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commit 414fc856ff4e011e62b88a21d30294637a152dc7
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Author: Aurelien Jarno <aurelien@aurel32.net>
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Date:   Mon Oct 3 23:16:46 2022 +0200
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    x86-64: Require BMI2 for AVX2 str(n)casecmp implementations
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    The AVX2 str(n)casecmp implementations use the 'bzhi' instruction, which
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    belongs to the BMI2 CPU feature.
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    NB: It also uses the 'tzcnt' BMI1 instruction, but it is executed as BSF
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    as BSF if the CPU doesn't support TZCNT, and produces the same result
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    for non-zero input.
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    Partially fixes: b77b06e0e296 ("x86: Optimize strcmp-avx2.S")
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    Partially resolves: BZ #29611
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    Reviewed-by: Noah Goldstein  <goldstein.w.n@gmail.com>
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    (cherry picked from commit 10f79d3670b036925da63dc532b122d27ce65ff8)
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diff --git a/sysdeps/x86_64/multiarch/ifunc-impl-list.c b/sysdeps/x86_64/multiarch/ifunc-impl-list.c
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index 8d649e263eb24b8a..ca64b34c146a76f9 100644
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--- a/sysdeps/x86_64/multiarch/ifunc-impl-list.c
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+++ b/sysdeps/x86_64/multiarch/ifunc-impl-list.c
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@@ -386,13 +386,16 @@ __libc_ifunc_impl_list (const char *name, struct libc_ifunc_impl *array,
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   IFUNC_IMPL (i, name, strcasecmp,
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 	      IFUNC_IMPL_ADD (array, i, strcasecmp,
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 			      (CPU_FEATURE_USABLE (AVX512VL)
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-			       && CPU_FEATURE_USABLE (AVX512BW)),
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+			       && CPU_FEATURE_USABLE (AVX512BW)
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+			       && CPU_FEATURE_USABLE (BMI2)),
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 			      __strcasecmp_evex)
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 	      IFUNC_IMPL_ADD (array, i, strcasecmp,
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-			      CPU_FEATURE_USABLE (AVX2),
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+			      (CPU_FEATURE_USABLE (AVX2)
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+			       && CPU_FEATURE_USABLE (BMI2)),
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 			      __strcasecmp_avx2)
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 	      IFUNC_IMPL_ADD (array, i, strcasecmp,
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 			      (CPU_FEATURE_USABLE (AVX2)
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+			       && CPU_FEATURE_USABLE (BMI2)
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 			       && CPU_FEATURE_USABLE (RTM)),
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 			      __strcasecmp_avx2_rtm)
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 	      IFUNC_IMPL_ADD (array, i, strcasecmp,
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@@ -407,13 +410,16 @@ __libc_ifunc_impl_list (const char *name, struct libc_ifunc_impl *array,
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   IFUNC_IMPL (i, name, strcasecmp_l,
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 	      IFUNC_IMPL_ADD (array, i, strcasecmp,
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 			      (CPU_FEATURE_USABLE (AVX512VL)
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-			       && CPU_FEATURE_USABLE (AVX512BW)),
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+			       && CPU_FEATURE_USABLE (AVX512BW)
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+			       && CPU_FEATURE_USABLE (BMI2)),
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 			      __strcasecmp_l_evex)
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 	      IFUNC_IMPL_ADD (array, i, strcasecmp,
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-			      CPU_FEATURE_USABLE (AVX2),
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+			      (CPU_FEATURE_USABLE (AVX2)
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+			       && CPU_FEATURE_USABLE (BMI2)),
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 			      __strcasecmp_l_avx2)
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 	      IFUNC_IMPL_ADD (array, i, strcasecmp,
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 			      (CPU_FEATURE_USABLE (AVX2)
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+			       && CPU_FEATURE_USABLE (BMI2)
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 			       && CPU_FEATURE_USABLE (RTM)),
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 			      __strcasecmp_l_avx2_rtm)
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 	      IFUNC_IMPL_ADD (array, i, strcasecmp_l,
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@@ -542,13 +548,16 @@ __libc_ifunc_impl_list (const char *name, struct libc_ifunc_impl *array,
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   IFUNC_IMPL (i, name, strncasecmp,
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 	      IFUNC_IMPL_ADD (array, i, strncasecmp,
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 			      (CPU_FEATURE_USABLE (AVX512VL)
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-			       && CPU_FEATURE_USABLE (AVX512BW)),
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+			       && CPU_FEATURE_USABLE (AVX512BW)
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+			       && CPU_FEATURE_USABLE (BMI2)),
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 			      __strncasecmp_evex)
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 	      IFUNC_IMPL_ADD (array, i, strncasecmp,
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-			      CPU_FEATURE_USABLE (AVX2),
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+			      (CPU_FEATURE_USABLE (AVX2)
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+			       && CPU_FEATURE_USABLE (BMI2)),
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 			      __strncasecmp_avx2)
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 	      IFUNC_IMPL_ADD (array, i, strncasecmp,
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 			      (CPU_FEATURE_USABLE (AVX2)
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+			       && CPU_FEATURE_USABLE (BMI2)
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 			       && CPU_FEATURE_USABLE (RTM)),
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 			      __strncasecmp_avx2_rtm)
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 	      IFUNC_IMPL_ADD (array, i, strncasecmp,
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@@ -564,13 +573,16 @@ __libc_ifunc_impl_list (const char *name, struct libc_ifunc_impl *array,
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   IFUNC_IMPL (i, name, strncasecmp_l,
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 	      IFUNC_IMPL_ADD (array, i, strncasecmp,
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 			      (CPU_FEATURE_USABLE (AVX512VL)
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-			       && CPU_FEATURE_USABLE (AVX512BW)),
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+			       & CPU_FEATURE_USABLE (AVX512BW)
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+			       && CPU_FEATURE_USABLE (BMI2)),
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 			      __strncasecmp_l_evex)
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 	      IFUNC_IMPL_ADD (array, i, strncasecmp,
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-			      CPU_FEATURE_USABLE (AVX2),
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+			      (CPU_FEATURE_USABLE (AVX2)
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+			       && CPU_FEATURE_USABLE (BMI2)),
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 			      __strncasecmp_l_avx2)
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 	      IFUNC_IMPL_ADD (array, i, strncasecmp,
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 			      (CPU_FEATURE_USABLE (AVX2)
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+			       && CPU_FEATURE_USABLE (BMI2)
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 			       && CPU_FEATURE_USABLE (RTM)),
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 			      __strncasecmp_l_avx2_rtm)
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 	      IFUNC_IMPL_ADD (array, i, strncasecmp_l,
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diff --git a/sysdeps/x86_64/multiarch/ifunc-strcasecmp.h b/sysdeps/x86_64/multiarch/ifunc-strcasecmp.h
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index 40819caf5ab10337..e61d6e9497bce9d9 100644
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--- a/sysdeps/x86_64/multiarch/ifunc-strcasecmp.h
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+++ b/sysdeps/x86_64/multiarch/ifunc-strcasecmp.h
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@@ -32,6 +32,7 @@ IFUNC_SELECTOR (void)
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   const struct cpu_features* cpu_features = __get_cpu_features ();
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   if (CPU_FEATURE_USABLE_P (cpu_features, AVX2)
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+      && CPU_FEATURE_USABLE_P (cpu_features, BMI2)
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       && CPU_FEATURES_ARCH_P (cpu_features, AVX_Fast_Unaligned_Load))
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     {
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       if (CPU_FEATURE_USABLE_P (cpu_features, AVX512VL)