[llvm] r207939 - SLPVectorizer: Bring back the insertelement patch (r205965) with fixes
Arnold Schwaighofer
aschwaighofer at apple.com
Sun May 4 10:10:15 PDT 2014
Author: arnolds
Date: Sun May 4 12:10:15 2014
New Revision: 207939
URL: http://llvm.org/viewvc/llvm-project?rev=207939&view=rev
Log:
SLPVectorizer: Bring back the insertelement patch (r205965) with fixes
When can't assume a vectorized tree is rooted in an instruction. The IRBuilder
could have constant folded it. When we rebuild the build_vector (the series of
InsertElement instructions) use the last original InsertElement instruction. The
vectorized tree root is guaranteed to be before it.
Also, we can't assume that the n-th InsertElement inserts the n-th element into
a vector.
This reverts r207746 which reverted the revert of the revert of r205018 or so.
Fixes the test case in PR19621.
Added:
llvm/trunk/test/Transforms/SLPVectorizer/X86/value-bug.ll
Modified:
llvm/trunk/lib/Transforms/Vectorize/SLPVectorizer.cpp
llvm/trunk/test/Transforms/SLPVectorizer/X86/insert-element-build-vector.ll
Modified: llvm/trunk/lib/Transforms/Vectorize/SLPVectorizer.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/Vectorize/SLPVectorizer.cpp?rev=207939&r1=207938&r2=207939&view=diff
==============================================================================
--- llvm/trunk/lib/Transforms/Vectorize/SLPVectorizer.cpp (original)
+++ llvm/trunk/lib/Transforms/Vectorize/SLPVectorizer.cpp Sun May 4 12:10:15 2014
@@ -31,6 +31,7 @@
#include "llvm/IR/Instructions.h"
#include "llvm/IR/IntrinsicInst.h"
#include "llvm/IR/Module.h"
+#include "llvm/IR/NoFolder.h"
#include "llvm/IR/Type.h"
#include "llvm/IR/Value.h"
#include "llvm/IR/Verifier.h"
@@ -357,13 +358,13 @@ public:
/// A negative number means that this is profitable.
int getTreeCost();
- /// Construct a vectorizable tree that starts at \p Roots and is possibly
- /// used by a reduction of \p RdxOps.
- void buildTree(ArrayRef<Value *> Roots, ValueSet *RdxOps = 0);
+ /// Construct a vectorizable tree that starts at \p Roots, ignoring users for
+ /// the purpose of scheduling and extraction in the \p UserIgnoreLst.
+ void buildTree(ArrayRef<Value *> Roots,
+ ArrayRef<Value *> UserIgnoreLst = None);
/// Clear the internal data structures that are created by 'buildTree'.
void deleteTree() {
- RdxOps = 0;
VectorizableTree.clear();
ScalarToTreeEntry.clear();
MustGather.clear();
@@ -526,8 +527,8 @@ private:
return I.first->second;
}
- /// Reduction operators.
- ValueSet *RdxOps;
+ /// List of users to ignore during scheduling and that don't need extracting.
+ ArrayRef<Value *> UserIgnoreList;
// Analysis and block reference.
Function *F;
@@ -542,9 +543,10 @@ private:
IRBuilder<> Builder;
};
-void BoUpSLP::buildTree(ArrayRef<Value *> Roots, ValueSet *Rdx) {
+void BoUpSLP::buildTree(ArrayRef<Value *> Roots,
+ ArrayRef<Value *> UserIgnoreLst) {
deleteTree();
- RdxOps = Rdx;
+ UserIgnoreList = UserIgnoreLst;
if (!getSameType(Roots))
return;
buildTree_rec(Roots, 0);
@@ -576,8 +578,9 @@ void BoUpSLP::buildTree(ArrayRef<Value *
if (!UserInst)
continue;
- // Ignore uses that are part of the reduction.
- if (Rdx && std::find(Rdx->begin(), Rdx->end(), UserInst) != Rdx->end())
+ // Ignore users in the user ignore list.
+ if (std::find(UserIgnoreList.begin(), UserIgnoreList.end(), UserInst) !=
+ UserIgnoreList.end())
continue;
DEBUG(dbgs() << "SLP: Need to extract:" << *U << " from lane " <<
@@ -708,8 +711,9 @@ void BoUpSLP::buildTree_rec(ArrayRef<Val
continue;
}
- // This user is part of the reduction.
- if (RdxOps && RdxOps->count(UI))
+ // Ignore users in the user ignore list.
+ if (std::find(UserIgnoreList.begin(), UserIgnoreList.end(), UI) !=
+ UserIgnoreList.end())
continue;
// Make sure that we can schedule this unknown user.
@@ -1747,8 +1751,9 @@ Value *BoUpSLP::vectorizeTree() {
DEBUG(dbgs() << "SLP: \tvalidating user:" << *U << ".\n");
assert((ScalarToTreeEntry.count(U) ||
- // It is legal to replace the reduction users by undef.
- (RdxOps && RdxOps->count(U))) &&
+ // It is legal to replace users in the ignorelist by undef.
+ (std::find(UserIgnoreList.begin(), UserIgnoreList.end(), U) !=
+ UserIgnoreList.end())) &&
"Replacing out-of-tree value with undef");
}
#endif
@@ -1954,8 +1959,11 @@ private:
bool tryToVectorizePair(Value *A, Value *B, BoUpSLP &R);
/// \brief Try to vectorize a list of operands.
+ /// \@param BuildVector A list of users to ignore for the purpose of
+ /// scheduling and that don't need extracting.
/// \returns true if a value was vectorized.
- bool tryToVectorizeList(ArrayRef<Value *> VL, BoUpSLP &R);
+ bool tryToVectorizeList(ArrayRef<Value *> VL, BoUpSLP &R,
+ ArrayRef<Value *> BuildVector = None);
/// \brief Try to vectorize a chain that may start at the operands of \V;
bool tryToVectorize(BinaryOperator *V, BoUpSLP &R);
@@ -2128,7 +2136,8 @@ bool SLPVectorizer::tryToVectorizePair(V
return tryToVectorizeList(VL, R);
}
-bool SLPVectorizer::tryToVectorizeList(ArrayRef<Value *> VL, BoUpSLP &R) {
+bool SLPVectorizer::tryToVectorizeList(ArrayRef<Value *> VL, BoUpSLP &R,
+ ArrayRef<Value *> BuildVector) {
if (VL.size() < 2)
return false;
@@ -2178,13 +2187,38 @@ bool SLPVectorizer::tryToVectorizeList(A
<< "\n");
ArrayRef<Value *> Ops = VL.slice(i, OpsWidth);
- R.buildTree(Ops);
+ ArrayRef<Value *> BuildVectorSlice;
+ if (!BuildVector.empty())
+ BuildVectorSlice = BuildVector.slice(i, OpsWidth);
+
+ R.buildTree(Ops, BuildVectorSlice);
int Cost = R.getTreeCost();
if (Cost < -SLPCostThreshold) {
DEBUG(dbgs() << "SLP: Vectorizing list at cost:" << Cost << ".\n");
- R.vectorizeTree();
+ Value *VectorizedRoot = R.vectorizeTree();
+ // Reconstruct the build vector by extracting the vectorized root. This
+ // way we handle the case where some elements of the vector are undefined.
+ // (return (inserelt <4 xi32> (insertelt undef (opd0) 0) (opd1) 2))
+ if (!BuildVectorSlice.empty()) {
+ // The insert point is the last build vector instruction. The vectorized
+ // root will precede it. This guarantees that we get an instruction. The
+ // vectorized tree could have been constant folded.
+ Instruction *InsertAfter = cast<Instruction>(BuildVectorSlice.back());
+ unsigned VecIdx = 0;
+ for (auto &V : BuildVectorSlice) {
+ IRBuilder<true, NoFolder> Builder(
+ ++BasicBlock::iterator(InsertAfter));
+ InsertElementInst *IE = cast<InsertElementInst>(V);
+ Instruction *Extract = cast<Instruction>(Builder.CreateExtractElement(
+ VectorizedRoot, Builder.getInt32(VecIdx++)));
+ IE->setOperand(1, Extract);
+ IE->removeFromParent();
+ IE->insertAfter(Extract);
+ InsertAfter = IE;
+ }
+ }
// Move to the next bundle.
i += VF - 1;
Changed = true;
@@ -2293,7 +2327,7 @@ static Value *createRdxShuffleMask(unsig
/// *p =
///
class HorizontalReduction {
- SmallPtrSet<Value *, 16> ReductionOps;
+ SmallVector<Value *, 16> ReductionOps;
SmallVector<Value *, 32> ReducedVals;
BinaryOperator *ReductionRoot;
@@ -2387,7 +2421,7 @@ public:
// We need to be able to reassociate the adds.
if (!TreeN->isAssociative())
return false;
- ReductionOps.insert(TreeN);
+ ReductionOps.push_back(TreeN);
}
// Retract.
Stack.pop_back();
@@ -2424,7 +2458,7 @@ public:
for (; i < NumReducedVals - ReduxWidth + 1; i += ReduxWidth) {
ArrayRef<Value *> ValsToReduce(&ReducedVals[i], ReduxWidth);
- V.buildTree(ValsToReduce, &ReductionOps);
+ V.buildTree(ValsToReduce, ReductionOps);
// Estimate cost.
int Cost = V.getTreeCost() + getReductionCost(TTI, ReducedVals[i]);
@@ -2543,13 +2577,16 @@ private:
///
/// Returns true if it matches
///
-static bool findBuildVector(InsertElementInst *IE,
- SmallVectorImpl<Value *> &Ops) {
- if (!isa<UndefValue>(IE->getOperand(0)))
+static bool findBuildVector(InsertElementInst *FirstInsertElem,
+ SmallVectorImpl<Value *> &BuildVector,
+ SmallVectorImpl<Value *> &BuildVectorOpds) {
+ if (!isa<UndefValue>(FirstInsertElem->getOperand(0)))
return false;
+ InsertElementInst *IE = FirstInsertElem;
while (true) {
- Ops.push_back(IE->getOperand(1));
+ BuildVector.push_back(IE);
+ BuildVectorOpds.push_back(IE->getOperand(1));
if (IE->use_empty())
return false;
@@ -2720,12 +2757,16 @@ bool SLPVectorizer::vectorizeChainsInBlo
}
// Try to vectorize trees that start at insertelement instructions.
- if (InsertElementInst *IE = dyn_cast<InsertElementInst>(it)) {
- SmallVector<Value *, 8> Ops;
- if (!findBuildVector(IE, Ops))
+ if (InsertElementInst *FirstInsertElem = dyn_cast<InsertElementInst>(it)) {
+ SmallVector<Value *, 16> BuildVector;
+ SmallVector<Value *, 16> BuildVectorOpds;
+ if (!findBuildVector(FirstInsertElem, BuildVector, BuildVectorOpds))
continue;
- if (tryToVectorizeList(Ops, R)) {
+ // Vectorize starting with the build vector operands ignoring the
+ // BuildVector instructions for the purpose of scheduling and user
+ // extraction.
+ if (tryToVectorizeList(BuildVectorOpds, R, BuildVector)) {
Changed = true;
it = BB->begin();
e = BB->end();
Modified: llvm/trunk/test/Transforms/SLPVectorizer/X86/insert-element-build-vector.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Transforms/SLPVectorizer/X86/insert-element-build-vector.ll?rev=207939&r1=207938&r2=207939&view=diff
==============================================================================
--- llvm/trunk/test/Transforms/SLPVectorizer/X86/insert-element-build-vector.ll (original)
+++ llvm/trunk/test/Transforms/SLPVectorizer/X86/insert-element-build-vector.ll Sun May 4 12:10:15 2014
@@ -195,6 +195,30 @@ define <4 x float> @simple_select_partia
ret <4 x float> %rb
}
+; Make sure that vectorization happens even if insertelements operations
+; must be rescheduled. The case here is from compiling Julia.
+define <4 x float> @reschedule_extract(<4 x float> %a, <4 x float> %b) {
+; CHECK-LABEL: @reschedule_extract(
+; CHECK: %1 = fadd <4 x float> %a, %b
+ %a0 = extractelement <4 x float> %a, i32 0
+ %b0 = extractelement <4 x float> %b, i32 0
+ %c0 = fadd float %a0, %b0
+ %v0 = insertelement <4 x float> undef, float %c0, i32 0
+ %a1 = extractelement <4 x float> %a, i32 1
+ %b1 = extractelement <4 x float> %b, i32 1
+ %c1 = fadd float %a1, %b1
+ %v1 = insertelement <4 x float> %v0, float %c1, i32 1
+ %a2 = extractelement <4 x float> %a, i32 2
+ %b2 = extractelement <4 x float> %b, i32 2
+ %c2 = fadd float %a2, %b2
+ %v2 = insertelement <4 x float> %v1, float %c2, i32 2
+ %a3 = extractelement <4 x float> %a, i32 3
+ %b3 = extractelement <4 x float> %b, i32 3
+ %c3 = fadd float %a3, %b3
+ %v3 = insertelement <4 x float> %v2, float %c3, i32 3
+ ret <4 x float> %v3
+}
+
; Check that cost model for vectorization takes credit for
; instructions that are erased.
define <4 x float> @take_credit(<4 x float> %a, <4 x float> %b) {
@@ -219,4 +243,40 @@ define <4 x float> @take_credit(<4 x flo
ret <4 x float> %v3
}
+; Make sure we handle multiple trees that feed one build vector correctly.
+define <4 x double> @multi_tree(double %w, double %x, double %y, double %z) {
+entry:
+ %t0 = fadd double %w , 0.000000e+00
+ %t1 = fadd double %x , 1.000000e+00
+ %t2 = fadd double %y , 2.000000e+00
+ %t3 = fadd double %z , 3.000000e+00
+ %t4 = fmul double %t0, 1.000000e+00
+ %i1 = insertelement <4 x double> undef, double %t4, i32 3
+ %t5 = fmul double %t1, 1.000000e+00
+ %i2 = insertelement <4 x double> %i1, double %t5, i32 2
+ %t6 = fmul double %t2, 1.000000e+00
+ %i3 = insertelement <4 x double> %i2, double %t6, i32 1
+ %t7 = fmul double %t3, 1.000000e+00
+ %i4 = insertelement <4 x double> %i3, double %t7, i32 0
+ ret <4 x double> %i4
+}
+; CHECK-LABEL: @multi_tree
+; CHECK-DAG: %[[V0:.+]] = insertelement <2 x double> undef, double %w, i32 0
+; CHECK-DAG: %[[V1:.+]] = insertelement <2 x double> %[[V0]], double %x, i32 1
+; CHECK-DAG: %[[V2:.+]] = fadd <2 x double> %[[V1]], <double 0.000000e+00, double 1.000000e+00>
+; CHECK-DAG: %[[V3:.+]] = insertelement <2 x double> undef, double %y, i32 0
+; CHECK-DAG: %[[V4:.+]] = insertelement <2 x double> %[[V3]], double %z, i32 1
+; CHECK-DAG: %[[V5:.+]] = fadd <2 x double> %[[V4]], <double 2.000000e+00, double 3.000000e+00>
+; CHECK-DAG: %[[V6:.+]] = fmul <2 x double> <double 1.000000e+00, double 1.000000e+00>, %[[V2]]
+; CHECK-DAG: %[[V7:.+]] = extractelement <2 x double> %[[V6]], i32 0
+; CHECK-DAG: %[[I1:.+]] = insertelement <4 x double> undef, double %[[V7]], i32 3
+; CHECK-DAG: %[[V8:.+]] = extractelement <2 x double> %[[V6]], i32 1
+; CHECK-DAG: %[[I2:.+]] = insertelement <4 x double> %[[I1]], double %[[V8]], i32 2
+; CHECK-DAG: %[[V9:.+]] = fmul <2 x double> <double 1.000000e+00, double 1.000000e+00>, %[[V5]]
+; CHECK-DAG: %[[V10:.+]] = extractelement <2 x double> %[[V9]], i32 0
+; CHECK-DAG: %[[I3:.+]] = insertelement <4 x double> %i2, double %[[V10]], i32 1
+; CHECK-DAG: %[[V11:.+]] = extractelement <2 x double> %[[V9]], i32 1
+; CHECK-DAG: %[[I4:.+]] = insertelement <4 x double> %i3, double %[[V11]], i32 0
+; CHECK: ret <4 x double> %[[I4]]
+
attributes #0 = { nounwind ssp uwtable "less-precise-fpmad"="false" "no-frame-pointer-elim"="true" "no-frame-pointer-elim-non-leaf"="true" "no-infs-fp-math"="false" "no-nans-fp-math"="false" "stack-protector-buffer-size"="8" "unsafe-fp-math"="false" "use-soft-float"="false" }
Added: llvm/trunk/test/Transforms/SLPVectorizer/X86/value-bug.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Transforms/SLPVectorizer/X86/value-bug.ll?rev=207939&view=auto
==============================================================================
--- llvm/trunk/test/Transforms/SLPVectorizer/X86/value-bug.ll (added)
+++ llvm/trunk/test/Transforms/SLPVectorizer/X86/value-bug.ll Sun May 4 12:10:15 2014
@@ -0,0 +1,80 @@
+; RUN: opt -slp-vectorizer < %s -S -mtriple="x86_64-grtev3-linux-gnu" -mcpu=corei7-avx | FileCheck %s
+
+target datalayout = "e-m:e-i64:64-f80:128-n8:16:32:64-S128"
+target triple = "x86_64-grtev3-linux-gnu"
+
+; We used to crash on this example because we were building a constant
+; expression during vectorization and the vectorizer expects instructions
+; as elements of the vectorized tree.
+; CHECK-LABEL: @test
+; PR19621
+
+define void @test() {
+bb279:
+ br label %bb283
+
+bb283:
+ %Av.sroa.8.0 = phi float [ undef, %bb279 ], [ %tmp315, %exit ]
+ %Av.sroa.5.0 = phi float [ undef, %bb279 ], [ %tmp319, %exit ]
+ %Av.sroa.3.0 = phi float [ undef, %bb279 ], [ %tmp307, %exit ]
+ %Av.sroa.0.0 = phi float [ undef, %bb279 ], [ %tmp317, %exit ]
+ br label %bb284
+
+bb284:
+ %tmp7.i = fpext float %Av.sroa.3.0 to double
+ %tmp8.i = fsub double %tmp7.i, undef
+ %tmp9.i = fsub double %tmp8.i, undef
+ %tmp17.i = fpext float %Av.sroa.8.0 to double
+ %tmp19.i = fsub double %tmp17.i, undef
+ %tmp20.i = fsub double %tmp19.i, undef
+ br label %bb21.i
+
+bb21.i:
+ br i1 undef, label %bb22.i, label %exit
+
+bb22.i:
+ %tmp24.i = fadd double undef, %tmp9.i
+ %tmp26.i = fadd double undef, %tmp20.i
+ br label %bb32.i
+
+bb32.i:
+ %xs.0.i = phi double [ %tmp24.i, %bb22.i ], [ 0.000000e+00, %bb32.i ]
+ %ys.0.i = phi double [ %tmp26.i, %bb22.i ], [ 0.000000e+00, %bb32.i ]
+ br i1 undef, label %bb32.i, label %bb21.i
+
+exit:
+ %tmp303 = fpext float %Av.sroa.0.0 to double
+ %tmp304 = fmul double %tmp303, undef
+ %tmp305 = fadd double undef, %tmp304
+ %tmp306 = fadd double %tmp305, undef
+ %tmp307 = fptrunc double %tmp306 to float
+ %tmp311 = fpext float %Av.sroa.5.0 to double
+ %tmp312 = fmul double %tmp311, 0.000000e+00
+ %tmp313 = fadd double undef, %tmp312
+ %tmp314 = fadd double %tmp313, undef
+ %tmp315 = fptrunc double %tmp314 to float
+ %tmp317 = fptrunc double undef to float
+ %tmp319 = fptrunc double undef to float
+ br label %bb283
+}
+
+; Make sure that we probably handle constant folded vectorized trees. The
+; vectorizer starts at the type (%t2, %t3) and wil constant fold the tree.
+; The code that handles insertelement instructions must handle this.
+define <4 x double> @constant_folding() {
+entry:
+ %t0 = fadd double 1.000000e+00 , 0.000000e+00
+ %t1 = fadd double 1.000000e+00 , 1.000000e+00
+ %t2 = fmul double %t0, 1.000000e+00
+ %i1 = insertelement <4 x double> undef, double %t2, i32 1
+ %t3 = fmul double %t1, 1.000000e+00
+ %i2 = insertelement <4 x double> %i1, double %t3, i32 0
+ ret <4 x double> %i2
+}
+
+; CHECK-LABEL: @constant_folding
+; CHECK: %[[V0:.+]] = extractelement <2 x double> <double 1.000000e+00, double 2.000000e+00>, i32 0
+; CHECK: %[[V1:.+]] = insertelement <4 x double> undef, double %[[V0]], i32 1
+; CHECK: %[[V2:.+]] = extractelement <2 x double> <double 1.000000e+00, double 2.000000e+00>, i32 1
+; CHECK: %[[V3:.+]] = insertelement <4 x double> %[[V1]], double %[[V2]], i32 0
+; CHECK: ret <4 x double> %[[V3]]
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