| From d836f008a96aa9b2e88c7b394bfc110542e57176 Mon Sep 17 00:00:00 2001 |
| From: Khem Raj <raj.khem@gmail.com> |
| Date: Fri, 4 Aug 2023 09:34:50 -0700 |
| Subject: [PATCH] aarch64/configure: Pass -mcpu along with -march to detect sve |
| support |
| |
| SVE support logic in configure is rightly passing -march=<arch>+sve to |
| compiler to override whatever user might have passed via environment, |
| however GCC does not do as intended when -mcpu is part of environment |
| compiler flags, then it overrides the -march computed from -mcpu and |
| igonores other -march values so this test fails for lot of aarch64 |
| machines which pass -mcpu that does not support sve. This is seemingly a |
| bug in GCC [1], until that is fixed we preempt -mcpu along with -march |
| in the configure test itself. It does not change functionality and yet |
| lets us through the GCC inconsistency. |
| |
| [1] https://gcc.gnu.org/bugzilla/show_bug.cgi?id=110901 |
| |
| Upstream-Status: Inappropriate [Workaround for a GCC issue] |
| Signed-off-by: Khem Raj <raj.khem@gmail.com> |
| |
| Signed-off-by: Khem Raj <raj.khem@gmail.com> |
| --- |
| sysdeps/aarch64/configure | 2 +- |
| sysdeps/aarch64/configure.ac | 2 +- |
| 2 files changed, 2 insertions(+), 2 deletions(-) |
| |
| diff --git a/sysdeps/aarch64/configure b/sysdeps/aarch64/configure |
| index 5e91fab023..39dddc66d4 100644 |
| --- a/sysdeps/aarch64/configure |
| +++ b/sysdeps/aarch64/configure |
| @@ -327,7 +327,7 @@ else $as_nop |
| cat > conftest.s <<\EOF |
| ptrue p0.b |
| EOF |
| -if { ac_try='${CC-cc} -c -march=armv8.2-a+sve conftest.s 1>&5' |
| +if { ac_try='${CC-cc} -c -mcpu=generic+sve -march=armv8.2-a+sve conftest.s 1>&5' |
| { { eval echo "\"\$as_me\":${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 8a708f2ef4..b6a146d2be 100644 |
| --- a/sysdeps/aarch64/configure.ac |
| +++ b/sysdeps/aarch64/configure.ac |
| @@ -92,7 +92,7 @@ AC_CACHE_CHECK([for SVE support in assembler], [libc_cv_aarch64_sve_asm], [dnl |
| cat > conftest.s <<\EOF |
| 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 -mcpu=generic+sve -march=armv8.2-a+sve conftest.s 1>&AS_MESSAGE_LOG_FD); then |
| libc_cv_aarch64_sve_asm=yes |
| else |
| libc_cv_aarch64_sve_asm=no |
| -- |
| 2.41.0 |
| |