[DAGCombiner] Add add/sub saturation undef handling
Match ConstantFolding.cpp:
(add_sat x, undef) -> -1
(sub_sat x, undef) -> 0
llvm-svn: 351070
diff --git a/llvm/test/CodeGen/X86/combine-add-usat.ll b/llvm/test/CodeGen/X86/combine-add-usat.ll
index 260d6ba..7565f06 100644
--- a/llvm/test/CodeGen/X86/combine-add-usat.ll
+++ b/llvm/test/CodeGen/X86/combine-add-usat.ll
@@ -15,9 +15,7 @@
define i32 @combine_undef_i32(i32 %a0) {
; CHECK-LABEL: combine_undef_i32:
; CHECK: # %bb.0:
-; CHECK-NEXT: addl %eax, %edi
; CHECK-NEXT: movl $-1, %eax
-; CHECK-NEXT: cmovael %edi, %eax
; CHECK-NEXT: retq
%res = call i32 @llvm.uadd.sat.i32(i32 %a0, i32 undef)
ret i32 %res
@@ -26,12 +24,12 @@
define <8 x i16> @combine_undef_v8i16(<8 x i16> %a0) {
; SSE-LABEL: combine_undef_v8i16:
; SSE: # %bb.0:
-; SSE-NEXT: paddusw %xmm0, %xmm0
+; SSE-NEXT: pcmpeqd %xmm0, %xmm0
; SSE-NEXT: retq
;
; AVX-LABEL: combine_undef_v8i16:
; AVX: # %bb.0:
-; AVX-NEXT: vpaddusw %xmm0, %xmm0, %xmm0
+; AVX-NEXT: vpcmpeqd %xmm0, %xmm0, %xmm0
; AVX-NEXT: retq
%res = call <8 x i16> @llvm.uadd.sat.v8i16(<8 x i16> undef, <8 x i16> %a0)
ret <8 x i16> %res
@@ -64,14 +62,12 @@
define <8 x i16> @combine_constfold_undef_v8i16() {
; SSE-LABEL: combine_constfold_undef_v8i16:
; SSE: # %bb.0:
-; SSE-NEXT: movdqa {{.*#+}} xmm0 = <u,1,u,65535,65535,65281,1,1>
-; SSE-NEXT: paddusw {{.*}}(%rip), %xmm0
+; SSE-NEXT: movaps {{.*#+}} xmm0 = [65535,65535,65535,65535,65535,65535,2,65535]
; SSE-NEXT: retq
;
; AVX-LABEL: combine_constfold_undef_v8i16:
; AVX: # %bb.0:
-; AVX-NEXT: vmovdqa {{.*#+}} xmm0 = <u,1,u,65535,65535,65281,1,1>
-; AVX-NEXT: vpaddusw {{.*}}(%rip), %xmm0, %xmm0
+; AVX-NEXT: vmovaps {{.*#+}} xmm0 = [65535,65535,65535,65535,65535,65535,2,65535]
; AVX-NEXT: retq
%res = call <8 x i16> @llvm.uadd.sat.v8i16(<8 x i16> <i16 undef, i16 1, i16 undef, i16 65535, i16 -1, i16 -255, i16 -65535, i16 1>, <8 x i16> <i16 1, i16 undef, i16 undef, i16 65535, i16 1, i16 65535, i16 1, i16 65535>)
ret <8 x i16> %res