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NewGVN: Clean up after removing possibility of null expressions.

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llvm-svn: 290828
This commit is contained in:
Daniel Berlin 2017-01-02 19:49:17 +00:00
parent 350bde6601
commit a22cbcda66
1 changed files with 14 additions and 17 deletions
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31
lib/Transforms/Scalar/NewGVN.cpp
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@ -714,16 +714,15 @@ const Expression *NewGVN::performSymbolicStoreEvaluation(Instruction *I,
// Unlike loads, we never try to eliminate stores, so we do not check if they
// are simple and avoid value numbering them.
auto *SI = cast<StoreInst>(I);
// If this store's memorydef stores the same value as the last store, the
// memory accesses are equivalent.
// Get the expression, if any, for the RHS of the MemoryDef.
MemoryAccess *StoreAccess = MSSA->getMemoryAccess(SI);
MemoryAccess *StoreRHS = lookupMemoryAccessEquiv(
cast<MemoryDef>(StoreAccess)->getDefiningAccess());
const Expression *OldStore = createStoreExpression(SI, StoreRHS, B);
// See if this store expression already has a value, and it's the same as our
// current store. FIXME: Right now, we only do this for simple stores.
// See if we are defined by a previous store expression, it already has a
// value, and it's the same value as our current store. FIXME: Right now, we
// only do this for simple stores, we should expand to cover memcpys, etc.
if (SI->isSimple()) {
// Get the expression, if any, for the RHS of the MemoryDef.
MemoryAccess *StoreRHS = lookupMemoryAccessEquiv(
cast<MemoryDef>(StoreAccess)->getDefiningAccess());
const Expression *OldStore = createStoreExpression(SI, StoreRHS, B);
CongruenceClass *CC = ExpressionToClass.lookup(OldStore);
if (CC && CC->DefiningExpr && isa<StoreExpression>(CC->DefiningExpr) &&
CC->RepLeader == lookupOperandLeader(SI->getValueOperand(), SI, B))
@ -1094,16 +1093,14 @@ void NewGVN::performCongruenceFinding(Value *V, const Expression *E) {
// If this is a MemoryDef, we need to update the equivalence table. If
// we determined the expression is congruent to a different memory
// state, use that different memory state. If we determined it didn't,
// we update that as well.
// Right now, the only way they can be equivalent is for store
// we update that as well. Right now, we only support store
// expressions.
if (!isa<MemoryUse>(MA)) {
if (E && isa<StoreExpression>(E) && EClass->Members.size() != 1) {
auto *DefAccess = cast<StoreExpression>(E)->getDefiningAccess();
setMemoryAccessEquivTo(MA, DefAccess != MA ? DefAccess : nullptr);
} else {
setMemoryAccessEquivTo(MA, nullptr);
}
if (!isa<MemoryUse>(MA) && isa<StoreExpression>(E) &&
EClass->Members.size() != 1) {
auto *DefAccess = cast<StoreExpression>(E)->getDefiningAccess();
setMemoryAccessEquivTo(MA, DefAccess != MA ? DefAccess : nullptr);
} else {
setMemoryAccessEquivTo(MA, nullptr);
}
markMemoryUsersTouched(MA);
}