Set d.one_operand_p to true when TARGET_SSSE3 in ix86_expand_vecop_qihi_partial.

pshufb is available under TARGET_SSSE3, so
ix86_expand_vec_perm_const_1 must return true when TARGET_SSSE3.

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

	vs.

> 	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

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.

diff --git a/gcc/config/i386/i386-expand.cc b/gcc/config/i386/i386-expand.cc
index 4c47cfe468eff13716989bab461a09bb80fb33f2..4e16aedc5c138bff3cadb68dcc1694422ce64d49 100644 (file)
--- a/gcc/config/i386/i386-expand.cc
+++ b/gcc/config/i386/i386-expand.cc
@@ -24458,7 +24458,7 @@ 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 (file)
index 0000000..71fdc9d
--- /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;
+}
+