Constant-fold GEP-of-GEP into a single GEP.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@98178 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Analysis/ConstantFolding.cpp b/lib/Analysis/ConstantFolding.cpp
index 114db2d..62020af 100644
--- a/lib/Analysis/ConstantFolding.cpp
+++ b/lib/Analysis/ConstantFolding.cpp
@@ -589,6 +589,17 @@
APInt Offset = APInt(BitWidth,
TD->getIndexedOffset(Ptr->getType(),
(Value**)Ops+1, NumOps-1));
+
+ // If this is a GEP of a GEP, fold it all into a single GEP.
+ while (GEPOperator *GEP = dyn_cast<GEPOperator>(Ptr)) {
+ SmallVector<Value *, 4> NestedOps(GEP->op_begin()+1, GEP->op_end());
+ Ptr = cast<Constant>(GEP->getOperand(0));
+ Offset += APInt(BitWidth,
+ TD->getIndexedOffset(Ptr->getType(),
+ (Value**)NestedOps.data(),
+ NestedOps.size()));
+ }
+
// If the base value for this address is a literal integer value, fold the
// getelementptr to the resulting integer value casted to the pointer type.
if (BaseIsInt) {