[SLP] Fixed non-deterministic behavior in Loop Vectorizer.
Differential Revision: https://reviews.llvm.org/D30638
llvm-svn: 297257
diff --git a/llvm/lib/Analysis/LoopAccessAnalysis.cpp b/llvm/lib/Analysis/LoopAccessAnalysis.cpp
index a3ed412..c294527 100644
--- a/llvm/lib/Analysis/LoopAccessAnalysis.cpp
+++ b/llvm/lib/Analysis/LoopAccessAnalysis.cpp
@@ -498,7 +498,7 @@
public:
/// \brief Read or write access location.
typedef PointerIntPair<Value *, 1, bool> MemAccessInfo;
- typedef SmallPtrSet<MemAccessInfo, 8> MemAccessInfoSet;
+ typedef SmallVector<MemAccessInfo, 8> MemAccessInfoList;
AccessAnalysis(const DataLayout &Dl, AliasAnalysis *AA, LoopInfo *LI,
MemoryDepChecker::DepCandidates &DA,
@@ -550,7 +550,7 @@
DepChecker.clearDependences();
}
- MemAccessInfoSet &getDependenciesToCheck() { return CheckDeps; }
+ MemAccessInfoList &getDependenciesToCheck() { return CheckDeps; }
private:
typedef SetVector<MemAccessInfo> PtrAccessSet;
@@ -564,8 +564,8 @@
const DataLayout &DL;
- /// Set of accesses that need a further dependence check.
- MemAccessInfoSet CheckDeps;
+ /// List of accesses that need a further dependence check.
+ MemAccessInfoList CheckDeps;
/// Set of pointers that are read only.
SmallPtrSet<Value*, 16> ReadOnlyPtr;
@@ -822,7 +822,7 @@
// there is no other write to the ptr - this is an optimization to
// catch "a[i] = a[i] + " without having to do a dependence check).
if ((IsWrite || IsReadOnlyPtr) && SetHasWrite) {
- CheckDeps.insert(Access);
+ CheckDeps.push_back(Access);
IsRTCheckAnalysisNeeded = true;
}
@@ -1530,12 +1530,14 @@
}
bool MemoryDepChecker::areDepsSafe(DepCandidates &AccessSets,
- MemAccessInfoSet &CheckDeps,
+ MemAccessInfoList &CheckDeps,
const ValueToValueMap &Strides) {
MaxSafeDepDistBytes = -1;
- while (!CheckDeps.empty()) {
- MemAccessInfo CurAccess = *CheckDeps.begin();
+ SmallPtrSet<MemAccessInfo, 8> Visited;
+ for (MemAccessInfo CurAccess : CheckDeps) {
+ if (Visited.count(CurAccess))
+ continue;
// Get the relevant memory access set.
EquivalenceClasses<MemAccessInfo>::iterator I =
@@ -1549,7 +1551,7 @@
// Check every access pair.
while (AI != AE) {
- CheckDeps.erase(*AI);
+ Visited.insert(*AI);
EquivalenceClasses<MemAccessInfo>::member_iterator OI = std::next(AI);
while (OI != AE) {
// Check every accessing instruction pair in program order.