implement a FIXME: limit the depth that DecomposeGEPExpression goes the same
way that getUnderlyingObject does it.
This fixes the 'DecomposeGEPExpression and getUnderlyingObject disagree!'
assertion on sqlite3.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@90038 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Analysis/ValueTracking.cpp b/lib/Analysis/ValueTracking.cpp
index 3e6af58..31d3ccc 100644
--- a/lib/Analysis/ValueTracking.cpp
+++ b/lib/Analysis/ValueTracking.cpp
@@ -1028,9 +1028,11 @@
const Value *llvm::DecomposeGEPExpression(const Value *V, int64_t &BaseOffs,
SmallVectorImpl<std::pair<const Value*, int64_t> > &VarIndices,
const TargetData *TD) {
- // FIXME: Should limit depth like getUnderlyingObject?
+ // Limit recursion depth to limit compile time in crazy cases.
+ unsigned MaxLookup = 6;
+
BaseOffs = 0;
- while (1) {
+ do {
// See if this is a bitcast or GEP.
const Operator *Op = dyn_cast<Operator>(V);
if (Op == 0) {
@@ -1128,7 +1130,10 @@
// Analyze the base pointer next.
V = GEPOp->getOperand(0);
- }
+ } while (--MaxLookup);
+
+ // If the chain of expressions is too deep, just return early.
+ return V;
}