https://gcc.gnu.org/g:090714e6cf8029f4ff8883dce687200024adbaeb
commit r15-530-g090714e6cf8029f4ff8883dce687200024adbaeb
Author: liuhongt <hongtao....@intel.com>
Date: Wed May 15 10:56:24 2024 +0800
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:
---
gcc/config/i386/i386-expand.cc | 2 +-
gcc/testsuite/gcc.target/i386/pr114514-shufb.c | 35 ++++++++++++++++++++++++++
2 files changed, 36 insertions(+), 1 deletion(-)
diff --git a/gcc/config/i386/i386-expand.cc b/gcc/config/i386/i386-expand.cc
index 4c47cfe468ef..4e16aedc5c13 100644
--- 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
index 000000000000..71fdc9d8daf1
--- /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;
+}
+
