[llvm] 93d8d74 - [VectorCombine] Remove requirement for Instructions in shuffleToIdentity (#93543)

[via llvm-commits]

Author: David Green
Date: 2024-05-29T09:36:53+01:00
New Revision: 93d8d74ae6717c8e7c8b25ad5a6cfa212d3a4d37

URL: https://github.com/llvm/llvm-project/commit/93d8d74ae6717c8e7c8b25ad5a6cfa212d3a4d37
DIFF: https://github.com/llvm/llvm-project/commit/93d8d74ae6717c8e7c8b25ad5a6cfa212d3a4d37.diff

LOG: [VectorCombine] Remove requirement for Instructions in shuffleToIdentity (#93543)

This removes the check that both operands of the original shuffle are
instructions, which is a relic from a previous version that held more
variables as Instructions.

Added: 
    

Modified: 
    llvm/lib/Transforms/Vectorize/VectorCombine.cpp
    llvm/test/Transforms/VectorCombine/AArch64/shuffletoidentity.ll

Removed: 
    


################################################################################
diff  --git a/llvm/lib/Transforms/Vectorize/VectorCombine.cpp b/llvm/lib/Transforms/Vectorize/VectorCombine.cpp
index c3c4ee8479766..7ecfe5218ef67 100644
--- a/llvm/lib/Transforms/Vectorize/VectorCombine.cpp
+++ b/llvm/lib/Transforms/Vectorize/VectorCombine.cpp
@@ -1760,8 +1760,7 @@ static Value *generateNewInstTree(ArrayRef<InstLane> Item, FixedVectorType *Ty,
 // do so.
 bool VectorCombine::foldShuffleToIdentity(Instruction &I) {
   auto *Ty = dyn_cast<FixedVectorType>(I.getType());
-  if (!Ty || !isa<Instruction>(I.getOperand(0)) ||
-      !isa<Instruction>(I.getOperand(1)))
+  if (!Ty)
     return false;
 
   SmallVector<InstLane> Start(Ty->getNumElements());

diff  --git a/llvm/test/Transforms/VectorCombine/AArch64/shuffletoidentity.ll b/llvm/test/Transforms/VectorCombine/AArch64/shuffletoidentity.ll
index 62fb0e6c7c11d..c2e9be5688967 100644
--- a/llvm/test/Transforms/VectorCombine/AArch64/shuffletoidentity.ll
+++ b/llvm/test/Transforms/VectorCombine/AArch64/shuffletoidentity.ll
@@ -15,9 +15,7 @@ define <8 x i8> @trivial(<8 x i8> %a) {
 
 define <4 x i32> @add_same_operands(<4 x i32> %x) {
 ; CHECK-LABEL: @add_same_operands(
-; CHECK-NEXT:    [[SHUF:%.*]] = shufflevector <4 x i32> [[X:%.*]], <4 x i32> poison, <4 x i32> <i32 3, i32 2, i32 1, i32 0>
-; CHECK-NEXT:    [[ADD:%.*]] = add <4 x i32> [[SHUF]], [[SHUF]]
-; CHECK-NEXT:    [[REVSHUF:%.*]] = shufflevector <4 x i32> [[ADD]], <4 x i32> poison, <4 x i32> <i32 3, i32 2, i32 1, i32 0>
+; CHECK-NEXT:    [[REVSHUF:%.*]] = add <4 x i32> [[X:%.*]], [[X]]
 ; CHECK-NEXT:    ret <4 x i32> [[REVSHUF]]
 ;
   %shuf = shufflevector <4 x i32> %x, <4 x i32> poison, <4 x i32> <i32 3, i32 2, i32 1, i32 0>
@@ -364,8 +362,7 @@ define <8 x i8> @inner_shuffle(<8 x i8> %a, <8 x i8> %b, <8 x i8> %c) {
 define <4 x i32> @extrause_add_same_operands(<4 x i32> %x) {
 ; CHECK-LABEL: @extrause_add_same_operands(
 ; CHECK-NEXT:    [[SHUF:%.*]] = shufflevector <4 x i32> [[X:%.*]], <4 x i32> poison, <4 x i32> <i32 3, i32 2, i32 1, i32 0>
-; CHECK-NEXT:    [[ADD:%.*]] = add <4 x i32> [[SHUF]], [[SHUF]]
-; CHECK-NEXT:    [[REVSHUF:%.*]] = shufflevector <4 x i32> [[ADD]], <4 x i32> poison, <4 x i32> <i32 3, i32 2, i32 1, i32 0>
+; CHECK-NEXT:    [[REVSHUF:%.*]] = add <4 x i32> [[X]], [[X]]
 ; CHECK-NEXT:    [[ADD2:%.*]] = add <4 x i32> [[SHUF]], [[REVSHUF]]
 ; CHECK-NEXT:    ret <4 x i32> [[ADD2]]
 ;
@@ -513,9 +510,7 @@ define <8 x half> @fma(<8 x half> %a, <8 x half> %b, <8 x half> %c) {
 
 define <4 x i64> @single_zext(<4 x i32> %x) {
 ; CHECK-LABEL: @single_zext(
-; CHECK-NEXT:    [[SHUF:%.*]] = shufflevector <4 x i32> [[X:%.*]], <4 x i32> poison, <4 x i32> <i32 3, i32 2, i32 1, i32 0>
-; CHECK-NEXT:    [[ZEXT:%.*]] = zext <4 x i32> [[SHUF]] to <4 x i64>
-; CHECK-NEXT:    [[REVSHUF:%.*]] = shufflevector <4 x i64> [[ZEXT]], <4 x i64> poison, <4 x i32> <i32 3, i32 2, i32 1, i32 0>
+; CHECK-NEXT:    [[REVSHUF:%.*]] = zext <4 x i32> [[X:%.*]] to <4 x i64>
 ; CHECK-NEXT:    ret <4 x i64> [[REVSHUF]]
 ;
   %shuf = shufflevector <4 x i32> %x, <4 x i32> poison, <4 x i32> <i32 3, i32 2, i32 1, i32 0>
@@ -695,10 +690,8 @@ define void @trunc(<8 x i64> %a, <8 x i64> %b, ptr %p) {
 
 define <4 x i64> @zext_chain(<4 x i16> %x) {
 ; CHECK-LABEL: @zext_chain(
-; CHECK-NEXT:    [[SHUF:%.*]] = shufflevector <4 x i16> [[X:%.*]], <4 x i16> poison, <4 x i32> <i32 3, i32 2, i32 1, i32 0>
-; CHECK-NEXT:    [[ZEXT:%.*]] = zext <4 x i16> [[SHUF]] to <4 x i32>
-; CHECK-NEXT:    [[SEXT:%.*]] = sext <4 x i32> [[ZEXT]] to <4 x i64>
-; CHECK-NEXT:    [[REVSHUF:%.*]] = shufflevector <4 x i64> [[SEXT]], <4 x i64> poison, <4 x i32> <i32 3, i32 2, i32 1, i32 0>
+; CHECK-NEXT:    [[TMP1:%.*]] = zext <4 x i16> [[X:%.*]] to <4 x i32>
+; CHECK-NEXT:    [[REVSHUF:%.*]] = sext <4 x i32> [[TMP1]] to <4 x i64>
 ; CHECK-NEXT:    ret <4 x i64> [[REVSHUF]]
 ;
   %shuf = shufflevector <4 x i16> %x, <4 x i16> poison, <4 x i32> <i32 3, i32 2, i32 1, i32 0>
@@ -899,13 +892,11 @@ entry:
 
 define <4 x i8> @singleop(<4 x i8> %a, <4 x i8> %b) {
 ; CHECK-LABEL: @singleop(
-; CHECK-NEXT:    [[A1:%.*]] = shufflevector <4 x i8> [[A:%.*]], <4 x i8> poison, <4 x i32> <i32 3, i32 2, i32 1, i32 0>
-; CHECK-NEXT:    [[B1:%.*]] = shufflevector <4 x i8> [[B:%.*]], <4 x i8> poison, <4 x i32> zeroinitializer
-; CHECK-NEXT:    [[A2:%.*]] = zext <4 x i8> [[A1]] to <4 x i16>
-; CHECK-NEXT:    [[B2:%.*]] = zext <4 x i8> [[B1]] to <4 x i16>
-; CHECK-NEXT:    [[AB:%.*]] = add <4 x i16> [[A2]], [[B2]]
-; CHECK-NEXT:    [[T:%.*]] = trunc <4 x i16> [[AB]] to <4 x i8>
-; CHECK-NEXT:    [[R:%.*]] = shufflevector <4 x i8> [[T]], <4 x i8> poison, <4 x i32> <i32 3, i32 2, i32 1, i32 0>
+; CHECK-NEXT:    [[TMP1:%.*]] = shufflevector <4 x i8> [[B:%.*]], <4 x i8> poison, <4 x i32> zeroinitializer
+; CHECK-NEXT:    [[TMP2:%.*]] = zext <4 x i8> [[A:%.*]] to <4 x i16>
+; CHECK-NEXT:    [[TMP3:%.*]] = zext <4 x i8> [[TMP1]] to <4 x i16>
+; CHECK-NEXT:    [[TMP4:%.*]] = add <4 x i16> [[TMP2]], [[TMP3]]
+; CHECK-NEXT:    [[R:%.*]] = trunc <4 x i16> [[TMP4]] to <4 x i8>
 ; CHECK-NEXT:    ret <4 x i8> [[R]]
 ;
   %a1 = shufflevector <4 x i8> %a, <4 x i8> poison, <4 x i32> <i32 3, i32 2, i32 1, i32 0>