[llvm] 19918ac - [VPlan] Mark Select VPInstructions as not having sideeffects.

[Florian Hahn via llvm-commits]

Author: Florian Hahn
Date: 2023-12-11T12:26:32Z
New Revision: 19918ac34dc5d304ec6ad413ceae1d4394abe28f

URL: https://github.com/llvm/llvm-project/commit/19918ac34dc5d304ec6ad413ceae1d4394abe28f
DIFF: https://github.com/llvm/llvm-project/commit/19918ac34dc5d304ec6ad413ceae1d4394abe28f.diff

LOG: [VPlan] Mark Select VPInstructions as not having sideeffects.

Select VPInstructions don't have sideeffects, mark them accordingly.

Added: 
    

Modified: 
    llvm/lib/Transforms/Vectorize/VPlanRecipes.cpp
    llvm/test/Transforms/LoopVectorize/reduction-small-size.ll

Removed: 
    


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diff  --git a/llvm/lib/Transforms/Vectorize/VPlanRecipes.cpp b/llvm/lib/Transforms/Vectorize/VPlanRecipes.cpp
index c23428e2ba34e8..ffdeea80fa074b 100644
--- a/llvm/lib/Transforms/Vectorize/VPlanRecipes.cpp
+++ b/llvm/lib/Transforms/Vectorize/VPlanRecipes.cpp
@@ -118,6 +118,7 @@ bool VPRecipeBase::mayHaveSideEffects() const {
   case VPInstructionSC:
     switch (cast<VPInstruction>(this)->getOpcode()) {
     case Instruction::ICmp:
+    case Instruction::Select:
     case VPInstruction::Not:
     case VPInstruction::CalculateTripCountMinusVF:
     case VPInstruction::CanonicalIVIncrementForPart:

diff  --git a/llvm/test/Transforms/LoopVectorize/reduction-small-size.ll b/llvm/test/Transforms/LoopVectorize/reduction-small-size.ll
index 3973a288fe71fb..2a58748d8fb67d 100644
--- a/llvm/test/Transforms/LoopVectorize/reduction-small-size.ll
+++ b/llvm/test/Transforms/LoopVectorize/reduction-small-size.ll
@@ -11,15 +11,12 @@ define i8 @PR34687(i1 %c, i32 %x, i32 %n) {
 ; CHECK:       vector.ph:
 ; CHECK-NEXT:    [[N_MOD_VF:%.*]] = urem i32 [[N]], 4
 ; CHECK-NEXT:    [[N_VEC:%.*]] = sub i32 [[N]], [[N_MOD_VF]]
-; CHECK-NEXT:    [[BROADCAST_SPLATINSERT:%.*]] = insertelement <4 x i1> poison, i1 [[C:%.*]], i64 0
-; CHECK-NEXT:    [[BROADCAST_SPLAT:%.*]] = shufflevector <4 x i1> [[BROADCAST_SPLATINSERT]], <4 x i1> poison, <4 x i32> zeroinitializer
 ; CHECK-NEXT:    [[BROADCAST_SPLATINSERT1:%.*]] = insertelement <4 x i32> poison, i32 [[X:%.*]], i64 0
 ; CHECK-NEXT:    [[BROADCAST_SPLAT2:%.*]] = shufflevector <4 x i32> [[BROADCAST_SPLATINSERT1]], <4 x i32> poison, <4 x i32> zeroinitializer
 ; CHECK-NEXT:    br label [[VECTOR_BODY:%.*]]
 ; CHECK:       vector.body:
 ; CHECK-NEXT:    [[INDEX:%.*]] = phi i32 [ 0, [[VECTOR_PH]] ], [ [[INDEX_NEXT:%.*]], [[VECTOR_BODY]] ]
 ; CHECK-NEXT:    [[VEC_PHI:%.*]] = phi <4 x i32> [ zeroinitializer, [[VECTOR_PH]] ], [ [[TMP4:%.*]], [[VECTOR_BODY]] ]
-; CHECK-NEXT:    [[TMP0:%.*]] = select <4 x i1> [[BROADCAST_SPLAT]], <4 x i32> undef, <4 x i32> <i32 1, i32 1, i32 1, i32 1>
 ; CHECK-NEXT:    [[TMP1:%.*]] = and <4 x i32> [[VEC_PHI]], <i32 255, i32 255, i32 255, i32 255>
 ; CHECK-NEXT:    [[TMP2:%.*]] = add <4 x i32> [[TMP1]], [[BROADCAST_SPLAT2]]
 ; CHECK-NEXT:    [[TMP3:%.*]] = trunc <4 x i32> [[TMP2]] to <4 x i8>
@@ -40,7 +37,7 @@ define i8 @PR34687(i1 %c, i32 %x, i32 %n) {
 ; CHECK:       for.body:
 ; CHECK-NEXT:    [[I:%.*]] = phi i32 [ [[BC_RESUME_VAL]], [[SCALAR_PH]] ], [ [[I_NEXT:%.*]], [[IF_END:%.*]] ]
 ; CHECK-NEXT:    [[R:%.*]] = phi i32 [ [[BC_MERGE_RDX]], [[SCALAR_PH]] ], [ [[R_NEXT:%.*]], [[IF_END]] ]
-; CHECK-NEXT:    br i1 [[C]], label [[IF_THEN:%.*]], label [[IF_END]]
+; CHECK-NEXT:    br i1 [[C:%.*]], label [[IF_THEN:%.*]], label [[IF_END]]
 ; CHECK:       if.then:
 ; CHECK-NEXT:    [[T0:%.*]] = sdiv i32 undef, undef
 ; CHECK-NEXT:    br label [[IF_END]]