x86-64: Require BMI2 for AVX2 (raw|w)memchr implementations

The AVX2 memchr, rawmemchr and wmemchr implementations use the 'bzhi'
and 'sarx' instructions, which belongs to the BMI2 CPU feature.

Fixes: acfd088a1963 ("x86: Optimize memchr-avx2.S")
Partially resolves: BZ #29611

Reviewed-by: Noah Goldstein  <goldstein.w.n@gmail.com>
(cherry picked from commit e3e7fab7fe5186d18ca2046d99ba321c27db30ad)

diff --git a/sysdeps/x86_64/multiarch/ifunc-impl-list.c b/sysdeps/x86_64/multiarch/ifunc-impl-list.c
index e76a991dc671c1a97340b2bce18db464be67761e..81640cf00664e3edd16467083c102b7ce27d963d 100644 (file)
--- a/sysdeps/x86_64/multiarch/ifunc-impl-list.c
+++ b/sysdeps/x86_64/multiarch/ifunc-impl-list.c
@@ -41,10 +41,12 @@ __libc_ifunc_impl_list (const char *name, struct libc_ifunc_impl *array,
   /* Support sysdeps/x86_64/multiarch/memchr.c.  */
   IFUNC_IMPL (i, name, memchr,
              IFUNC_IMPL_ADD (array, i, memchr,
-                             CPU_FEATURE_USABLE (AVX2),
+                             (CPU_FEATURE_USABLE (AVX2)
+                              && CPU_FEATURE_USABLE (BMI2)),
                              __memchr_avx2)
              IFUNC_IMPL_ADD (array, i, memchr,
                              (CPU_FEATURE_USABLE (AVX2)
+                              && CPU_FEATURE_USABLE (BMI2)
                               && CPU_FEATURE_USABLE (RTM)),
                              __memchr_avx2_rtm)
              IFUNC_IMPL_ADD (array, i, memchr,
@@ -283,10 +285,12 @@ __libc_ifunc_impl_list (const char *name, struct libc_ifunc_impl *array,
   /* Support sysdeps/x86_64/multiarch/rawmemchr.c.  */
   IFUNC_IMPL (i, name, rawmemchr,
              IFUNC_IMPL_ADD (array, i, rawmemchr,
-                             CPU_FEATURE_USABLE (AVX2),
+                             (CPU_FEATURE_USABLE (AVX2)
+                              && CPU_FEATURE_USABLE (BMI2)),
                              __rawmemchr_avx2)
              IFUNC_IMPL_ADD (array, i, rawmemchr,
                              (CPU_FEATURE_USABLE (AVX2)
+                              && CPU_FEATURE_USABLE (BMI2)
                               && CPU_FEATURE_USABLE (RTM)),
                              __rawmemchr_avx2_rtm)
              IFUNC_IMPL_ADD (array, i, rawmemchr,
@@ -787,10 +791,12 @@ __libc_ifunc_impl_list (const char *name, struct libc_ifunc_impl *array,
   /* Support sysdeps/x86_64/multiarch/wmemchr.c.  */
   IFUNC_IMPL (i, name, wmemchr,
              IFUNC_IMPL_ADD (array, i, wmemchr,
-                             CPU_FEATURE_USABLE (AVX2),
+                             (CPU_FEATURE_USABLE (AVX2)
+                              && CPU_FEATURE_USABLE (BMI2)),
                              __wmemchr_avx2)
              IFUNC_IMPL_ADD (array, i, wmemchr,
                              (CPU_FEATURE_USABLE (AVX2)
+                              && CPU_FEATURE_USABLE (BMI2)
                               && CPU_FEATURE_USABLE (RTM)),
                              __wmemchr_avx2_rtm)
              IFUNC_IMPL_ADD (array, i, wmemchr,