Teach SCEVExpander::InsertCastOfTo to avoid creating inttoptr-of-ptrtoint
and ptrtoint-of-inttoptr expressions. This fixes a regression in 300.twolf.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@69293 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Analysis/ScalarEvolutionExpander.cpp b/lib/Analysis/ScalarEvolutionExpander.cpp
index d91061b..0033fb4 100644
--- a/lib/Analysis/ScalarEvolutionExpander.cpp
+++ b/lib/Analysis/ScalarEvolutionExpander.cpp
@@ -26,6 +26,14 @@
if (opcode == Instruction::BitCast && V->getType() == Ty)
return V;
+ // Short-circuit unnecessary inttoptr<->ptrtoint casts.
+ if (opcode == Instruction::PtrToInt && Ty == TD.getIntPtrType())
+ if (IntToPtrInst *ITP = dyn_cast<IntToPtrInst>(V))
+ return ITP->getOperand(0);
+ if (opcode == Instruction::IntToPtr && V->getType() == TD.getIntPtrType())
+ if (PtrToIntInst *PTI = dyn_cast<PtrToIntInst>(V))
+ return PTI->getOperand(0);
+
// FIXME: keep track of the cast instruction.
if (Constant *C = dyn_cast<Constant>(V))
return ConstantExpr::getCast(opcode, C, Ty);