commit 395a89f61e19fa916ae4cc93fc10d81a28ce3039
Author: Szabolcs Nagy <szabolcs.nagy@arm.com>
Date: Wed Mar 13 14:34:14 2024 +0000
aarch64: fix check for SVE support in assembler
Due to GCC bug 110901 -mcpu can override -march setting when compiling
asm code and thus a compiler targetting a specific cpu can fail the
configure check even when binutils gas supports SVE.
The workaround is that explicit .arch directive overrides both -mcpu
and -march, and since that's what the actual SVE memcpy uses the
configure check should use that too even if the GCC issue is fixed
independently.
Reviewed-by: Florian Weimer <fweimer@redhat.com>
(cherry picked from commit 73c26018ed0ecd9c807bb363cc2c2ab4aca66a82)
diff --git a/sysdeps/aarch64/configure b/sysdeps/aarch64/configure
old mode 100644
new mode 100755
index ca57edce472e4507..9606137e8ddae545
--- a/sysdeps/aarch64/configure
+++ b/sysdeps/aarch64/configure
@@ -325,9 +325,10 @@ then :
printf %s "(cached) " >&6
else $as_nop
cat > conftest.s <<\EOF
- ptrue p0.b
+ .arch armv8.2-a+sve
+ ptrue p0.b
EOF
-if { ac_try='${CC-cc} -c -march=armv8.2-a+sve conftest.s 1>&5'
+if { ac_try='${CC-cc} -c conftest.s 1>&5'
{ { eval echo "\"\$as_me\":${as_lineno-$LINENO}: \"$ac_try\""; } >&5
(eval $ac_try) 2>&5
ac_status=$?
diff --git a/sysdeps/aarch64/configure.ac b/sysdeps/aarch64/configure.ac
index 27874eceb44911e4..56d12d661d726892 100644
--- a/sysdeps/aarch64/configure.ac
+++ b/sysdeps/aarch64/configure.ac
@@ -90,9 +90,10 @@ LIBC_CONFIG_VAR([aarch64-variant-pcs], [$libc_cv_aarch64_variant_pcs])
# Check if asm support armv8.2-a+sve
AC_CACHE_CHECK([for SVE support in assembler], [libc_cv_aarch64_sve_asm], [dnl
cat > conftest.s <<\EOF
- ptrue p0.b
+ .arch armv8.2-a+sve
+ ptrue p0.b
EOF
-if AC_TRY_COMMAND(${CC-cc} -c -march=armv8.2-a+sve conftest.s 1>&AS_MESSAGE_LOG_FD); then
+if AC_TRY_COMMAND(${CC-cc} -c conftest.s 1>&AS_MESSAGE_LOG_FD); then
libc_cv_aarch64_sve_asm=yes
else
libc_cv_aarch64_sve_asm=no