Convert ScalarEvolution to use CallbackVH for its internal map. This
makes ScalarEvolution::deleteValueFromRecords, and it's code that
subtly needed to be called before ReplaceAllUsesWith, unnecessary.
It also makes ValueDeletionListener unnecessary.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@70645 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Analysis/ScalarEvolution.cpp b/lib/Analysis/ScalarEvolution.cpp
index a6d3954..48a2f52 100644
--- a/lib/Analysis/ScalarEvolution.cpp
+++ b/lib/Analysis/ScalarEvolution.cpp
@@ -1466,34 +1466,6 @@
// Basic SCEV Analysis and PHI Idiom Recognition Code
//
-/// deleteValueFromRecords - This method should be called by the
-/// client before it removes an instruction from the program, to make sure
-/// that no dangling references are left around.
-void ScalarEvolution::deleteValueFromRecords(Value *V) {
- SmallVector<Value *, 16> Worklist;
-
- if (Scalars.erase(V)) {
- if (PHINode *PN = dyn_cast<PHINode>(V))
- ConstantEvolutionLoopExitValue.erase(PN);
- Worklist.push_back(V);
- }
-
- while (!Worklist.empty()) {
- Value *VV = Worklist.back();
- Worklist.pop_back();
-
- for (Instruction::use_iterator UI = VV->use_begin(), UE = VV->use_end();
- UI != UE; ++UI) {
- Instruction *Inst = cast<Instruction>(*UI);
- if (Scalars.erase(Inst)) {
- if (PHINode *PN = dyn_cast<PHINode>(VV))
- ConstantEvolutionLoopExitValue.erase(PN);
- Worklist.push_back(Inst);
- }
- }
- }
-}
-
/// isSCEVable - Test if values of the given type are analyzable within
/// the SCEV framework. This primarily includes integer types, and it
/// can optionally include pointer types if the ScalarEvolution class
@@ -1555,10 +1527,10 @@
SCEVHandle ScalarEvolution::getSCEV(Value *V) {
assert(isSCEVable(V->getType()) && "Value is not SCEVable!");
- std::map<Value*, SCEVHandle>::iterator I = Scalars.find(V);
+ std::map<SCEVCallbackVH, SCEVHandle>::iterator I = Scalars.find(V);
if (I != Scalars.end()) return I->second;
SCEVHandle S = createSCEV(V);
- Scalars.insert(std::make_pair(V, S));
+ Scalars.insert(std::make_pair(SCEVCallbackVH(V, this), S));
return S;
}
@@ -1647,7 +1619,8 @@
void ScalarEvolution::
ReplaceSymbolicValueWithConcrete(Instruction *I, const SCEVHandle &SymName,
const SCEVHandle &NewVal) {
- std::map<Value*, SCEVHandle>::iterator SI = Scalars.find(I);
+ std::map<SCEVCallbackVH, SCEVHandle>::iterator SI =
+ Scalars.find(SCEVCallbackVH(I, this));
if (SI == Scalars.end()) return;
SCEVHandle NV =
@@ -1679,7 +1652,7 @@
SCEVHandle SymbolicName = getUnknown(PN);
assert(Scalars.find(PN) == Scalars.end() &&
"PHI node already processed?");
- Scalars.insert(std::make_pair(PN, SymbolicName));
+ Scalars.insert(std::make_pair(SCEVCallbackVH(PN, this), SymbolicName));
// Using this symbolic name for the PHI, analyze the value coming around
// the back-edge.
@@ -2131,7 +2104,7 @@
void ScalarEvolution::forgetLoopPHIs(const Loop *L) {
for (BasicBlock::iterator I = L->getHeader()->begin();
PHINode *PN = dyn_cast<PHINode>(I); ++I)
- deleteValueFromRecords(PN);
+ Scalars.erase(PN);
}
/// ComputeBackedgeTakenCount - Compute the number of times the backedge
@@ -3344,6 +3317,25 @@
//===----------------------------------------------------------------------===//
+// SCEVCallbackVH Class Implementation
+//===----------------------------------------------------------------------===//
+
+void SCEVCallbackVH::deleted() {
+ assert(SE && "SCEVCallbackVH called with a non-null ScalarEvolution!");
+ SE->Scalars.erase(getValPtr());
+ // this now dangles!
+}
+
+void SCEVCallbackVH::allUsesReplacedWith(Value *V) {
+ assert(SE && "SCEVCallbackVH called with a non-null ScalarEvolution!");
+ SE->Scalars.erase(getValPtr());
+ // this now dangles!
+}
+
+SCEVCallbackVH::SCEVCallbackVH(Value *V, ScalarEvolution *se)
+ : CallbackVH(V), SE(se) {}
+
+//===----------------------------------------------------------------------===//
// ScalarEvolution Class Implementation
//===----------------------------------------------------------------------===//