[InstCombine] simplify code for bitcast of insertelement; NFC

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@362655 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/lib/Transforms/InstCombine/InstCombineCasts.cpp b/lib/Transforms/InstCombine/InstCombineCasts.cpp
index 1faaf0bf6af85aae23096de7b58be51fc465b583..36be8bdf6f3ec1f4a3ba2c15d88b038a49bbc3ee 100644 (file)
--- a/lib/Transforms/InstCombine/InstCombineCasts.cpp
+++ b/lib/Transforms/InstCombine/InstCombineCasts.cpp
@@ -2376,11 +2376,10 @@ Instruction *InstCombiner::visitBitCast(BitCastInst &CI) {
       }
 
       // Otherwise, see if our source is an insert. If so, then use the scalar
-      // component directly.
-      if (InsertElementInst *IEI =
-            dyn_cast<InsertElementInst>(CI.getOperand(0)))
-        return CastInst::Create(Instruction::BitCast, IEI->getOperand(1),
-                                DestTy);
+      // component directly:
+      // bitcast (inselt <1 x elt> V, X, 0) to <n x m> --> bitcast X to <n x m>
+      if (auto *InsElt = dyn_cast<InsertElementInst>(Src))
+        return new BitCastInst(InsElt->getOperand(1), DestTy);
     }
   }