On 20/03/2025 16:15, Christophe Lyon wrote: > Depending on if/how the testing flags are overridden, the first value > we try("") might not do what we want. > > For instance, if the whole testsuite is executed with > (A) -mthumb -march=armv7-m -mtune=cortex-m3 -mfloat-abi=softfp > > bf16_neon_ok is first compiled with > (A) (B) > where B = -mcpu=unset -march=armv8.2-a+bf16 > > which is accepted, so a testcase like vld2q_lane_bf16_indices_1.c > is compiled with: > (A) (C) (B) > where C = -mfpu=neon -mfloat-abi=softfp -mcpu=unset -march=armv7-a > -mfpu=neon-fp16 -mfp16-format=ieee > > because advsimd-intrinsics.exp has set additional_flags to (C) > via arm_neon_fp16_ok > > So the testcase is compiled with > [...] -mfpu=neon-fp16 -mcpu=unset -march=armv8.2-a+bf16 > (thus -mfpu=neon-fp16) and bf16 support is disabled. > > The patch replaces "" with -mfpu=auto which matches the intended > effect of -march=armv8.2-a+bf16 as added by bf16_neon_ok, and the > testcase is now compiled with > (A) (C) -mfpu=auto (B) > > However, since this effective-target is also used on aarch64 (which > does not support -mfpu=auto), we do this only on arm. > > This patch improves coverage, and makes > v{ld,st}[234]q_lane_bf16_indices_1.c pass when testsuite flags are > overridden as described above (e.g. for M-profile). > > gcc/testsuite/ > * lib/target-supports.exp > (check_effective_target_arm_v8_2a_bf16_neon_ok_nocache): > Conditionally use -mfpu=auto. > --- > gcc/testsuite/lib/target-supports.exp | 9 ++++++++- > 1 file changed, 8 insertions(+), 1 deletion(-) > > diff --git a/gcc/testsuite/lib/target-supports.exp > b/gcc/testsuite/lib/target-supports.exp > index e2622a445c5..09b16a14024 100644 > --- a/gcc/testsuite/lib/target-supports.exp > +++ b/gcc/testsuite/lib/target-supports.exp > @@ -6871,12 +6871,19 @@ proc add_options_for_arm_fp16fml_neon { flags } { > proc check_effective_target_arm_v8_2a_bf16_neon_ok_nocache { } { > global et_arm_v8_2a_bf16_neon_flags > set et_arm_v8_2a_bf16_neon_flags "" > + set fpu_auto "" > > if { ![istarget arm*-*-*] && ![istarget aarch64*-*-*] } { > return 0; > } > > - foreach flags {"" "-mfloat-abi=softfp -mfpu=neon-fp-armv8" > "-mfloat-abi=hard -mfpu=neon-fp-armv8" } { > + if { [istarget arm*-*-*] } { > + set fpu_auto "-mfpu=auto" > + } > + > + foreach flags [list "$fpu_auto" \
Shouldn't we try first with "", even on Arm? Thus foreach flags [list "" "$fpu_auto" \ ... > + "-mfloat-abi=softfp -mfpu=neon-fp-armv8" \ > + "-mfloat-abi=hard -mfpu=neon-fp-armv8" ] { > if { [check_no_compiler_messages_nocache arm_v8_2a_bf16_neon_ok object { > #include <arm_neon.h> > #if !defined (__ARM_FEATURE_BF16_VECTOR_ARITHMETIC) In fact, since aarch64 doesn't support -mfpu at all, only "" is ever going to work here, so perhaps we can recast all this code, perhaps along the lines of that in check_effective_target_arm_neon_h_ok_nocache so that we don't need to actually try to include arm_neon.h at all while figuring out the options. R.