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| author | Aurelien Jarno <aurelien@aurel32.net> | 2022-10-03 23:16:46 +0200 |
|---|---|---|
| committer | Aurelien Jarno <aurelien@aurel32.net> | 2022-10-04 00:00:58 +0200 |
| commit | 414fc856ff4e011e62b88a21d30294637a152dc7 (patch) | |
| tree | fbf72cc1576ecfc5a690108379bbc26430c0581a | |
| parent | 95f5089d4a57cd1e738be908c7a628cb7d0ce512 (diff) | |
| download | glibc-414fc856ff4e011e62b88a21d30294637a152dc7.tar glibc-414fc856ff4e011e62b88a21d30294637a152dc7.tar.gz glibc-414fc856ff4e011e62b88a21d30294637a152dc7.tar.bz2 glibc-414fc856ff4e011e62b88a21d30294637a152dc7.zip | |
x86-64: Require BMI2 for AVX2 str(n)casecmp implementations
The AVX2 str(n)casecmp implementations use the 'bzhi' instruction, which
belongs to the BMI2 CPU feature.
NB: It also uses the 'tzcnt' BMI1 instruction, but it is executed as BSF
as BSF if the CPU doesn't support TZCNT, and produces the same result
for non-zero input.
Partially fixes: b77b06e0e296 ("x86: Optimize strcmp-avx2.S")
Partially resolves: BZ #29611
Reviewed-by: Noah Goldstein <goldstein.w.n@gmail.com>
(cherry picked from commit 10f79d3670b036925da63dc532b122d27ce65ff8)
| -rw-r--r-- | sysdeps/x86_64/multiarch/ifunc-impl-list.c | 28 | ||||
| -rw-r--r-- | sysdeps/x86_64/multiarch/ifunc-strcasecmp.h | 1 |
2 files changed, 21 insertions, 8 deletions
diff --git a/sysdeps/x86_64/multiarch/ifunc-impl-list.c b/sysdeps/x86_64/multiarch/ifunc-impl-list.c index 8d649e263e..ca64b34c14 100644 --- a/sysdeps/x86_64/multiarch/ifunc-impl-list.c +++ b/sysdeps/x86_64/multiarch/ifunc-impl-list.c @@ -386,13 +386,16 @@ __libc_ifunc_impl_list (const char *name, struct libc_ifunc_impl *array, IFUNC_IMPL (i, name, strcasecmp, IFUNC_IMPL_ADD (array, i, strcasecmp, (CPU_FEATURE_USABLE (AVX512VL) - && CPU_FEATURE_USABLE (AVX512BW)), + && CPU_FEATURE_USABLE (AVX512BW) + && CPU_FEATURE_USABLE (BMI2)), __strcasecmp_evex) IFUNC_IMPL_ADD (array, i, strcasecmp, - CPU_FEATURE_USABLE (AVX2), + (CPU_FEATURE_USABLE (AVX2) + && CPU_FEATURE_USABLE (BMI2)), __strcasecmp_avx2) IFUNC_IMPL_ADD (array, i, strcasecmp, (CPU_FEATURE_USABLE (AVX2) + && CPU_FEATURE_USABLE (BMI2) && CPU_FEATURE_USABLE (RTM)), __strcasecmp_avx2_rtm) IFUNC_IMPL_ADD (array, i, strcasecmp, @@ -407,13 +410,16 @@ __libc_ifunc_impl_list (const char *name, struct libc_ifunc_impl *array, IFUNC_IMPL (i, name, strcasecmp_l, IFUNC_IMPL_ADD (array, i, strcasecmp, (CPU_FEATURE_USABLE (AVX512VL) - && CPU_FEATURE_USABLE (AVX512BW)), + && CPU_FEATURE_USABLE (AVX512BW) + && CPU_FEATURE_USABLE (BMI2)), __strcasecmp_l_evex) IFUNC_IMPL_ADD (array, i, strcasecmp, - CPU_FEATURE_USABLE (AVX2), + (CPU_FEATURE_USABLE (AVX2) + && CPU_FEATURE_USABLE (BMI2)), __strcasecmp_l_avx2) IFUNC_IMPL_ADD (array, i, strcasecmp, (CPU_FEATURE_USABLE (AVX2) + && CPU_FEATURE_USABLE (BMI2) && CPU_FEATURE_USABLE (RTM)), __strcasecmp_l_avx2_rtm) IFUNC_IMPL_ADD (array, i, strcasecmp_l, @@ -542,13 +548,16 @@ __libc_ifunc_impl_list (const char *name, struct libc_ifunc_impl *array, IFUNC_IMPL (i, name, strncasecmp, IFUNC_IMPL_ADD (array, i, strncasecmp, (CPU_FEATURE_USABLE (AVX512VL) - && CPU_FEATURE_USABLE (AVX512BW)), + && CPU_FEATURE_USABLE (AVX512BW) + && CPU_FEATURE_USABLE (BMI2)), __strncasecmp_evex) IFUNC_IMPL_ADD (array, i, strncasecmp, - CPU_FEATURE_USABLE (AVX2), + (CPU_FEATURE_USABLE (AVX2) + && CPU_FEATURE_USABLE (BMI2)), __strncasecmp_avx2) IFUNC_IMPL_ADD (array, i, strncasecmp, (CPU_FEATURE_USABLE (AVX2) + && CPU_FEATURE_USABLE (BMI2) && CPU_FEATURE_USABLE (RTM)), __strncasecmp_avx2_rtm) IFUNC_IMPL_ADD (array, i, strncasecmp, @@ -564,13 +573,16 @@ __libc_ifunc_impl_list (const char *name, struct libc_ifunc_impl *array, IFUNC_IMPL (i, name, strncasecmp_l, IFUNC_IMPL_ADD (array, i, strncasecmp, (CPU_FEATURE_USABLE (AVX512VL) - && CPU_FEATURE_USABLE (AVX512BW)), + & CPU_FEATURE_USABLE (AVX512BW) + && CPU_FEATURE_USABLE (BMI2)), __strncasecmp_l_evex) IFUNC_IMPL_ADD (array, i, strncasecmp, - CPU_FEATURE_USABLE (AVX2), + (CPU_FEATURE_USABLE (AVX2) + && CPU_FEATURE_USABLE (BMI2)), __strncasecmp_l_avx2) IFUNC_IMPL_ADD (array, i, strncasecmp, (CPU_FEATURE_USABLE (AVX2) + && CPU_FEATURE_USABLE (BMI2) && CPU_FEATURE_USABLE (RTM)), __strncasecmp_l_avx2_rtm) IFUNC_IMPL_ADD (array, i, strncasecmp_l, diff --git a/sysdeps/x86_64/multiarch/ifunc-strcasecmp.h b/sysdeps/x86_64/multiarch/ifunc-strcasecmp.h index 40819caf5a..e61d6e9497 100644 --- a/sysdeps/x86_64/multiarch/ifunc-strcasecmp.h +++ b/sysdeps/x86_64/multiarch/ifunc-strcasecmp.h @@ -32,6 +32,7 @@ IFUNC_SELECTOR (void) const struct cpu_features* cpu_features = __get_cpu_features (); if (CPU_FEATURE_USABLE_P (cpu_features, AVX2) + && CPU_FEATURE_USABLE_P (cpu_features, BMI2) && CPU_FEATURES_ARCH_P (cpu_features, AVX_Fast_Unaligned_Load)) { if (CPU_FEATURE_USABLE_P (cpu_features, AVX512VL) |