SLP Vectorizer: Fix a bug in the code that does CSE on the generated gather sequences.

Make sure that we don't replace and RAUW two sequences if one does not dominate the other.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@184674 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Nadav Rotem 2013-06-23 21:57:27 +00:00
parent 787ad64b98
commit 722b0a4d29
2 changed files with 61 additions and 4 deletions

View File

@ -127,8 +127,9 @@ public:
static const int MAX_COST = INT_MIN;
FuncSLP(Function *Func, ScalarEvolution *Se, DataLayout *Dl,
TargetTransformInfo *Tti, AliasAnalysis *Aa, LoopInfo *Li) :
F(Func), SE(Se), DL(Dl), TTI(Tti), AA(Aa), LI(Li),
TargetTransformInfo *Tti, AliasAnalysis *Aa, LoopInfo *Li,
DominatorTree *Dt) :
F(Func), SE(Se), DL(Dl), TTI(Tti), AA(Aa), LI(Li), DT(Dt),
Builder(Se->getContext()) {
for (Function::iterator it = F->begin(), e = F->end(); it != e; ++it) {
BasicBlock *BB = it;
@ -255,6 +256,7 @@ public:
TargetTransformInfo *TTI;
AliasAnalysis *AA;
LoopInfo *LI;
DominatorTree *DT;
/// Instruction builder to construct the vectorized tree.
IRBuilder<> Builder;
};
@ -1197,7 +1199,8 @@ void FuncSLP::optimizeGatherSequence() {
// visited instructions.
for (SmallPtrSet<Instruction*, 16>::iterator v = Visited.begin(),
ve = Visited.end(); v != ve; ++v) {
if (Insert->isIdenticalTo(*v)) {
if (Insert->isIdenticalTo(*v) &&
DT->dominates((*v)->getParent(), Insert->getParent())) {
Insert->replaceAllUsesWith(*v);
break;
}
@ -1224,6 +1227,7 @@ struct SLPVectorizer : public FunctionPass {
TargetTransformInfo *TTI;
AliasAnalysis *AA;
LoopInfo *LI;
DominatorTree *DT;
virtual bool runOnFunction(Function &F) {
SE = &getAnalysis<ScalarEvolution>();
@ -1231,6 +1235,7 @@ struct SLPVectorizer : public FunctionPass {
TTI = &getAnalysis<TargetTransformInfo>();
AA = &getAnalysis<AliasAnalysis>();
LI = &getAnalysis<LoopInfo>();
DT = &getAnalysis<DominatorTree>();
StoreRefs.clear();
bool Changed = false;
@ -1244,7 +1249,7 @@ struct SLPVectorizer : public FunctionPass {
// Use the bollom up slp vectorizer to construct chains that start with
// he store instructions.
FuncSLP R(&F, SE, DL, TTI, AA, LI);
FuncSLP R(&F, SE, DL, TTI, AA, LI, DT);
for (Function::iterator it = F.begin(), e = F.end(); it != e; ++it) {
BasicBlock *BB = it;
@ -1274,6 +1279,7 @@ struct SLPVectorizer : public FunctionPass {
AU.addRequired<AliasAnalysis>();
AU.addRequired<TargetTransformInfo>();
AU.addRequired<LoopInfo>();
AU.addRequired<DominatorTree>();
}
private:

View File

@ -83,3 +83,54 @@ entry:
ret i32 undef
}
; int test2(double *G, int k) {
; if (k) {
; G[0] = 1+G[5]*4;
; G[1] = 6+G[6]*3;
; } else {
; G[2] = 7+G[5]*4;
; G[3] = 8+G[6]*3;
; }
; }
; We can't merge the gather sequences because one does not dominate the other.
; CHECK: test2
; CHECK: insertelement
; CHECK: insertelement
; CHECK: insertelement
; CHECK: insertelement
; CHECK: ret
define i32 @test2(double* nocapture %G, i32 %k) {
%1 = icmp eq i32 %k, 0
%2 = getelementptr inbounds double* %G, i64 5
%3 = load double* %2, align 8
%4 = fmul double %3, 4.000000e+00
br i1 %1, label %12, label %5
; <label>:5 ; preds = %0
%6 = fadd double %4, 1.000000e+00
store double %6, double* %G, align 8
%7 = getelementptr inbounds double* %G, i64 6
%8 = load double* %7, align 8
%9 = fmul double %8, 3.000000e+00
%10 = fadd double %9, 6.000000e+00
%11 = getelementptr inbounds double* %G, i64 1
store double %10, double* %11, align 8
br label %20
; <label>:12 ; preds = %0
%13 = fadd double %4, 7.000000e+00
%14 = getelementptr inbounds double* %G, i64 2
store double %13, double* %14, align 8
%15 = getelementptr inbounds double* %G, i64 6
%16 = load double* %15, align 8
%17 = fmul double %16, 3.000000e+00
%18 = fadd double %17, 8.000000e+00
%19 = getelementptr inbounds double* %G, i64 3
store double %18, double* %19, align 8
br label %20
; <label>:20 ; preds = %12, %5
ret i32 undef
}