[CostModel] Treat Identity shuffle masks as zero cost
As discussed on D47985, identity shuffle masks should probably be free.
I've limited this to the case where the input and output types all match - but we could probably accept all cases.
Differential Revision: https://reviews.llvm.org/D47986
llvm-svn: 334506
diff --git a/llvm/test/Analysis/CostModel/X86/shuffle-single-src.ll b/llvm/test/Analysis/CostModel/X86/shuffle-single-src.ll
index 2a9d85f..f93a826 100644
--- a/llvm/test/Analysis/CostModel/X86/shuffle-single-src.ll
+++ b/llvm/test/Analysis/CostModel/X86/shuffle-single-src.ll
@@ -353,52 +353,16 @@
;
define void @identity_vXf32(<4 x float> %a128, <4 x float> %b128, <8 x float> %a256, <8 x float> %b256, <16 x float> %a512, <16 x float> %b512) {
-; SSE2-LABEL: 'identity_vXf32'
-; SSE2-NEXT: Cost Model: Found an estimated cost of 2 for instruction: %V128 = shufflevector <4 x float> %a128, <4 x float> %b128, <4 x i32> <i32 0, i32 undef, i32 2, i32 undef>
-; SSE2-NEXT: Cost Model: Found an estimated cost of 4 for instruction: %V256 = shufflevector <8 x float> %a256, <8 x float> %b256, <8 x i32> <i32 8, i32 9, i32 10, i32 11, i32 undef, i32 undef, i32 undef, i32 undef>
-; SSE2-NEXT: Cost Model: Found an estimated cost of 24 for instruction: %V512 = shufflevector <16 x float> %a512, <16 x float> %b512, <16 x i32> <i32 0, i32 undef, i32 2, i32 undef, i32 4, i32 undef, i32 6, i32 7, i32 8, i32 9, i32 10, i32 11, i32 12, i32 13, i32 14, i32 undef>
-; SSE2-NEXT: Cost Model: Found an estimated cost of 0 for instruction: ret void
-;
-; SSSE3-LABEL: 'identity_vXf32'
-; SSSE3-NEXT: Cost Model: Found an estimated cost of 2 for instruction: %V128 = shufflevector <4 x float> %a128, <4 x float> %b128, <4 x i32> <i32 0, i32 undef, i32 2, i32 undef>
-; SSSE3-NEXT: Cost Model: Found an estimated cost of 4 for instruction: %V256 = shufflevector <8 x float> %a256, <8 x float> %b256, <8 x i32> <i32 8, i32 9, i32 10, i32 11, i32 undef, i32 undef, i32 undef, i32 undef>
-; SSSE3-NEXT: Cost Model: Found an estimated cost of 24 for instruction: %V512 = shufflevector <16 x float> %a512, <16 x float> %b512, <16 x i32> <i32 0, i32 undef, i32 2, i32 undef, i32 4, i32 undef, i32 6, i32 7, i32 8, i32 9, i32 10, i32 11, i32 12, i32 13, i32 14, i32 undef>
-; SSSE3-NEXT: Cost Model: Found an estimated cost of 0 for instruction: ret void
-;
-; SSE42-LABEL: 'identity_vXf32'
-; SSE42-NEXT: Cost Model: Found an estimated cost of 1 for instruction: %V128 = shufflevector <4 x float> %a128, <4 x float> %b128, <4 x i32> <i32 0, i32 undef, i32 2, i32 undef>
-; SSE42-NEXT: Cost Model: Found an estimated cost of 4 for instruction: %V256 = shufflevector <8 x float> %a256, <8 x float> %b256, <8 x i32> <i32 8, i32 9, i32 10, i32 11, i32 undef, i32 undef, i32 undef, i32 undef>
-; SSE42-NEXT: Cost Model: Found an estimated cost of 24 for instruction: %V512 = shufflevector <16 x float> %a512, <16 x float> %b512, <16 x i32> <i32 0, i32 undef, i32 2, i32 undef, i32 4, i32 undef, i32 6, i32 7, i32 8, i32 9, i32 10, i32 11, i32 12, i32 13, i32 14, i32 undef>
-; SSE42-NEXT: Cost Model: Found an estimated cost of 0 for instruction: ret void
-;
-; XOP-LABEL: 'identity_vXf32'
-; XOP-NEXT: Cost Model: Found an estimated cost of 1 for instruction: %V128 = shufflevector <4 x float> %a128, <4 x float> %b128, <4 x i32> <i32 0, i32 undef, i32 2, i32 undef>
-; XOP-NEXT: Cost Model: Found an estimated cost of 2 for instruction: %V256 = shufflevector <8 x float> %a256, <8 x float> %b256, <8 x i32> <i32 8, i32 9, i32 10, i32 11, i32 undef, i32 undef, i32 undef, i32 undef>
-; XOP-NEXT: Cost Model: Found an estimated cost of 8 for instruction: %V512 = shufflevector <16 x float> %a512, <16 x float> %b512, <16 x i32> <i32 0, i32 undef, i32 2, i32 undef, i32 4, i32 undef, i32 6, i32 7, i32 8, i32 9, i32 10, i32 11, i32 12, i32 13, i32 14, i32 undef>
-; XOP-NEXT: Cost Model: Found an estimated cost of 0 for instruction: ret void
-;
-; AVX1-LABEL: 'identity_vXf32'
-; AVX1-NEXT: Cost Model: Found an estimated cost of 1 for instruction: %V128 = shufflevector <4 x float> %a128, <4 x float> %b128, <4 x i32> <i32 0, i32 undef, i32 2, i32 undef>
-; AVX1-NEXT: Cost Model: Found an estimated cost of 4 for instruction: %V256 = shufflevector <8 x float> %a256, <8 x float> %b256, <8 x i32> <i32 8, i32 9, i32 10, i32 11, i32 undef, i32 undef, i32 undef, i32 undef>
-; AVX1-NEXT: Cost Model: Found an estimated cost of 8 for instruction: %V512 = shufflevector <16 x float> %a512, <16 x float> %b512, <16 x i32> <i32 0, i32 undef, i32 2, i32 undef, i32 4, i32 undef, i32 6, i32 7, i32 8, i32 9, i32 10, i32 11, i32 12, i32 13, i32 14, i32 undef>
-; AVX1-NEXT: Cost Model: Found an estimated cost of 0 for instruction: ret void
-;
-; AVX2-LABEL: 'identity_vXf32'
-; AVX2-NEXT: Cost Model: Found an estimated cost of 1 for instruction: %V128 = shufflevector <4 x float> %a128, <4 x float> %b128, <4 x i32> <i32 0, i32 undef, i32 2, i32 undef>
-; AVX2-NEXT: Cost Model: Found an estimated cost of 1 for instruction: %V256 = shufflevector <8 x float> %a256, <8 x float> %b256, <8 x i32> <i32 8, i32 9, i32 10, i32 11, i32 undef, i32 undef, i32 undef, i32 undef>
-; AVX2-NEXT: Cost Model: Found an estimated cost of 6 for instruction: %V512 = shufflevector <16 x float> %a512, <16 x float> %b512, <16 x i32> <i32 0, i32 undef, i32 2, i32 undef, i32 4, i32 undef, i32 6, i32 7, i32 8, i32 9, i32 10, i32 11, i32 12, i32 13, i32 14, i32 undef>
-; AVX2-NEXT: Cost Model: Found an estimated cost of 0 for instruction: ret void
-;
-; AVX512-LABEL: 'identity_vXf32'
-; AVX512-NEXT: Cost Model: Found an estimated cost of 1 for instruction: %V128 = shufflevector <4 x float> %a128, <4 x float> %b128, <4 x i32> <i32 0, i32 undef, i32 2, i32 undef>
-; AVX512-NEXT: Cost Model: Found an estimated cost of 1 for instruction: %V256 = shufflevector <8 x float> %a256, <8 x float> %b256, <8 x i32> <i32 8, i32 9, i32 10, i32 11, i32 undef, i32 undef, i32 undef, i32 undef>
-; AVX512-NEXT: Cost Model: Found an estimated cost of 1 for instruction: %V512 = shufflevector <16 x float> %a512, <16 x float> %b512, <16 x i32> <i32 0, i32 undef, i32 2, i32 undef, i32 4, i32 undef, i32 6, i32 7, i32 8, i32 9, i32 10, i32 11, i32 12, i32 13, i32 14, i32 undef>
-; AVX512-NEXT: Cost Model: Found an estimated cost of 0 for instruction: ret void
+; CHECK-LABEL: 'identity_vXf32'
+; CHECK-NEXT: Cost Model: Found an estimated cost of 0 for instruction: %V128 = shufflevector <4 x float> %a128, <4 x float> %b128, <4 x i32> <i32 0, i32 undef, i32 2, i32 undef>
+; CHECK-NEXT: Cost Model: Found an estimated cost of 0 for instruction: %V256 = shufflevector <8 x float> %a256, <8 x float> %b256, <8 x i32> <i32 8, i32 9, i32 10, i32 11, i32 undef, i32 undef, i32 undef, i32 undef>
+; CHECK-NEXT: Cost Model: Found an estimated cost of 0 for instruction: %V512 = shufflevector <16 x float> %a512, <16 x float> %b512, <16 x i32> <i32 0, i32 undef, i32 2, i32 undef, i32 4, i32 undef, i32 6, i32 7, i32 8, i32 9, i32 10, i32 11, i32 12, i32 13, i32 14, i32 undef>
+; CHECK-NEXT: Cost Model: Found an estimated cost of 0 for instruction: ret void
;
; BTVER2-LABEL: 'identity_vXf32'
-; BTVER2-NEXT: Cost Model: Found an estimated cost of 1 for instruction: %V128 = shufflevector <4 x float> %a128, <4 x float> %b128, <4 x i32> <i32 0, i32 undef, i32 2, i32 undef>
-; BTVER2-NEXT: Cost Model: Found an estimated cost of 4 for instruction: %V256 = shufflevector <8 x float> %a256, <8 x float> %b256, <8 x i32> <i32 8, i32 9, i32 10, i32 11, i32 undef, i32 undef, i32 undef, i32 undef>
-; BTVER2-NEXT: Cost Model: Found an estimated cost of 8 for instruction: %V512 = shufflevector <16 x float> %a512, <16 x float> %b512, <16 x i32> <i32 0, i32 undef, i32 2, i32 undef, i32 4, i32 undef, i32 6, i32 7, i32 8, i32 9, i32 10, i32 11, i32 12, i32 13, i32 14, i32 undef>
+; BTVER2-NEXT: Cost Model: Found an estimated cost of 0 for instruction: %V128 = shufflevector <4 x float> %a128, <4 x float> %b128, <4 x i32> <i32 0, i32 undef, i32 2, i32 undef>
+; BTVER2-NEXT: Cost Model: Found an estimated cost of 0 for instruction: %V256 = shufflevector <8 x float> %a256, <8 x float> %b256, <8 x i32> <i32 8, i32 9, i32 10, i32 11, i32 undef, i32 undef, i32 undef, i32 undef>
+; BTVER2-NEXT: Cost Model: Found an estimated cost of 0 for instruction: %V512 = shufflevector <16 x float> %a512, <16 x float> %b512, <16 x i32> <i32 0, i32 undef, i32 2, i32 undef, i32 4, i32 undef, i32 6, i32 7, i32 8, i32 9, i32 10, i32 11, i32 12, i32 13, i32 14, i32 undef>
; BTVER2-NEXT: Cost Model: Found an estimated cost of 0 for instruction: ret void
;
%V128 = shufflevector <4 x float> %a128, <4 x float> %b128, <4 x i32> <i32 0, i32 undef, i32 2, i32 undef>