Reapply a fixed version of r133285.

[oota-llvm.git] / lib / Transforms / InstCombine / InstCombineVectorOps.cpp

diff --git a/lib/Transforms/InstCombine/InstCombineVectorOps.cpp b/lib/Transforms/InstCombine/InstCombineVectorOps.cpp
index 5caa12dfdfa5e07c3d8bdee5e9e2316e1b2881b9..ad6a8d054ee753f1714855a0e8a6995b0e45b401 100644 (file)
--- a/lib/Transforms/InstCombine/InstCombineVectorOps.cpp
+++ b/lib/Transforms/InstCombine/InstCombineVectorOps.cpp
@@ -230,8 +230,16 @@ Instruction *InstCombiner::visitExtractElementInst(ExtractElementInst &EI) {
                                           ConstantInt::get(Int32Ty,
                                                            SrcIdx, false));
       }
+    } else if (CastInst *CI = dyn_cast<CastInst>(I)) {
+      // Canonicalize extractelement(cast) -> cast(extractelement)
+      // bitcasts can change the number of vector elements and they cost nothing
+      if (CI->hasOneUse() && EI.hasOneUse() &&
+          (CI->getOpcode() != Instruction::BitCast)) {
+        Value *EE = Builder->CreateExtractElement(CI->getOperand(0),
+                                                  EI.getIndexOperand());
+        return CastInst::Create(CI->getOpcode(), EE, EI.getType());
+      }
     }
-    // FIXME: Canonicalize extractelement(bitcast) -> bitcast(extractelement)
   }
   return 0;
 }