[PATCH] [x86] Set d.one_operand_p to true when TARGET_SSSE3 in ix86_expand_vecop_qihi_partial.

[liuhongt]

pshufb is available under TARGET_SSSE3, so
ix86_expand_vec_perm_const_1 must return true when TARGET_SSSE3.
w/o TARGET_SSSE3, if we set one_operand_p to true, ix86_expand_vec_perm_const_1 
could return false.

With the patch under -march=x86-64-v2

v8qi
foo (v8qi a)
{
  return a >> 5;
}

<       pmovsxbw        %xmm0, %xmm0
<       psraw   $5, %xmm0
<       pshufb  .LC0(%rip), %xmm0
---
>       movdqa  %xmm0, %xmm1
>       pcmpeqd %xmm0, %xmm0
>       pmovsxbw        %xmm1, %xmm1
>       psrlw   $8, %xmm0
>       psraw   $5, %xmm1
>       pand    %xmm1, %xmm0
>       packuswb        %xmm0, %xmm0

Although there's a memory load from constant pool, but it should be
better when it's inside a loop. The load from constant pool can be
hoist out. it's 1 instruction vs 4 instructions.

<       pshufb  .LC0(%rip), %xmm0

vs.

>       pcmpeqd %xmm0, %xmm0
>       psrlw   $8, %xmm0
>       pand    %xmm1, %xmm0
>       packuswb        %xmm0, %xmm0


Bootstrapped and regtested on x86_64-pc-linux-gnu{-m32,}.
Ok for trunk.

gcc/ChangeLog:

        PR target/114514
        * config/i386/i386-expand.cc (ix86_expand_vecop_qihi_partial):
        Set d.one_operand_p to true when TARGET_SSSE3.

gcc/testsuite/ChangeLog:

        * gcc.target/i386/pr114514-shufb.c: New test.
---
 gcc/config/i386/i386-expand.cc                |  2 +-
 .../gcc.target/i386/pr114514-shufb.c          | 35 +++++++++++++++++++
 2 files changed, 36 insertions(+), 1 deletion(-)
 create mode 100644 gcc/testsuite/gcc.target/i386/pr114514-shufb.c

diff --git a/gcc/config/i386/i386-expand.cc b/gcc/config/i386/i386-expand.cc
index ab6631f51e3..ae2e9ab4e05 100644
--- a/gcc/config/i386/i386-expand.cc
+++ b/gcc/config/i386/i386-expand.cc
@@ -24394,7 +24394,7 @@ ix86_expand_vecop_qihi_partial (enum rtx_code code, rtx 
dest, rtx op1, rtx op2)
       d.op0 = d.op1 = qres;
       d.vmode = V16QImode;
       d.nelt = 16;
-      d.one_operand_p = false;
+      d.one_operand_p = TARGET_SSSE3;
       d.testing_p = false;
 
       for (i = 0; i < d.nelt; ++i)
diff --git a/gcc/testsuite/gcc.target/i386/pr114514-shufb.c 
b/gcc/testsuite/gcc.target/i386/pr114514-shufb.c
new file mode 100644
index 00000000000..71fdc9d8daf
--- /dev/null
+++ b/gcc/testsuite/gcc.target/i386/pr114514-shufb.c
@@ -0,0 +1,35 @@
+/* { dg-do compile } */
+/* { dg-options "-msse4.1 -O2 -mno-avx512f" } */
+/* { dg-final { scan-assembler-not "packuswb" } }  */
+/* { dg-final { scan-assembler-times "pshufb" 4 { target { ! ia32 } } } }  */
+/* { dg-final { scan-assembler-times "pshufb" 6 { target  ia32 } } }  */
+
+typedef unsigned char v8uqi __attribute__((vector_size(8)));
+typedef  char v8qi __attribute__((vector_size(8)));
+typedef unsigned char v4uqi __attribute__((vector_size(4)));
+typedef  char v4qi __attribute__((vector_size(4)));
+
+v8qi
+foo (v8qi a)
+{
+  return a >> 5;
+}
+
+v8uqi
+foo1 (v8uqi a)
+{
+  return a >> 5;
+}
+
+v4qi
+foo2 (v4qi a)
+{
+  return a >> 5;
+}
+
+v4uqi
+foo3 (v4uqi a)
+{
+  return a >> 5;
+}
+
-- 
2.31.1