https://gcc.gnu.org/bugzilla/show_bug.cgi?id=114568
--- Comment #5 from Maxim Kuvyrkov <mkuvyrkov at gcc dot gnu.org> ---
Looking at this problem more, I think the issue is due to ARM target trying
hard to avoid UNSUPPORTED tests, instead of embracing them.
For the vectorization NEON check we have ...
===
proc check_effective_target_arm_neon_ok_nocache { } {
global et_arm_neon_flags
set et_arm_neon_flags ""
if { [check_effective_target_arm32] } {
foreach flags {"" "-mfloat-abi=softfp" "-mfpu=neon" "-mfpu=neon
-mfloat-abi=softfp" "-mfpu=neon -mfloat-abi=softfp -march=armv7-a"
"-mfloat-abi=hard" "-mfpu=neon -mfloat-abi=hard" "-mfpu=neon -mfloat-abi=hard
-march=armv7-a"} {
if { [check_no_compiler_messages_nocache arm_neon_ok object {
#include <arm_neon.h>
...
===
... where target tries to find a set of flags compatible with _any_ of the
built multilibs to run the testsuite.
I think this is excessive, since each multilib should be tested on its own
merits, and if armv7-m does not support vectorization, there should be no
effort to try and switch to armv7-a or armv8-m+mve multilib in order to run
vectorization tests. In other words, vectorization tests should be marked
UNSUPPORTED in armv7-m, and PASS/FAIL in armv7-a and/or armv8-m+mve.
In practical terms, my proposed solution to this problem is to remove all
"foreach flags" options except for the default "".
ARM maintainers, what am I missing?
