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| author | Adhemerval Zanella <adhemerval.zanella@linaro.org> | 2017-11-16 19:52:59 -0200 |
|---|---|---|
| committer | Adhemerval Zanella <adhemerval.zanella@linaro.org> | 2017-11-17 09:23:07 -0200 |
| commit | 58a813bf6e732211af53e690c92c14a50bb06e0e (patch) | |
| tree | 3e1e9d399d6ee88abf654de335d310255c2ad882 /sysdeps | |
| parent | 6a6aa1f38959a5d17ff776b252604bece45864dc (diff) | |
| download | glibc-58a813bf6e732211af53e690c92c14a50bb06e0e.zip glibc-58a813bf6e732211af53e690c92c14a50bb06e0e.tar.gz glibc-58a813bf6e732211af53e690c92c14a50bb06e0e.tar.bz2 | |
aarch64: Fix f{max,min}{f} build for GCC 4.9 and 5
GCC 4.9 and 5 do not generate a correct f{max,min}nm instruction for
__builtin_{fmax,fmin}{f} without -ffinite-math-only. It is clear a
compiler issue since the instruction can handle NaN and Inf correctly
and GCC6+ does not show this issue.
We can backport a fix to GCC 5, raise the minimum required GCC version
for aarch64 (since GCC 4.9 branch is now closed [1]) and/or add
configure check to check for this issue. However I think
-ffinite-math-only should be safe for these specific implementations
and it is a simpler solution.
Checked on aarch64-linux-gnu with GCC 5.3.1.
* sysdeps/aarch64/fpu/Makefile (CFLAGS-s_fmax.c, CFLAGS-s_fmaxf.c,
CFLAGS-s_fmin.c, CFLAGS-s_fminf.c): New rule: add -ffinite-math-only.
[1] https://gcc.gnu.org/ml/gcc/2016-08/msg00010.html
Signed-off-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
Reviewed-by: Szabolcs Nagy <szabolcs.nagy@arm.com>
Diffstat (limited to 'sysdeps')
| -rw-r--r-- | sysdeps/aarch64/fpu/Makefile | 6 |
1 files changed, 6 insertions, 0 deletions
diff --git a/sysdeps/aarch64/fpu/Makefile b/sysdeps/aarch64/fpu/Makefile index bf38f2c..4a182bd 100644 --- a/sysdeps/aarch64/fpu/Makefile +++ b/sysdeps/aarch64/fpu/Makefile @@ -5,4 +5,10 @@ CFLAGS-s_lroundf.c += -fno-math-errno CFLAGS-s_lround.c += -fno-math-errno CFLAGS-s_llroundf.c += -fno-math-errno CFLAGS-s_llround.c += -fno-math-errno +# GCC 4.9 and 5 requires the flag to correct emits a f{max,min}nm +# for a __builtin_{fmax,fmin}{f}. +CFLAGS-s_fmax.c += -ffinite-math-only +CFLAGS-s_fmaxf.c += -ffinite-math-only +CFLAGS-s_fmin.c += -ffinite-math-only +CFLAGS-s_fminf.c += -ffinite-math-only endif |