[llvm] 88f010a - [X86] Improve test coverage for concat(pmaddubsw(),pmaddubsw()) -> pmaddubsw(concat(),concat())

[Simon Pilgrim via llvm-commits]

Author: Simon Pilgrim
Date: 2025-03-10T12:22:15Z
New Revision: 88f010a2ebe828a1a3a1faa25b36716e9b45549a

URL: https://github.com/llvm/llvm-project/commit/88f010a2ebe828a1a3a1faa25b36716e9b45549a
DIFF: https://github.com/llvm/llvm-project/commit/88f010a2ebe828a1a3a1faa25b36716e9b45549a.diff

LOG: [X86] Improve test coverage for concat(pmaddubsw(),pmaddubsw()) -> pmaddubsw(concat(),concat())

Ensure we have tests for both beneficial/non-beneficial concatenation cases

Added: 
    

Modified: 
    llvm/test/CodeGen/X86/combine-pmadd.ll

Removed: 
    


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diff  --git a/llvm/test/CodeGen/X86/combine-pmadd.ll b/llvm/test/CodeGen/X86/combine-pmadd.ll
index eb627f13db08f..242dfb030d2f8 100644
--- a/llvm/test/CodeGen/X86/combine-pmadd.ll
+++ b/llvm/test/CodeGen/X86/combine-pmadd.ll
@@ -179,22 +179,53 @@ define <8 x i16> @combine_pmaddubsw_zero_commute(<16 x i8> %a0, <16 x i8> %a1) {
   ret <8 x i16> %1
 }
 
-define <16 x i16> @combine_pmaddubsw_concat(<16 x i8> %a0, <16 x i8> %a1, <16 x i8> %a2, <16 x i8> %a3) {
+define <16 x i16> @combine_pmaddubsw_concat(<32 x i8> %a0, <32 x i8> %a1) {
 ; SSE-LABEL: combine_pmaddubsw_concat:
 ; SSE:       # %bb.0:
+; SSE-NEXT:    pmaddubsw %xmm2, %xmm0
+; SSE-NEXT:    pmaddubsw %xmm3, %xmm1
+; SSE-NEXT:    retq
+;
+; AVX1-LABEL: combine_pmaddubsw_concat:
+; AVX1:       # %bb.0:
+; AVX1-NEXT:    vextractf128 $1, %ymm0, %xmm2
+; AVX1-NEXT:    vextractf128 $1, %ymm1, %xmm3
+; AVX1-NEXT:    vpmaddubsw %xmm3, %xmm2, %xmm2
+; AVX1-NEXT:    vpmaddubsw %xmm1, %xmm0, %xmm0
+; AVX1-NEXT:    vinsertf128 $1, %xmm2, %ymm0, %ymm0
+; AVX1-NEXT:    retq
+;
+; AVX2-LABEL: combine_pmaddubsw_concat:
+; AVX2:       # %bb.0:
+; AVX2-NEXT:    vpmaddubsw %ymm1, %ymm0, %ymm0
+; AVX2-NEXT:    retq
+  %lo0 = shufflevector <32 x i8> %a0, <32 x i8> undef, <16 x i32> <i32 0, i32 1, i32 2, i32 3, i32 4, i32 5, i32 6, i32 7, i32 8, i32 9, i32 10, i32 11, i32 12, i32 13, i32 14, i32 15>
+  %lo1 = shufflevector <32 x i8> %a1, <32 x i8> undef, <16 x i32> <i32 0, i32 1, i32 2, i32 3, i32 4, i32 5, i32 6, i32 7, i32 8, i32 9, i32 10, i32 11, i32 12, i32 13, i32 14, i32 15>
+  %hi0 = shufflevector <32 x i8> %a0, <32 x i8> undef, <16 x i32> <i32 16, i32 17, i32 18, i32 19, i32 20, i32 21, i32 22, i32 23, i32 24, i32 25, i32 26, i32 27, i32 28, i32 29, i32 30, i32 31>
+  %hi1 = shufflevector <32 x i8> %a1, <32 x i8> undef, <16 x i32> <i32 16, i32 17, i32 18, i32 19, i32 20, i32 21, i32 22, i32 23, i32 24, i32 25, i32 26, i32 27, i32 28, i32 29, i32 30, i32 31>
+  %lo = call <8 x i16> @llvm.x86.ssse3.pmadd.ub.sw.128(<16 x i8> %lo0, <16 x i8> %lo1)
+  %hi = call <8 x i16> @llvm.x86.ssse3.pmadd.ub.sw.128(<16 x i8> %hi0, <16 x i8> %hi1)
+  %res = shufflevector <8 x i16> %lo, <8 x i16> %hi, <16 x i32> <i32 0, i32 1, i32 2, i32 3, i32 4, i32 5, i32 6, i32 7, i32 8, i32 9, i32 10, i32 11, i32 12, i32 13, i32 14, i32 15>
+  ret <16 x i16> %res
+}
+
+; TODO: Not beneficial to concatenate both inputs just to create a 256-bit pmaddubsw
+define <16 x i16> @combine_pmaddubsw_concat_unecessary(<16 x i8> %a0, <16 x i8> %a1, <16 x i8> %a2, <16 x i8> %a3) {
+; SSE-LABEL: combine_pmaddubsw_concat_unecessary:
+; SSE:       # %bb.0:
 ; SSE-NEXT:    pmaddubsw %xmm1, %xmm0
 ; SSE-NEXT:    pmaddubsw %xmm3, %xmm2
 ; SSE-NEXT:    movdqa %xmm2, %xmm1
 ; SSE-NEXT:    retq
 ;
-; AVX1-LABEL: combine_pmaddubsw_concat:
+; AVX1-LABEL: combine_pmaddubsw_concat_unecessary:
 ; AVX1:       # %bb.0:
 ; AVX1-NEXT:    vpmaddubsw %xmm1, %xmm0, %xmm0
 ; AVX1-NEXT:    vpmaddubsw %xmm3, %xmm2, %xmm1
 ; AVX1-NEXT:    vinsertf128 $1, %xmm1, %ymm0, %ymm0
 ; AVX1-NEXT:    retq
 ;
-; AVX2-LABEL: combine_pmaddubsw_concat:
+; AVX2-LABEL: combine_pmaddubsw_concat_unecessary:
 ; AVX2:       # %bb.0:
 ; AVX2-NEXT:    # kill: def $xmm1 killed $xmm1 def $ymm1
 ; AVX2-NEXT:    # kill: def $xmm0 killed $xmm0 def $ymm0