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* [PATCH v1 1/2] x86: Add comment explaining no Slow_SSE4_2 check in ifunc-sse4_2
@ 2022-06-28 15:27 Noah Goldstein
  2022-06-28 15:27 ` [PATCH v1 2/2] x86: Add support for building str{c|p}{brk|spn} with explicit ISA level Noah Goldstein
                   ` (7 more replies)
  0 siblings, 8 replies; 36+ messages in thread
From: Noah Goldstein @ 2022-06-28 15:27 UTC (permalink / raw)
  To: libc-alpha

Just for clarities sake and so that if a future implementation is
added we remember to add the check.
---
 sysdeps/x86_64/multiarch/ifunc-sse4_2.h | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/sysdeps/x86_64/multiarch/ifunc-sse4_2.h b/sysdeps/x86_64/multiarch/ifunc-sse4_2.h
index ee36525bcf..204c4b5406 100644
--- a/sysdeps/x86_64/multiarch/ifunc-sse4_2.h
+++ b/sysdeps/x86_64/multiarch/ifunc-sse4_2.h
@@ -27,7 +27,11 @@ IFUNC_SELECTOR (void)
 {
   const struct cpu_features* cpu_features = __get_cpu_features ();
 
-  if (CPU_FEATURE_USABLE_P (cpu_features, SSE4_2))
+  /* This function uses slow sse4.2 instructions (pcmpstri) but since
+     there is no other optimized implementation keep using.  If an
+     optimized fallback is added add a X86_ISA_CPU_FEATURE_USABLE_P
+     (cpu_features, SSE4_2) check.  */
+  if (ISA_CPU_FEATURE_USABLE_P (cpu_features, SSE4_2))
     return OPTIMIZE (sse42);
 
   return OPTIMIZE (generic);
-- 
2.34.1


^ permalink raw reply	[flat|nested] 36+ messages in thread

end of thread, other threads:[~2022-07-05 15:41 UTC | newest]

Thread overview: 36+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2022-06-28 15:27 [PATCH v1 1/2] x86: Add comment explaining no Slow_SSE4_2 check in ifunc-sse4_2 Noah Goldstein
2022-06-28 15:27 ` [PATCH v1 2/2] x86: Add support for building str{c|p}{brk|spn} with explicit ISA level Noah Goldstein
2022-06-29 19:20   ` H.J. Lu
2022-06-29 22:07     ` Noah Goldstein
2022-06-29 18:53 ` [PATCH v1 1/2] x86: Add comment explaining no Slow_SSE4_2 check in ifunc-sse4_2 H.J. Lu
2022-06-29 19:19   ` Noah Goldstein
2022-06-29 22:06     ` Noah Goldstein
2022-06-29 22:05 ` [PATCH v2 " Noah Goldstein
2022-06-29 22:05   ` [PATCH v2 2/2] x86: Add support for building str{c|p}{brk|spn} with explicit ISA level Noah Goldstein
2022-06-29 22:15     ` H.J. Lu
2022-06-30  3:11       ` Noah Goldstein
2022-06-30  3:27         ` Noah Goldstein
2022-06-29 22:12   ` [PATCH v2 1/2] x86: Add comment explaining no Slow_SSE4_2 check in ifunc-sse4_2 H.J. Lu
2022-06-30  3:09     ` Noah Goldstein
2022-06-30  3:08 ` [PATCH v4 1/2] x86: Add missing IS_IN (libc) check to strncmp-sse4_2.S Noah Goldstein
2022-06-30  3:08   ` [PATCH v4 2/2] x86: Add comment explaining no Slow_SSE4_2 check in ifunc-sse4_2 Noah Goldstein
2022-06-30  3:10   ` [PATCH v4 1/2] x86: Add missing IS_IN (libc) check to strncmp-sse4_2.S Noah Goldstein
2022-06-30  3:10 ` [PATCH v5 1/2] x86: Add comment explaining no Slow_SSE4_2 check in ifunc-sse4_2 Noah Goldstein
2022-06-30  3:10   ` [PATCH v5 2/2] x86: Add support for building str{c|p}{brk|spn} with explicit ISA level Noah Goldstein
2022-06-30  3:44 ` [PATCH v6 1/2] x86: Add comment explaining no Slow_SSE4_2 check in ifunc-sse4_2 Noah Goldstein
2022-06-30  3:44   ` [PATCH v6 2/2] x86: Add support for building str{c|p}{brk|spn} with explicit ISA level Noah Goldstein
2022-06-30  7:47   ` [PATCH v6 1/2] x86: Add comment explaining no Slow_SSE4_2 check in ifunc-sse4_2 Andreas Schwab
2022-06-30 20:13     ` Noah Goldstein
2022-06-30 20:13 ` Noah Goldstein
2022-06-30 20:13   ` [PATCH v6 2/2] x86: Add support for building str{c|p}{brk|spn} with explicit ISA level Noah Goldstein
2022-07-01 22:35     ` H.J. Lu
2022-06-30 23:20   ` [PATCH v6 1/2] x86: Add comment explaining no Slow_SSE4_2 check in ifunc-sse4_2 H.J. Lu
2022-07-01  0:01     ` Noah Goldstein
2022-07-01  0:01       ` Noah Goldstein
2022-07-01 22:38         ` H.J. Lu
2022-07-01 22:52           ` Noah Goldstein
2022-07-03 18:00             ` H.J. Lu
2022-07-04  4:28               ` Noah Goldstein
2022-07-04  4:28 ` [PATCH v7 " Noah Goldstein
2022-07-04  4:28   ` [PATCH v7 2/2] x86: Add support for building str{c|p}{brk|spn} with explicit ISA level Noah Goldstein
2022-07-05 15:41   ` [PATCH v7 1/2] x86: Add comment explaining no Slow_SSE4_2 check in ifunc-sse4_2 H.J. Lu

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