[llvm] r181674 - SLPVectorizer: Fix a bug in the code that generates extracts for values with multiple users.
Nadav Rotem
nrotem at apple.com
Sun May 12 15:58:45 PDT 2013
Author: nadav
Date: Sun May 12 17:58:45 2013
New Revision: 181674
URL: http://llvm.org/viewvc/llvm-project?rev=181674&view=rev
Log:
SLPVectorizer: Fix a bug in the code that generates extracts for values with multiple users.
The external user does not have to be in lane #0. We have to save the lane for each scalar so that we know which vector lane to extract.
Modified:
llvm/trunk/lib/Transforms/Vectorize/VecUtils.cpp
llvm/trunk/test/Transforms/SLPVectorizer/X86/diamond.ll
Modified: llvm/trunk/lib/Transforms/Vectorize/VecUtils.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/Vectorize/VecUtils.cpp?rev=181674&r1=181673&r2=181674&view=diff
==============================================================================
--- llvm/trunk/lib/Transforms/Vectorize/VecUtils.cpp (original)
+++ llvm/trunk/lib/Transforms/Vectorize/VecUtils.cpp Sun May 12 17:58:45 2013
@@ -282,6 +282,7 @@ int BoUpSLP::getTreeCost(ArrayRef<Value
DEBUG(dbgs()<<"SLP: Adding to MustExtract "
"because of a safe out of tree usage.\n");
MustExtract.insert(*it);
+ continue;
}
if (Lane == -1) Lane = LaneMap[*I];
if (Lane != LaneMap[*I]) {
@@ -610,6 +611,9 @@ Value *BoUpSLP::Scalarize(ArrayRef<Value
GatherInstructions.push_back(Vec);
}
+ for (unsigned i = 0; i < Ty->getNumElements(); ++i)
+ VectorizedValues[VL[i]] = Vec;
+
return Vec;
}
@@ -617,6 +621,7 @@ Value *BoUpSLP::vectorizeTree(ArrayRef<V
Value *V = vectorizeTree_rec(VL, VF);
Instruction *LastInstr = GetLastInstr(VL, VL.size());
+ int LastInstrIdx = InstrIdx[LastInstr];
IRBuilder<> Builder(LastInstr);
for (ValueSet::iterator it = MustExtract.begin(), e = MustExtract.end();
it != e; ++it) {
@@ -625,7 +630,15 @@ Value *BoUpSLP::vectorizeTree(ArrayRef<V
assert(LaneMap.count(I) && "Unable to find the lane for the external use");
Value *Idx = Builder.getInt32(LaneMap[I]);
Value *Extract = Builder.CreateExtractElement(Vec, Idx);
- I->replaceAllUsesWith(Extract);
+ bool Replaced = false;
+ for (Value::use_iterator U = I->use_begin(), UE = U->use_end(); U != UE;
+ ++U) {
+ Instruction *UI = cast<Instruction>(*U);
+ if (UI->getParent() != I->getParent() || InstrIdx[UI] > LastInstrIdx)
+ UI->replaceUsesOfWith(I ,Extract);
+ Replaced = true;
+ }
+ assert(Replaced && "Must replace at least one outside user");
}
// We moved some instructions around. We have to number them again
@@ -691,7 +704,10 @@ Value *BoUpSLP::vectorizeTree_rec(ArrayR
IRBuilder<> Builder(GetLastInstr(VL, VF));
CastInst *CI = dyn_cast<CastInst>(VL0);
Value *V = Builder.CreateCast(CI->getOpcode(), InVec, VecTy);
- VectorizedValues[VL0] = V;
+
+ for (int i = 0; i < VF; ++i)
+ VectorizedValues[VL[i]] = V;
+
return V;
}
case Instruction::Add:
@@ -723,7 +739,10 @@ Value *BoUpSLP::vectorizeTree_rec(ArrayR
IRBuilder<> Builder(GetLastInstr(VL, VF));
BinaryOperator *BinOp = cast<BinaryOperator>(VL0);
Value *V = Builder.CreateBinOp(BinOp->getOpcode(), RHS,LHS);
- VectorizedValues[VL0] = V;
+
+ for (int i = 0; i < VF; ++i)
+ VectorizedValues[VL[i]] = V;
+
return V;
}
case Instruction::Load: {
@@ -740,7 +759,10 @@ Value *BoUpSLP::vectorizeTree_rec(ArrayR
VecTy->getPointerTo());
LI = Builder.CreateLoad(VecPtr);
LI->setAlignment(Alignment);
- VectorizedValues[VL0] = LI;
+
+ for (int i = 0; i < VF; ++i)
+ VectorizedValues[VL[i]] = LI;
+
return LI;
}
case Instruction::Store: {
@@ -763,9 +785,7 @@ Value *BoUpSLP::vectorizeTree_rec(ArrayR
return 0;
}
default:
- Value *S = Scalarize(VL, VecTy);
- VectorizedValues[VL0] = S;
- return S;
+ return Scalarize(VL, VecTy);
}
}
Modified: llvm/trunk/test/Transforms/SLPVectorizer/X86/diamond.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Transforms/SLPVectorizer/X86/diamond.ll?rev=181674&r1=181673&r2=181674&view=diff
==============================================================================
--- llvm/trunk/test/Transforms/SLPVectorizer/X86/diamond.ll (original)
+++ llvm/trunk/test/Transforms/SLPVectorizer/X86/diamond.ll Sun May 12 17:58:45 2013
@@ -1,4 +1,4 @@
-; RUN: opt < %s -basicaa -slp-vectorizer -dce -S -mtriple=x86_64-apple-macosx10.8.0 -mcpu=corei7-avx | FileCheck %s
+; RUN: opt < %s -basicaa -slp-vectorizer -S -mtriple=x86_64-apple-macosx10.8.0 -mcpu=corei7-avx | FileCheck %s
target datalayout = "e-p:64:64:64-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:64:64-f32:32:32-f64:64:64-v64:64:64-v128:128:128-a0:0:64-s0:64:64-f80:128:128-n8:16:32:64-S128"
target triple = "x86_64-apple-macosx10.8.0"
@@ -74,6 +74,34 @@ entry:
%add20 = mul i32 %3, %mul238
%arrayidx21 = getelementptr inbounds i32* %B, i64 3
store i32 %add20, i32* %arrayidx21, align 4
- ret i32 %0 ;<--------- This value has multiple users and can't be vectorized.
+ ret i32 %0 ;<--------- This value has multiple users
}
+; In this example we have an external user that is not the first element in the vector.
+; CHECK: @extr_user1
+; CHECK: store <4 x i32>
+; CHECK-NEXT: extractelement <4 x i32>
+; CHECK: ret
+define i32 @extr_user1(i32* noalias nocapture %B, i32* noalias nocapture %A, i32 %n, i32 %m) {
+entry:
+ %0 = load i32* %A, align 4
+ %mul238 = add i32 %m, %n
+ %add = mul i32 %0, %mul238
+ store i32 %add, i32* %B, align 4
+ %arrayidx4 = getelementptr inbounds i32* %A, i64 1
+ %1 = load i32* %arrayidx4, align 4
+ %add8 = mul i32 %1, %mul238
+ %arrayidx9 = getelementptr inbounds i32* %B, i64 1
+ store i32 %add8, i32* %arrayidx9, align 4
+ %arrayidx10 = getelementptr inbounds i32* %A, i64 2
+ %2 = load i32* %arrayidx10, align 4
+ %add14 = mul i32 %2, %mul238
+ %arrayidx15 = getelementptr inbounds i32* %B, i64 2
+ store i32 %add14, i32* %arrayidx15, align 4
+ %arrayidx16 = getelementptr inbounds i32* %A, i64 3
+ %3 = load i32* %arrayidx16, align 4
+ %add20 = mul i32 %3, %mul238
+ %arrayidx21 = getelementptr inbounds i32* %B, i64 3
+ store i32 %add20, i32* %arrayidx21, align 4
+ ret i32 %1 ;<--------- This value has multiple users
+}
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