < buffsize; i++) mask[i] = fill;
     }
@@ -2940,14 +2943,17 @@ void dt_develop_blend_process(struct dt_iop_module_t *self, struct dt_dev_pixelp
       // we fill the buffer with 1.0f or 0.0f depending on mask_combine
       const float fill = (d->mask_combine & DEVELOP_COMBINE_INCL) ? 0.0f : 1.0f;
 #ifdef _OPENMP
-#pragma omp parallel for default(none)
+  #pragma omp parallel for default(none) \
+      dt_omp_firstprivate(buffsize, mask, fill)
 #endif
       for(size_t i = 0; i < buffsize; i++) mask[i] = fill;
     }
 
     // get parametric mask (if any) and apply global opacity
 #ifdef _OPENMP
-#pragma omp parallel for default(none)
+#pragma omp parallel for default(none) \
+    dt_omp_firstprivate(bch, ch, cst, d, oheight, opacity, ivoid, iwidth, \
+                        mask, owidth, ovoid, xoffs, yoffs)
 #endif
     for(size_t y = 0; y < oheight; y++)
     {
@@ -2985,7 +2991,8 @@ void dt_develop_blend_process(struct dt_iop_module_t *self, struct dt_dev_pixelp
       {
         float *const guide_tmp = dt_alloc_align(64, sizeof(*guide_tmp) * buffsize * ch);
 #ifdef _OPENMP
-#pragma omp parallel for default(none)
+#pragma omp parallel for default(none) \
+    dt_omp_firstprivate(ch, guide_tmp, ivoid, iwidth, oheight, owidth, xoffs, yoffs)
 #endif
         for(size_t y = 0; y < oheight; y++)
         {
@@ -3018,7 +3025,8 @@ void dt_develop_blend_process(struct dt_iop_module_t *self, struct dt_dev_pixelp
       const float e = expf(3.f * d->contrast);
       const float brightness = d->brightness;
 #ifdef _OPENMP
-#pragma omp parallel for default(none)
+#pragma omp parallel for default(none) \
+      dt_omp_firstprivate(brightness, buffsize, e, mask, opacity)
 #endif
       for(size_t k = 0; k < buffsize; k++)
       {
@@ -3047,7 +3055,10 @@ void dt_develop_blend_process(struct dt_iop_module_t *self, struct dt_dev_pixelp
   // select the blend operator
   _blend_row_func *const blend = dt_develop_choose_blend_func(d->blend_mode);
 #ifdef _OPENMP
-#pragma omp parallel for default(none)
+#pragma omp parallel for default(none) \
+  dt_omp_firstprivate(bch, blend, blendflag, ch, cst, ivoid, iwidth, mask, \
+                      mask_display, oheight, ovoid, owidth, \
+                      request_mask_display, xoffs, yoffs)
 #endif
   for(size_t y = 0; y < oheight; y++)
   {
@@ -3224,7 +3235,8 @@ int dt_develop_blend_process_cl(struct dt_iop_module_t *self, struct dt_dev_pixe
       {
         // if we have a mask and this flag is set -> invert the mask
 #ifdef _OPENMP
-#pragma omp parallel for default(none)
+  #pragma omp parallel for default(none) \
+      dt_omp_firstprivate(buffsize, mask)
 #endif
         for(size_t i = 0; i < buffsize; i++) mask[i] = 1.0f - mask[i];
       }
@@ -3235,7 +3247,8 @@ int dt_develop_blend_process_cl(struct dt_iop_module_t *self, struct dt_dev_pixe
       // we fill the buffer with 1.0f or 0.0f depending on mask_combine
       const float fill = (d->mask_combine & DEVELOP_COMBINE_MASKS_POS) ? 0.0f : 1.0f;
 #ifdef _OPENMP
-#pragma omp parallel for default(none)
+  #pragma omp parallel for default(none) \
+      dt_omp_firstprivate(buffsize, mask, fill)
 #endif
       for(size_t i = 0; i < buffsize; i++) mask[i] = fill;
     }
@@ -3244,7 +3257,8 @@ int dt_develop_blend_process_cl(struct dt_iop_module_t *self, struct dt_dev_pixe
       // we fill the buffer with 1.0f or 0.0f depending on mask_combine
       const float fill = (d->mask_combine & DEVELOP_COMBINE_INCL) ? 0.0f : 1.0f;
 #ifdef _OPENMP
-#pragma omp parallel for default(none)
+  #pragma omp parallel for default(none) \
+      dt_omp_firstprivate(buffsize, mask, fill)
 #endif
       for(size_t i = 0; i < buffsize; i++) mask[i] = fill;
     }
diff --git a/src/develop/imageop_math.c b/src/develop/imageop_math.c
index 3159e14..a10492c 100644
--- a/src/develop/imageop_math.c
+++ b/src/develop/imageop_math.c
@@ -67,7 +67,10 @@ void dt_iop_flip_and_zoom_8(const uint8_t *in, int32_t iw, int32_t ih, uint8_t *
   const int32_t offm = half_pixel * bpp * MIN(MIN(0, si), MIN(sj, si + sj));
   const int32_t offM = half_pixel * bpp * MAX(MAX(0, si), MAX(sj, si + sj));
 #ifdef _OPENMP
-#pragma omp parallel for schedule(static) default(none) shared(in, out, jj, ii, sj, si, iw, ih)
+#pragma omp parallel for default(none) \
+  dt_omp_firstprivate(bpp, half_pixel, ht, offM, offm, scale, wd) \
+  shared(in, out, jj, ii, sj, si, iw, ih) \
+  schedule(static)
 #endif
   for(uint32_t j = 0; j < ht; j++)
   {
@@ -211,7 +214,9 @@ void dt_iop_clip_and_zoom_mosaic_half_size_plain(uint16_t *const out, const uint
     }
 
 #ifdef _OPENMP
-#pragma omp parallel for default(none) shared(clut) schedule(static)
+#pragma omp parallel for default(none) \
+  dt_omp_firstprivate(filters, in, in_stride, out, out_stride, px_footprint, rggbx, rggby, roi_in, roi_out) \
+  shared(clut) schedule(static)
 #endif
   for(int y = 0; y < roi_out->height; y++)
   {
@@ -270,7 +275,9 @@ void dt_iop_clip_and_zoom_mosaic_half_size_sse2(uint16_t *const out, const uint1
   const int rggbx = trggbx, rggby = trggby;
 
 #ifdef _OPENMP
-#pragma omp parallel for default(none) schedule(static)
+#pragma omp parallel for default(none) \
+  dt_omp_firstprivate(in, in_stride, out, out_stride, px_footprint, rggbx, rggby, roi_in, roi_out, samples) \
+  schedule(static)
 #endif
   for(int y = 0; y < roi_out->height; y++)
   {
@@ -479,7 +486,9 @@ void dt_iop_clip_and_zoom_mosaic_half_size_f_plain(float *const out, const float
   const int rggbx = trggbx, rggby = trggby;
 
 #ifdef _OPENMP
-#pragma omp parallel for default(none) schedule(static)
+#pragma omp parallel for default(none) \
+  dt_omp_firstprivate(in, in_stride, out, out_stride, px_footprint, rggbx, rggby, roi_in, roi_out, samples) \
+  schedule(static)
 #endif
   for(int y = 0; y < roi_out->height; y++)
   {
@@ -666,7 +675,10 @@ void dt_iop_clip_and_zoom_mosaic_half_size_f_sse2(float *const out, const float
   const int rggbx = trggbx, rggby = trggby;
 
 #ifdef _OPENMP
-#pragma omp parallel for default(none) schedule(static)
+#pragma omp parallel for default(none) \
+  dt_omp_firstprivate(in, in_stride, out, out_stride, px_footprint, rggbx, \
+                      rggby, roi_in, roi_out, samples) \
+  schedule(static)
 #endif
   for(int y = 0; y < roi_out->height; y++)
   {
@@ -867,7 +879,9 @@ void dt_iop_clip_and_zoom_mosaic_third_size_xtrans(uint16_t *const out, const ui
   // sample (rounded to nearest input pixel) to anti-alias. Higher MP
   // images need larger filters to avoid artifacts.
 #ifdef _OPENMP
-#pragma omp parallel for default(none) schedule(static)
+#pragma omp parallel for default(none) \
+  dt_omp_firstprivate(in, in_stride, out, out_stride, px_footprint, roi_in, roi_out, xtrans) \
+  schedule(static)
 #endif
   for(int y = 0; y < roi_out->height; y++)
   {
@@ -906,7 +920,9 @@ void dt_iop_clip_and_zoom_mosaic_third_size_xtrans_f(float *const out, const flo
 {
   const float px_footprint = 1.f / roi_out->scale;
 #ifdef _OPENMP
-#pragma omp parallel for default(none) schedule(static)
+#pragma omp parallel for default(none) \
+  dt_omp_firstprivate(in, in_stride, out, out_stride, px_footprint, roi_in, roi_out, xtrans) \
+  schedule(static)
 #endif
   for(int y = 0; y < roi_out->height; y++)
   {
@@ -951,7 +967,10 @@ void dt_iop_clip_and_zoom_demosaic_passthrough_monochrome_f_plain(float *out, co
   const int samples = round(px_footprint);
 
 #ifdef _OPENMP
-#pragma omp parallel for default(none) shared(out) schedule(static)
+#pragma omp parallel for default(none) \
+  dt_omp_firstprivate(in, in_stride, out_stride, px_footprint, roi_in, roi_out, samples) \
+  shared(out) \
+  schedule(static)
 #endif
   for(int y = 0; y < roi_out->height; y++)
   {
@@ -1093,7 +1112,10 @@ void dt_iop_clip_and_zoom_demosaic_passthrough_monochrome_f_sse2(float *out, con
   const int samples = round(px_footprint);
 
 #ifdef _OPENMP
-#pragma omp parallel for default(none) shared(out) schedule(static)
+#pragma omp parallel for default(none) \
+  dt_omp_firstprivate(in, in_stride, out_stride, px_footprint, roi_in, roi_out, samples) \
+  shared(out) \
+  schedule(static)
 #endif
   for(int y = 0; y < roi_out->height; y++)
   {
@@ -1347,7 +1369,10 @@ void dt_iop_clip_and_zoom_demosaic_half_size_f_plain(float *out, const float *co
   const int rggbx = trggbx, rggby = trggby;
 
 #ifdef _OPENMP
-#pragma omp parallel for default(none) shared(out) schedule(static)
+#pragma omp parallel for default(none) \
+  dt_omp_firstprivate(in, in_stride, out_stride, px_footprint, rggbx, rggby, roi_in, roi_out, samples) \
+  shared(out) \
+  schedule(static)
 #endif
   for(int y = 0; y < roi_out->height; y++)
   {
@@ -1523,7 +1548,10 @@ void dt_iop_clip_and_zoom_demosaic_half_size_f_sse2(float *out, const float *con
   const int rggbx = trggbx, rggby = trggby;
 
 #ifdef _OPENMP
-#pragma omp parallel for default(none) shared(out) schedule(static)
+#pragma omp parallel for default(none) \
+  dt_omp_firstprivate(in, in_stride, px_footprint, rggbx, rggby, out_stride, roi_in, roi_out, samples) \
+  shared(out) \
+  schedule(static)
 #endif
   for(int y = 0; y < roi_out->height; y++)
   {
@@ -1712,7 +1740,10 @@ void dt_iop_clip_and_zoom_demosaic_third_size_xtrans_f(float *out, const float *
   // by non-integer number of samples.
 
 #ifdef _OPENMP
-#pragma omp parallel for default(none) shared(out) schedule(static)
+#pragma omp parallel for default(none) \
+  dt_omp_firstprivate(in, in_stride, out_stride, px_footprint, roi_in, roi_out, samples, xtrans) \
+  shared(out) \
+  schedule(static)
 #endif
   for(int y = 0; y < roi_out->height; y++)
   {
diff --git a/src/develop/masks/ellipse.c b/src/develop/masks/ellipse.c
index f498c84..f422b9c 100644
--- a/src/develop/masks/ellipse.c
+++ b/src/develop/masks/ellipse.c
@@ -1631,7 +1631,9 @@ static int dt_ellipse_get_mask_roi(dt_iop_module_t *module, dt_dev_pixelpipe_iop
 
 #ifdef _OPENMP
 #if !defined(__SUNOS__) && !defined(__NetBSD__)
-#pragma omp parallel for default(none) shared(points)
+#pragma omp parallel for default(none) \
+  dt_omp_firstprivate(iscale, mh, mw, py, px) \
+  shared(points)
 #else
 #pragma omp parallel for shared(points)
 #endif
@@ -1689,7 +1691,9 @@ static int dt_ellipse_get_mask_roi(dt_iop_module_t *module, dt_dev_pixelpipe_iop
 
 #ifdef _OPENMP
 #if !defined(__SUNOS__) && !defined(__NetBSD__)
-#pragma omp parallel for default(none) shared(points, a, b, ta, tb, alpha)
+#pragma omp parallel for default(none) \
+  dt_omp_firstprivate(center, mh, mw) \
+  shared(points, a, b, ta, tb, alpha)
 #else
 #pragma omp parallel for shared(points, a, b, ta, tb, alpha)
 #endif
@@ -1721,7 +1725,9 @@ static int dt_ellipse_get_mask_roi(dt_iop_module_t *module, dt_dev_pixelpipe_iop
 // we fill the output buffer by interpolation
 #ifdef _OPENMP
 #if !defined(__SUNOS__) && !defined(__NetBSD__)
-#pragma omp parallel for default(none) shared(points, buffer)
+#pragma omp parallel for default(none) \
+  dt_omp_firstprivate(h, mw, w) \
+  shared(points, buffer)
 #else
 #pragma omp parallel for shared(points, buffer)
 #endif
diff --git a/src/develop/masks/gradient.c b/src/develop/masks/gradient.c
index 5a22673..f3e5f56 100644
--- a/src/develop/masks/gradient.c
+++ b/src/develop/masks/gradient.c
@@ -805,7 +805,9 @@ static int dt_gradient_get_mask(dt_iop_module_t *module, dt_dev_pixelpipe_iop_t
 
 #ifdef _OPENMP
 #if !defined(__SUNOS__) && !defined(__NetBSD__)
-#pragma omp parallel for default(none) shared(points)
+#pragma omp parallel for default(none) \
+  dt_omp_firstprivate(mh, mw, px, py) \
+  shared(points)
 #else
 #pragma omp parallel for shared(points)
 #endif
@@ -849,7 +851,9 @@ static int dt_gradient_get_mask(dt_iop_module_t *module, dt_dev_pixelpipe_iop_t
 
 #ifdef _OPENMP
 #if !defined(__SUNOS__) && !defined(__NetBSD__)
-#pragma omp parallel for default(none) shared(points)
+#pragma omp parallel for default(none) \
+  dt_omp_firstprivate(cosv, hwscale, normf, offset, mh, mw, steepness, sinv) \
+  shared(points)
 #else
 #pragma omp parallel for shared(points)
 #endif
@@ -879,7 +883,9 @@ static int dt_gradient_get_mask(dt_iop_module_t *module, dt_dev_pixelpipe_iop_t
 // we fill the mask buffer by interpolation
 #ifdef _OPENMP
 #if !defined(__SUNOS__) && !defined(__NetBSD__)
-#pragma omp parallel for default(none) shared(points, buffer)
+#pragma omp parallel for default(none) \
+  dt_omp_firstprivate(h, mw, w) \
+  shared(points, buffer)
 #else
 #pragma omp parallel for shared(points, buffer)
 #endif
@@ -933,7 +939,9 @@ static int dt_gradient_get_mask_roi(dt_iop_module_t *module, dt_dev_pixelpipe_io
 
 #ifdef _OPENMP
 #if !defined(__SUNOS__) && !defined(__NetBSD__)
-#pragma omp parallel for default(none) shared(points)
+#pragma omp parallel for default(none) \
+  dt_omp_firstprivate(iscale, mh, mw, py, px) \
+  shared(points)
 #else
 #pragma omp parallel for shared(points)
 #endif
@@ -979,7 +987,9 @@ static int dt_gradient_get_mask_roi(dt_iop_module_t *module, dt_dev_pixelpipe_io
 
 #ifdef _OPENMP
 #if !defined(__SUNOS__) && !defined(__NetBSD__)
-#pragma omp parallel for default(none) shared(points)
+#pragma omp parallel for default(none) \
+  dt_omp_firstprivate(cosv, hwscale, mh, mw, normf, offset, sinv, steepness) \
+  shared(points)
 #else
 #pragma omp parallel for shared(points)
 #endif
@@ -1002,7 +1012,9 @@ static int dt_gradient_get_mask_roi(dt_iop_module_t *module, dt_dev_pixelpipe_io
 // we fill the mask buffer by interpolation
 #ifdef _OPENMP
 #if !defined(__SUNOS__) && !defined(__NetBSD__)
-#pragma omp parallel for default(none) shared(points, buffer)
+#pragma omp parallel for default(none) \
+  dt_omp_firstprivate(h, mw, w) \
+  shared(points, buffer)
 #else
 #pragma omp parallel for shared(points, buffer)
 #endif
diff --git a/src/develop/masks/group.c b/src/develop/masks/group.c
index f5b1ec8..df9c434 100644
--- a/src/develop/masks/group.c
+++ b/src/develop/masks/group.c
@@ -549,7 +549,9 @@ static int dt_group_get_mask_roi(dt_iop_module_t *module, dt_dev_pixelpipe_iop_t
         {
 #ifdef _OPENMP
 #if !defined(__SUNOS__) && !defined(__NetBSD__)
-#pragma omp parallel for default(none) shared(bufs)
+#pragma omp parallel for default(none) \
+          dt_omp_firstprivate(height, width) \
+          shared(bufs)
 #else
 #pragma omp parallel for shared(bufs)
 #endif
@@ -566,7 +568,9 @@ static int dt_group_get_mask_roi(dt_iop_module_t *module, dt_dev_pixelpipe_iop_t
         {
 #ifdef _OPENMP
 #if !defined(__SUNOS__) && !defined(__NetBSD__)
-#pragma omp parallel for default(none) shared(bufs, buffer)
+#pragma omp parallel for default(none) \
+          dt_omp_firstprivate(height, op, width) \
+          shared(bufs, buffer)
 #else
 #pragma omp parallel for shared(bufs, buffer)
 #endif
@@ -582,7 +586,9 @@ static int dt_group_get_mask_roi(dt_iop_module_t *module, dt_dev_pixelpipe_iop_t
         {
 #ifdef _OPENMP
 #if !defined(__SUNOS__) && !defined(__NetBSD__)
-#pragma omp parallel for default(none) shared(bufs, buffer)
+#pragma omp parallel for default(none) \
+            dt_omp_firstprivate(height, op, width) \
+            shared(bufs, buffer)
 #else
 #pragma omp parallel for shared(bufs, buffer)
 #endif
@@ -603,7 +609,9 @@ static int dt_group_get_mask_roi(dt_iop_module_t *module, dt_dev_pixelpipe_iop_t
         {
 #ifdef _OPENMP
 #if !defined(__SUNOS__) && !defined(__NetBSD__)
-#pragma omp parallel for default(none) shared(bufs, buffer)
+#pragma omp parallel for default(none) \
+          dt_omp_firstprivate(height, op, width) \
+          shared(bufs, buffer)
 #else
 #pragma omp parallel for shared(bufs, buffer)
 #endif
@@ -621,7 +629,9 @@ static int dt_group_get_mask_roi(dt_iop_module_t *module, dt_dev_pixelpipe_iop_t
         {
 #ifdef _OPENMP
 #if !defined(__SUNOS__) && !defined(__NetBSD__)
-#pragma omp parallel for default(none) shared(bufs, buffer)
+#pragma omp parallel for default(none) \
+          dt_omp_firstprivate(height, op, width) \
+          shared(bufs, buffer)
 #else
 #pragma omp parallel for shared(bufs, buffer)
 #endif
@@ -642,7 +652,9 @@ static int dt_group_get_mask_roi(dt_iop_module_t *module, dt_dev_pixelpipe_iop_t
         {
 #ifdef _OPENMP
 #if !defined(__SUNOS__) && !defined(__NetBSD__)
-#pragma omp parallel for default(none) shared(bufs, buffer)
+#pragma omp parallel for default(none) \
+          dt_omp_firstprivate(height, op, width) \
+          shared(bufs, buffer)
 #else
 #pragma omp parallel for shared(bufs, buffer)
 #endif
diff --git a/src/develop/masks/circle.c b/src/develop/masks/circle.c
index 7ba7edb..424d890 100644
--- a/src/develop/masks/circle.c
+++ b/src/develop/masks/circle.c
@@ -937,7 +937,9 @@ static int dt_circle_get_mask_roi(dt_iop_module_t *module, dt_dev_pixelpipe_iop_
 
 #ifdef _OPENMP
 #if !defined(__SUNOS__) && !defined(__NetBSD__)
-#pragma omp parallel for default(none) shared(points)
+#pragma omp parallel for default(none) \
+  dt_omp_firstprivate(iscale, mh, mw, px, py) \
+  shared(points)
 #else
 #pragma omp parallel for shared(points)
 #endif
@@ -976,7 +978,9 @@ static int dt_circle_get_mask_roi(dt_iop_module_t *module, dt_dev_pixelpipe_iop_
 
 #ifdef _OPENMP
 #if !defined(__SUNOS__) && !defined(__NetBSD__)
-#pragma omp parallel for default(none) shared(points)
+#pragma omp parallel for default(none) \
+  dt_omp_firstprivate(center, mh, mw, radius2, total2) \
+  shared(points)
 #else
 #pragma omp parallel for shared(points)
 #endif
@@ -1003,7 +1007,9 @@ static int dt_circle_get_mask_roi(dt_iop_module_t *module, dt_dev_pixelpipe_iop_
 // we fill the output buffer by interpolation
 #ifdef _OPENMP
 #if !defined(__SUNOS__) && !defined(__NetBSD__)
-#pragma omp parallel for default(none) shared(points, buffer)
+#pragma omp parallel for default(none) \
+  dt_omp_firstprivate(h, mw, w) \
+  shared(points, buffer)
 #else
 #pragma omp parallel for shared(points, buffer)
 #endif
diff --git a/src/develop/pixelpipe_hb.c b/src/develop/pixelpipe_hb.c
index 290c4cd..97057b3 100644
--- a/src/develop/pixelpipe_hb.c
+++ b/src/develop/pixelpipe_hb.c
@@ -689,7 +689,10 @@ static int dt_dev_pixelpipe_process_rec(dt_dev_pixelpipe_t *pipe, dt_develop_t *
           const int cp_height = MIN(roi_out->height, pipe->iheight - in_y);
 
 #ifdef _OPENMP
-#pragma omp parallel for schedule(static) default(none) shared(pipe, roi_out, roi_in, output)
+#pragma omp parallel for default(none) \
+          dt_omp_firstprivate(bpp, cp_height, cp_width, in_x, in_y) \
+          shared(pipe, roi_out, roi_in, output) \
+          schedule(static)
 #endif
           for(int j = 0; j < cp_height; j++)
             memcpy(((char *)*output) + (size_t)bpp * j * roi_out->width,
@@ -791,7 +794,10 @@ static int dt_dev_pixelpipe_process_rec(dt_dev_pixelpipe_t *pipe, dt_develop_t *
       else
       {
 #ifdef _OPENMP
-#pragma omp parallel for schedule(static) default(none) shared(roi_out, roi_in, output, input)
+#pragma omp parallel for default(none) \
+        dt_omp_firstprivate(in_bpp, out_bpp) \
+        shared(roi_out, roi_in, output, input) \
+        schedule(static)
 #endif
         for(int j = 0; j < roi_out->height; j++)
             memcpy(((char *)*output) + (size_t)out_bpp * j * roi_out->width,
@@ -800,7 +806,10 @@ static int dt_dev_pixelpipe_process_rec(dt_dev_pixelpipe_t *pipe, dt_develop_t *
       }
 #else // don't HAVE_OPENCL
 #ifdef _OPENMP
-#pragma omp parallel for schedule(static) default(none) shared(roi_out, roi_in, output, input)
+#pragma omp parallel for default(none) \
+      dt_omp_firstprivate(in_bpp, out_bpp) \
+      shared(roi_out, roi_in, output, input) \
+      schedule(static)
 #endif
       for(int j = 0; j < roi_out->height; j++)
             memcpy(((char *)*output) + (size_t)out_bpp * j * roi_out->width,
diff --git a/src/develop/tiling.c b/src/develop/tiling.c
index fdb5261..c8b363a 100644
--- a/src/develop/tiling.c
+++ b/src/develop/tiling.c
@@ -753,7 +753,10 @@ static void _default_process_tiling_ptp(struct dt_iop_module_t *self, struct dt_
 
 /* prepare input tile buffer */
 #ifdef _OPENMP
-#pragma omp parallel for default(none) shared(input, width, ioffs) schedule(static)
+#pragma omp parallel for default(none) \
+      dt_omp_firstprivate(ht, in_bpp, ipitch, ivoid, wd) \
+      shared(input, width, ioffs) \
+      schedule(static)
 #endif
       for(size_t j = 0; j < ht; j++)
         memcpy((char *)input + j * wd * in_bpp, (char *)ivoid + ioffs + j * ipitch, (size_t)wd * in_bpp);
@@ -794,7 +797,10 @@ static void _default_process_tiling_ptp(struct dt_iop_module_t *self, struct dt_
 
 /* copy "good" part of tile to output buffer */
 #ifdef _OPENMP
-#pragma omp parallel for default(none) shared(ooffs, output, width, origin, region) schedule(static)
+#pragma omp parallel for default(none) \
+      dt_omp_firstprivate(opitch, out_bpp, ovoid, wd) \
+      shared(ooffs, output, width, origin, region) \
+      schedule(static)
 #endif
       for(size_t j = 0; j < region[1]; j++)
         memcpy((char *)ovoid + ooffs + j * opitch,
@@ -1096,7 +1102,10 @@ static void _default_process_tiling_roi(struct dt_iop_module_t *self, struct dt_
       }
 
 #ifdef _OPENMP
-#pragma omp parallel for default(none) shared(input, ioffs, iroi_full) schedule(static)
+#pragma omp parallel for default(none) \
+      dt_omp_firstprivate(in_bpp, ipitch, ivoid) \
+      shared(input, ioffs, iroi_full) \
+      schedule(static)
 #endif
       for(size_t j = 0; j < iroi_full.height; j++)
         memcpy((char *)input + j * iroi_full.width * in_bpp, (char *)ivoid + ioffs + j * ipitch,
@@ -1125,7 +1134,10 @@ static void _default_process_tiling_roi(struct dt_iop_module_t *self, struct dt_
       const int origin_x = oroi_good.x - oroi_full.x;
       const int origin_y = oroi_good.y - oroi_full.y;
 #ifdef _OPENMP
-#pragma omp parallel for default(none) shared(ooffs, output, oroi_good, oroi_full) schedule(static)
+#pragma omp parallel for default(none) \
+      dt_omp_firstprivate(opitch, origin_x, origin_y, out_bpp, ovoid) \
+      shared(ooffs, output, oroi_good, oroi_full) \
+      schedule(static)
 #endif
       for(size_t j = 0; j < oroi_good.height; j++)
         memcpy((char *)ovoid + ooffs + j * opitch,
@@ -1408,7 +1420,10 @@ static int _default_process_tiling_cl_ptp(struct dt_iop_module_t *self, struct d
       {
 /* prepare pinned input tile buffer: copy part of input image */
 #ifdef _OPENMP
-#pragma omp parallel for default(none) shared(input_buffer, width, ioffs, wd, ht) schedule(static)
+#pragma omp parallel for default(none) \
+        dt_omp_firstprivate(in_bpp, ipitch, ivoid) \
+        shared(input_buffer, width, ioffs, wd, ht) \
+        schedule(static)
 #endif
         for(size_t j = 0; j < ht; j++)
           memcpy((char *)input_buffer + j * wd * in_bpp, (char *)ivoid + ioffs + j * ipitch,
@@ -1863,7 +1878,9 @@ static int _default_process_tiling_cl_roi(struct dt_iop_module_t *self, struct d
       {
 /* prepare pinned input tile buffer: copy part of input image */
 #ifdef _OPENMP
-#pragma omp parallel for default(none) shared(input_buffer, width, ioffs, iroi_full) schedule(static)
+#pragma omp parallel for default(none) \
+        dt_omp_firstprivate(in_bpp, ipitch, ivoid) \
+        shared(input_buffer, width, ioffs, iroi_full) schedule(static)
 #endif
         for(size_t j = 0; j < iroi_full.height; j++)
           memcpy((char *)input_buffer + j * iroi_full.width * in_bpp, (char *)ivoid + ioffs + j * ipitch,
@@ -1910,8 +1927,10 @@ static int _default_process_tiling_cl_roi(struct dt_iop_module_t *self, struct d
 
 /* copy "good" part of tile from pinned output buffer to output image */
 #ifdef _OPENMP
-#pragma omp parallel for default(none) shared(ooffs, output_buffer, oroi_full, oorigin,                      \
-                                              oregion) schedule(static)
+#pragma omp parallel for default(none) \
+        dt_omp_firstprivate(ipitch, opitch, ovoid, out_bpp) \
+        shared(ooffs, output_buffer, oroi_full, oorigin, oregion) \
+        schedule(static)
 #endif
         for(size_t j = 0; j < oregion[1]; j++)
           memcpy((char *)ovoid + ooffs + j * opitch,
diff --git a/src/gui/draw.h b/src/gui/draw.h
index 50d4550..dcaaf21 100644
--- a/src/gui/draw.h
+++ b/src/gui/draw.h
@@ -24,6 +24,7 @@
 #include "config.h"
 #endif
 
+#include "common/darktable.h"
 #include "common/curve_tools.h"
 #include <cairo.h>
 #include <glib.h>
@@ -229,14 +230,20 @@ static inline void dt_draw_curve_calc_values(dt_draw_curve_t *c, const float min
   if(x)
   {
 #ifdef _OPENMP
-#pragma omp parallel for SIMD() default(none) shared(x) schedule(static)
+#pragma omp parallel for SIMD() default(none) \
+    dt_omp_firstprivate(res) \
+    shared(x) \
+    schedule(static)
 #endif
     for(int k = 0; k < res; k++) x[k] = k * (1.0f / res);
   }
   if(y)
   {
 #ifdef _OPENMP
-#pragma omp parallel for SIMD() default(none) shared(y, c) schedule(static)
+#pragma omp parallel for SIMD() default(none) \
+    dt_omp_firstprivate(min, max, res) \
+    shared(y, c) \
+    schedule(static)
 #endif
     for(int k = 0; k < res; k++) y[k] = min + (max - min) * c->csample.m_Samples[k] * (1.0f / 0x10000);
   }
diff --git a/src/iop/hotpixels.c b/src/iop/hotpixels.c
index 0c07f7d..74bc0db 100644
--- a/src/iop/hotpixels.c
+++ b/src/iop/hotpixels.c
@@ -117,7 +117,11 @@ static int process_bayer(const dt_iop_hotpixels_data_t *data,
   int fixed = 0;
 
 #ifdef _OPENMP
-#pragma omp parallel for default(none) reduction(+ : fixed) schedule(static)
+#pragma omp parallel for default(none) \
+  dt_omp_firstprivate(ivoid, markfixed, min_neighbours, multiplier, ovoid, \
+                      roi_out, threshold, width, widthx2) \
+  reduction(+ : fixed) \
+  schedule(static)
 #endif
   for(int row = 2; row < roi_out->height - 2; row++)
   {
@@ -214,7 +218,12 @@ static int process_xtrans(const dt_iop_hotpixels_data_t *data,
   int fixed = 0;
 
 #ifdef _OPENMP
-#pragma omp parallel for default(none) shared(offsets) reduction(+ : fixed) schedule(static)
+#pragma omp parallel for default(none) \
+  dt_omp_firstprivate(ivoid, markfixed, min_neighbours, multiplier, ovoid, \
+                      roi_out, threshold, xtrans, width) \
+  shared(offsets) \
+  reduction(+ : fixed) \
+  schedule(static)
 #endif
   for(int row = 2; row < roi_out->height - 2; row++)
   {
diff --git a/src/iop/lens.c b/src/iop/lens.c
index ff0a72a..d9fea09 100644
--- a/src/iop/lens.c
+++ b/src/iop/lens.c
@@ -370,7 +370,11 @@ void process(dt_iop_module_t *self, dt_dev_pixelpipe_iop_t *piece, const void *c
       void *buf = dt_alloc_align(16, bufsize * dt_get_num_threads() * sizeof(float));
 
 #ifdef _OPENMP
-#pragma omp parallel for default(none) shared(buf, modifier) schedule(static)
+#pragma omp parallel for default(none) \
+      dt_omp_firstprivate(bufsize, ch, ch_width, d, interpolation, ivoid, \
+                          mask_display, ovoid, roi_in, roi_out) \
+      shared(buf, modifier) \
+      schedule(static)
 #endif
       for(int y = 0; y < roi_out->height; y++)
       {
@@ -424,7 +428,10 @@ void process(dt_iop_module_t *self, dt_dev_pixelpipe_iop_t *piece, const void *c
     if(modflags & LF_MODIFY_VIGNETTING)
     {
 #ifdef _OPENMP
-#pragma omp parallel for default(none) shared(modifier) schedule(static)
+#pragma omp parallel for default(none) \
+      dt_omp_firstprivate(ch, pixelformat, roi_out, ovoid) \
+      shared(modifier) \
+      schedule(static)
 #endif
       for(int y = 0; y < roi_out->height; y++)
       {
@@ -446,7 +453,10 @@ void process(dt_iop_module_t *self, dt_dev_pixelpipe_iop_t *piece, const void *c
     if(modflags & LF_MODIFY_VIGNETTING)
     {
 #ifdef _OPENMP
-#pragma omp parallel for default(none) shared(buf, modifier) schedule(static)
+#pragma omp parallel for default(none) \
+      dt_omp_firstprivate(ch, pixelformat, roi_in) \
+      shared(buf, modifier) \
+      schedule(static)
 #endif
       for(int y = 0; y < roi_in->height; y++)
       {
@@ -465,7 +475,10 @@ void process(dt_iop_module_t *self, dt_dev_pixelpipe_iop_t *piece, const void *c
       void *buf2 = dt_alloc_align(16, buf2size * sizeof(float) * dt_get_num_threads());
 
 #ifdef _OPENMP
-#pragma omp parallel for default(none) shared(buf2, buf, modifier) schedule(static)
+#pragma omp parallel for default(none) \
+      dt_omp_firstprivate(buf2size, ch, ch_width, d, interpolation, mask_display, ovoid, roi_in, roi_out) \
+      shared(buf2, buf, modifier) \
+      schedule(static)
 #endif
       for(int y = 0; y < roi_out->height; y++)
       {
@@ -616,7 +629,10 @@ int process_cl(struct dt_iop_module_t *self, dt_dev_pixelpipe_iop_t *piece, cl_m
     if(modflags & (LF_MODIFY_TCA | LF_MODIFY_DISTORTION | LF_MODIFY_GEOMETRY | LF_MODIFY_SCALE))
     {
 #ifdef _OPENMP
-#pragma omp parallel for default(none) shared(tmpbuf, d, modifier) schedule(static)
+#pragma omp parallel for default(none) \
+      dt_omp_firstprivate(tmpbufwidth, roi_out) \
+      shared(tmpbuf, d, modifier) \
+      schedule(static)
 #endif
       for(int y = 0; y < roi_out->height; y++)
       {
@@ -652,7 +668,10 @@ int process_cl(struct dt_iop_module_t *self, dt_dev_pixelpipe_iop_t *piece, cl_m
     if(modflags & LF_MODIFY_VIGNETTING)
     {
 #ifdef _OPENMP
-#pragma omp parallel for default(none) shared(tmpbuf, modifier, d) schedule(static)
+#pragma omp parallel for default(none) \
+      dt_omp_firstprivate(ch, pixelformat, roi_out) \
+      shared(tmpbuf, modifier, d) \
+      schedule(static)
 #endif
       for(int y = 0; y < roi_out->height; y++)
       {
@@ -691,7 +710,10 @@ int process_cl(struct dt_iop_module_t *self, dt_dev_pixelpipe_iop_t *piece, cl_m
     if(modflags & LF_MODIFY_VIGNETTING)
     {
 #ifdef _OPENMP
-#pragma omp parallel for default(none) shared(tmpbuf, modifier, d) schedule(static)
+#pragma omp parallel for default(none) \
+      dt_omp_firstprivate(ch, pixelformat, roi_in) \
+      shared(tmpbuf, modifier, d) \
+      schedule(static)
 #endif
       for(int y = 0; y < roi_in->height; y++)
       {
@@ -725,7 +747,10 @@ int process_cl(struct dt_iop_module_t *self, dt_dev_pixelpipe_iop_t *piece, cl_m
     if(modflags & (LF_MODIFY_TCA | LF_MODIFY_DISTORTION | LF_MODIFY_GEOMETRY | LF_MODIFY_SCALE))
     {
 #ifdef _OPENMP
-#pragma omp parallel for default(none) shared(tmpbuf, d, modifier) schedule(static)
+#pragma omp parallel for default(none) \
+      dt_omp_firstprivate(tmpbufwidth, roi_out) \
+      shared(tmpbuf, d, modifier) \
+      schedule(static)
 #endif
       for(int y = 0; y < roi_out->height; y++)
       {
@@ -888,7 +913,10 @@ void modify_roi_in(struct dt_iop_module_t *self, struct dt_dev_pixelpipe_iop_t *
     float *const buf = dt_alloc_align(16, nbpoints * 2 * 3 * sizeof(float));
 
 #ifdef _OPENMP
-#pragma omp parallel default(none) shared(modifier) reduction(min : xm, ym) reduction(max : xM, yM)
+#pragma omp parallel default(none) \
+    dt_omp_firstprivate(aheight, awidth, buf, height, nbpoints, width, xoff, \
+                        xstep, yoff, ystep) \
+    shared(modifier) reduction(min : xm, ym) reduction(max : xM, yM)
 #endif
     {
 #ifdef _OPENMP
diff --git a/src/develop/imageop_math.h b/src/develop/imageop_math.h
index 7203fa7..0b4acf8 100644
--- a/src/develop/imageop_math.h
+++ b/src/develop/imageop_math.h
@@ -158,7 +158,10 @@ static inline float dt_iop_eval_exp(const float *const coeff, const float x)
 static inline void dt_iop_alpha_copy(const void *ivoid, void *ovoid, const int width, const int height)
 {
 #ifdef _OPENMP
-#pragma omp parallel for schedule(static) default(none) shared(ovoid, ivoid)
+#pragma omp parallel for default(none) \
+  dt_omp_firstprivate(height, width) \
+  shared(ovoid, ivoid) \
+  schedule(static)
 #endif
   for(int j = 0; j < height; j++)
   {
diff --git a/src/iop/hazeremoval.c b/src/iop/hazeremoval.c
index 409e8d2..772a9ed 100644
--- a/src/iop/hazeremoval.c
+++ b/src/iop/hazeremoval.c
@@ -369,7 +369,9 @@ static void box_max(const gray_image img1, const gray_image img2, const int w)
   if(img1.data == img2.data)
   {
 #ifdef _OPENMP
-#pragma omp parallel default(none) private(img2_bak)
+#pragma omp parallel default(none) \
+    dt_omp_firstprivate(img1, img2, w) \
+    private(img2_bak)
 #endif
     {
       img2_bak = new_gray_image(img2.width, 1);
@@ -387,7 +389,9 @@ static void box_max(const gray_image img1, const gray_image img2, const int w)
   else
   {
 #ifdef _OPENMP
-#pragma omp parallel default(none) private(img2_bak)
+#pragma omp parallel default(none) \
+    dt_omp_firstprivate(img1, img2, w) \
+    private(img2_bak)
 #endif
     {
 #ifdef _OPENMP
@@ -398,7 +402,9 @@ static void box_max(const gray_image img1, const gray_image img2, const int w)
     }
   }
 #ifdef _OPENMP
-#pragma omp parallel default(none) private(img2_bak)
+#pragma omp parallel default(none) \
+  dt_omp_firstprivate(img1, img2, w) \
+  private(img2_bak)
 #endif
   {
     img2_bak = new_gray_image(1, img2.height);
@@ -440,7 +446,9 @@ static void box_min(const gray_image img1, const gray_image img2, const int w)
   if(img1.data == img2.data)
   {
 #ifdef _OPENMP
-#pragma omp parallel default(none) private(img2_bak)
+#pragma omp parallel default(none) \
+    dt_omp_firstprivate(img1, img2, w) \
+    private(img2_bak)
 #endif
     {
       img2_bak = new_gray_image(img2.width, 1);
@@ -458,7 +466,9 @@ static void box_min(const gray_image img1, const gray_image img2, const int w)
   else
   {
 #ifdef _OPENMP
-#pragma omp parallel default(none) private(img2_bak)
+#pragma omp parallel default(none) \
+    dt_omp_firstprivate(img1, img2, w) \
+    private(img2_bak)
 #endif
     {
 #ifdef _OPENMP
@@ -469,7 +479,9 @@ static void box_min(const gray_image img1, const gray_image img2, const int w)
     }
   }
 #ifdef _OPENMP
-#pragma omp parallel default(none) private(img2_bak)
+#pragma omp parallel default(none) \
+  dt_omp_firstprivate(img1, img2, w) \
+  private(img2_bak)
 #endif
   {
     img2_bak = new_gray_image(1, img2.height);
@@ -490,7 +502,9 @@ static void dark_channel(const const_rgb_image img1, const gray_image img2, cons
 {
   const size_t size = (size_t)img1.height * img1.width;
 #ifdef _OPENMP
-#pragma omp parallel for default(none) schedule(static)
+#pragma omp parallel for default(none) \
+  dt_omp_firstprivate(img1, img2, size) \
+  schedule(static)
 #endif
   for(size_t i = 0; i < size; i++)
   {
@@ -509,7 +523,9 @@ static void transition_map(const const_rgb_image img1, const gray_image img2, co
 {
   const size_t size = (size_t)img1.height * img1.width;
 #ifdef _OPENMP
-#pragma omp parallel for default(none) schedule(static)
+#pragma omp parallel for default(none) \
+  dt_omp_firstprivate(A0, img1, img2, size, strength) \
+  schedule(static)
 #endif
   for(size_t i = 0; i < size; i++)
   {
@@ -782,7 +798,10 @@ static float ambient_light(const const_rgb_image img, int w1, rgb_pixel *pA0)
   size_t N_bright_hazy = 0;
   const float *const data = dark_ch.data;
 #ifdef _OPENMP
-#pragma omp parallel for default(none) schedule(static) reduction(+ : N_bright_hazy, A0_r, A0_g, A0_b)
+#pragma omp parallel for default(none) \
+  dt_omp_firstprivate(crit_brightness, crit_haze_level, data, img, size) \
+  schedule(static) \
+  reduction(+ : N_bright_hazy, A0_r, A0_g, A0_b)
 #endif
   for(size_t i = 0; i < size; i++)
   {
@@ -898,7 +917,10 @@ void process(struct dt_iop_module_t *self, dt_dev_pixelpipe_iop_t *piece, const
   const gray_image c_trans_map_filtered = trans_map_filtered;
 #ifdef _OPENMP
 // use dynamic load ballancing as tiles may have varying size
-#pragma omp parallel for default(none) schedule(dynamic) collapse(2)
+#pragma omp parallel for default(none) \
+  dt_omp_firstprivate(c_trans_map, c_trans_map_filtered, height, img_in, w2, eps, tile_width, width) \
+  schedule(dynamic) \
+  collapse(2)
 #endif
   for(int j = 0; j < height; j += tile_width)
   {
@@ -914,7 +936,9 @@ void process(struct dt_iop_module_t *self, dt_dev_pixelpipe_iop_t *piece, const
       = fmaxf(expf(-distance * distance_max), 1.f / 1024); // minimum allowed value for transition map
   const float *const c_A0 = A0;
 #ifdef _OPENMP
-#pragma omp parallel for default(none) schedule(static)
+#pragma omp parallel for default(none) \
+  dt_omp_firstprivate(c_A0, c_trans_map_filtered, img_in, img_out, size, t_min) \
+  schedule(static)
 #endif
   for(size_t i = 0; i < size; i++)
   {
diff --git a/src/iop/ashift.c b/src/iop/ashift.c
index 1245178..8650cf9 100644
--- a/src/iop/ashift.c
+++ b/src/iop/ashift.c
@@ -878,7 +878,10 @@ int distort_transform(dt_iop_module_t *self, dt_dev_pixelpipe_iop_t *piece, floa
   const float cy = fullheight * data->ct;
 
 #ifdef _OPENMP
-#pragma omp parallel for schedule(static) default(none) shared(points, points_count, homograph)
+#pragma omp parallel for default(none) \
+  dt_omp_firstprivate(cx, cy) \
+  shared(points, points_count, homograph) \
+  schedule(static)
 #endif
   for(size_t i = 0; i < points_count * 2; i += 2)
   {
@@ -912,7 +915,10 @@ int distort_backtransform(dt_iop_module_t *self, dt_dev_pixelpipe_iop_t *piece,
   const float cy = fullheight * data->ct;
 
 #ifdef _OPENMP
-#pragma omp parallel for schedule(static) default(none) shared(points, points_count, ihomograph)
+#pragma omp parallel for default(none) \
+  dt_omp_firstprivate(cx, cy) \
+  shared(points, points_count, ihomograph) \
+  schedule(static)
 #endif
   for(size_t i = 0; i < points_count * 2; i += 2)
   {
@@ -1062,7 +1068,10 @@ static void rgb2grey256(const float *in, double *out, const int width, const int
   const int ch = 4;
 
 #ifdef _OPENMP
-#pragma omp parallel for schedule(static) default(none) shared(in, out)
+#pragma omp parallel for default(none) \
+  dt_omp_firstprivate(height, width) \
+  shared(in, out) \
+  schedule(static)
 #endif
   for(int j = 0; j < height; j++)
   {
@@ -1089,7 +1098,10 @@ static void edge_enhance_1d(const double *in, double *out, const int width, cons
   const double *kernel = (dir == ASHIFT_ENHANCE_HORIZONTAL) ? (const double *)hkernel : (const double *)vkernel;
 
 #ifdef _OPENMP
-#pragma omp parallel for schedule(static) default(none) shared(in, out, kernel)
+#pragma omp parallel for default(none) \
+  dt_omp_firstprivate(height, width) \
+  shared(in, out, kernel) \
+  schedule(static)
 #endif
   // loop over image pixels and perform sobel convolution
   for(int j = khwidth; j < height - khwidth; j++)
@@ -1113,7 +1125,10 @@ static void edge_enhance_1d(const double *in, double *out, const int width, cons
   }
 
 #ifdef _OPENMP
-#pragma omp parallel for schedule(static) default(none) shared(out)
+#pragma omp parallel for default(none) \
+  dt_omp_firstprivate(height, width) \
+  shared(out) \
+  schedule(static)
 #endif
   // border fill in output buffer, so we don't get pseudo lines at image frame
   for(int j = 0; j < height; j++)
@@ -1155,7 +1170,10 @@ static int edge_enhance(const double *in, double *out, const int width, const in
 
 // calculate absolute values
 #ifdef _OPENMP
-#pragma omp parallel for schedule(static) default(none) shared(Gx, Gy, out)
+#pragma omp parallel for default(none) \
+  dt_omp_firstprivate(height, width) \
+  shared(Gx, Gy, out) \
+  schedule(static)
 #endif
   for(size_t k = 0; k < (size_t)width * height; k++)
   {
@@ -1202,7 +1220,10 @@ static int detail_enhance(const float *in, float *out, const int width, const in
 
   // convert RGB input to Lab, use output buffer for intermediate storage
 #ifdef _OPENMP
-#pragma omp parallel for schedule(static) default(none) shared(in, out)
+#pragma omp parallel for default(none) \
+  dt_omp_firstprivate(height, width) \
+  shared(in, out) \
+  schedule(static)
 #endif
   for(int j = 0; j < height; j++)
   {
@@ -1231,7 +1252,10 @@ static int detail_enhance(const float *in, float *out, const int width, const in
 
   // convert resulting Lab to RGB output
 #ifdef _OPENMP
-#pragma omp parallel for schedule(static) default(none) shared(out)
+#pragma omp parallel for default(none) \
+  dt_omp_firstprivate(height, width) \
+  shared(out) \
+  schedule(static)
 #endif
   for(int j = 0; j < height; j++)
   {
@@ -1251,7 +1275,10 @@ static int detail_enhance(const float *in, float *out, const int width, const in
 static void gamma_correct(const float *in, float *out, const int width, const int height)
 {
 #ifdef _OPENMP
-#pragma omp parallel for schedule(static) default(none) shared(in, out)
+#pragma omp parallel for default(none) \
+  dt_omp_firstprivate(height, width) \
+  shared(in, out) \
+  schedule(static)
 #endif
   for(int j = 0; j < height; j++)
   {
@@ -2835,7 +2862,10 @@ void process(struct dt_iop_module_t *self, dt_dev_pixelpipe_iop_t *piece, const
 
 
 #ifdef _OPENMP
-#pragma omp parallel for schedule(static) default(none) shared(ihomograph, interpolation)
+#pragma omp parallel for default(none) \
+  dt_omp_firstprivate(ch, ch_width, cx, cy, ivoid, ovoid, roi_in, roi_out) \
+  shared(ihomograph, interpolation) \
+  schedule(static)
 #endif
   // go over all pixels of output image
   for(int j = 0; j < roi_out->height; j++)
diff --git a/src/iop/globaltonemap.c b/src/iop/globaltonemap.c
index 45493e3..e71e744 100644
--- a/src/iop/globaltonemap.c
+++ b/src/iop/globaltonemap.c
@@ -139,7 +139,10 @@ static inline void process_reinhard(struct dt_iop_module_t *self, dt_dev_pixelpi
   const int ch = piece->colors;
 
 #ifdef _OPENMP
-#pragma omp parallel for default(none) shared(in, out, data) schedule(static)
+#pragma omp parallel for default(none) \
+  dt_omp_firstprivate(ch, roi_out) \
+  shared(in, out, data) \
+  schedule(static)
 #endif
   for(size_t k = 0; k < (size_t)roi_out->width * roi_out->height; k++)
   {
@@ -216,7 +219,10 @@ static inline void process_drago(struct dt_iop_module_t *self, dt_dev_pixelpipe_
   const float bl = logf(fmaxf(eps, data->drago.bias)) / logf(0.5);
 
 #ifdef _OPENMP
-#pragma omp parallel for default(none) shared(in, out, lwmax) schedule(static)
+#pragma omp parallel for default(none) \
+  dt_omp_firstprivate(ch, bl, ldc, roi_out) \
+  shared(in, out, lwmax) \
+  schedule(static)
 #endif
   for(size_t k = 0; k < (size_t)roi_out->width * roi_out->height; k++)
   {
@@ -240,7 +246,10 @@ static inline void process_filmic(struct dt_iop_module_t *self, dt_dev_pixelpipe
   const int ch = piece->colors;
 
 #ifdef _OPENMP
-#pragma omp parallel for default(none) shared(in, out, data) schedule(static)
+#pragma omp parallel for default(none) \
+  dt_omp_firstprivate(ch, roi_out) \
+  shared(in, out, data) \
+  schedule(static)
 #endif
   for(size_t k = 0; k < (size_t)roi_out->width * roi_out->height; k++)
   {
diff --git a/src/iop/colorcontrast.c b/src/iop/colorcontrast.c
index f88dd15..b7de39d 100644
--- a/src/iop/colorcontrast.c
+++ b/src/iop/colorcontrast.c
@@ -153,7 +153,9 @@ void process(struct dt_iop_module_t *self, dt_dev_pixelpipe_iop_t *piece, const
   if(d->unbound)
   {
 #ifdef _OPENMP
-#pragma omp parallel for SIMD() default(none) schedule(static)
+#pragma omp parallel for SIMD() default(none) \
+    dt_omp_firstprivate(ch, d, in, out, roi_out) \
+    schedule(static)
 #endif
     for(size_t k = 0; k < (size_t)ch * roi_out->width * roi_out->height; k += ch)
     {
@@ -166,7 +168,9 @@ void process(struct dt_iop_module_t *self, dt_dev_pixelpipe_iop_t *piece, const
   else
   {
 #ifdef _OPENMP
-#pragma omp parallel for SIMD() default(none) schedule(static)
+#pragma omp parallel for SIMD() default(none) \
+    dt_omp_firstprivate(ch, d, in, out, roi_out) \
+    schedule(static)
 #endif
     for(size_t k = 0; k < (size_t)ch * roi_out->width * roi_out->height; k += ch)
     {
@@ -200,7 +204,11 @@ void process_sse2(struct dt_iop_module_t *self, dt_dev_pixelpipe_iop_t *piece, c
 
 // iterate over all output pixels (same coordinates as input)
 #ifdef _OPENMP
-#pragma omp parallel for default(none) schedule(static) shared(d)
+#pragma omp parallel for default(none) \
+  dt_omp_firstprivate(ch, ivoid, max, min, offset, ovoid, roi_in, roi_out, \
+                      scale, unbound) \
+  shared(d) \
+  schedule(static)
 #endif
   for(int j = 0; j < roi_out->height; j++)
   {
diff --git a/src/iop/colorize.c b/src/iop/colorize.c
index 23f0340..5fb0db7 100644
--- a/src/iop/colorize.c
+++ b/src/iop/colorize.c
@@ -144,7 +144,10 @@ void process(struct dt_iop_module_t *self, dt_dev_pixelpipe_iop_t *piece, const
   const float Lmlmix = L - (mix * 100.0f) / 2.0f;
 
 #ifdef _OPENMP
-#pragma omp parallel for default(none) private(in, out) schedule(static)
+#pragma omp parallel for default(none) \
+  dt_omp_firstprivate(a, b, ch, ivoid, Lmlmix, mix, ovoid, roi_out) \
+  private(in, out) \
+  schedule(static)
 #endif
   for(int k = 0; k < roi_out->height; k++)
   {
diff --git a/src/iop/nlmeans.c b/src/iop/nlmeans.c
index a9c1e5d..d3e6cd7 100644
--- a/src/iop/nlmeans.c
+++ b/src/iop/nlmeans.c
@@ -410,7 +410,11 @@ void process(struct dt_iop_module_t *self, dt_dev_pixelpipe_iop_t *piece, const
 // do this in parallel with a little threading overhead. could parallelize the outer loops with a bit more
 // memory
 #ifdef _OPENMP
-#pragma omp parallel for schedule(static) default(none) firstprivate(inited_slide) shared(kj, ki, Sa)
+#pragma omp parallel for default(none) \
+      dt_omp_firstprivate(ivoid, norm2, ovoid, P, roi_in, roi_out, sharpness) \
+      firstprivate(inited_slide) \
+      shared(kj, ki, Sa) \
+      schedule(static)
 #endif
       for(int j = 0; j < roi_out->height; j++)
       {
@@ -496,7 +500,10 @@ void process(struct dt_iop_module_t *self, dt_dev_pixelpipe_iop_t *piece, const
   float *const out = ((float *const)ovoid);
 
 #ifdef _OPENMP
-#pragma omp parallel for SIMD() default(none) schedule(static) collapse(2)
+#pragma omp parallel for SIMD() default(none) \
+  dt_omp_firstprivate(ch, in, invert, out, roi_out, weight) \
+  schedule(static) \
+  collapse(2)
 #endif
   for(size_t k = 0; k < (size_t)ch * roi_out->width * roi_out->height; k += ch)
   {
@@ -554,7 +561,11 @@ void process_sse2(struct dt_iop_module_t *self, dt_dev_pixelpipe_iop_t *piece, c
 // do this in parallel with a little threading overhead. could parallelize the outer loops with a bit more
 // memory
 #ifdef _OPENMP
-#pragma omp parallel for schedule(static) default(none) firstprivate(inited_slide) shared(kj, ki, Sa)
+#pragma omp parallel for default(none) \
+  dt_omp_firstprivate(ivoid, norm2, ovoid, P, roi_in, roi_out, sharpness) \
+  firstprivate(inited_slide) \
+  shared(kj, ki, Sa) \
+  schedule(static)
 #endif
       for(int j = 0; j < roi_out->height; j++)
       {
@@ -686,7 +697,10 @@ void process_sse2(struct dt_iop_module_t *self, dt_dev_pixelpipe_iop_t *piece, c
   const __m128 weight = _mm_set_ps(1.0f, d->chroma, d->chroma, d->luma);
   const __m128 invert = _mm_sub_ps(_mm_set1_ps(1.0f), weight);
 #ifdef _OPENMP
-#pragma omp parallel for default(none) schedule(static) shared(d)
+#pragma omp parallel for default(none) \
+  dt_omp_firstprivate(invert, ivoid, ovoid, roi_out, weight) \
+  shared(d) \
+  schedule(static)
 #endif
   for(int j = 0; j < roi_out->height; j++)
   {
diff --git a/src/iop/lowlight.c b/src/iop/lowlight.c
index 59b56e9..24cf8a6 100644
--- a/src/iop/lowlight.c
+++ b/src/iop/lowlight.c
@@ -132,7 +132,10 @@ void process(struct dt_iop_module_t *self, dt_dev_pixelpipe_iop_t *piece, const
   dt_Lab_to_XYZ(Lab_sw, XYZ_sw);
 
 #ifdef _OPENMP
-#pragma omp parallel for default(none) schedule(static) shared(d, XYZ_sw)
+#pragma omp parallel for default(none) \
+  dt_omp_firstprivate(ch, i, o, roi_out) \
+  shared(d, XYZ_sw) \
+  schedule(static)
 #endif
   for(size_t k = 0; k < (size_t)roi_out->width * roi_out->height; k++)
   {
diff --git a/src/iop/overexposed.c b/src/iop/overexposed.c
index 2969f2b..a417ec7 100644
--- a/src/iop/overexposed.c
+++ b/src/iop/overexposed.c
@@ -125,7 +125,10 @@ void process(struct dt_iop_module_t *self, dt_dev_pixelpipe_iop_t *piece, const
   float *const out = (float *const)ovoid;
 
 #ifdef _OPENMP
-#pragma omp parallel for default(none) schedule(static)
+#pragma omp parallel for default(none) \
+  dt_omp_firstprivate(ch, in, lower, lower_color, out, roi_out, \
+                      upper, upper_color) \
+  schedule(static)
 #endif
   for(size_t k = 0; k < (size_t)ch * roi_out->width * roi_out->height; k += ch)
   {
@@ -174,7 +177,10 @@ void process_sse2(struct dt_iop_module_t *self, dt_dev_pixelpipe_iop_t *piece, c
   const __m128 lower_color = _mm_load_ps(dt_iop_overexposed_colors[colorscheme][1]);
 
 #ifdef _OPENMP
-#pragma omp parallel for default(none) schedule(static)
+#pragma omp parallel for default(none) \
+  dt_omp_firstprivate(ch, ivoid, lower, lower_color, ovoid, roi_out, \
+                      mupper, mlower, upper, upper_color) \
+  schedule(static)
 #endif
   for(int k = 0; k < roi_out->height; k++)
   {
diff --git a/src/iop/clipping.c b/src/iop/clipping.c
index 3e72040..42bb0ca 100644
--- a/src/iop/clipping.c
+++ b/src/iop/clipping.c
@@ -844,7 +844,10 @@ void process(struct dt_iop_module_t *self, dt_dev_pixelpipe_iop_t *piece, const
      && roi_in->height == roi_out->height)
   {
 #ifdef _OPENMP
-#pragma omp parallel for schedule(static) default(none) shared(d)
+#pragma omp parallel for default(none) \
+    dt_omp_firstprivate(ch, ivoid, ovoid, roi_out) \
+    shared(d) \
+    schedule(static)
 #endif
     for(int j = 0; j < roi_out->height; j++)
     {
@@ -870,8 +873,10 @@ void process(struct dt_iop_module_t *self, dt_dev_pixelpipe_iop_t *piece, const
     keystone_get_matrix(k_space, kxa, kxb, kxc, kxd, kya, kyb, kyc, kyd, &ma, &mb, &md, &me, &mg, &mh);
 
 #ifdef _OPENMP
-#pragma omp parallel for schedule(static) default(none) shared(d, interpolation, k_space, ma, mb, md, me,    \
-                                                               mg, mh)
+#pragma omp parallel for default(none) \
+    dt_omp_firstprivate(ch, ch_width, ivoid, kxa, kya, ovoid, roi_in, roi_out) \
+    shared(d, interpolation, k_space, ma, mb, md, me, mg, mh) \
+    schedule(static)
 #endif
     // (slow) point-by-point transformation.
     // TODO: optimize with scanlines and linear steps between?
diff --git a/src/iop/rawdenoise.c b/src/iop/rawdenoise.c
index 0a4773f..86173b0 100644
--- a/src/iop/rawdenoise.c
+++ b/src/iop/rawdenoise.c
@@ -235,7 +235,10 @@ static void wavelet_denoise(const float *const in, float *const out, const dt_io
     const int halfheight = roi->height / 2 + (roi->height & (~c) & 1);
 
 #ifdef _OPENMP
-#pragma omp parallel for default(none) shared(c) schedule(static)
+#pragma omp parallel for default(none) \
+    dt_omp_firstprivate(in, fimg, roi, size, halfwidth) \
+    shared(c) \
+    schedule(static)
 #endif
     for(int row = c & 1; row < roi->height; row += 2)
     {
@@ -255,7 +258,10 @@ static void wavelet_denoise(const float *const in, float *const out, const dt_io
 
 // filter horizontally and transpose
 #ifdef _OPENMP
-#pragma omp parallel for default(none) shared(lev) schedule(static)
+#pragma omp parallel for default(none) \
+      dt_omp_firstprivate(fimg, halfheight, halfwidth, pass1, pass2) \
+      shared(lev) \
+      schedule(static)
 #endif
       for(int col = 0; col < halfwidth; col++)
       {
@@ -264,7 +270,10 @@ static void wavelet_denoise(const float *const in, float *const out, const dt_io
       }
 // filter vertically and transpose back
 #ifdef _OPENMP
-#pragma omp parallel for default(none) shared(lev) schedule(static)
+#pragma omp parallel for default(none) \
+      dt_omp_firstprivate(fimg, halfheight, halfwidth, pass2, pass3) \
+      shared(lev) \
+      schedule(static)
 #endif
       for(int row = 0; row < halfheight; row++)
       {
@@ -274,7 +283,9 @@ static void wavelet_denoise(const float *const in, float *const out, const dt_io
 
       const float thold = threshold * noise[lev];
 #ifdef _OPENMP
-#pragma omp parallel for default(none) shared(lev)
+#pragma omp parallel for default(none) \
+      dt_omp_firstprivate(fimg, halfheight, halfwidth, pass1, pass3, thold) \
+      shared(lev)
 #endif
       for(size_t i = 0; i < (size_t)halfwidth * halfheight; i++)
       {
@@ -286,7 +297,10 @@ static void wavelet_denoise(const float *const in, float *const out, const dt_io
       lastpass = pass3;
     }
 #ifdef _OPENMP
-#pragma omp parallel for default(none) shared(c, lastpass) schedule(static)
+#pragma omp parallel for default(none) \
+    dt_omp_firstprivate(fimg, halfwidth, out, roi) \
+    shared(c, lastpass) \
+    schedule(static)
 #endif
     for(int row = c & 1; row < roi->height; row += 2)
     {
@@ -390,7 +404,10 @@ static void wavelet_denoise_xtrans(const float *const in, float *out, const dt_i
     memset(fimg, 0, size * sizeof(float));
 
 #ifdef _OPENMP
-#pragma omp parallel for default(none) shared(c) schedule(static)
+#pragma omp parallel for default(none) \
+    dt_omp_firstprivate(fimg, height, in, roi, size, width, xtrans) \
+    shared(c) \
+    schedule(static)
 #endif
     for(int row = (c != 1); row < height - 1; row++)
     {
@@ -423,20 +440,28 @@ static void wavelet_denoise_xtrans(const float *const in, float *out, const dt_i
 
 // filter horizontally and transpose
 #ifdef _OPENMP
-#pragma omp parallel for default(none) shared(lev) schedule(static)
+#pragma omp parallel for default(none) \
+      dt_omp_firstprivate(fimg, height, pass1, pass2, width) \
+      shared(lev) \
+      schedule(static)
 #endif
       for(int col = 0; col < width; col++)
         hat_transform(fimg + pass2 + (size_t)col * height, fimg + pass1 + col, width, height, 1 << lev);
 // filter vertically and transpose back
 #ifdef _OPENMP
-#pragma omp parallel for default(none) shared(lev) schedule(static)
+#pragma omp parallel for default(none) \
+      dt_omp_firstprivate(fimg, height, pass2, pass3, width) \
+      shared(lev) \
+      schedule(static)
 #endif
       for(int row = 0; row < height; row++)
         hat_transform(fimg + pass3 + (size_t)row * width, fimg + pass2 + row, height, width, 1 << lev);
 
       const float thold = threshold * noise[lev];
 #ifdef _OPENMP
-#pragma omp parallel for default(none) shared(lev)
+#pragma omp parallel for default(none) \
+      dt_omp_firstprivate(fimg, pass1, pass3, size, thold) \
+      shared(lev)
 #endif
       for(size_t i = 0; i < size; i++)
       {
@@ -449,7 +474,10 @@ static void wavelet_denoise_xtrans(const float *const in, float *out, const dt_i
     }
 
 #ifdef _OPENMP
-#pragma omp parallel for default(none) shared(c, lastpass, out) schedule(static)
+#pragma omp parallel for default(none) \
+    dt_omp_firstprivate(height, fimg, roi, width, xtrans) \
+    shared(c, lastpass, out) \
+    schedule(static)
 #endif
     for(int row = 0; row < height; row++)
     {
diff --git a/src/iop/colorchecker.c b/src/iop/colorchecker.c
index 1218a59..a32557d 100644
--- a/src/iop/colorchecker.c
+++ b/src/iop/colorchecker.c
@@ -380,7 +380,10 @@ void process(struct dt_iop_module_t *self, dt_dev_pixelpipe_iop_t *piece, const
   const dt_iop_colorchecker_data_t *const data = (dt_iop_colorchecker_data_t *)piece->data;
   const int ch = piece->colors;
 #ifdef _OPENMP
-#pragma omp parallel for default(none) schedule(static) collapse(2)
+#pragma omp parallel for default(none) \
+  dt_omp_firstprivate(ch, data, ivoid, ovoid, roi_in, roi_out) \
+  schedule(static) \
+  collapse(2)
 #endif
   for(int j=0;j<roi_out->height;j++)
   {
diff --git a/src/iop/colorzones.c b/src/iop/colorzones.c
index d798cf4..604b583 100644
--- a/src/iop/colorzones.c
+++ b/src/iop/colorzones.c
@@ -203,7 +203,10 @@ void process(struct dt_iop_module_t *self, dt_dev_pixelpipe_iop_t *piece, const
   dt_iop_colorzones_data_t *d = (dt_iop_colorzones_data_t *)(piece->data);
   const int ch = piece->colors;
 #ifdef _OPENMP
-#pragma omp parallel for default(none) schedule(static) shared(d)
+#pragma omp parallel for default(none) \
+  dt_omp_firstprivate(ch, i, o, roi_out) \
+  shared(d) \
+  schedule(static)
 #endif
   for(size_t k = 0; k < (size_t)roi_out->width * roi_out->height; k++)
   {
diff --git a/src/iop/colorout.c b/src/iop/colorout.c
index e9108a0..be9995b 100644
--- a/src/iop/colorout.c
+++ b/src/iop/colorout.c
@@ -292,7 +292,9 @@ static void process_fastpath_apply_tonecurves(struct dt_iop_module_t *self, dt_d
     { // apply profile
       float *const out = (float *const)ovoid;
 #ifdef _OPENMP
-#pragma omp parallel for schedule(static) default(none)
+#pragma omp parallel for default(none) \
+      dt_omp_firstprivate(ch, d, out, roi_out) \
+      schedule(static)
 #endif
       for(size_t k = 0; k < (size_t)ch * roi_out->width * roi_out->height; k += ch)
       {
@@ -307,7 +309,9 @@ static void process_fastpath_apply_tonecurves(struct dt_iop_module_t *self, dt_d
     { // apply profile
       float *const out = (float *const)ovoid;
 #ifdef _OPENMP
-#pragma omp parallel for schedule(static) default(none)
+#pragma omp parallel for default(none) \
+      dt_omp_firstprivate(ch, d, out, roi_out) \
+      schedule(static)
 #endif
       for(size_t k = 0; k < (size_t)ch * roi_out->width * roi_out->height; k += ch)
       {
@@ -340,7 +344,9 @@ void process(struct dt_iop_module_t *self, dt_dev_pixelpipe_iop_t *piece, const
 // fprintf(stderr,"Using cmatrix codepath\n");
 // convert to rgb using matrix
 #ifdef _OPENMP
-#pragma omp parallel for schedule(static) default(none)
+#pragma omp parallel for default(none) \
+      dt_omp_firstprivate(ch, d, ivoid, ovoid, roi_out) \
+      schedule(static)
 #endif
     for(size_t k = 0; k < (size_t)ch * roi_out->width * roi_out->height; k += ch)
     {
@@ -366,7 +372,9 @@ void process(struct dt_iop_module_t *self, dt_dev_pixelpipe_iop_t *piece, const
   {
 // fprintf(stderr,"Using xform codepath\n");
 #ifdef _OPENMP
-#pragma omp parallel for schedule(static) default(none)
+#pragma omp parallel for default(none) \
+      dt_omp_firstprivate(ch, d, gamutcheck, ivoid, ovoid, roi_out) \
+      schedule(static)
 #endif
     for(int k = 0; k < roi_out->height; k++)
     {
@@ -410,7 +418,9 @@ void process_sse2(struct dt_iop_module_t *self, dt_dev_pixelpipe_iop_t *piece, c
 // fprintf(stderr,"Using cmatrix codepath\n");
 // convert to rgb using matrix
 #ifdef _OPENMP
-#pragma omp parallel for schedule(static) default(none)
+#pragma omp parallel for default(none) \
+    dt_omp_firstprivate(d, ch, ivoid, ovoid, roi_in, roi_out) \
+    schedule(static)
 #endif
     for(int j = 0; j < roi_out->height; j++)
     {
@@ -441,7 +451,9 @@ void process_sse2(struct dt_iop_module_t *self, dt_dev_pixelpipe_iop_t *piece, c
     // fprintf(stderr,"Using xform codepath\n");
     const __m128 outofgamutpixel = _mm_set_ps(0.0f, 1.0f, 1.0f, 0.0f);
 #ifdef _OPENMP
-#pragma omp parallel for schedule(static) default(none)
+#pragma omp parallel for default(none) \
+    dt_omp_firstprivate(ch, d, ivoid, gamutcheck, outofgamutpixel, ovoid, roi_out) \
+    schedule(static)
 #endif
     for(int k = 0; k < roi_out->height; k++)
     {
diff --git a/src/iop/bilateral.cc b/src/iop/bilateral.cc
index 79cf150..2a0cac7 100644
--- a/src/iop/bilateral.cc
+++ b/src/iop/bilateral.cc
@@ -144,7 +144,11 @@ void process(struct dt_iop_module_t *self, dt_dev_pixelpipe_iop_t *piece, const
     float *const weights_buf = (float *)malloc(weights_size * dt_get_num_threads() * sizeof(float));
 
 #ifdef _OPENMP
-#pragma omp parallel for default(none) schedule(static) shared(m, mat, isig2col) private(in, out)
+#pragma omp parallel for default(none) \
+    dt_omp_firstprivate(ch, ivoid, ovoid, rad, roi_in, roi_out, wd, weights_buf) \
+    shared(m, mat, isig2col) \
+    private(in, out) \
+    schedule(static)
 #endif
     for(int j = rad; j < roi_out->height - rad; j++)
     {
diff --git a/src/iop/colorbalance.c b/src/iop/colorbalance.c
index 19270e4..a966442 100644
--- a/src/iop/colorbalance.c
+++ b/src/iop/colorbalance.c
@@ -334,7 +334,11 @@ void process(struct dt_iop_module_t *self, dt_dev_pixelpipe_iop_t *piece, const
                               (gamma[2] != 0.0) ? 1.0 / gamma[2] : 1000000.0 };
 
 #ifdef _OPENMP
-#pragma omp parallel for SIMD() default(none) shared(d) schedule(static)
+#pragma omp parallel for SIMD() default(none) \
+      dt_omp_firstprivate(ch, gain, gamma_inv, lift, ivoid, ovoid, roi_in, \
+                          roi_out) \
+      shared(d) \
+      schedule(static)
 #endif
       for(size_t k = 0; k < (size_t)ch * roi_in->width * roi_out->height; k += ch)
       {
@@ -381,7 +385,12 @@ void process(struct dt_iop_module_t *self, dt_dev_pixelpipe_iop_t *piece, const
                               (gamma[2] != 0.0) ? 1.0 / gamma[2] : 1000000.0 };
 
 #ifdef _OPENMP
-#pragma omp parallel for SIMD() default(none) shared(d) schedule(static)
+#pragma omp parallel for SIMD() default(none) \
+      dt_omp_firstprivate(ch, contrast, gain, gamma_inv, grey, ivoid, lift, \
+                          ovoid, roi_in, roi_out, run_contrast, \
+                          run_saturation, run_saturation_out) \
+      shared(d) \
+      schedule(static)
 #endif
       for(size_t k = 0; k < (size_t)ch * roi_in->width * roi_out->height; k += ch)
       {
@@ -445,7 +454,12 @@ void process(struct dt_iop_module_t *self, dt_dev_pixelpipe_iop_t *piece, const
                               (2.0f - d->gamma[CHANNEL_BLUE]) * (2.0f - d->gamma[CHANNEL_FACTOR])};
 
 #ifdef _OPENMP
-#pragma omp parallel for SIMD() default(none) shared(d) schedule(static)
+#pragma omp parallel for SIMD() default(none) \
+      dt_omp_firstprivate(ch, contrast, gain, gamma, grey, ivoid, lift, ovoid, \
+                          roi_in, roi_out, run_contrast, run_saturation, \
+                          run_saturation_out) \
+      shared(d) \
+      schedule(static)
 #endif
       for(size_t k = 0; k < (size_t)ch * roi_in->width * roi_out->height; k += ch)
       {
@@ -543,7 +557,9 @@ void process_sse2(struct dt_iop_module_t *self, dt_dev_pixelpipe_iop_t *piece, c
                                        0.0f);
 
 #ifdef _OPENMP
-#pragma omp parallel for SIMD() default(none) schedule(static)
+#pragma omp parallel for SIMD() default(none) \
+      dt_omp_firstprivate(ch, gain, gamma_inv, ivoid, lift, one, ovoid, roi_in, roi_out, zero) \
+      schedule(static)
 #endif
       for(size_t k = 0; k < (size_t)ch * roi_in->width * roi_out->height; k += ch)
       {
@@ -591,7 +607,13 @@ void process_sse2(struct dt_iop_module_t *self, dt_dev_pixelpipe_iop_t *piece, c
       const __m128 gamma_inv_RGB = _mm_set1_ps(1.0f/2.2f);
 
 #ifdef _OPENMP
-#pragma omp parallel for SIMD()default(none) schedule(static)
+#pragma omp parallel for SIMD() default(none) \
+      dt_omp_firstprivate(ch, contrast, gain, gamma_inv, gamma_inv_RGB, \
+                          gamma_RGB, grey, ivoid, lift, one, ovoid, roi_in, \
+                          roi_out, run_contrast, run_saturation, \
+                          run_saturation_out, saturation, saturation_out, \
+                          zero) \
+      schedule(static)
 #endif
       for(size_t k = 0; k < (size_t)ch * roi_in->width * roi_out->height; k += ch)
       {
@@ -659,7 +681,12 @@ void process_sse2(struct dt_iop_module_t *self, dt_dev_pixelpipe_iop_t *piece, c
                                       0.0f);
 
 #ifdef _OPENMP
-#pragma omp parallel for SIMD() default(none) schedule(static)
+#pragma omp parallel for SIMD() default(none) \
+      dt_omp_firstprivate(ch, contrast, gain, gamma, grey, ivoid, lift, ovoid, \
+                          roi_in, roi_out, run_contrast, run_saturation, \
+                          run_saturation_out, saturation, saturation_out, \
+                          zero) \
+      schedule(static)
 #endif
       for(size_t k = 0; k < (size_t)ch * roi_in->width * roi_out->height; k += ch)
       {
diff --git a/src/iop/equalizer_eaw.h b/src/iop/equalizer_eaw.h
index 1d58e24..e2afc51 100644
--- a/src/iop/equalizer_eaw.h
+++ b/src/iop/equalizer_eaw.h
@@ -43,7 +43,11 @@ static void dt_iop_equalizer_wtf(float *buf, float **weight_a, const int l, cons
 
   float *const tmp_width_buf = (float *)malloc(width * dt_get_num_threads() * sizeof(float));
 #ifdef _OPENMP
-#pragma omp parallel for default(none) shared(weight_a, buf) private(ch) schedule(static)
+#pragma omp parallel for default(none) \
+  dt_omp_firstprivate(height, l, st, step, tmp_width_buf, wd, width) \
+  shared(weight_a, buf) \
+  private(ch) \
+  schedule(static)
 #endif
   for(int j = 0; j < height; j++)
   {
@@ -73,7 +77,11 @@ static void dt_iop_equalizer_wtf(float *buf, float **weight_a, const int l, cons
 
   float *const tmp_height_buf = (float *)malloc(height * dt_get_num_threads() * sizeof(float));
 #ifdef _OPENMP
-#pragma omp parallel for default(none) shared(weight_a, buf) private(ch) schedule(static)
+#pragma omp parallel for default(none) \
+  dt_omp_firstprivate(height, l, st, step, tmp_height_buf, wd, width) \
+  shared(weight_a, buf) \
+  private(ch) \
+  schedule(static)
 #endif
   for(int i = 0; i < width; i++)
   {
@@ -110,7 +118,10 @@ static void dt_iop_equalizer_iwtf(float *buf, float **weight_a, const int l, con
 
   float *const tmp_height_buf = (float *)malloc(height * dt_get_num_threads() * sizeof(float));
 #ifdef _OPENMP
-#pragma omp parallel for default(none) shared(weight_a, buf) schedule(static)
+#pragma omp parallel for default(none) \
+  dt_omp_firstprivate(height, l, st, step, tmp_height_buf, wd, width) \
+  shared(weight_a, buf) \
+  schedule(static)
 #endif
   for(int i = 0; i < width; i++)
   {
@@ -139,7 +150,10 @@ static void dt_iop_equalizer_iwtf(float *buf, float **weight_a, const int l, con
 
   float *const tmp_width_buf = (float *)malloc(width * dt_get_num_threads() * sizeof(float));
 #ifdef _OPENMP
-#pragma omp parallel for default(none) shared(weight_a, buf) schedule(static)
+#pragma omp parallel for default(none) \
+  dt_omp_firstprivate(height, l, st, step, tmp_width_buf, wd, width) \
+  shared(weight_a, buf) \
+  schedule(static)
 #endif
   for(int j = 0; j < height; j++)
   {
diff --git a/src/iop/rotatepixels.c b/src/iop/rotatepixels.c
index 519180a..eacc681 100644
--- a/src/iop/rotatepixels.c
+++ b/src/iop/rotatepixels.c
@@ -257,7 +257,10 @@ void process(dt_iop_module_t *self, dt_dev_pixelpipe_iop_t *piece, const void *c
   const struct dt_interpolation *interpolation = dt_interpolation_new(DT_INTERPOLATION_USERPREF);
 
 #ifdef _OPENMP
-#pragma omp parallel for schedule(static) default(none) shared(piece, interpolation)
+#pragma omp parallel for default(none) \
+  dt_omp_firstprivate(ch, ch_width, ivoid, ovoid, roi_in, roi_out, scale) \
+  shared(piece, interpolation) \
+  schedule(static)
 #endif
   // (slow) point-by-point transformation.
   // TODO: optimize with scanlines and linear steps between?
diff --git a/src/iop/vibrance.c b/src/iop/vibrance.c
index c9eaafd..f3fe554 100644
--- a/src/iop/vibrance.c
+++ b/src/iop/vibrance.c
@@ -101,7 +101,10 @@ void process(struct dt_iop_module_t *self, dt_dev_pixelpipe_iop_t *piece, const
   const float amount = (d->amount * 0.01);
 
 #ifdef _OPENMP
-#pragma omp parallel for default(none) shared(in, out) schedule(static)
+#pragma omp parallel for default(none) \
+  dt_omp_firstprivate(amount, ch, roi_out) \
+  shared(in, out) \
+  schedule(static)
 #endif
   for(int k = 0; k < roi_out->height; k++)
   {
diff --git a/src/iop/colorreconstruction.c b/src/iop/colorreconstruction.c
index a5e3ffe..ac7e98a 100644
--- a/src/iop/colorreconstruction.c
+++ b/src/iop/colorreconstruction.c
@@ -365,7 +365,9 @@ static void dt_iop_colorreconstruct_bilateral_splat(dt_iop_colorreconstruct_bila
 
   // splat into downsampled grid
 #ifdef _OPENMP
-#pragma omp parallel for default(none) shared(b, precedence, params)
+#pragma omp parallel for default(none) \
+  dt_omp_firstprivate(in, threshold) \
+  shared(b, precedence, params)
 #endif
   for(int j = 0; j < b->height; j++)
   {
@@ -439,7 +441,9 @@ static void blur_line(dt_iop_colorreconstruct_Lab_t *buf, const int offset1, con
   const float w1 = 4.f / 16.f;
   const float w2 = 1.f / 16.f;
 #ifdef _OPENMP
-#pragma omp parallel for default(none) shared(buf)
+#pragma omp parallel for default(none) \
+  dt_omp_firstprivate(offset1, offset2, offset3, size1, size2, size3) \
+  shared(buf)
 #endif
   for(int k = 0; k < size1; k++)
   {
@@ -515,7 +519,8 @@ static void dt_iop_colorreconstruct_bilateral_slice(const dt_iop_colorreconstruc
   const int oy = b->size_x;
   const int oz = b->size_y * b->size_x;
 #ifdef _OPENMP
-#pragma omp parallel for default(none)
+#pragma omp parallel for default(none) \
+  dt_omp_firstprivate(b, in, out, oy, oz, rescale, roi, threshold)
 #endif
   for(int j = 0; j < roi->height; j++)
   {
diff --git a/src/iop/bloom.c b/src/iop/bloom.c
index d76ce73..2e03ce0 100644
--- a/src/iop/bloom.c
+++ b/src/iop/bloom.c
@@ -126,7 +126,10 @@ void process(struct dt_iop_module_t *self, dt_dev_pixelpipe_iop_t *piece, const
 
 /* get the thresholded lights into buffer */
 #ifdef _OPENMP
-#pragma omp parallel for default(none) shared(data, blurlightness) schedule(static)
+#pragma omp parallel for default(none) \
+  dt_omp_firstprivate(ch, ivoid, roi_out, scale) \
+  shared(data, blurlightness) \
+  schedule(static)
 #endif
   for(size_t k = 0; k < (size_t)roi_out->width * roi_out->height; k++)
   {
@@ -146,7 +149,10 @@ void process(struct dt_iop_module_t *self, dt_dev_pixelpipe_iop_t *piece, const
   for(int iteration = 0; iteration < BOX_ITERATIONS; iteration++)
   {
 #ifdef _OPENMP
-#pragma omp parallel for default(none) shared(blurlightness) schedule(static)
+#pragma omp parallel for default(none) \
+    dt_omp_firstprivate(hr, roi_out, scanline_buf, size) \
+    shared(blurlightness) \
+    schedule(static)
 #endif
     for(int y = 0; y < roi_out->height; y++)
     {
@@ -180,7 +186,10 @@ void process(struct dt_iop_module_t *self, dt_dev_pixelpipe_iop_t *piece, const
 
 
 #ifdef _OPENMP
-#pragma omp parallel for default(none) shared(blurlightness) schedule(static)
+#pragma omp parallel for default(none) \
+    dt_omp_firstprivate(hr, npoffs, opoffs, roi_out, size, scanline_buf) \
+    shared(blurlightness) \
+    schedule(static)
 #endif
     for(int x = 0; x < roi_out->width; x++)
     {
@@ -214,7 +223,10 @@ void process(struct dt_iop_module_t *self, dt_dev_pixelpipe_iop_t *piece, const
 
 /* screen blend lightness with original */
 #ifdef _OPENMP
-#pragma omp parallel for default(none) shared(in, out, data, blurlightness) schedule(static)
+#pragma omp parallel for default(none) \
+  dt_omp_firstprivate(ch, roi_out) \
+  shared(in, out, data, blurlightness) \
+  schedule(static)
 #endif
   for(size_t k = 0; k < (size_t)roi_out->width * roi_out->height; k++)
   {
diff --git a/src/iop/rawprepare.c b/src/iop/rawprepare.c
index 030fe5b..d985637 100644
--- a/src/iop/rawprepare.c
+++ b/src/iop/rawprepare.c
@@ -301,7 +301,10 @@ void process(struct dt_iop_module_t *self, dt_dev_pixelpipe_iop_t *piece, const
     float *const out = (float *const)ovoid;
 
 #ifdef _OPENMP
-#pragma omp parallel for SIMD() default(none) schedule(static) collapse(2)
+#pragma omp parallel for SIMD() default(none) \
+    dt_omp_firstprivate(csx, csy, d, in, out, roi_in, roi_out) \
+    schedule(static) \
+    collapse(2)
 #endif
     for(int j = 0; j < roi_out->height; j++)
     {
@@ -325,7 +328,10 @@ void process(struct dt_iop_module_t *self, dt_dev_pixelpipe_iop_t *piece, const
     float *const out = (float *const)ovoid;
 
 #ifdef _OPENMP
-#pragma omp parallel for SIMD() default(none) schedule(static) collapse(2)
+#pragma omp parallel for SIMD() default(none) \
+    dt_omp_firstprivate(csx, csy, d, in, out, roi_in, roi_out) \
+    schedule(static) \
+    collapse(2)
 #endif
     for(int j = 0; j < roi_out->height; j++)
     {
@@ -353,7 +359,9 @@ void process(struct dt_iop_module_t *self, dt_dev_pixelpipe_iop_t *piece, const
     const int ch = piece->colors;
 
 #ifdef _OPENMP
-#pragma omp parallel for SIMD() default(none) schedule(static) collapse(3)
+#pragma omp parallel for SIMD() default(none) \
+    dt_omp_firstprivate(ch, csx, csy, div, in, out, roi_in, roi_out, sub) \
+    schedule(static) collapse(3)
 #endif
     for(int j = 0; j < roi_out->height; j++)
     {
@@ -387,7 +395,9 @@ void process_sse2(dt_iop_module_t *self, dt_dev_pixelpipe_iop_t *piece, const vo
   if(piece->pipe->dsc.filters && piece->dsc_in.channels == 1 && piece->dsc_in.datatype == TYPE_UINT16)
   { // raw mosaic
 #ifdef _OPENMP
-#pragma omp parallel for default(none) schedule(static)
+#pragma omp parallel for default(none) \
+    dt_omp_firstprivate(csx, csy, d, ivoid, ovoid, roi_in, roi_out) \
+    schedule(static)
 #endif
     for(int j = 0; j < roi_out->height; j++)
     {
@@ -446,7 +456,9 @@ void process_sse2(dt_iop_module_t *self, dt_dev_pixelpipe_iop_t *piece, const vo
   else if(piece->pipe->dsc.filters && piece->dsc_in.channels == 1 && piece->dsc_in.datatype == TYPE_FLOAT)
   { // raw mosaic, fp, unnormalized
 #ifdef _OPENMP
-#pragma omp parallel for default(none) schedule(static)
+#pragma omp parallel for default(none) \
+    dt_omp_firstprivate(csx, csy, d, ivoid, ovoid, roi_in, roi_out) \
+    schedule(static)
 #endif
     for(int j = 0; j < roi_out->height; j++)
     {
@@ -498,7 +510,9 @@ void process_sse2(dt_iop_module_t *self, dt_dev_pixelpipe_iop_t *piece, const vo
     const __m128 sub = _mm_load_ps(d->sub), div = _mm_load_ps(d->div);
 
 #ifdef _OPENMP
-#pragma omp parallel for default(none) schedule(static)
+#pragma omp parallel for default(none) \
+    dt_omp_firstprivate(csx, csy, div, ivoid, ovoid, roi_in, roi_out, sub) \
+    schedule(static)
 #endif
     for(int j = 0; j < roi_out->height; j++)
     {
diff --git a/src/iop/filmic.c b/src/iop/filmic.c
index 91afe02..9739a62 100644
--- a/src/iop/filmic.c
+++ b/src/iop/filmic.c
@@ -431,7 +431,9 @@ void process(dt_iop_module_t *self, dt_dev_pixelpipe_iop_t *piece, const void *c
   const float saturation = data->global_saturation / 100.0f;
 
 #ifdef _OPENMP
-#pragma omp parallel for SIMD() default(none) schedule(static)
+#pragma omp parallel for SIMD() default(none) \
+  dt_omp_firstprivate(ch, data, desaturate, ivoid, ovoid, preserve_color, roi_out, saturation) \
+  schedule(static)
 #endif
   for(size_t k = 0; k < roi_out->height * roi_out->width * ch; k += ch)
   {
@@ -556,7 +558,12 @@ void process_sse2(struct dt_iop_module_t *self, dt_dev_pixelpipe_iop_t *piece, c
   const __m128 one = _mm_set1_ps(1.0f);
 
 #ifdef _OPENMP
-#pragma omp parallel for default(none) schedule(static)
+#pragma omp parallel for default(none) \
+  dt_omp_firstprivate(black, black_sse, ch, data, desaturate, dynamic_range, \
+                      dynamic_range_sse, EPS, grey, grey_sse, ivoid, one, \
+                      ovoid, power, preserve_color, roi_out, saturation_sse, \
+                      zero) \
+  schedule(static)
 #endif
   for(size_t k = 0; k < roi_out->height * roi_out->width * ch; k += ch)
   {
@@ -1421,7 +1428,10 @@ void commit_params(dt_iop_module_t *self, dt_iop_params_t *p1, dt_dev_pixelpipe_
   const float sigma = saturation * saturation * latitude * latitude;
 
 #ifdef _OPENMP
-#pragma omp parallel for SIMD() default(none) shared(d) schedule(static)
+#pragma omp parallel for SIMD() default(none) \
+  dt_omp_firstprivate(center, sigma) \
+  shared(d) \
+  schedule(static)
 #endif
   for(int k = 0; k < 65536; k++)
   {
diff --git a/src/iop/monochrome.c b/src/iop/monochrome.c
index ba98c59..e8ca0c5 100644
--- a/src/iop/monochrome.c
+++ b/src/iop/monochrome.c
@@ -153,7 +153,10 @@ void process(struct dt_iop_module_t *self, dt_dev_pixelpipe_iop_t *piece, const
   const float sigma2 = (d->size * 128.0) * (d->size * 128.0f);
 // first pass: evaluate color filter:
 #ifdef _OPENMP
-#pragma omp parallel for default(none) shared(d) schedule(static)
+#pragma omp parallel for default(none) \
+  dt_omp_firstprivate(i, o, roi_out, sigma2) \
+  shared(d) \
+  schedule(static)
 #endif
   for(int k = 0; k < roi_out->height; k++)
   {
@@ -180,7 +183,10 @@ void process(struct dt_iop_module_t *self, dt_dev_pixelpipe_iop_t *piece, const
   dt_bilateral_free(b);
 
 #ifdef _OPENMP
-#pragma omp parallel for default(none) shared(d) schedule(static)
+#pragma omp parallel for default(none) \
+  dt_omp_firstprivate(i, o, roi_out) \
+  shared(d) \
+  schedule(static)
 #endif
   for(int k = 0; k < roi_out->height; k++)
   {
diff --git a/src/iop/colorin.c b/src/iop/colorin.c
index 107b4e3..59914ab 100644
--- a/src/iop/colorin.c
+++ b/src/iop/colorin.c
@@ -483,7 +483,9 @@ static void process_cmatrix_bm(struct dt_iop_module_t *self, dt_dev_pixelpipe_io
     // fprintf(stderr, "Using cmatrix codepath\n");
     // only color matrix. use our optimized fast path!
 #ifdef _OPENMP
-#pragma omp parallel for default(none) schedule(static)
+#pragma omp parallel for default(none) \
+  dt_omp_firstprivate(ch, clipping, d, ivoid, ovoid, roi_out) \
+  schedule(static)
 #endif
   for(int j = 0; j < roi_out->height; j++)
   {
@@ -562,7 +564,9 @@ static void process_cmatrix_fastpath_simple(struct dt_iop_module_t *self, dt_dev
 // fprintf(stderr, "Using cmatrix codepath\n");
 // only color matrix. use our optimized fast path!
 #ifdef _OPENMP
-#pragma omp parallel for default(none) schedule(static)
+#pragma omp parallel for default(none) \
+  dt_omp_firstprivate(ch, d, ivoid, ovoid, roi_out) \
+  schedule(static)
 #endif
   for(int k = 0; k < (size_t)roi_out->width * roi_out->height; k++)
   {
@@ -594,7 +598,9 @@ static void process_cmatrix_fastpath_clipping(struct dt_iop_module_t *self, dt_d
 // fprintf(stderr, "Using cmatrix codepath\n");
 // only color matrix. use our optimized fast path!
 #ifdef _OPENMP
-#pragma omp parallel for default(none) schedule(static)
+#pragma omp parallel for default(none) \
+  dt_omp_firstprivate(ch, d, ivoid, ovoid, roi_out) \
+  schedule(static)
 #endif
   for(int k = 0; k < (size_t)roi_out->width * roi_out->height; k++)
   {
@@ -659,7 +665,9 @@ static void process_cmatrix_proper(struct dt_iop_module_t *self, dt_dev_pixelpip
 // fprintf(stderr, "Using cmatrix codepath\n");
 // only color matrix. use our optimized fast path!
 #ifdef _OPENMP
-#pragma omp parallel for default(none) schedule(static)
+#pragma omp parallel for default(none) \
+  dt_omp_firstprivate(ch, clipping, d, ivoid, ovoid, roi_out) \
+  schedule(static)
 #endif
   for(int j = 0; j < roi_out->height; j++)
   {
@@ -755,7 +763,9 @@ static void process_lcms2_bm(struct dt_iop_module_t *self, dt_dev_pixelpipe_iop_
 
 // use general lcms2 fallback
 #ifdef _OPENMP
-#pragma omp parallel for schedule(static) default(none)
+#pragma omp parallel for default(none) \
+  dt_omp_firstprivate(ch, d, ivoid, ovoid, roi_out) \
+  schedule(static)
 #endif
   for(int k = 0; k < roi_out->height; k++)
   {
@@ -800,7 +810,9 @@ static void process_lcms2_proper(struct dt_iop_module_t *self, dt_dev_pixelpipe_
 
 // use general lcms2 fallback
 #ifdef _OPENMP
-#pragma omp parallel for schedule(static) default(none)
+#pragma omp parallel for default(none) \
+  dt_omp_firstprivate(ch, d, ivoid, ovoid, roi_out) \
+  schedule(static)
 #endif
   for(int k = 0; k < roi_out->height; k++)
   {
@@ -884,7 +896,10 @@ static void process_sse2_cmatrix_bm(struct dt_iop_module_t *self, dt_dev_pixelpi
   float *in = (float *)ivoid;
   float *out = (float *)ovoid;
 #ifdef _OPENMP
-#pragma omp parallel for default(none) shared(out, in) schedule(static)
+#pragma omp parallel for default(none) \
+  dt_omp_firstprivate(ch, clipping, cmat, d, lmat, nmat, roi_in, roi_out) \
+  shared(out, in) \
+  schedule(static)
 #endif
   for(int j = 0; j < roi_out->height; j++)
   {
@@ -956,7 +971,9 @@ static void process_sse2_cmatrix_fastpath_simple(struct dt_iop_module_t *self, d
   const __m128 cm2 = _mm_set_ps(0.0f, cmat[8], cmat[5], cmat[2]);
 
 #ifdef _OPENMP
-#pragma omp parallel for default(none) schedule(static)
+#pragma omp parallel for default(none) \
+  dt_omp_firstprivate(ch, cm0, cm1, cm2, ivoid, ovoid, roi_out) \
+  schedule(static)
 #endif
   for(int k = 0; k < (size_t)roi_out->width * roi_out->height; k++)
   {
@@ -994,7 +1011,9 @@ static void process_sse2_cmatrix_fastpath_clipping(struct dt_iop_module_t *self,
   const __m128 lm2 = _mm_set_ps(0.0f, lmat[8], lmat[5], lmat[2]);
 
 #ifdef _OPENMP
-#pragma omp parallel for default(none) schedule(static)
+#pragma omp parallel for default(none) \
+  dt_omp_firstprivate(ch, ivoid, lm0, lm1, lm2, nm0, nm1, nm2, ovoid, roi_out) \
+  schedule(static)
 #endif
   for(int k = 0; k < (size_t)roi_out->width * roi_out->height; k++)
   {
@@ -1047,7 +1066,10 @@ static void process_sse2_cmatrix_proper(struct dt_iop_module_t *self, dt_dev_pix
   float *in = (float *)ivoid;
   float *out = (float *)ovoid;
 #ifdef _OPENMP
-#pragma omp parallel for default(none) shared(out, in) schedule(static)
+#pragma omp parallel for default(none) \
+  dt_omp_firstprivate(ch, clipping, cmat, d, lmat, nmat, roi_in, roi_out) \
+  shared(out, in) \
+  schedule(static)
 #endif
   for(int j = 0; j < roi_out->height; j++)
   {
@@ -1131,7 +1153,9 @@ static void process_sse2_lcms2_bm(struct dt_iop_module_t *self, dt_dev_pixelpipe
 
 // use general lcms2 fallback
 #ifdef _OPENMP
-#pragma omp parallel for schedule(static) default(none)
+#pragma omp parallel for default(none) \
+  dt_omp_firstprivate(ch, d, ivoid, ovoid, roi_out) \
+  schedule(static)
 #endif
   for(int k = 0; k < roi_out->height; k++)
   {
@@ -1179,7 +1203,9 @@ static void process_sse2_lcms2_proper(struct dt_iop_module_t *self, dt_dev_pixel
 
 // use general lcms2 fallback
 #ifdef _OPENMP
-#pragma omp parallel for schedule(static) default(none)
+#pragma omp parallel for default(none) \
+  dt_omp_firstprivate(ch, d, ivoid, ovoid, roi_out) \
+  schedule(static)
 #endif
   for(int k = 0; k < roi_out->height; k++)
   {
diff --git a/src/iop/basecurve.c b/src/iop/basecurve.c
index 72dc2a8..44a3b05 100644
--- a/src/iop/basecurve.c
+++ b/src/iop/basecurve.c
@@ -823,7 +823,9 @@ static inline void apply_ev_and_curve(
     const float *const unbounded_coeffs)
 {
 #ifdef _OPENMP
-#pragma omp parallel for default(none) schedule(static)
+#pragma omp parallel for default(none) \
+  dt_omp_firstprivate(height, in, mul, out, table, unbounded_coeffs, width) \
+  schedule(static)
 #endif
   for(size_t k = 0; k < (size_t)width * height; k++)
   {
@@ -852,7 +854,10 @@ static inline void compute_features(
   // 2) saturation
   // 3) local contrast (handled in laplacian form later)
 #ifdef _OPENMP
-#pragma omp parallel for default(none) schedule(static) collapse(2)
+#pragma omp parallel for default(none) \
+  dt_omp_firstprivate(col, ht, wd) \
+  schedule(static) \
+  collapse(2)
 #endif
   for(int j=0;j<ht;j++) for(int i=0;i<wd;i++)
   {
@@ -882,7 +887,10 @@ static inline void gauss_blur(
   float *tmp = dt_alloc_align(64, (size_t)wd*ht*4*sizeof(float));
   memset(tmp, 0, 4*wd*ht*sizeof(float));
 #ifdef _OPENMP
-#pragma omp parallel for default(none) schedule(static) shared(tmp)
+#pragma omp parallel for default(none) \
+  dt_omp_firstprivate(ht, input, w, wd) \
+  shared(tmp) \
+  schedule(static)
 #endif
   for(int j=0;j<ht;j++)
   { // horizontal pass
@@ -901,7 +909,10 @@ static inline void gauss_blur(
   }
   memset(output, 0, 4*wd*ht*sizeof(float));
 #ifdef _OPENMP
-#pragma omp parallel for default(none) schedule(static) shared(tmp)
+#pragma omp parallel for default(none) \
+  dt_omp_firstprivate(ht, output, w, wd) \
+  shared(tmp) \
+  schedule(static)
 #endif
   for(int i=0;i<wd;i++)
   { // vertical pass
@@ -928,7 +939,10 @@ static inline void gauss_expand(
   // fill numbers in even pixels, zero odd ones
   memset(fine, 0, 4*wd*ht*sizeof(float));
 #ifdef _OPENMP
-#pragma omp parallel for default(none) schedule(static) collapse(2)
+#pragma omp parallel for default(none) \
+  dt_omp_firstprivate(cw, fine, ht, input, wd) \
+  schedule(static) \
+  collapse(2)
 #endif
   for(int j=0;j<ht;j+=2)
     for(int i=0;i<wd;i+=2)
@@ -1015,7 +1029,10 @@ void process_fusion(struct dt_iop_module_t *self, dt_dev_pixelpipe_iop_t *piece,
     h = ht;
     gauss_reduce(col[0], col[1], out, w, h);
 #ifdef _OPENMP
-#pragma omp parallel for default(none) shared(col) schedule(static)
+#pragma omp parallel for default(none) \
+    dt_omp_firstprivate(ht, out, wd) \
+    shared(col) \
+    schedule(static)
 #endif
     for(size_t k = 0; k < 4ul * wd * ht; k += 4)
       col[0][k + 3] *= .1f + sqrtf(out[k] * out[k] + out[k + 1] * out[k + 1] + out[k + 2] * out[k + 2]);
@@ -1051,7 +1068,10 @@ void process_fusion(struct dt_iop_module_t *self, dt_dev_pixelpipe_iop_t *piece,
       // abuse output buffer as temporary memory:
       if(k != num_levels - 1) gauss_expand(col[k + 1], out, w, h);
 #ifdef _OPENMP
-#pragma omp parallel for default(none) shared(col, comb, w, h, num_levels, k) schedule(static)
+#pragma omp parallel for default(none) \
+      dt_omp_firstprivate(out) \
+      shared(col, comb, w, h, num_levels, k) \
+      schedule(static)
 #endif
       for(int j = 0; j < h; j++)
         for(int i = 0; i < w; i++)
@@ -1095,7 +1115,10 @@ void process_fusion(struct dt_iop_module_t *self, dt_dev_pixelpipe_iop_t *piece,
     { // reconstruct output image
       gauss_expand(comb[k + 1], out, w, h);
 #ifdef _OPENMP
-#pragma omp parallel for default(none) shared(comb, w, h, k) schedule(static)
+#pragma omp parallel for default(none) \
+      dt_omp_firstprivate(out) \
+      shared(comb, w, h, k) \
+      schedule(static)
 #endif
       for(int j = 0; j < h; j++)
         for(int i = 0; i < w; i++)
@@ -1108,7 +1131,10 @@ void process_fusion(struct dt_iop_module_t *self, dt_dev_pixelpipe_iop_t *piece,
 #endif
   // copy output buffer
 #ifdef _OPENMP
-#pragma omp parallel for default(none) shared(comb) schedule(static)
+#pragma omp parallel for default(none) \
+  dt_omp_firstprivate(col, in, ht, out, wd) \
+  shared(comb) \
+  schedule(static)
 #endif
   for(size_t k = 0; k < (size_t)4 * wd * ht; k += 4)
   {
@@ -1137,7 +1163,9 @@ void process_lut(struct dt_iop_module_t *self, dt_dev_pixelpipe_iop_t *piece, co
   dt_iop_basecurve_data_t *const d = (dt_iop_basecurve_data_t *)(piece->data);
 
 #ifdef _OPENMP
-#pragma omp parallel for default(none) schedule(static)
+#pragma omp parallel for default(none) \
+  dt_omp_firstprivate(ch, d, in, out, roi_out) \
+  schedule(static)
 #endif
   for(size_t k = 0; k < (size_t)roi_out->width * roi_out->height; k++)
   {
diff --git a/src/iop/shadhi.c b/src/iop/shadhi.c
index b1ed33b..930b066 100644
--- a/src/iop/shadhi.c
+++ b/src/iop/shadhi.c
@@ -373,7 +373,10 @@ void process(struct dt_iop_module_t *self, dt_dev_pixelpipe_iop_t *piece, const
 
 // invert and desaturate
 #ifdef _OPENMP
-#pragma omp parallel for default(none) shared(out) schedule(static)
+#pragma omp parallel for default(none) \
+  dt_omp_firstprivate(roi_out) \
+  shared(out) \
+  schedule(static)
 #endif
   for(size_t j = 0; j < (size_t)roi_out->width * roi_out->height * 4; j += 4)
   {
@@ -391,7 +394,13 @@ void process(struct dt_iop_module_t *self, dt_dev_pixelpipe_iop_t *piece, const
 
 
 #ifdef _OPENMP
-#pragma omp parallel for default(none) shared(in, out) schedule(static)
+#pragma omp parallel for default(none) \
+  dt_omp_firstprivate(ch, compress, doublemax, flags, halfmax, height, \
+                      highlights, highlights_ccorrect, lmax, lmin, \
+                      low_approximation, max, min,  shadows, \
+                      shadows_ccorrect, unbound_mask, whitepoint, width) \
+  shared(in, out) \
+  schedule(static)
 #endif
   for(size_t j = 0; j < (size_t)width * height * ch; j += ch)
   {
diff --git a/src/iop/sharpen.c b/src/iop/sharpen.c
index 06f7e71..ffd00fd 100644
--- a/src/iop/sharpen.c
+++ b/src/iop/sharpen.c
@@ -318,7 +318,9 @@ void process(struct dt_iop_module_t *self, dt_dev_pixelpipe_iop_t *piece, const
 
 // gauss blur the image horizontally
 #ifdef _OPENMP
-#pragma omp parallel for default(none) schedule(static)
+#pragma omp parallel for default(none) \
+  dt_omp_firstprivate(ch, ivoid, mat, rad, roi_in, roi_out, tmp, wd4) \
+  schedule(static)
 #endif
   for(int j = 0; j < roi_out->height; j++)
   {
@@ -358,7 +360,9 @@ void process(struct dt_iop_module_t *self, dt_dev_pixelpipe_iop_t *piece, const
 
 // gauss blur the image vertically
 #ifdef _OPENMP
-#pragma omp parallel for default(none) schedule(static)
+#pragma omp parallel for default(none) \
+  dt_omp_firstprivate(ch, mat, ovoid, rad, roi_in, roi_out, tmp, wd4) \
+  schedule(static)
 #endif
   for(int j = rad; j < roi_out->height - wd4 * 4 + rad; j++)
   {
@@ -385,7 +389,9 @@ void process(struct dt_iop_module_t *self, dt_dev_pixelpipe_iop_t *piece, const
     }
   }
 #ifdef _OPENMP
-#pragma omp parallel for default(none) schedule(static)
+#pragma omp parallel for default(none) \
+  dt_omp_firstprivate(ch, mat, ovoid, rad, roi_in, roi_out, tmp, wd4) \
+  schedule(static)
 #endif
   for(int j = roi_out->height - wd4 * 4 + rad; j < roi_out->height - rad; j++)
   {
@@ -418,7 +424,9 @@ void process(struct dt_iop_module_t *self, dt_dev_pixelpipe_iop_t *piece, const
   dt_free_align(tmp);
 
 #ifdef _OPENMP
-#pragma omp parallel for default(none) schedule(static)
+#pragma omp parallel for default(none) \
+  dt_omp_firstprivate(ch, ivoid, ovoid, rad, roi_out) \
+  schedule(static)
 #endif
   for(int j = rad; j < roi_out->height - rad; j++)
   {
@@ -429,7 +437,9 @@ void process(struct dt_iop_module_t *self, dt_dev_pixelpipe_iop_t *piece, const
   }
 
 #ifdef _OPENMP
-#pragma omp parallel for default(none) schedule(static)
+#pragma omp parallel for default(none) \
+  dt_omp_firstprivate(ch, data, ivoid, ovoid, roi_out) \
+  schedule(static)
 #endif
   // subtract blurred image, if diff > thrs, add *amount to original image
   for(int j = 0; j < roi_out->height; j++)
@@ -502,7 +512,9 @@ void process_sse2(struct dt_iop_module_t *self, dt_dev_pixelpipe_iop_t *piece, c
 
 // gauss blur the image horizontally
 #ifdef _OPENMP
-#pragma omp parallel for default(none) schedule(static)
+#pragma omp parallel for default(none) \
+  dt_omp_firstprivate(ch, ivoid, mat, rad, roi_in, roi_out, tmp, wd4) \
+  schedule(static)
 #endif
   for(int j = 0; j < roi_out->height; j++)
   {
@@ -543,7 +555,9 @@ void process_sse2(struct dt_iop_module_t *self, dt_dev_pixelpipe_iop_t *piece, c
 
 // gauss blur the image vertically
 #ifdef _OPENMP
-#pragma omp parallel for default(none) schedule(static)
+#pragma omp parallel for default(none) \
+  dt_omp_firstprivate(ch, mat, ovoid, rad, roi_in, roi_out, tmp, wd4) \
+  schedule(static)
 #endif
   for(int j = rad; j < roi_out->height - wd4 * 4 + rad; j++)
   {
@@ -571,7 +585,9 @@ void process_sse2(struct dt_iop_module_t *self, dt_dev_pixelpipe_iop_t *piece, c
     }
   }
 #ifdef _OPENMP
-#pragma omp parallel for default(none) schedule(static)
+#pragma omp parallel for default(none) \
+  dt_omp_firstprivate(ch, ivoid, mat, ovoid, rad, roi_in, roi_out, tmp, wd4) \
+  schedule(static)
 #endif
   for(int j = roi_out->height - wd4 * 4 + rad; j < roi_out->height - rad; j++)
   {
@@ -606,7 +622,9 @@ void process_sse2(struct dt_iop_module_t *self, dt_dev_pixelpipe_iop_t *piece, c
   dt_free_align(tmp);
 
 #ifdef _OPENMP
-#pragma omp parallel for default(none) schedule(static)
+#pragma omp parallel for default(none) \
+  dt_omp_firstprivate(ch, ivoid, ovoid, rad, roi_out) \
+  schedule(static)
 #endif
   for(int j = rad; j < roi_out->height - rad; j++)
   {
@@ -617,7 +635,10 @@ void process_sse2(struct dt_iop_module_t *self, dt_dev_pixelpipe_iop_t *piece, c
   }
 
 #ifdef _OPENMP
-#pragma omp parallel for default(none) shared(data) schedule(static)
+#pragma omp parallel for default(none) \
+  dt_omp_firstprivate(ch, ivoid, ovoid, roi_out) \
+  shared(data) \
+  schedule(static)
 #endif
   // subtract blurred image, if diff > thrs, add *amount to original image
   for(int j = 0; j < roi_out->height; j++)
diff --git a/src/iop/highpass.c b/src/iop/highpass.c
index 7920c7e..e765b59 100644
--- a/src/iop/highpass.c
+++ b/src/iop/highpass.c
@@ -288,7 +288,10 @@ void process(struct dt_iop_module_t *self, dt_dev_pixelpipe_iop_t *piece, const
 
 /* create inverted image and then blur */
 #ifdef _OPENMP
-#pragma omp parallel for default(none) shared(in, out) schedule(static)
+#pragma omp parallel for default(none) \
+  dt_omp_firstprivate(ch, roi_out) \
+  shared(in, out) \
+  schedule(static)
 #endif
   for(size_t k = 0; k < (size_t)roi_out->width * roi_out->height; k++)
     out[ch * k] = 100.0f - LCLIP(in[ch * k]); // only L in Lab space
@@ -365,7 +368,10 @@ void process(struct dt_iop_module_t *self, dt_dev_pixelpipe_iop_t *piece, const
 
   const float contrast_scale = ((data->contrast / 100.0) * 7.5);
 #ifdef _OPENMP
-#pragma omp parallel for default(none) shared(in, out, data) schedule(static)
+#pragma omp parallel for default(none) \
+  dt_omp_firstprivate(ch, contrast_scale, roi_out) \
+  shared(in, out, data) \
+  schedule(static)
 #endif
   for(size_t k = 0; k < (size_t)roi_out->width * roi_out->height; k++)
   {
diff --git a/src/iop/invert.c b/src/iop/invert.c
index f5ceae4..6106906 100644
--- a/src/iop/invert.c
+++ b/src/iop/invert.c
@@ -250,7 +250,10 @@ void process(struct dt_iop_module_t *self, dt_dev_pixelpipe_iop_t *piece, const
   if(filters == 9u)
   { // xtrans float mosaiced
 #ifdef _OPENMP
-#pragma omp parallel for SIMD() default(none) schedule(static) collapse(2)
+#pragma omp parallel for SIMD() default(none) \
+    dt_omp_firstprivate(film_rgb_f, in, out, roi_out, xtrans) \
+    schedule(static) \
+    collapse(2)
 #endif
     for(int j = 0; j < roi_out->height; j++)
     {
@@ -267,7 +270,10 @@ void process(struct dt_iop_module_t *self, dt_dev_pixelpipe_iop_t *piece, const
   { // bayer float mosaiced
 
 #ifdef _OPENMP
-#pragma omp parallel for SIMD() default(none) schedule(static) collapse(2)
+#pragma omp parallel for SIMD() default(none) \
+    dt_omp_firstprivate(film_rgb_f, filters, in, out, roi_out) \
+    schedule(static) \
+    collapse(2)
 #endif
     for(int j = 0; j < roi_out->height; j++)
     {
@@ -285,7 +291,10 @@ void process(struct dt_iop_module_t *self, dt_dev_pixelpipe_iop_t *piece, const
     const int ch = piece->colors;
 
 #ifdef _OPENMP
-#pragma omp parallel for SIMD() default(none) schedule(static) collapse(2)
+#pragma omp parallel for SIMD() default(none) \
+    dt_omp_firstprivate(ch, d, in, out, roi_out) \
+    schedule(static) \
+    collapse(2)
 #endif
     for(size_t k = 0; k < (size_t)ch * roi_out->width * roi_out->height; k += ch)
     {
@@ -326,7 +335,9 @@ void process_sse2(struct dt_iop_module_t *self, dt_dev_pixelpipe_iop_t *piece, c
     const __m128 val_max = _mm_set1_ps(1.0f);
 
 #ifdef _OPENMP
-#pragma omp parallel for default(none) schedule(static)
+#pragma omp parallel for default(none) \
+    dt_omp_firstprivate(film_rgb_f, ivoid, ovoid, roi_out, val_max, val_min, xtrans) \
+    schedule(static)
 #endif
     for(int j = 0; j < roi_out->height; j++)
     {
@@ -381,7 +392,9 @@ void process_sse2(struct dt_iop_module_t *self, dt_dev_pixelpipe_iop_t *piece, c
     const __m128 val_max = _mm_set1_ps(1.0f);
 
 #ifdef _OPENMP
-#pragma omp parallel for default(none) schedule(static)
+#pragma omp parallel for default(none) \
+    dt_omp_firstprivate(film_rgb_f, filters, ivoid, ovoid, roi_out, val_max, val_min) \
+    schedule(static)
 #endif
     for(int j = 0; j < roi_out->height; j++)
     {
@@ -423,7 +436,9 @@ void process_sse2(struct dt_iop_module_t *self, dt_dev_pixelpipe_iop_t *piece, c
     const __m128 film = _mm_set_ps(1.0f, d->color[2], d->color[1], d->color[0]);
 
 #ifdef _OPENMP
-#pragma omp parallel for default(none) schedule(static)
+#pragma omp parallel for default(none) \
+    dt_omp_firstprivate(ch, film, ivoid, ovoid, roi_out) \
+    schedule(static)
 #endif
     for(int k = 0; k < roi_out->height; k++)
     {
diff --git a/src/iop/gamma.c b/src/iop/gamma.c
index 7cbd8a7..a9fbaad 100644
--- a/src/iop/gamma.c
+++ b/src/iop/gamma.c
@@ -199,7 +199,9 @@ void process(struct dt_iop_module_t *self, dt_dev_pixelpipe_iop_t *piece, const
   {
     const float yellow[3] = { 1.0f, 1.0f, 0.0f };
 #ifdef _OPENMP
-#pragma omp parallel for default(none) schedule(static)
+#pragma omp parallel for default(none) \
+    dt_omp_firstprivate(ch, i, mask_display, o, roi_out, yellow) \
+    schedule(static)
 #endif
     for(int k = 0; k < roi_out->height; k++)
     {
@@ -222,7 +224,9 @@ void process(struct dt_iop_module_t *self, dt_dev_pixelpipe_iop_t *piece, const
   {
     const float yellow[3] = { 1.0f, 1.0f, 0.0f };
 #ifdef _OPENMP
-#pragma omp parallel for default(none) schedule(static)
+#pragma omp parallel for default(none) \
+    dt_omp_firstprivate(ch, i, mask_display, o, roi_out, yellow) \
+    schedule(static)
 #endif
     for(int k = 0; k < roi_out->height; k++)
     {
@@ -243,7 +247,9 @@ void process(struct dt_iop_module_t *self, dt_dev_pixelpipe_iop_t *piece, const
   {
     const float yellow[3] = { 1.0f, 1.0f, 0.0f };
 #ifdef _OPENMP
-#pragma omp parallel for default(none) schedule(static)
+#pragma omp parallel for default(none) \
+    dt_omp_firstprivate(ch, i, o, roi_out, yellow) \
+    schedule(static)
 #endif
     for(int k = 0; k < roi_out->height; k++)
     {
@@ -264,7 +270,9 @@ void process(struct dt_iop_module_t *self, dt_dev_pixelpipe_iop_t *piece, const
   else
   {
 #ifdef _OPENMP
-#pragma omp parallel for default(none) schedule(static)
+#pragma omp parallel for default(none) \
+    dt_omp_firstprivate(ch, i, o, roi_out) \
+    schedule(static)
 #endif
     for(int k = 0; k < roi_out->height; k++)
     {
diff --git a/src/iop/defringe.c b/src/iop/defringe.c
index fdab4dc..950c101 100644
--- a/src/iop/defringe.c
+++ b/src/iop/defringe.c
@@ -251,8 +251,11 @@ void process(struct dt_iop_module_t *module, dt_dev_pixelpipe_iop_t *piece, cons
   }
 
 #ifdef _OPENMP
-#pragma omp parallel for default(none) shared(width, height,                                                 \
-                                              d) reduction(+ : avg_edge_chroma) schedule(static)
+#pragma omp parallel for default(none) \
+  dt_omp_firstprivate(ch, in, out) \
+  shared(width, height, d) \
+  reduction(+ : avg_edge_chroma) \
+  schedule(static)
 #endif
   for(int v = 0; v < height; v++)
   {
@@ -288,8 +291,11 @@ void process(struct dt_iop_module_t *module, dt_dev_pixelpipe_iop_t *piece, cons
 #ifdef _OPENMP
 // dynamically/guided scheduled due to possible uneven edge-chroma distribution (thanks to rawtherapee code
 // for this hint!)
-#pragma omp parallel for default(none) shared(width, height, d, xy_small, xy_avg, xy_artifact)               \
-    firstprivate(thresh, avg_edge_chroma) schedule(guided, 32)
+#pragma omp parallel for default(none) \
+  dt_omp_firstprivate(ch, in, out, samples_avg, samples_small) \
+  shared(width, height, d, xy_small, xy_avg, xy_artifact) \
+  firstprivate(thresh, avg_edge_chroma) \
+  schedule(guided, 32)
 #endif
   for(int v = 0; v < height; v++)
   {
diff --git a/src/iop/atrous.c b/src/iop/atrous.c
index d915429..16a4395 100644
--- a/src/iop/atrous.c
+++ b/src/iop/atrous.c
@@ -324,7 +324,9 @@ static void eaw_decompose(float *const out, const float *const in, float *const
 /* The first "2*mult" lines use the macro with tests because the 5x5 kernel
  * requires nearest pixel interpolation for at least a pixel in the sum */
 #ifdef _OPENMP
-#pragma omp parallel for default(none) schedule(static)
+#pragma omp parallel for default(none) \
+  dt_omp_firstprivate(detail, filter, height, in, mult, out, sharpen, width) \
+  schedule(static)
 #endif
   for(int j = 0; j < 2 * mult; j++)
   {
@@ -345,7 +347,9 @@ static void eaw_decompose(float *const out, const float *const in, float *const
   }
 
 #ifdef _OPENMP
-#pragma omp parallel for default(none) schedule(static)
+#pragma omp parallel for default(none) \
+  dt_omp_firstprivate(detail, filter, height, in, mult, out, sharpen, width) \
+  schedule(static)
 #endif
   for(int j = 2 * mult; j < height - 2 * mult; j++)
   {
@@ -402,7 +406,9 @@ static void eaw_decompose(float *const out, const float *const in, float *const
 /* The last "2*mult" lines use the macro with tests because the 5x5 kernel
  * requires nearest pixel interpolation for at least a pixel in the sum */
 #ifdef _OPENMP
-#pragma omp parallel for default(none) schedule(static)
+#pragma omp parallel for default(none) \
+  dt_omp_firstprivate(detail, filter, height, in, mult, out, sharpen, width) \
+  schedule(static)
 #endif
   for(int j = height - 2 * mult; j < height; j++)
   {
@@ -439,7 +445,9 @@ static void eaw_decompose_sse2(float *const out, const float *const in, float *c
 /* The first "2*mult" lines use the macro with tests because the 5x5 kernel
  * requires nearest pixel interpolation for at least a pixel in the sum */
 #ifdef _OPENMP
-#pragma omp parallel for default(none) schedule(static)
+#pragma omp parallel for default(none) \
+  dt_omp_firstprivate(detail, filter, height, in, mult, out, sharpen, width) \
+  schedule(static)
 #endif
   for(int j = 0; j < 2 * mult; j++)
   {
@@ -460,7 +468,9 @@ static void eaw_decompose_sse2(float *const out, const float *const in, float *c
   }
 
 #ifdef _OPENMP
-#pragma omp parallel for default(none) schedule(static)
+#pragma omp parallel for default(none) \
+  dt_omp_firstprivate(detail, filter, height, in, mult, out, sharpen, width) \
+  schedule(static)
 #endif
   for(int j = 2 * mult; j < height - 2 * mult; j++)
   {
@@ -517,7 +527,9 @@ static void eaw_decompose_sse2(float *const out, const float *const in, float *c
 /* The last "2*mult" lines use the macro with tests because the 5x5 kernel
  * requires nearest pixel interpolation for at least a pixel in the sum */
 #ifdef _OPENMP
-#pragma omp parallel for default(none) schedule(static)
+#pragma omp parallel for default(none) \
+  dt_omp_firstprivate(detail, filter, height, in, mult, out, sharpen, width) \
+  schedule(static)
 #endif
   for(int j = height - 2 * mult; j < height; j++)
   {
@@ -558,7 +570,10 @@ static void eaw_synthesize(float *const out, const float *const in, const float
   const float boost[4] = { boostf[0], boostf[1], boostf[2], boostf[3] };
 
 #ifdef _OPENMP
-#pragma omp parallel for SIMD() default(none) schedule(static) collapse(2)
+#pragma omp parallel for SIMD() default(none) \
+  dt_omp_firstprivate(boost, detail, height, in, out, width, threshold) \
+  schedule(static) \
+  collapse(2)
 #endif
   for(size_t k = 0; k < (size_t)4 * width * height; k += 4)
   {
@@ -580,7 +595,9 @@ static void eaw_synthesize_sse2(float *const out, const float *const in, const f
   const __m128 boost = _mm_set_ps(boostf[3], boostf[2], boostf[1], boostf[0]);
 
 #ifdef _OPENMP
-#pragma omp parallel for default(none) schedule(static)
+#pragma omp parallel for default(none) \
+  dt_omp_firstprivate(boost, detail, height, in, out, threshold, width) \
+  schedule(static)
 #endif
   for(int j = 0; j < height; j++)
   {
diff --git a/src/iop/colisa.c b/src/iop/colisa.c
index 99acf04..777306b 100644
--- a/src/iop/colisa.c
+++ b/src/iop/colisa.c
@@ -180,7 +180,10 @@ void process(struct dt_iop_module_t *self, dt_dev_pixelpipe_iop_t *piece, const
   const int ch = piece->colors;
 
 #ifdef _OPENMP
-#pragma omp parallel for default(none) shared(in, out, data) schedule(static)
+#pragma omp parallel for default(none) \
+  dt_omp_firstprivate(ch, height, width) \
+  shared(in, out, data) \
+  schedule(static)
 #endif
   for(size_t k = 0; k < (size_t)width * height; k++)
   {
@@ -250,7 +253,10 @@ void commit_params(struct dt_iop_module_t *self, dt_iop_params_t *p1, dt_dev_pix
     const float contrastm1sq = boost * (d->contrast - 1.0f) * (d->contrast - 1.0f);
     const float contrastscale = sqrt(1.0f + contrastm1sq);
 #ifdef _OPENMP
-#pragma omp parallel for default(none) shared(d) schedule(static)
+#pragma omp parallel for default(none) \
+    dt_omp_firstprivate(contrastm1sq, contrastscale) \
+    shared(d) \
+    schedule(static)
 #endif
     for(int k = 0; k < 0x10000; k++)
     {
@@ -272,7 +278,10 @@ void commit_params(struct dt_iop_module_t *self, dt_iop_params_t *p1, dt_dev_pix
   const float gamma = (d->brightness >= 0.0f) ? 1.0f / (1.0f + d->brightness) : (1.0f - d->brightness);
 
 #ifdef _OPENMP
-#pragma omp parallel for default(none) shared(d) schedule(static)
+#pragma omp parallel for default(none) \
+  dt_omp_firstprivate(gamma) \
+  shared(d) \
+  schedule(static)
 #endif
   for(int k = 0; k < 0x10000; k++)
   {
diff --git a/src/iop/profile_gamma.c b/src/iop/profile_gamma.c
index 33975bf..c7e9049 100644
--- a/src/iop/profile_gamma.c
+++ b/src/iop/profile_gamma.c
@@ -333,7 +333,10 @@ void process(dt_iop_module_t *self, dt_dev_pixelpipe_iop_t *piece, const void *c
       const float noise = powf(2.0f, -16.0f);
 
 #ifdef _OPENMP
-#pragma omp parallel for SIMD() default(none) shared(data) schedule(static)
+#pragma omp parallel for SIMD() default(none) \
+      dt_omp_firstprivate(ch, grey, ivoid, ovoid, roi_out) \
+      shared(data) \
+      schedule(static)
 #endif
       for(size_t k = 0; k < (size_t)ch * roi_out->width * roi_out->height; k++)
       {
@@ -356,7 +359,10 @@ void process(dt_iop_module_t *self, dt_dev_pixelpipe_iop_t *piece, const void *c
     case PROFILEGAMMA_GAMMA:
     {
 #ifdef _OPENMP
-#pragma omp parallel for default(none) shared(data) schedule(static)
+#pragma omp parallel for default(none) \
+      dt_omp_firstprivate(ch, ivoid, ovoid, roi_out) \
+      shared(data) \
+      schedule(static)
 #endif
       for(int k = 0; k < roi_out->height; k++)
       {
@@ -688,7 +694,10 @@ void commit_params(dt_iop_module_t *self, dt_iop_params_t *p1, dt_dev_pixelpipe_
     if(linear == 0.0)
     {
 #ifdef _OPENMP
-#pragma omp parallel for default(none) shared(d) schedule(static)
+#pragma omp parallel for default(none) \
+      dt_omp_firstprivate(gamma) \
+      shared(d) \
+      schedule(static)
 #endif
       for(int k = 0; k < 0x10000; k++) d->table[k] = powf(1.00 * k / 0x10000, gamma);
     }
@@ -707,7 +716,10 @@ void commit_params(dt_iop_module_t *self, dt_iop_params_t *p1, dt_dev_pixelpipe_
         c = 1.0;
       }
 #ifdef _OPENMP
-#pragma omp parallel for default(none) shared(d, a, b, c, g) schedule(static)
+#pragma omp parallel for default(none) \
+      dt_omp_firstprivate(linear) \
+      shared(d, a, b, c, g) \
+      schedule(static)
 #endif
       for(int k = 0; k < 0x10000; k++)
       {
diff --git a/src/iop/rawoverexposed.c b/src/iop/rawoverexposed.c
index 0016762..aafd4de 100644
--- a/src/iop/rawoverexposed.c
+++ b/src/iop/rawoverexposed.c
@@ -188,7 +188,12 @@ void process(dt_iop_module_t *self, dt_dev_pixelpipe_iop_t *piece, const void *c
   void *coordbuf = dt_alloc_align(16, coordbufsize * sizeof(float) * dt_get_num_threads());
 
 #ifdef _OPENMP
-#pragma omp parallel for SIMD() default(none) shared(self, coordbuf, buf) schedule(static)
+#pragma omp parallel for SIMD() default(none) \
+  dt_omp_firstprivate(ch, color, coordbufsize, d, \
+                      dt_iop_rawoverexposed_colors, filters, priority, mode, \
+                      out, raw, roi_in, roi_out, xtrans) \
+  shared(self, coordbuf, buf) \
+  schedule(static)
 #endif
   for(int j = 0; j < roi_out->height; j++)
   {
@@ -311,7 +316,10 @@ int process_cl(struct dt_iop_module_t *self, dt_dev_pixelpipe_iop_t *piece, cl_m
   if(coordbuf == NULL) goto error;
 
 #ifdef _OPENMP
-#pragma omp parallel for SIMD() default(none) shared(self, coordbuf, buf) schedule(static)
+#pragma omp parallel for SIMD() default(none) \
+  dt_omp_firstprivate(height, roi_in, roi_out, width) \
+  shared(self, coordbuf, buf) \
+  schedule(static)
 #endif
   for(int j = 0; j < height; j++)
   {
diff --git a/src/iop/soften.c b/src/iop/soften.c
index cee9f87..b20752d 100644
--- a/src/iop/soften.c
+++ b/src/iop/soften.c
@@ -129,7 +129,9 @@ void process(struct dt_iop_module_t *self, dt_dev_pixelpipe_iop_t *piece, const
 
 /* create overexpose image and then blur */
 #ifdef _OPENMP
-#pragma omp parallel for default(none) schedule(static)
+#pragma omp parallel for default(none) \
+  dt_omp_firstprivate(brightness, ch, in, out, roi_out, saturation) \
+  schedule(static)
 #endif
   for(size_t k = 0; k < (size_t)ch * roi_out->width * roi_out->height; k += ch)
   {
@@ -154,7 +156,9 @@ void process(struct dt_iop_module_t *self, dt_dev_pixelpipe_iop_t *piece, const
   for(int iteration = 0; iteration < BOX_ITERATIONS; iteration++)
   {
 #ifdef _OPENMP
-#pragma omp parallel for default(none) schedule(static)
+#pragma omp parallel for default(none) \
+    dt_omp_firstprivate(ch, radius, out, roi_out, scanline_buf, scanline_size) \
+    schedule(static)
 #endif
     /* horizontal blur out into out */
     for(int y = 0; y < roi_out->height; y++)
@@ -206,7 +210,10 @@ void process(struct dt_iop_module_t *self, dt_dev_pixelpipe_iop_t *piece, const
     const int opoffs = -(radius + 1) * roi_out->width;
     const int npoffs = (radius)*roi_out->width;
 #ifdef _OPENMP
-#pragma omp parallel for default(none) schedule(static)
+#pragma omp parallel for default(none) \
+    dt_omp_firstprivate(ch, npoffs, opoffs, radius, out, roi_out, \
+                        scanline_buf, scanline_size) \
+    schedule(static)
 #endif
     for(int x = 0; x < roi_out->width; x++)
     {
@@ -262,7 +269,10 @@ void process(struct dt_iop_module_t *self, dt_dev_pixelpipe_iop_t *piece, const
   const float amount_1 = (1 - (d->amount) / 100.0);
 
 #ifdef _OPENMP
-#pragma omp parallel for SIMD() default(none) schedule(static) collapse(2)
+#pragma omp parallel for SIMD() default(none) \
+  dt_omp_firstprivate(amount, amount_1, ch, in, out, roi_out) \
+  schedule(static) \
+  collapse(2)
 #endif
   for(size_t k = 0; k < (size_t)ch * roi_out->width * roi_out->height; k += ch)
   {
@@ -286,7 +296,10 @@ void process_sse2(struct dt_iop_module_t *self, dt_dev_pixelpipe_iop_t *piece, c
   const float saturation = data->saturation / 100.0;
 /* create overexpose image and then blur */
 #ifdef _OPENMP
-#pragma omp parallel for default(none) shared(in, out) schedule(static)
+#pragma omp parallel for default(none) \
+  dt_omp_firstprivate(ch, brightness, roi_out, saturation) \
+  shared(in, out) \
+  schedule(static)
 #endif
   for(size_t k = 0; k < (size_t)roi_out->width * roi_out->height; k++)
   {
@@ -311,7 +324,10 @@ void process_sse2(struct dt_iop_module_t *self, dt_dev_pixelpipe_iop_t *piece, c
   for(int iteration = 0; iteration < BOX_ITERATIONS; iteration++)
   {
 #ifdef _OPENMP
-#pragma omp parallel for default(none) shared(out) schedule(static)
+#pragma omp parallel for default(none) \
+    dt_omp_firstprivate(ch, radius, roi_out, scanline_buf, size) \
+    shared(out) \
+    schedule(static)
 #endif
     /* horizontal blur out into out */
     for(int y = 0; y < roi_out->height; y++)
@@ -344,7 +360,10 @@ void process_sse2(struct dt_iop_module_t *self, dt_dev_pixelpipe_iop_t *piece, c
     const int opoffs = -(radius + 1) * roi_out->width;
     const int npoffs = (radius)*roi_out->width;
 #ifdef _OPENMP
-#pragma omp parallel for default(none) shared(out) schedule(static)
+#pragma omp parallel for default(none) \
+    dt_omp_firstprivate(ch, npoffs, opoffs, radius, roi_out, scanline_buf, size) \
+    shared(out) \
+    schedule(static)
 #endif
     for(int x = 0; x < roi_out->width; x++)
     {
@@ -381,7 +400,10 @@ void process_sse2(struct dt_iop_module_t *self, dt_dev_pixelpipe_iop_t *piece, c
   const __m128 amount = _mm_set1_ps(data->amount / 100.0);
   const __m128 amount_1 = _mm_set1_ps(1 - (data->amount) / 100.0);
 #ifdef _OPENMP
-#pragma omp parallel for default(none) shared(in, out, data) schedule(static)
+#pragma omp parallel for default(none) \
+  dt_omp_firstprivate(ch, amount, amount_1, roi_out) \
+  shared(in, out, data) \
+  schedule(static)
 #endif
   for(size_t k = 0; k < (size_t)roi_out->width * roi_out->height; k++)
   {
diff --git a/src/iop/denoiseprofile.c b/src/iop/denoiseprofile.c
index 8eaa05e..5901eee 100644
--- a/src/iop/denoiseprofile.c
+++ b/src/iop/denoiseprofile.c
@@ -377,7 +377,10 @@ static inline void precondition(const float *const in, float *const buf, const i
           (b[2] / a[2]) * (b[2] / a[2]) + 3.f / 8.f };
 
 #ifdef _OPENMP
-#pragma omp parallel for schedule(static) default(none) shared(a)
+#pragma omp parallel for default(none) \
+  dt_omp_firstprivate(buf, ht, in, sigma2_plus_3_8, wd) \
+  shared(a) \
+  schedule(static)
 #endif
   for(int j = 0; j < ht; j++)
   {
@@ -405,7 +408,10 @@ static inline void backtransform(float *const buf, const int wd, const int ht, c
           (b[2] / a[2]) * (b[2] / a[2]) + 1.f / 8.f };
 
 #ifdef _OPENMP
-#pragma omp parallel for schedule(static) default(none) shared(a)
+#pragma omp parallel for default(none) \
+  dt_omp_firstprivate(buf, ht, sigma2_plus_1_8, wd) \
+  shared(a) \
+  schedule(static)
 #endif
   for(int j = 0; j < ht; j++)
   {
@@ -590,7 +596,9 @@ static void eaw_decompose(float *const out, const float *const in, float *const
 /* The first "2*mult" lines use the macro with tests because the 5x5 kernel
  * requires nearest pixel interpolation for at least a pixel in the sum */
 #ifdef _OPENMP
-#pragma omp parallel for default(none) schedule(static)
+#pragma omp parallel for default(none) \
+  dt_omp_firstprivate(detail, filter, height, in, inv_sigma2, mult, out, width) \
+  schedule(static)
 #endif
   for(int j = 0; j < 2 * mult; j++)
   {
@@ -611,7 +619,9 @@ static void eaw_decompose(float *const out, const float *const in, float *const
   }
 
 #ifdef _OPENMP
-#pragma omp parallel for default(none) schedule(static)
+#pragma omp parallel for default(none) \
+  dt_omp_firstprivate(detail, filter, height, in, inv_sigma2, mult, out, width) \
+  schedule(static)
 #endif
   for(int j = 2 * mult; j < height - 2 * mult; j++)
   {
@@ -668,7 +678,9 @@ static void eaw_decompose(float *const out, const float *const in, float *const
 /* The last "2*mult" lines use the macro with tests because the 5x5 kernel
  * requires nearest pixel interpolation for at least a pixel in the sum */
 #ifdef _OPENMP
-#pragma omp parallel for default(none) schedule(static)
+#pragma omp parallel for default(none) \
+  dt_omp_firstprivate(detail, filter, height, in, inv_sigma2, mult, out, width) \
+  schedule(static)
 #endif
   for(int j = height - 2 * mult; j < height; j++)
   {
@@ -705,7 +717,9 @@ static void eaw_decompose_sse(float *const out, const float *const in, float *co
 /* The first "2*mult" lines use the macro with tests because the 5x5 kernel
  * requires nearest pixel interpolation for at least a pixel in the sum */
 #ifdef _OPENMP
-#pragma omp parallel for default(none) schedule(static)
+#pragma omp parallel for default(none) \
+  dt_omp_firstprivate(detail, filter, height, in, inv_sigma2, mult, out, width) \
+  schedule(static)
 #endif
   for(int j = 0; j < 2 * mult; j++)
   {
@@ -726,7 +740,9 @@ static void eaw_decompose_sse(float *const out, const float *const in, float *co
   }
 
 #ifdef _OPENMP
-#pragma omp parallel for default(none) schedule(static)
+#pragma omp parallel for default(none) \
+  dt_omp_firstprivate(detail, filter, height, in, inv_sigma2, mult, out, width) \
+  schedule(static)
 #endif
   for(int j = 2 * mult; j < height - 2 * mult; j++)
   {
@@ -783,7 +799,9 @@ static void eaw_decompose_sse(float *const out, const float *const in, float *co
 /* The last "2*mult" lines use the macro with tests because the 5x5 kernel
  * requires nearest pixel interpolation for at least a pixel in the sum */
 #ifdef _OPENMP
-#pragma omp parallel for default(none) schedule(static)
+#pragma omp parallel for default(none) \
+  dt_omp_firstprivate(detail, filter, height, in, inv_sigma2, mult, out, width) \
+  schedule(static)
 #endif
   for(int j = height - 2 * mult; j < height; j++)
   {
@@ -824,7 +842,10 @@ static void eaw_synthesize(float *const out, const float *const in, const float
   const float boost[4] = { boostf[0], boostf[1], boostf[2], boostf[3] };
 
 #ifdef _OPENMP
-#pragma omp parallel for SIMD() default(none) schedule(static) collapse(2)
+#pragma omp parallel for SIMD() default(none) \
+  dt_omp_firstprivate(boost, detail, height, in, out, threshold, width) \
+  schedule(static) \
+  collapse(2)
 #endif
   for(size_t k = 0; k < (size_t)4 * width * height; k += 4)
   {
@@ -846,7 +867,9 @@ static void eaw_synthesize_sse2(float *const out, const float *const in, const f
   const __m128 boost = _mm_set_ps(boostf[3], boostf[2], boostf[1], boostf[0]);
 
 #ifdef _OPENMP
-#pragma omp parallel for default(none) schedule(static)
+#pragma omp parallel for default(none) \
+  dt_omp_firstprivate(boost, detail, height, in, out, threshold, width) \
+  schedule(static)
 #endif
   for(int j = 0; j < height; j++)
   {
@@ -1102,7 +1125,11 @@ static void process_nlmeans(struct dt_iop_module_t *self, dt_dev_pixelpipe_iop_t
 // do this in parallel with a little threading overhead. could parallelize the outer loops with a bit more
 // memory
 #ifdef _OPENMP
-#pragma omp parallel for schedule(static) default(none) firstprivate(inited_slide) shared(kj, ki, in, Sa)
+#pragma omp parallel for default(none) \
+      dt_omp_firstprivate(d, ovoid, P, roi_in, roi_out) \
+      firstprivate(inited_slide) \
+      shared(kj, ki, in, Sa) \
+      schedule(static)
 #endif
       for(int j = 0; j < roi_out->height; j++)
       {
@@ -1188,7 +1215,9 @@ static void process_nlmeans(struct dt_iop_module_t *self, dt_dev_pixelpipe_iop_t
 
 // normalize
 #ifdef _OPENMP
-#pragma omp parallel for default(none) schedule(static)
+#pragma omp parallel for default(none) \
+  dt_omp_firstprivate(ch, out, roi_out) \
+  schedule(static)
 #endif
   for(size_t k = 0; k < (size_t)ch * roi_out->width * roi_out->height; k += ch)
   {
@@ -1246,7 +1275,11 @@ static void process_nlmeans_sse(struct dt_iop_module_t *self, dt_dev_pixelpipe_i
 // do this in parallel with a little threading overhead. could parallelize the outer loops with a bit more
 // memory
 #ifdef _OPENMP
-#pragma omp parallel for schedule(static) default(none) firstprivate(inited_slide) shared(kj, ki, in, Sa)
+#pragma omp parallel for default(none) \
+      dt_omp_firstprivate(ovoid, P, roi_in, roi_out) \
+      firstprivate(inited_slide) \
+      shared(kj, ki, in, Sa) \
+      schedule(static)
 #endif
       for(int j = 0; j < roi_out->height; j++)
       {
@@ -1379,7 +1412,10 @@ static void process_nlmeans_sse(struct dt_iop_module_t *self, dt_dev_pixelpipe_i
   }
 // normalize
 #ifdef _OPENMP
-#pragma omp parallel for default(none) schedule(static) shared(d)
+#pragma omp parallel for default(none) \
+  dt_omp_firstprivate(ovoid, roi_out) \
+  shared(d) \
+  schedule(static)
 #endif
   for(int j = 0; j < roi_out->height; j++)
   {
diff --git a/src/iop/spots.c b/src/iop/spots.c
index 80601de..f4fa791 100644
--- a/src/iop/spots.c
+++ b/src/iop/spots.c
@@ -372,7 +372,9 @@ void process(struct dt_iop_module_t *self, dt_dev_pixelpipe_iop_t *piece, const
 
 // we don't modify most of the image:
 #ifdef _OPENMP
-#pragma omp parallel for schedule(static) default(none) shared(out, in)
+#pragma omp parallel for default(none) \
+  dt_omp_firstprivate(ch, in, out, roi_in, roi_out) \
+  schedule(static)
 #endif
   for(int k = 0; k < roi_out->height; k++)
   {
diff --git a/src/iop/lowpass.c b/src/iop/lowpass.c
index 6076de7..c97f126 100644
--- a/src/iop/lowpass.c
+++ b/src/iop/lowpass.c
@@ -420,7 +420,10 @@ void process(struct dt_iop_module_t *self, dt_dev_pixelpipe_iop_t *piece, const
   const float *const Labminf = (float *)&Labmin;
   const float *const Labmaxf = (float *)&Labmax;
 #ifdef _OPENMP
-#pragma omp parallel for default(none) shared(in, out, data) schedule(static)
+#pragma omp parallel for default(none) \
+  dt_omp_firstprivate(ch, Labmaxf, Labminf, roi_out) \
+  shared(in, out, data) \
+  schedule(static)
 #endif
   for(size_t k = 0; k < (size_t)roi_out->width * roi_out->height; k++)
   {
@@ -529,7 +532,10 @@ void commit_params(struct dt_iop_module_t *self, dt_iop_params_t *p1, dt_dev_pix
     const float contrastm1sq = boost * (fabs(d->contrast) - 1.0f) * (fabs(d->contrast) - 1.0f);
     const float contrastscale = copysign(sqrt(1.0f + contrastm1sq), d->contrast);
 #ifdef _OPENMP
-#pragma omp parallel for default(none) shared(d) schedule(static)
+#pragma omp parallel for default(none) \
+    dt_omp_firstprivate(contrastm1sq, contrastscale) \
+    shared(d) \
+    schedule(static)
 #endif
     for(int k = 0; k < 0x10000; k++)
     {
@@ -551,7 +557,10 @@ void commit_params(struct dt_iop_module_t *self, dt_iop_params_t *p1, dt_dev_pix
   const float gamma = (d->brightness >= 0.0f) ? 1.0f / (1.0f + d->brightness) : (1.0f - d->brightness);
 
 #ifdef _OPENMP
-#pragma omp parallel for default(none) shared(d) schedule(static)
+#pragma omp parallel for default(none) \
+  dt_omp_firstprivate(gamma) \
+  shared(d) \
+  schedule(static)
 #endif
   for(int k = 0; k < 0x10000; k++)
   {
diff --git a/src/iop/temperature.c b/src/iop/temperature.c
index 2bdf8d8..927980e 100644
--- a/src/iop/temperature.c
+++ b/src/iop/temperature.c
@@ -454,7 +454,10 @@ void process(struct dt_iop_module_t *self, dt_dev_pixelpipe_iop_t *piece, const
   if(filters == 9u)
   { // xtrans float mosaiced
 #ifdef _OPENMP
-#pragma omp parallel for SIMD() default(none) schedule(static) collapse(2)
+#pragma omp parallel for SIMD() default(none) \
+    dt_omp_firstprivate(d, in, out, roi_out, xtrans) \
+    schedule(static) \
+    collapse(2)
 #endif
     for(int j = 0; j < roi_out->height; j++)
     {
@@ -468,7 +471,10 @@ void process(struct dt_iop_module_t *self, dt_dev_pixelpipe_iop_t *piece, const
   else if(filters)
   { // bayer float mosaiced
 #ifdef _OPENMP
-#pragma omp parallel for SIMD() default(none) schedule(static) collapse(2)
+#pragma omp parallel for SIMD() default(none) \
+    dt_omp_firstprivate(d, filters, in, out, roi_out) \
+    schedule(static) \
+    collapse(2)
 #endif
     for(int j = 0; j < roi_out->height; j++)
     {
@@ -484,7 +490,10 @@ void process(struct dt_iop_module_t *self, dt_dev_pixelpipe_iop_t *piece, const
     const int ch = piece->colors;
 
 #ifdef _OPENMP
-#pragma omp parallel for SIMD() default(none) schedule(static) collapse(2)
+#pragma omp parallel for SIMD() default(none) \
+    dt_omp_firstprivate(ch, d, in, out, roi_out) \
+    schedule(static) \
+    collapse(2)
 #endif
     for(size_t k = 0; k < (size_t)ch * roi_out->width * roi_out->height; k += ch)
     {
@@ -516,7 +525,10 @@ void process_sse2(struct dt_iop_module_t *self, dt_dev_pixelpipe_iop_t *piece, c
   if(filters == 9u)
   { // xtrans float mosaiced
 #ifdef _OPENMP
-#pragma omp parallel for default(none) shared(d) schedule(static)
+#pragma omp parallel for default(none) \
+    dt_omp_firstprivate(ivoid, ovoid, roi_out, xtrans) \
+    shared(d) \
+    schedule(static)
 #endif
     for(int j = 0; j < roi_out->height; j++)
     {
@@ -557,7 +569,10 @@ void process_sse2(struct dt_iop_module_t *self, dt_dev_pixelpipe_iop_t *piece, c
   else if(filters)
   { // bayer float mosaiced
 #ifdef _OPENMP
-#pragma omp parallel for default(none) shared(d) schedule(static)
+#pragma omp parallel for default(none) \
+    dt_omp_firstprivate(filters, ivoid, ovoid, roi_out) \
+    shared(d) \
+    schedule(static)
 #endif
     for(int j = 0; j < roi_out->height; j++)
     {
@@ -599,7 +614,10 @@ void process_sse2(struct dt_iop_module_t *self, dt_dev_pixelpipe_iop_t *piece, c
     const __m128 coeffs = _mm_set_ps(1.0f, d->coeffs[2], d->coeffs[1], d->coeffs[0]);
 
 #ifdef _OPENMP
-#pragma omp parallel for default(none) shared(d) schedule(static)
+#pragma omp parallel for default(none) \
+    dt_omp_firstprivate(ch, coeffs, ivoid, ovoid, roi_out) \
+    shared(d) \
+    schedule(static)
 #endif
     for(int k = 0; k < roi_out->height; k++)
     {
diff --git a/src/iop/scalepixels.c b/src/iop/scalepixels.c
index 9db887c..037fb21 100644
--- a/src/iop/scalepixels.c
+++ b/src/iop/scalepixels.c
@@ -185,7 +185,10 @@ void process(dt_iop_module_t *self, dt_dev_pixelpipe_iop_t *piece, const void *c
   const dt_iop_scalepixels_data_t * const d = piece->data;
 
 #ifdef _OPENMP
-#pragma omp parallel for schedule(static) default(none) shared(interpolation)
+#pragma omp parallel for default(none) \
+  dt_omp_firstprivate(ch_width, d, ivoid, ovoid, roi_in, roi_out) \
+  shared(interpolation) \
+  schedule(static)
 #endif
   // (slow) point-by-point transformation.
   // TODO: optimize with scanlines and linear steps between?
diff --git a/src/iop/velvia.c b/src/iop/velvia.c
index 99c97e9..1701d8a 100644
--- a/src/iop/velvia.c
+++ b/src/iop/velvia.c
@@ -140,7 +140,9 @@ void process(struct dt_iop_module_t *self, dt_dev_pixelpipe_iop_t *piece, const
   else
   {
 #ifdef _OPENMP
-#pragma omp parallel for SIMD() default(none) schedule(static)
+#pragma omp parallel for SIMD() default(none) \
+    dt_omp_firstprivate(ch, data, ivoid, ovoid, roi_out, strength) \
+    schedule(static)
 #endif
     for(size_t k = 0; k < (size_t)roi_out->width * roi_out->height; k++)
     {
@@ -186,7 +188,10 @@ void process_sse2(struct dt_iop_module_t *self, dt_dev_pixelpipe_iop_t *piece, c
   else
   {
 #ifdef _OPENMP
-#pragma omp parallel for default(none) shared(in, out, data) schedule(static)
+#pragma omp parallel for default(none) \
+    dt_omp_firstprivate(ch, roi_out, strength) \
+    shared(in, out, data) \
+    schedule(static)
 #endif
     for(size_t k = 0; k < (size_t)roi_out->width * roi_out->height; k++)
     {
diff --git a/src/iop/vignette.c b/src/iop/vignette.c
index cdf529f..4df43e5 100644
--- a/src/iop/vignette.c
+++ b/src/iop/vignette.c
@@ -740,7 +740,11 @@ void process(struct dt_iop_module_t *self, dt_dev_pixelpipe_iop_t *piece, const
   unsigned int *const tea_states = calloc(2 * dt_get_num_threads(), sizeof(unsigned int));
 
 #ifdef _OPENMP
-#pragma omp parallel for default(none) shared(data, yscale, xscale, dither) schedule(static)
+#pragma omp parallel for default(none) \
+  dt_omp_firstprivate(ch, dscale, exp1, exp2, fscale, ivoid, ovoid, \
+                      roi_center_scaled, roi_out, tea_states, unbound) \
+  shared(data, yscale, xscale, dither) \
+  schedule(static)
 #endif
   for(int j = 0; j < roi_out->height; j++)
   {
diff --git a/src/iop/levels.c b/src/iop/levels.c
index 8bef474..f183d15 100644
--- a/src/iop/levels.c
+++ b/src/iop/levels.c
@@ -301,7 +301,9 @@ void process(dt_iop_module_t *self, dt_dev_pixelpipe_iop_t *piece, const void *c
   }
 
 #ifdef _OPENMP
-#pragma omp parallel for default(none) schedule(static)
+#pragma omp parallel for default(none) \
+  dt_omp_firstprivate(ch, d, ivoid, ovoid, roi_out) \
+  schedule(static)
 #endif
   for(int k = 0; k < roi_out->height; k++)
   {
diff --git a/src/iop/liquify.c b/src/iop/liquify.c
index 70193c5..d91248b 100644
--- a/src/iop/liquify.c
+++ b/src/iop/liquify.c
@@ -1337,7 +1337,9 @@ void process(struct dt_iop_module_t *module, dt_dev_pixelpipe_iop_t *piece, cons
   assert (ch == 4);
 
 #ifdef _OPENMP
-#pragma omp parallel for schedule(static) default(none)
+#pragma omp parallel for default(none) \
+  dt_omp_firstprivate(ch, in, out, roi_in, roi_out) \
+  schedule(static)
 #endif
   for (int i = 0; i < roi_out->height; i++)
   {
diff --git a/src/iop/tonecurve.c b/src/iop/tonecurve.c
index b8a6e93..ba051a3 100644
--- a/src/iop/tonecurve.c
+++ b/src/iop/tonecurve.c
@@ -307,7 +307,11 @@ void process(struct dt_iop_module_t *self, dt_dev_pixelpipe_iop_t *piece, const
   const int unbound_ab = d->unbound_ab;
 
 #ifdef _OPENMP
-#pragma omp parallel for default(none) shared(d) schedule(static)
+#pragma omp parallel for default(none) \
+  dt_omp_firstprivate(autoscale_ab, ch, height, i, low_approximation, o, \
+                      xm_al, xm_ar, xm_bl, xm_br, xm_L, unbound_ab, width) \
+  shared(d) \
+  schedule(static)
 #endif
   for(int k = 0; k < height; k++)
   {
diff --git a/src/iop/splittoning.c b/src/iop/splittoning.c
index 7259a30..9cb8375 100644
--- a/src/iop/splittoning.c
+++ b/src/iop/splittoning.c
@@ -165,7 +165,11 @@ void process(struct dt_iop_module_t *self, dt_dev_pixelpipe_iop_t *piece, const
 
   const float compress = (data->compress / 110.0) / 2.0; // Don't allow 100% compression..
 #ifdef _OPENMP
-#pragma omp parallel for default(none) shared(data) private(in, out) schedule(static)
+#pragma omp parallel for default(none) \
+  dt_omp_firstprivate(ch, compress, ivoid, ovoid, roi_out) \
+  shared(data) \
+  private(in, out) \
+  schedule(static)
 #endif
   for(int k = 0; k < roi_out->height; k++)
   {
diff --git a/src/iop/relight.c b/src/iop/relight.c
index ed20436..6269386 100644
--- a/src/iop/relight.c
+++ b/src/iop/relight.c
@@ -128,7 +128,10 @@ void process(struct dt_iop_module_t *self, dt_dev_pixelpipe_iop_t *piece, const
   const float c = (data->width / 10.0) / 2.0; // Width
 
 #ifdef _OPENMP
-#pragma omp parallel for default(none) shared(data) schedule(static)
+#pragma omp parallel for default(none) \
+  dt_omp_firstprivate(b, c, ch, ivoid, ovoid, roi_out) \
+  shared(data) \
+  schedule(static)
 #endif
   for(int k = 0; k < roi_out->height; k++)
   {
diff --git a/src/iop/grain.c b/src/iop/grain.c
index 0cabbad..d610348 100644
--- a/src/iop/grain.c
+++ b/src/iop/grain.c
@@ -477,7 +477,10 @@ void process(struct dt_iop_module_t *self, dt_dev_pixelpipe_iop_t *piece, const
   const float fib1div2 = fib1 / fib2;
 
 #ifdef _OPENMP
-#pragma omp parallel for default(none) shared(data, hash)
+#pragma omp parallel for default(none) \
+  dt_omp_firstprivate(ch, filter, filtermul, ivoid, ovoid, roi_out, strength, \
+                      wd, zoom) \
+  shared(data, hash)
 #endif
   for(int j = 0; j < roi_out->height; j++)
   {
diff --git a/src/iop/dither.c b/src/iop/dither.c
index 00fecb3..ebb5b0e 100644
--- a/src/iop/dither.c
+++ b/src/iop/dither.c
@@ -308,7 +308,9 @@ static void process_floyd_steinberg(struct dt_iop_module_t *self, dt_dev_pixelpi
   }
 
 #ifdef _OPENMP
-#pragma omp parallel for default(none) schedule(static)
+#pragma omp parallel for default(none) \
+  dt_omp_firstprivate(ch, height, ivoid, ovoid, width) \
+  schedule(static)
 #endif
   for(int j = 0; j < height; j++)
   {
@@ -474,7 +476,9 @@ static void process_floyd_steinberg_sse2(struct dt_iop_module_t *self, dt_dev_pi
   }
 
 #ifdef _OPENMP
-#pragma omp parallel for default(none) schedule(static)
+#pragma omp parallel for default(none) \
+  dt_omp_firstprivate(ch, height, ivoid, ovoid, width) \
+  schedule(static)
 #endif
   for(int j = 0; j < height; j++)
   {
@@ -604,7 +608,9 @@ static void process_random(struct dt_iop_module_t *self, dt_dev_pixelpipe_iop_t
   unsigned int *const tea_states = calloc(2 * dt_get_num_threads(), sizeof(unsigned int));
 
 #ifdef _OPENMP
-#pragma omp parallel for default(none) schedule(static)
+#pragma omp parallel for default(none) \
+  dt_omp_firstprivate(ch, dither, height, ivoid, ovoid, tea_states, width) \
+  schedule(static)
 #endif
   for(int j = 0; j < height; j++)
   {
diff --git a/src/iop/clahe.c b/src/iop/clahe.c
index 1978862..72b0a9f 100644
--- a/src/iop/clahe.c
+++ b/src/iop/clahe.c
@@ -86,7 +86,10 @@ void process(struct dt_iop_module_t *self, dt_dev_pixelpipe_iop_t *piece, const
   float *luminance = (float *)malloc(((size_t)roi_out->width * roi_out->height) * sizeof(float));
 // double lsmax=0.0,lsmin=1.0;
 #ifdef _OPENMP
-#pragma omp parallel for default(none) schedule(static) shared(luminance)
+#pragma omp parallel for default(none) \
+  dt_omp_firstprivate(ch, ivoid, roi_out) \
+  shared(luminance) \
+  schedule(static)
 #endif
   for(int j = 0; j < roi_out->height; j++)
   {
@@ -115,7 +118,11 @@ void process(struct dt_iop_module_t *self, dt_dev_pixelpipe_iop_t *piece, const
 
 // CLAHE
 #ifdef _OPENMP
-#pragma omp parallel for default(none) schedule(static) shared(luminance)
+#pragma omp parallel for default(none) \
+  dt_omp_firstprivate(ch, dest_buf, destbuf_size, ivoid, ovoid, rad, roi_in, \
+                      roi_out, slope) \
+  shared(luminance) \
+  schedule(static)
 #endif
   for(int j = 0; j < roi_out->height; j++)
   {
diff --git a/src/iop/exposure.c b/src/iop/exposure.c
index 79a9131..5b24b21 100644
--- a/src/iop/exposure.c
+++ b/src/iop/exposure.c
@@ -400,7 +400,9 @@ void process(struct dt_iop_module_t *self, dt_dev_pixelpipe_iop_t *piece, const
   const int ch = piece->colors;
 
 #ifdef _OPENMP
-#pragma omp parallel for SIMD() default(none) schedule(static)
+#pragma omp parallel for SIMD() default(none) \
+  dt_omp_firstprivate(ch, d, i, o, roi_out) \
+  schedule(static)
 #endif
   for(size_t k = 0; k < (size_t)ch * roi_out->width * roi_out->height; k++)
   {
@@ -425,7 +427,9 @@ void process_sse2(struct dt_iop_module_t *self, dt_dev_pixelpipe_iop_t *piece, c
   const __m128 scalev = _mm_set1_ps(d->scale);
 
 #ifdef _OPENMP
-#pragma omp parallel for default(none) schedule(static)
+#pragma omp parallel for default(none) \
+  dt_omp_firstprivate(blackv, ch, i, o, roi_out, scalev) \
+  schedule(static)
 #endif
   for(int k = 0; k < roi_out->height; k++)
   {
diff --git a/src/iop/colortransfer.c b/src/iop/colortransfer.c
index a3ed68c..8c41b42 100644
--- a/src/iop/colortransfer.c
+++ b/src/iop/colortransfer.c
@@ -260,7 +260,10 @@ static void kmeans(const float *col, const dt_iop_roi_t *const roi, const int n,
     for(int k = 0; k < n; k++) cnt[k] = 0;
 // randomly sample col positions inside roi
 #ifdef _OPENMP
-#pragma omp parallel for default(none) schedule(static) shared(col, mean_out)
+#pragma omp parallel for default(none) \
+    dt_omp_firstprivate(cnt, mean, n, roi, samples, var) \
+    shared(col, mean_out) \
+    schedule(static)
 #endif
     for(int s = 0; s < samples; s++)
     {
@@ -358,7 +361,10 @@ void process(struct dt_iop_module_t *self, dt_dev_pixelpipe_iop_t *piece, const
     int hist[HISTN];
     capture_histogram(in, roi_in, hist);
 #ifdef _OPENMP
-#pragma omp parallel for default(none) schedule(static) shared(data, in, out, hist)
+#pragma omp parallel for default(none) \
+    dt_omp_firstprivate(ch, roi_out) \
+    shared(data, in, out, hist) \
+    schedule(static)
 #endif
     for(int k = 0; k < roi_out->height; k++)
     {
@@ -385,7 +391,10 @@ void process(struct dt_iop_module_t *self, dt_dev_pixelpipe_iop_t *piece, const
 
 // for all pixels: find input cluster, transfer to mapped target cluster
 #ifdef _OPENMP
-#pragma omp parallel for default(none) schedule(static) shared(data, in, out)
+#pragma omp parallel for default(none) \
+    dt_omp_firstprivate(ch, mapio, mean, roi_out, var) \
+    shared(data, in, out) \
+    schedule(static) 
 #endif
     for(int k = 0; k < roi_out->height; k++)
     {
diff --git a/src/iop/colormapping.c b/src/iop/colormapping.c
index 7de02c9..1495087 100644
--- a/src/iop/colormapping.c
+++ b/src/iop/colormapping.c
@@ -333,7 +333,10 @@ static void kmeans(const float *col, const int width, const int height, const in
     for(int k = 0; k < n; k++) cnt[k] = 0;
 // randomly sample col positions inside roi
 #ifdef _OPENMP
-#pragma omp parallel for default(none) schedule(static) shared(col, mean_out)
+#pragma omp parallel for default(none) \
+    dt_omp_firstprivate(cnt, height, mean, n, samples, var, width) \
+    shared(col, mean_out) \
+    schedule(static)
 #endif
     for(int s = 0; s < samples; s++)
     {
@@ -493,7 +496,10 @@ void process(struct dt_iop_module_t *self, dt_dev_pixelpipe_iop_t *piece, const
 
 // first get delta L of equalized L minus original image L, scaled to fit into [0 .. 100]
 #ifdef _OPENMP
-#pragma omp parallel for default(none) schedule(static) shared(data, in, out, equalization)
+#pragma omp parallel for default(none) \
+    dt_omp_firstprivate(ch, height, width) \
+    shared(data, in, out, equalization) \
+    schedule(static)
 #endif
     for(int k = 0; k < height; k++)
     {
@@ -528,7 +534,10 @@ void process(struct dt_iop_module_t *self, dt_dev_pixelpipe_iop_t *piece, const
     float *const weight_buf = malloc(data->n * dt_get_num_threads() * sizeof(float));
 
 #ifdef _OPENMP
-#pragma omp parallel for default(none) schedule(static) shared(data, in, out, equalization)
+#pragma omp parallel for default(none) \
+    dt_omp_firstprivate(ch, height, mapio, var_ratio, weight_buf, width) \
+    shared(data, in, out, equalization) \
+    schedule(static)
 #endif
     for(int k = 0; k < height; k++)
     {
diff --git a/src/iop/highlights.c b/src/iop/highlights.c
index 1a5e192..bced8ba 100644
--- a/src/iop/highlights.c
+++ b/src/iop/highlights.c
@@ -526,7 +526,9 @@ static void process_lch_bayer(dt_iop_module_t *self, dt_dev_pixelpipe_iop_t *pie
   const uint32_t filters = piece->pipe->dsc.filters;
 
 #ifdef _OPENMP
-#pragma omp parallel for schedule(dynamic) default(none)
+#pragma omp parallel for default(none) \
+  dt_omp_firstprivate(clip, filters, ivoid, ovoid, roi_out) \
+  schedule(dynamic)
 #endif
   for(int j = 0; j < roi_out->height; j++)
   {
@@ -625,7 +627,9 @@ static void process_lch_xtrans(dt_iop_module_t *self, dt_dev_pixelpipe_iop_t *pi
   const uint8_t(*const xtrans)[6] = (const uint8_t(*const)[6])piece->pipe->dsc.xtrans;
 
 #ifdef _OPENMP
-#pragma omp parallel for schedule(dynamic) default(none)
+#pragma omp parallel for default(none) \
+  dt_omp_firstprivate(clip, ivoid, ovoid, roi_in, roi_out, xtrans) \
+  schedule(dynamic)
 #endif
   for(int j = 0; j < roi_out->height; j++)
   {
@@ -760,7 +764,9 @@ static void process_clip_plain(dt_dev_pixelpipe_iop_t *piece, const void *const
   if(piece->pipe->dsc.filters)
   { // raw mosaic
 #ifdef _OPENMP
-#pragma omp parallel for SIMD() default(none) schedule(static)
+#pragma omp parallel for SIMD() default(none) \
+    dt_omp_firstprivate(clip, in, out, roi_out) \
+    schedule(static)
 #endif
     for(size_t k = 0; k < (size_t)roi_out->width * roi_out->height; k++)
     {
@@ -772,7 +778,9 @@ static void process_clip_plain(dt_dev_pixelpipe_iop_t *piece, const void *const
     const int ch = piece->colors;
 
 #ifdef _OPENMP
-#pragma omp parallel for SIMD() default(none) schedule(static)
+#pragma omp parallel for SIMD() default(none) \
+    dt_omp_firstprivate(ch, clip, in, out, roi_out) \
+    schedule(static)
 #endif
     for(size_t k = 0; k < (size_t)ch * roi_out->width * roi_out->height; k++)
     {
@@ -793,7 +801,9 @@ static void process_clip_sse2(dt_dev_pixelpipe_iop_t *piece, const void *const i
     float *const out = (float *)ovoid;
     float *const in = (float *)ivoid;
 #ifdef _OPENMP
-#pragma omp parallel for schedule(static) default(none)
+#pragma omp parallel for default(none) \
+    dt_omp_firstprivate(clipm, in, n, out) \
+    schedule(static)
 #endif
     for(size_t j = 0; j < (n & ~3u); j += 4) _mm_stream_ps(out + j, _mm_min_ps(clipm, _mm_load_ps(in + j)));
     _mm_sfence();
@@ -807,7 +817,9 @@ static void process_clip_sse2(dt_dev_pixelpipe_iop_t *piece, const void *const i
     const int ch = piece->colors;
 
 #ifdef _OPENMP
-#pragma omp parallel for default(none) schedule(static)
+#pragma omp parallel for default(none) \
+    dt_omp_firstprivate(ch, clipm, ivoid, ovoid, roi_in, roi_out) \
+    schedule(static)
 #endif
     for(int j = 0; j < roi_out->height; j++)
     {
@@ -868,7 +880,10 @@ void process(struct dt_iop_module_t *self, dt_dev_pixelpipe_iop_t *piece, const
       {
         const uint8_t(*const xtrans)[6] = (const uint8_t(*const)[6])piece->pipe->dsc.xtrans;
 #ifdef _OPENMP
-#pragma omp parallel for schedule(dynamic) default(none)
+#pragma omp parallel for default(none) \
+        dt_omp_firstprivate(clips, filters, ivoid, ovoid, roi_in, roi_out, \
+                            xtrans) \
+        schedule(dynamic)
 #endif
         for(int j = 0; j < roi_out->height; j++)
         {
@@ -876,7 +891,10 @@ void process(struct dt_iop_module_t *self, dt_dev_pixelpipe_iop_t *piece, const
           interpolate_color_xtrans(ivoid, ovoid, roi_in, roi_out, 0, -1, j, clips, xtrans, 1);
         }
 #ifdef _OPENMP
-#pragma omp parallel for schedule(dynamic) default(none)
+#pragma omp parallel for default(none) \
+        dt_omp_firstprivate(clips, filters, ivoid, ovoid, roi_in, roi_out, \
+                            xtrans) \
+        schedule(dynamic)
 #endif
         for(int i = 0; i < roi_out->width; i++)
         {
@@ -887,7 +905,10 @@ void process(struct dt_iop_module_t *self, dt_dev_pixelpipe_iop_t *piece, const
       else
       {
 #ifdef _OPENMP
-#pragma omp parallel for schedule(dynamic) default(none) shared(data, piece)
+#pragma omp parallel for default(none) \
+        dt_omp_firstprivate(clips, filters, ivoid, ovoid, roi_out) \
+        shared(data, piece) \
+        schedule(dynamic)
 #endif
         for(int j = 0; j < roi_out->height; j++)
         {
@@ -897,7 +918,10 @@ void process(struct dt_iop_module_t *self, dt_dev_pixelpipe_iop_t *piece, const
 
 // up/down directions
 #ifdef _OPENMP
-#pragma omp parallel for schedule(dynamic) default(none) shared(data, piece)
+#pragma omp parallel for default(none) \
+        dt_omp_firstprivate(clips, filters, ivoid, ovoid, roi_out) \
+        shared(data, piece) \
+        schedule(dynamic)
 #endif
         for(int i = 0; i < roi_out->width; i++)
         {
diff --git a/src/iop/channelmixer.c b/src/iop/channelmixer.c
index 5f3a03f..1bb3f19 100644
--- a/src/iop/channelmixer.c
+++ b/src/iop/channelmixer.c
@@ -155,7 +155,10 @@ void process(struct dt_iop_module_t *self, dt_dev_pixelpipe_iop_t *piece, const
   const int ch = piece->colors;
 
 #ifdef _OPENMP
-#pragma omp parallel for default(none) shared(data) schedule(static)
+#pragma omp parallel for default(none) \
+  dt_omp_firstprivate(ch, gray_mix_mode, ivoid, ovoid, roi_out) \
+  shared(data) \
+  schedule(static)
 #endif
   for(int j = 0; j < roi_out->height; j++)
   {
diff --git a/src/iop/retouch.c b/src/iop/retouch.c
index 68a36c7..7c966b1 100644
--- a/src/iop/retouch.c
+++ b/src/iop/retouch.c
@@ -3525,7 +3525,10 @@ static void image_rgb2lab(float *img_src, const int width, const int height, con
   if(ch == 4 && use_sse)
   {
 #ifdef _OPENMP
-#pragma omp parallel for default(none) shared(img_src) schedule(static)
+#pragma omp parallel for default(none) \
+    dt_omp_firstprivate(ch, stride) \
+    shared(img_src) \
+    schedule(static)
 #endif
     for(int i = 0; i < stride; i += ch)
     {
@@ -3541,7 +3544,10 @@ static void image_rgb2lab(float *img_src, const int width, const int height, con
 #endif
 
 #ifdef _OPENMP
-#pragma omp parallel for default(none) shared(img_src) schedule(static)
+#pragma omp parallel for default(none) \
+  dt_omp_firstprivate(ch, stride) \
+  shared(img_src) \
+  schedule(static)
 #endif
   for(int i = 0; i < stride; i += ch)
   {
@@ -3560,7 +3566,10 @@ static void image_lab2rgb(float *img_src, const int width, const int height, con
   if(ch == 4 && use_sse)
   {
 #ifdef _OPENMP
-#pragma omp parallel for default(none) shared(img_src) schedule(static)
+#pragma omp parallel for default(none) \
+    dt_omp_firstprivate(ch, stride) \
+    shared(img_src) \
+    schedule(static)
 #endif
     for(int i = 0; i < stride; i += ch)
     {
@@ -3576,7 +3585,10 @@ static void image_lab2rgb(float *img_src, const int width, const int height, con
 #endif
 
 #ifdef _OPENMP
-#pragma omp parallel for default(none) shared(img_src) schedule(static)
+#pragma omp parallel for default(none) \
+  dt_omp_firstprivate(ch, stride) \
+  shared(img_src) \
+  schedule(static)
 #endif
   for(int i = 0; i < stride; i += ch)
   {
@@ -3597,8 +3609,12 @@ static void rt_process_stats(const float *const img_src, const int width, const
   int count = 0;
 
 #ifdef _OPENMP
-#pragma omp parallel for default(none) schedule(static) reduction(+ : count, l_sum) reduction(max : l_max)        \
-                                                                      reduction(min : l_min)
+#pragma omp parallel for default(none) \
+  dt_omp_firstprivate(ch, img_src, size) \
+  schedule(static) \
+  reduction(+ : count, l_sum) \
+  reduction(max : l_max) \
+  reduction(min : l_min)
 #endif
   for(int i = 0; i < size; i += ch)
   {
@@ -3636,7 +3652,10 @@ static void rt_adjust_levels(float *img_src, const int width, const int height,
   const float in_inv_gamma = pow(10, tmp);
 
 #ifdef _OPENMP
-#pragma omp parallel for default(none) shared(img_src) schedule(static)
+#pragma omp parallel for default(none) \
+  dt_omp_firstprivate(ch, in_inv_gamma, left, right, size) \
+  shared(img_src) \
+  schedule(static)
 #endif
   for(int i = 0; i < size; i += ch)
   {
@@ -3701,7 +3720,10 @@ static void rt_copy_in_to_out(const float *const in, const struct dt_iop_roi_t *
   const int y_to = MIN(roi_out->height, roi_in->height);
 
 #ifdef _OPENMP
-#pragma omp parallel for default(none) schedule(static)
+#pragma omp parallel for default(none) \
+  dt_omp_firstprivate(ch, in, out, roi_in, roi_out, rowsize, xoffs,  yoffs, \
+                      y_to) \
+  schedule(static)
 #endif
   for(int y = 0; y < y_to; y++)
   {
@@ -3744,7 +3766,10 @@ static void rt_build_scaled_mask(float *const mask, dt_iop_roi_t *const roi_mask
   }
 
 #ifdef _OPENMP
-#pragma omp parallel for default(none) shared(mask_tmp, roi_mask_scaled) schedule(static)
+#pragma omp parallel for default(none) \
+  dt_omp_firstprivate(mask, roi_in, roi_mask, x_to, y_to) \
+  shared(mask_tmp, roi_mask_scaled) \
+  schedule(static)
 #endif
   for(int yy = roi_mask_scaled->y; yy < y_to; yy++)
   {
@@ -3778,7 +3803,10 @@ static void rt_copy_image_masked(float *const img_src, float *img_dest, dt_iop_r
   if(ch == 4 && use_sse)
   {
 #ifdef _OPENMP
-#pragma omp parallel for default(none) shared(img_dest) schedule(static)
+#pragma omp parallel for default(none) \
+    dt_omp_firstprivate(ch, img_src, mask_scaled, opacity, roi_dest, roi_mask_scaled) \
+    shared(img_dest) \
+    schedule(static)
 #endif
     for(int yy = 0; yy < roi_mask_scaled->height; yy++)
     {
@@ -3809,7 +3837,10 @@ static void rt_copy_image_masked(float *const img_src, float *img_dest, dt_iop_r
     const int ch1 = (ch == 4) ? ch - 1 : ch;
 
 #ifdef _OPENMP
-#pragma omp parallel for default(none) shared(img_dest) schedule(static)
+#pragma omp parallel for default(none) \
+    dt_omp_firstprivate(ch, ch1, img_src, mask_scaled, opacity, roi_dest, roi_mask_scaled) \
+    shared(img_dest) \
+    schedule(static)
 #endif
     for(int yy = 0; yy < roi_mask_scaled->height; yy++)
     {
@@ -3841,7 +3872,9 @@ static void rt_copy_mask_to_alpha(float *const img, dt_iop_roi_t *const roi_img,
                                   const float opacity)
 {
 #ifdef _OPENMP
-#pragma omp parallel for default(none) schedule(static)
+#pragma omp parallel for default(none) \
+  dt_omp_firstprivate(ch, img, mask_scaled, opacity, roi_img, roi_mask_scaled) \
+  schedule(static)
 #endif
   for(int yy = 0; yy < roi_mask_scaled->height; yy++)
   {
@@ -3871,7 +3904,9 @@ static void retouch_fill_sse(float *const in, dt_iop_roi_t *const roi_in, float
   const __m128 val_fill = _mm_load_ps(valf4_fill);
 
 #ifdef _OPENMP
-#pragma omp parallel for default(none) schedule(static)
+#pragma omp parallel for default(none) \
+  dt_omp_firstprivate(ch, in, mask_scaled, opacity, roi_in, roi_mask_scaled, val_fill) \
+  schedule(static)
 #endif
   for(int yy = 0; yy < roi_mask_scaled->height; yy++)
   {
@@ -3909,7 +3944,9 @@ static void retouch_fill(float *const in, dt_iop_roi_t *const roi_in, const int
   const int ch1 = (ch == 4) ? ch - 1 : ch;
 
 #ifdef _OPENMP
-#pragma omp parallel for default(none) schedule(static)
+#pragma omp parallel for default(none) \
+  dt_omp_firstprivate(ch, ch1, fill_color, in, mask_scaled, opacity, roi_in, roi_mask_scaled) \
+  schedule(static)
 #endif
   for(int yy = 0; yy < roi_mask_scaled->height; yy++)
   {
diff --git a/src/iop/graduatednd.c b/src/iop/graduatednd.c
index e48b4ab..6473b4a 100644
--- a/src/iop/graduatednd.c
+++ b/src/iop/graduatednd.c
@@ -705,7 +705,10 @@ void process(struct dt_iop_module_t *self, dt_dev_pixelpipe_iop_t *piece, const
   if(data->density > 0)
   {
 #ifdef _OPENMP
-#pragma omp parallel for default(none) schedule(static)
+#pragma omp parallel for default(none) \
+    dt_omp_firstprivate(ch, cosv, data, filter_compression, hh_inv, hw_inv, \
+                        ivoid, ix, iy, offset, ovoid, roi_out, sinv) \
+    schedule(static)
 #endif
     for(int y = 0; y < roi_out->height; y++)
     {
@@ -751,7 +754,10 @@ void process(struct dt_iop_module_t *self, dt_dev_pixelpipe_iop_t *piece, const
   else
   {
 #ifdef _OPENMP
-#pragma omp parallel for default(none) schedule(static)
+#pragma omp parallel for default(none) \
+    dt_omp_firstprivate(ch, cosv, data, filter_compression, hh_inv, hw_inv, \
+                        ivoid, ix, iy, offset, ovoid, roi_out, sinv) \
+    schedule(static)
 #endif
     for(int y = 0; y < roi_out->height; y++)
     {
@@ -830,7 +836,10 @@ void process_sse2(struct dt_iop_module_t *self, dt_dev_pixelpipe_iop_t *piece, c
   if(data->density > 0)
   {
 #ifdef _OPENMP
-#pragma omp parallel for default(none) schedule(static)
+#pragma omp parallel for default(none) \
+    dt_omp_firstprivate(ch, cosv, data, filter_compression, hh_inv, hw_inv, \
+                        ivoid, ix, iy, offset, ovoid, roi_out, sinv) \
+    schedule(static)
 #endif
     for(int y = 0; y < roi_out->height; y++)
     {
@@ -878,7 +887,10 @@ void process_sse2(struct dt_iop_module_t *self, dt_dev_pixelpipe_iop_t *piece, c
   else
   {
 #ifdef _OPENMP
-#pragma omp parallel for default(none) schedule(static)
+#pragma omp parallel for default(none) \
+    dt_omp_firstprivate(ch, cosv, data, filter_compression, hh_inv, hw_inv, \
+                        ivoid, ix, iy, offset, ovoid, roi_out, sinv) \
+    schedule(static)
 #endif
     for(int y = 0; y < roi_out->height; y++)
     {
diff --git a/src/iop/zonesystem.c b/src/iop/zonesystem.c
index b8a4437..a4be9ed 100644
--- a/src/iop/zonesystem.c
+++ b/src/iop/zonesystem.c
@@ -224,7 +224,10 @@ static void process_common_cleanup(struct dt_iop_module_t *self, dt_dev_pixelpip
     if(gauss && tmp)
     {
 #ifdef _OPENMP
-#pragma omp parallel for default(none) shared(tmp) schedule(static)
+#pragma omp parallel for default(none) \
+      dt_omp_firstprivate(ch, height, width, ivoid) \
+      shared(tmp) \
+      schedule(static)
 #endif
       for(size_t k = 0; k < (size_t)width * height; k++) tmp[k] = ((float *)ivoid)[ch * k];
 
@@ -233,7 +236,10 @@ static void process_common_cleanup(struct dt_iop_module_t *self, dt_dev_pixelpip
       /* create zonemap preview for input */
       dt_pthread_mutex_lock(&g->lock);
 #ifdef _OPENMP
-#pragma omp parallel for default(none) shared(tmp, g) schedule(static)
+#pragma omp parallel for default(none) \
+      dt_omp_firstprivate(height, size, width) \
+      shared(tmp, g) \
+      schedule(static)
 #endif
       for(size_t k = 0; k < (size_t)width * height; k++)
       {
@@ -243,7 +249,10 @@ static void process_common_cleanup(struct dt_iop_module_t *self, dt_dev_pixelpip
 
 
 #ifdef _OPENMP
-#pragma omp parallel for default(none) shared(tmp) schedule(static)
+#pragma omp parallel for default(none) \
+      dt_omp_firstprivate(ch, height, ovoid, width) \
+      shared(tmp) \
+      schedule(static)
 #endif
       for(size_t k = 0; k < (size_t)width * height; k++) tmp[k] = ((float *)ovoid)[ch * k];
 
@@ -253,7 +262,10 @@ static void process_common_cleanup(struct dt_iop_module_t *self, dt_dev_pixelpip
       /* create zonemap preview for output */
       dt_pthread_mutex_lock(&g->lock);
 #ifdef _OPENMP
-#pragma omp parallel for default(none) shared(tmp, g) schedule(static)
+#pragma omp parallel for default(none) \
+      dt_omp_firstprivate(height, size, width) \
+      shared(tmp, g) \
+      schedule(static)
 #endif
       for(size_t k = 0; k < (size_t)width * height; k++)
       {
@@ -281,7 +293,10 @@ void process(struct dt_iop_module_t *self, dt_dev_pixelpipe_iop_t *piece, const
   float *const out = (float *const)ovoid;
 
 #ifdef _OPENMP
-#pragma omp parallel for SIMD() default(none) schedule(static) collapse(2)
+#pragma omp parallel for SIMD() default(none) \
+  dt_omp_firstprivate(ch, d, in, out, roi_out, size) \
+  schedule(static) \
+  collapse(2)
 #endif
   for(size_t k = 0; k < (size_t)ch * roi_out->width * roi_out->height; k += ch)
   {
@@ -311,7 +326,9 @@ void process_sse2(struct dt_iop_module_t *self, dt_dev_pixelpipe_iop_t *piece, c
   const int size = d->params.size;
 
 #ifdef _OPENMP
-#pragma omp parallel for default(none) schedule(static)
+#pragma omp parallel for default(none) \
+  dt_omp_firstprivate(ch, d, ivoid, ovoid, roi_out, size) \
+  schedule(static)
 #endif
   for(int j = 0; j < roi_out->height; j++)
   {
diff --git a/src/iop/demosaic.c b/src/iop/demosaic.c
index f4a943d..57f0141 100644
--- a/src/iop/demosaic.c
+++ b/src/iop/demosaic.c
@@ -310,7 +310,10 @@ static void pre_median_b(float *out, const float *const in, const dt_iop_roi_t *
   for(int pass = 0; pass < num_passes; pass++)
   {
 #ifdef _OPENMP
-#pragma omp parallel for default(none) shared(out) schedule(static)
+#pragma omp parallel for default(none) \
+    dt_omp_firstprivate(filters, in, lim, roi, threshold) \
+    shared(out) \
+    schedule(static)
 #endif
     for(int row = 3; row < roi->height - 3; row++)
     {
@@ -370,7 +373,10 @@ static void color_smoothing(float *out, const dt_iop_roi_t *const roi_out, const
           for(int i = 0; i < roi_out->width; i++, outp += 4) outp[3] = outp[c];
       }
 #ifdef _OPENMP
-#pragma omp parallel for schedule(static) default(none) shared(out, c)
+#pragma omp parallel for default(none) \
+      dt_omp_firstprivate(roi_out, width4) \
+      shared(out, c) \
+      schedule(static)
 #endif
       for(int j = 1; j < roi_out->height - 1; j++)
       {
@@ -425,7 +431,10 @@ static void green_equilibration_lavg(float *out, const float *const in, const in
   memcpy(out, in, height * width * sizeof(float));
 
 #ifdef _OPENMP
-#pragma omp parallel for schedule(static) default(none) shared(out, oi, oj)
+#pragma omp parallel for default(none) \
+  dt_omp_firstprivate(height, in, thr, width) \
+  shared(out, oi, oj) \
+  schedule(static)
 #endif
   for(size_t j = oj; j < height - 2; j += 2)
   {
@@ -471,7 +480,11 @@ static void green_equilibration_favg(float *out, const float *const in, const in
   const int g2_offset = oi ? -1 : 1;
   memcpy(out, in, (size_t)height * width * sizeof(float));
 #ifdef _OPENMP
-#pragma omp parallel for schedule(static) default(none) reduction(+ : sum1, sum2) shared(oi, oj)
+#pragma omp parallel for default(none) \
+  dt_omp_firstprivate(g2_offset, height, in, width) \
+  reduction(+ : sum1, sum2) \
+  shared(oi, oj) \
+  schedule(static)
 #endif
   for(size_t j = oj; j < (height - 1); j += 2)
   {
@@ -488,7 +501,10 @@ static void green_equilibration_favg(float *out, const float *const in, const in
     return;
 
 #ifdef _OPENMP
-#pragma omp parallel for schedule(static) default(none) shared(out, oi, oj, gr_ratio)
+#pragma omp parallel for default(none) \
+  dt_omp_firstprivate(g2_offset, height, in, width) \
+  shared(out, oi, oj, gr_ratio) \
+  schedule(static)
 #endif
   for(int j = oj; j < (height - 1); j += 2)
   {
@@ -584,7 +600,10 @@ static void xtrans_markesteijn_interpolate(float *out, const float *const in,
   // extra passes propagates out errors at edges, hence need more padding
   const int pad_tile = (passes == 1) ? 12 : 17;
 #ifdef _OPENMP
-#pragma omp parallel for default(none) shared(sgrow, sgcol, allhex, out) schedule(dynamic)
+#pragma omp parallel for default(none) \
+  dt_omp_firstprivate(all_buffers, buffer_size, dir, height, in, ndir, pad_tile, passes, roi_in, width, xtrans) \
+  shared(sgrow, sgcol, allhex, out) \
+  schedule(dynamic)
 #endif
   // step through TSxTS cells of image, each tile overlapping the
   // prior as interpolation needs a substantial border
@@ -1597,7 +1616,10 @@ static void xtrans_fdc_interpolate(float *out, const float *const in, const dt_i
   }
 
 #ifdef _OPENMP
-#pragma omp parallel for default(none) shared(sgrow, sgcol, allhex, out, rowoffset, coloffset) schedule(dynamic)
+#pragma omp parallel for default(none) \
+  dt_omp_firstprivate(all_buffers, buffer_size, dir, height, in, ndir, pad_tile, roi_in, width, xtrans, directionality, harr, Minv, modarr) \
+  shared(sgrow, sgcol, allhex, out, rowoffset, coloffset) \
+  schedule(dynamic)
 #endif
   // step through TSxTS cells of image, each tile overlapping the
   // prior as interpolation needs a substantial border
@@ -2089,7 +2111,10 @@ static void lin_interpolate(float *out, const float *const in, const dt_iop_roi_
 
 // border interpolate
 #ifdef _OPENMP
-#pragma omp parallel for default(none) shared(out) schedule(static)
+#pragma omp parallel for default(none) \
+  dt_omp_firstprivate(colors, filters, in, roi_in, roi_out, xtrans) \
+  shared(out) \
+  schedule(static)
 #endif
   for(int row = 0; row < roi_out->height; row++)
     for(int col = 0; col < roi_out->width; col++)
@@ -2163,7 +2188,10 @@ static void lin_interpolate(float *out, const float *const in, const dt_iop_roi_
     }
 
 #ifdef _OPENMP
-#pragma omp parallel for default(none) shared(out) schedule(static)
+#pragma omp parallel for default(none) \
+  dt_omp_firstprivate(colors, in, lookup, roi_in, roi_out, size) \
+  shared(out) \
+  schedule(static)
 #endif
   for(int row = 1; row < roi_out->height - 1; row++)
   {
@@ -2297,7 +2325,11 @@ static void vng_interpolate(float *out, const float *const in,
   for(int row = 2; row < height - 2; row++) /* Do VNG interpolation */
   {
 #ifdef _OPENMP
-#pragma omp parallel for default(none) shared(row, code, brow, out, filters4) private(ip) schedule(static)
+#pragma omp parallel for default(none) \
+    dt_omp_firstprivate(colors, pcol, prow, roi_in, width, xtrans) \
+    shared(row, code, brow, out, filters4) \
+    private(ip) \
+    schedule(static)
 #endif
     for(int col = 2; col < width - 2; col++)
     {
@@ -2362,7 +2394,10 @@ static void vng_interpolate(float *out, const float *const in,
   if(filters != 9 && !FILTERS_ARE_4BAYER(filters)) // x-trans or CYGM/RGBE
 // for Bayer mix the two greens to make VNG4
 #ifdef _OPENMP
-#pragma omp parallel for default(none) shared(out) schedule(static)
+#pragma omp parallel for default(none) \
+    dt_omp_firstprivate(height, width) \
+    shared(out) \
+    schedule(static)
 #endif
     for(int i = 0; i < height * width; i++) out[i * 4 + 1] = (out[i * 4 + 1] + out[i * 4 + 3]) / 2.0f;
 }
@@ -2376,7 +2411,10 @@ static void passthrough_monochrome(float *out, const float *const in, dt_iop_roi
   assert(roi_in->height >= roi_out->height);
 
 #ifdef _OPENMP
-#pragma omp parallel for default(none) shared(out) schedule(static)
+#pragma omp parallel for default(none) \
+  dt_omp_firstprivate(in, roi_out, roi_in) \
+  shared(out) \
+  schedule(static)
 #endif
   for(int j = 0; j < roi_out->height; j++)
   {
@@ -2445,7 +2483,10 @@ static void demosaic_ppg(float *const out, const float *const in, const dt_iop_r
   }
 // for all pixels: interpolate green into float array, or copy color.
 #ifdef _OPENMP
-#pragma omp parallel for default(none) shared(input) schedule(static)
+#pragma omp parallel for default(none) \
+  dt_omp_firstprivate(filters, out, roi_in, roi_out) \
+  shared(input) \
+  schedule(static)
 #endif
   for(int j = offy; j < roi_out->height - offY; j++)
   {
@@ -2525,7 +2566,9 @@ static void demosaic_ppg(float *const out, const float *const in, const dt_iop_r
 
 // for all pixels: interpolate colors into float array
 #ifdef _OPENMP
-#pragma omp parallel for default(none) schedule(static)
+#pragma omp parallel for default(none) \
+  dt_omp_firstprivate(filters, out, roi_out) \
+  schedule(static)
 #endif
   for(int j = 1; j < roi_out->height - 1; j++)
   {
diff --git a/src/chart/main.c b/src/chart/main.c
index 2df0c83..450758c 100644
--- a/src/chart/main.c
+++ b/src/chart/main.c
@@ -1424,10 +1424,13 @@ static void get_xyz_sample_from_image(const image_t *const image, float shrink,
   double sample_x = 0.0, sample_y = 0.0, sample_z = 0.0;
   size_t n_samples = 0;
 #ifdef _OPENMP
-#pragma omp parallel for schedule(static) default(none)                                                           \
-    shared(corners, x_start, y_start, x_end, y_end, delta_x_top, delta_y_top, delta_x_bottom, delta_y_bottom,     \
-           delta_x_left, delta_y_left, delta_x_right,                                                             \
-           delta_y_right) reduction(+ : n_samples, sample_x, sample_y, sample_z)
+#pragma omp parallel for default(none) \
+  dt_omp_firstprivate(image) \
+  shared(corners, x_start, y_start, x_end, y_end, delta_x_top, delta_y_top, \
+         delta_x_bottom, delta_y_bottom, delta_x_left, delta_y_left, \
+         delta_x_right, delta_y_right) \
+  reduction(+ : n_samples, sample_x, sample_y, sample_z) \
+  schedule(static) 
 #endif
   for(int y = y_start; y < y_end; y++)
     for(int x = x_start; x < x_end; x++)
@@ -1542,7 +1545,10 @@ static void free_image(image_t *image)
 static void image_lab_to_xyz(float *image, const int width, const int height)
 {
 #ifdef _OPENMP
-#pragma omp parallel for schedule(static) default(none) shared(image)
+#pragma omp parallel for default(none) \
+  dt_omp_firstprivate(height, width) \
+  shared(image) \
+  schedule(static)
 #endif
   for(int y = 0; y < height; y++)
     for(int x = 0; x < width; x++)
diff --git a/src/chart/cairo.c b/src/chart/cairo.c
index acc2717..e5b4f12 100644
--- a/src/chart/cairo.c
+++ b/src/chart/cairo.c
@@ -187,7 +187,10 @@ cairo_surface_t *cairo_surface_create_from_xyz_data(const float *const image, co
   unsigned char *rgbbuf = (unsigned char *)malloc(sizeof(unsigned char) * height * width * 4);
 
 #ifdef _OPENMP
-#pragma omp parallel for schedule(static) default(none) shared(rgbbuf)
+#pragma omp parallel for default(none) \
+  dt_omp_firstprivate(height, image, width) \
+  shared(rgbbuf) \
+  schedule(static)
 #endif
   for(int y = 0; y < height; y++)
   {
-- 
2.22.0