From f0fd8c553fa024c599f4aff65d7c603ceeaa6a58 Mon Sep 17 00:00:00 2001

From: Adenilson Cavalcanti <adenilson.cavalcanti@arm.com>

Date: Mon, 9 Apr 2018 13:52:17 -0700

Subject: [PATCH 1/3] Neon-Optimized hash chain rebase

This should help with compression of data, using NEON instructions

(therefore useful for ARMv7/ARMv8).

Original patch by Jun He.

---

 CMakeLists.txt                | 18 ++++++++

 contrib/arm/neon_slide_hash.h | 84 +++++++++++++++++++++++++++++++++++

 deflate.c                     |  7 +++

 3 files changed, 109 insertions(+)

 create mode 100644 contrib/arm/neon_slide_hash.h

diff --git a/CMakeLists.txt b/CMakeLists.txt

index 0fe939d..e9a74e9 100644

--- a/CMakeLists.txt

+++ b/CMakeLists.txt

@@ -136,6 +136,24 @@ if(CMAKE_COMPILER_IS_GNUCC)

         set(ZLIB_ASMS contrib/amd64/amd64-match.S)

     endif ()

+    if(ARM_NEON)

+        list(REMOVE_ITEM ZLIB_SRCS inflate.c)

+        set(ZLIB_ARM_NEON_HDRS

+            contrib/arm/chunkcopy.h

+            contrib/arm/inffast_chunk.h

+            contrib/arm/neon_slide_hash.h)

+        set(ZLIB_ARM_NEON contrib/arm/inflate.c contrib/arm/inffast_chunk.c)

+        add_definitions(-DARM_NEON)

+        set(COMPILER ${CMAKE_C_COMPILER})

+        # NEON is mandatory in ARMv8.

+        if(${COMPILER} MATCHES "aarch64")

+          set_source_files_properties(${ZLIB_ARM_NEON} PROPERTIES LANGUAGE C COMPILE_FLAGS -march=armv8-a)

+          # But it was optional for ARMv7.

+        elseif(${COMPILER} MATCHES "arm")

+          set_source_files_properties(${ZLIB_ARM_NEON} PROPERTIES LANGUAGE C COMPILE_FLAGS -mfpu=neon)

+        endif()

+    endif()

+

 	if(ZLIB_ASMS)

 		add_definitions(-DASMV)

 		set_source_files_properties(${ZLIB_ASMS} PROPERTIES LANGUAGE C COMPILE_FLAGS -DNO_UNDERLINE)

diff --git a/contrib/arm/neon_slide_hash.h b/contrib/arm/neon_slide_hash.h

new file mode 100644

index 0000000..0daffa1

--- /dev/null

+++ b/contrib/arm/neon_slide_hash.h

@@ -0,0 +1,84 @@

+/* Copyright (C) 1995-2011, 2016 Mark Adler

+ * Copyright (C) 2017 ARM Holdings Inc.

+ * Authors: Adenilson Cavalcanti <adenilson.cavalcanti@arm.com>

+ *          Jun He <jun.he@arm.com>

+ * This software is provided 'as-is', without any express or implied

+ * warranty.  In no event will the authors be held liable for any damages

+ * arising from the use of this software.

+ * Permission is granted to anyone to use this software for any purpose,

+ * including commercial applications, and to alter it and redistribute it

+ * freely, subject to the following restrictions:

+ * 1. The origin of this software must not be misrepresented; you must not

+ *  claim that you wrote the original software. If you use this software

+ *    in a product, an acknowledgment in the product documentation would be

+ *    appreciated but is not required.

+ * 2. Altered source versions must be plainly marked as such, and must not be

+ *    misrepresented as being the original software.

+ * 3. This notice may not be removed or altered from any source distribution.

+ */

+#ifndef __NEON_SLIDE_HASH__

+#define __NEON_SLIDE_HASH__

+

+#if (defined(__ARM_NEON__) || defined(__ARM_NEON))

+#include "deflate.h"

+#include <arm_neon.h>

+

+inline static void neon_slide_hash(deflate_state *s)

+{

+    /*

+     * This is ASIMD implementation for hash table rebase

+     * it assumes:

+     * 1. hash chain offset (Pos) is 2 bytes

+     * 2. hash table size is multiple*128 bytes

+     * #1 should be true as Pos is defined as "ush"

+     * #2 should be true as hash_bits are greater that 7

+     */

+    unsigned n, m;

+    unsigned short wsize = s->w_size;

+    uint16x8_t v, *p;

+    size_t size;

+

+    size = s->hash_size*sizeof(s->head[0]);

+    Assert((size % sizeof(uint16x8_t) * 8 == 0), "hash table size err");

+

+    Assert(sizeof(Pos) == 2, "Wrong Pos size");

+

+    /* slide s->head */

+    v = vdupq_n_u16(wsize);

+    p = (uint16x8_t *)(s->head);

+    n = size / (sizeof(uint16x8_t) * 8);

+    do {

+        p[0] = vqsubq_u16(p[0], v);

+        p[1] = vqsubq_u16(p[1], v);

+        p[2] = vqsubq_u16(p[2], v);

+        p[3] = vqsubq_u16(p[3], v);

+        p[4] = vqsubq_u16(p[4], v);

+        p[5] = vqsubq_u16(p[5], v);

+        p[6] = vqsubq_u16(p[6], v);

+        p[7] = vqsubq_u16(p[7], v);

+        p += 8;

+    } while (--n);

+#ifndef FASTEST

+    /* slide s->prev */

+    size = wsize*sizeof(s->prev[0]);

+

+    Assert((size % sizeof(uint16x8_t) * 8 == 0), "hash table size err");

+

+    p = (uint16x8_t *)(s->prev);

+    n = size / (sizeof(uint16x8_t) * 8);

+    do {

+        p[0] = vqsubq_u16(p[0], v);

+        p[1] = vqsubq_u16(p[1], v);

+        p[2] = vqsubq_u16(p[2], v);

+        p[3] = vqsubq_u16(p[3], v);

+        p[4] = vqsubq_u16(p[4], v);

+        p[5] = vqsubq_u16(p[5], v);

+        p[6] = vqsubq_u16(p[6], v);

+        p[7] = vqsubq_u16(p[7], v);

+        p += 8;

+    } while (--n);

+#endif

+}

+

+#endif

+#endif

diff --git a/deflate.c b/deflate.c

index 1ec7614..36f99ac 100644

--- a/deflate.c

+++ b/deflate.c

@@ -50,6 +50,9 @@

 /* @(#) $Id$ */

 #include "deflate.h"

+#if __ARM_NEON

+#include "contrib/arm/neon_slide_hash.h"

+#endif

 const char deflate_copyright[] =

    " deflate 1.2.11 Copyright 1995-2017 Jean-loup Gailly and Mark Adler ";

@@ -201,6 +204,9 @@ local const config configuration_table[10] = {

 local void slide_hash(s)

     deflate_state *s;

 {

+#if ARM_NEON

+    return neon_slide_hash(s);

+#else

     unsigned n, m;

     Posf *p;

     uInt wsize = s->w_size;

@@ -222,6 +228,7 @@ local void slide_hash(s)

          */

     } while (--n);

 #endif

+#endif

 }

 /* ========================================================================= */

-- 

2.19.0