Move an instance variable to a local variable based on review by Duncan.
Originally I had anticipated needing to thread this through more bits of
the SROA pass itself, but that ended up not happening. In the end, this
is a much simpler way to manange the variable.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@163893 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Transforms/Scalar/SROA.cpp b/lib/Transforms/Scalar/SROA.cpp
index 3d97527..acfa87a 100644
--- a/lib/Transforms/Scalar/SROA.cpp
+++ b/lib/Transforms/Scalar/SROA.cpp
@@ -1150,12 +1150,6 @@
/// uses as dead. Only used to guard insertion into DeadInsts.
SmallPtrSet<Instruction *, 4> DeadSplitInsts;
- /// \brief A set of deleted alloca instructions.
- ///
- /// These pointers are *no longer valid* as they have been deleted. They are
- /// used to remove deleted allocas from the list of promotable allocas.
- SmallPtrSet<AllocaInst *, 4> DeletedAllocas;
-
/// \brief A collection of alloca instructions we can directly promote.
std::vector<AllocaInst *> PromotableAllocas;
@@ -1178,7 +1172,7 @@
AllocaPartitioning::iterator PI);
bool splitAlloca(AllocaInst &AI, AllocaPartitioning &P);
bool runOnAlloca(AllocaInst &AI);
- void deleteDeadInstructions();
+ void deleteDeadInstructions(SmallPtrSet<AllocaInst *, 4> &DeletedAllocas);
};
}
@@ -2556,7 +2550,16 @@
return splitAlloca(AI, P) || Changed;
}
-void SROA::deleteDeadInstructions() {
+/// \brief Delete the dead instructions accumulated in this run.
+///
+/// Recursively deletes the dead instructions we've accumulated. This is done
+/// at the very end to maximize locality of the recursive delete and to
+/// minimize the problems of invalidated instruction pointers as such pointers
+/// are used heavily in the intermediate stages of the algorithm.
+///
+/// We also record the alloca instructions deleted here so that they aren't
+/// subsequently handed to mem2reg to promote.
+void SROA::deleteDeadInstructions(SmallPtrSet<AllocaInst*, 4> &DeletedAllocas) {
DeadSplitInsts.clear();
while (!DeadInsts.empty()) {
Instruction *I = DeadInsts.pop_back_val();
@@ -2607,9 +2610,13 @@
Worklist.insert(AI);
bool Changed = false;
+ // A set of deleted alloca instruction pointers which should be removed from
+ // the list of promotable allocas.
+ SmallPtrSet<AllocaInst *, 4> DeletedAllocas;
+
while (!Worklist.empty()) {
Changed |= runOnAlloca(*Worklist.pop_back_val());
- deleteDeadInstructions();
+ deleteDeadInstructions(DeletedAllocas);
if (!DeletedAllocas.empty()) {
PromotableAllocas.erase(std::remove_if(PromotableAllocas.begin(),
PromotableAllocas.end(),