Use the target-aware constant folder on expressions to improve the chance
they'll be simple enough to simulate, and to reduce the chance we'll encounter
equal but different simple pointer constants.
This removes the symptoms from PR11352 but is not a full fix. A proper fix would
either require a guarantee that two constant objects we simulate are folded
when equal, or a different way of handling equal pointers (ie., trying a
constantexpr icmp on them to see whether we know they're equal or non-equal or
unsure).
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@151093 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Transforms/IPO/GlobalOpt.cpp b/lib/Transforms/IPO/GlobalOpt.cpp
index bb37bf4..7c78a20 100644
--- a/lib/Transforms/IPO/GlobalOpt.cpp
+++ b/lib/Transforms/IPO/GlobalOpt.cpp
@@ -2388,6 +2388,8 @@
if (StoreInst *SI = dyn_cast<StoreInst>(CurInst)) {
if (!SI->isSimple()) return false; // no volatile/atomic accesses.
Constant *Ptr = getVal(SI->getOperand(1));
+ if (ConstantExpr *CE = dyn_cast<ConstantExpr>(Ptr))
+ Ptr = ConstantFoldConstantExpression(CE, TD, TLI);
if (!isSimpleEnoughPointerToCommit(Ptr))
// If this is too complex for us to commit, reject it.
return false;
@@ -2423,7 +2425,9 @@
Constant * const IdxList[] = {IdxZero, IdxZero};
Ptr = ConstantExpr::getGetElementPtr(Ptr, IdxList);
-
+ if (ConstantExpr *CE = dyn_cast<ConstantExpr>(Ptr))
+ Ptr = ConstantFoldConstantExpression(CE, TD, TLI);
+
// If we can't improve the situation by introspecting NewTy,
// we have to give up.
} else {
@@ -2464,7 +2468,10 @@
cast<GEPOperator>(GEP)->isInBounds());
} else if (LoadInst *LI = dyn_cast<LoadInst>(CurInst)) {
if (!LI->isSimple()) return false; // no volatile/atomic accesses.
- InstResult = ComputeLoadResult(getVal(LI->getOperand(0)));
+ Constant *Ptr = getVal(LI->getOperand(0));
+ if (ConstantExpr *CE = dyn_cast<ConstantExpr>(Ptr))
+ Ptr = ConstantFoldConstantExpression(CE, TD, TLI);
+ InstResult = ComputeLoadResult(Ptr);
if (InstResult == 0) return false; // Could not evaluate load.
} else if (AllocaInst *AI = dyn_cast<AllocaInst>(CurInst)) {
if (AI->isArrayAllocation()) return false; // Cannot handle array allocs.