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>
This commit is contained in:
Szabolcs Nagy 2024-03-13 14:34:14 +00:00
parent 2367bf468c
commit 73c26018ed
2 changed files with 6 additions and 4 deletions

3
sysdeps/aarch64/configure vendored Normal file → Executable file
View File

@ -325,9 +325,10 @@ then :
printf %s "(cached) " >&6
else $as_nop
cat > conftest.s <<\EOF
.arch armv8.2-a+sve
ptrue p0.b
EOF
if { ac_try='${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 $ac_try) 2>&5
ac_status=$?

View File

@ -90,9 +90,10 @@ LIBC_CONFIG_VAR([aarch64-variant-pcs], [$libc_cv_aarch64_variant_pcs])
# Check if asm support armv8.2-a+sve
AC_CACHE_CHECK([for SVE support in assembler], [libc_cv_aarch64_sve_asm], [dnl
cat > conftest.s <<\EOF
.arch armv8.2-a+sve
ptrue p0.b
EOF
if AC_TRY_COMMAND(${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