From e0ced62119ff1a28bf32fdd23a29b94056c34bef Mon Sep 17 00:00:00 2001
From: Andrew Trick <atrick@apple.com>
Date: Wed, 14 Dec 2011 22:07:19 +0000
Subject: LSR: Fold redundant bitcasts on-the-fly.

llvm-svn: 146597
---
 llvm/lib/Analysis/ScalarEvolutionExpander.cpp | 11 ++++++++---
 1 file changed, 8 insertions(+), 3 deletions(-)

(limited to 'llvm/lib/Analysis/ScalarEvolutionExpander.cpp')

diff --git a/llvm/lib/Analysis/ScalarEvolutionExpander.cpp b/llvm/lib/Analysis/ScalarEvolutionExpander.cpp
index 59901aaa839..f3cf5494551 100644
--- a/llvm/lib/Analysis/ScalarEvolutionExpander.cpp
+++ b/llvm/lib/Analysis/ScalarEvolutionExpander.cpp
@@ -73,9 +73,14 @@ Value *SCEVExpander::InsertNoopCastOfTo(Value *V, Type *Ty) {
          "InsertNoopCastOfTo cannot change sizes!");
 
   // Short-circuit unnecessary bitcasts.
-  if (Op == Instruction::BitCast && V->getType() == Ty)
-    return V;
-
+  if (Op == Instruction::BitCast) {
+    if (V->getType() == Ty)
+      return V;
+    if (CastInst *CI = dyn_cast<CastInst>(V)) {
+      if (CI->getOperand(0)->getType() == Ty)
+        return CI->getOperand(0);
+    }
+  }
   // Short-circuit unnecessary inttoptr<->ptrtoint casts.
   if ((Op == Instruction::PtrToInt || Op == Instruction::IntToPtr) &&
       SE.getTypeSizeInBits(Ty) == SE.getTypeSizeInBits(V->getType())) {
-- 
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