[X86][SSE] Add selective commutation support for insertps (PR40340)

When we are inserting 1 "inline" element, and zeroing 2 of the other elements then we can safely commute the insertps source inputs to improve memory folding.

Differential Revision: https://reviews.llvm.org/D56843

llvm-svn: 351807

1 files changed, 2 insertions, 5 deletions

diff --git a/llvm/test/CodeGen/X86/insertps-combine.ll b/llvm/test/CodeGen/X86/insertps-combine.ll
index 12773b61557..6bef76ee9df 100644
--- a/llvm/test/CodeGen/X86/insertps-combine.ll
+++ b/llvm/test/CodeGen/X86/insertps-combine.ll
@@ -302,15 +302,12 @@ define float @extract_lane_insertps_6123(<4 x float> %a0, <4 x float> *%p1) {
 define <4 x float> @commute_load_insertps(<4 x float>, <4 x float>* nocapture readonly) {
 ; SSE-LABEL: commute_load_insertps:
 ; SSE:       # %bb.0:
-; SSE-NEXT:    movaps (%rdi), %xmm1
-; SSE-NEXT:    insertps {{.*#+}} xmm1 = zero,xmm0[1],zero,xmm1[3]
-; SSE-NEXT:    movaps %xmm1, %xmm0
+; SSE-NEXT:    insertps {{.*#+}} xmm0 = zero,xmm0[1],zero,mem[0]
 ; SSE-NEXT:    retq
 ;
 ; AVX-LABEL: commute_load_insertps:
 ; AVX:       # %bb.0:
-; AVX-NEXT:    vmovaps (%rdi), %xmm1
-; AVX-NEXT:    vinsertps {{.*#+}} xmm0 = zero,xmm0[1],zero,xmm1[3]
+; AVX-NEXT:    vinsertps {{.*#+}} xmm0 = zero,xmm0[1],zero,mem[0]
 ; AVX-NEXT:    retq
   %3 = load <4 x float>, <4 x float>* %1
   %4 = tail call <4 x float> @llvm.x86.sse41.insertps(<4 x float> %3, <4 x float> %0, i8 85)