From 68d57fd288c47c3cec7b94e2b4f863e6b216d69d Mon Sep 17 00:00:00 2001 From: Khem Raj Date: Fri, 4 Aug 2023 09:34:50 -0700 Subject: [PATCH 2/2] aarch64/configure: Pass -mcpu along with -march to detect sve support SVE support logic in configure is rightly passing -march=+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 Signed-off-by: Khem Raj --- sysdeps/aarch64/configure | 2 +- sysdeps/aarch64/configure.ac | 2 +- 2 files changed, 2 insertions(+), 2 deletions(-) --- a/sysdeps/aarch64/configure +++ b/sysdeps/aarch64/configure @@ -327,7 +327,7 @@ 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 $ac_try) 2>&5 ac_status=$? --- a/sysdeps/aarch64/configure.ac +++ b/sysdeps/aarch64/configure.ac @@ -92,7 +92,7 @@ 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