[Bug target/115069] [14/15 regression] 8 bit integer vector performance regression, x86, between gcc-14 and gcc-13 using avx2 target clones on skylake platform

[haochen.jiang at intel dot com via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=115069

--- Comment #15 from Haochen Jiang <haochen.jiang at intel dot com> ---
I am doing like this way. Suppose should be same as Comment 8.

diff --git a/gcc/config/i386/i386-expand.cc b/gcc/config/i386/i386-expand.cc
index a6132911e6a..1e8334877d6 100644
--- a/gcc/config/i386/i386-expand.cc
+++ b/gcc/config/i386/i386-expand.cc
@@ -24323,8 +24323,8 @@ ix86_expand_vecop_qihi2 (enum rtx_code code, rtx dest,
rtx op1, rtx op2)
   bool op2vec = GET_MODE_CLASS (GET_MODE (op2)) == MODE_VECTOR_INT;
   bool uns_p = code != ASHIFTRT;

-  if ((qimode == V16QImode && !TARGET_AVX2)
-      || (qimode == V32QImode && (!TARGET_AVX512BW || !TARGET_EVEX512))
+  if (!TARGET_AVX512BW
+      || (qimode == V32QImode && !TARGET_EVEX512)
       /* There are no V64HImode instructions.  */
       || qimode == V64QImode)

Should we also run a SPEC on with -O2 -mtune=generic -march=x86-64-v3 to see if
there is any surprise?