Change Value::getUnderlyingObject to have the MaxLookup value specified as a

parameter with a default value, instead of just hardcoding it in the
implementation.  The limit of MaxLookup = 6 was introduced in r69151 to fix
a performance problem with O(n^2) behavior in instcombine, but the scalarrepl
pass is relying on getUnderlyingObject to go all the way back to an AllocaInst.
Making the limit part of the method signature makes it clear that by default
the result is limited and should help avoid similar problems in the future.
This fixes pr6126.

llvm-svn: 94433

1 files changed, 3 insertions, 3 deletions

diff --git a/llvm/lib/Transforms/Scalar/ScalarReplAggregates.cpp b/llvm/lib/Transforms/Scalar/ScalarReplAggregates.cpp
index f4734801e0f..1cf486bbdfa 100644
--- a/llvm/lib/Transforms/Scalar/ScalarReplAggregates.cpp
+++ b/llvm/lib/Transforms/Scalar/ScalarReplAggregates.cpp
@@ -1384,9 +1384,9 @@ void SROA::ConvertUsesToScalar(Value *Ptr, AllocaInst *NewAI, uint64_t Offset) {
       // If the source and destination are both to the same alloca, then this is
       // a noop copy-to-self, just delete it.  Otherwise, emit a load and store
       // as appropriate.
-      AllocaInst *OrigAI = cast<AllocaInst>(Ptr->getUnderlyingObject());
+      AllocaInst *OrigAI = cast<AllocaInst>(Ptr->getUnderlyingObject(0));
       
-      if (MTI->getSource()->getUnderlyingObject() != OrigAI) {
+      if (MTI->getSource()->getUnderlyingObject(0) != OrigAI) {
         // Dest must be OrigAI, change this to be a load from the original
         // pointer (bitcasted), then a store to our new alloca.
         assert(MTI->getRawDest() == Ptr && "Neither use is of pointer?");
@@ -1396,7 +1396,7 @@ void SROA::ConvertUsesToScalar(Value *Ptr, AllocaInst *NewAI, uint64_t Offset) {
         LoadInst *SrcVal = Builder.CreateLoad(SrcPtr, "srcval");
         SrcVal->setAlignment(MTI->getAlignment());
         Builder.CreateStore(SrcVal, NewAI);
-      } else if (MTI->getDest()->getUnderlyingObject() != OrigAI) {
+      } else if (MTI->getDest()->getUnderlyingObject(0) != OrigAI) {
         // Src must be OrigAI, change this to be a load from NewAI then a store
         // through the original dest pointer (bitcasted).
         assert(MTI->getRawSource() == Ptr && "Neither use is of pointer?");