Move ashr optimization from InstCombineShift to InstSimplify.

Refactor code, no functionality change, test case moved from instcombine to instsimplify.

Differential Revision: http://reviews.llvm.org/D4102
 

llvm-svn: 213231

1 files changed, 0 insertions, 5 deletions

diff --git a/llvm/lib/Transforms/InstCombine/InstCombineShifts.cpp b/llvm/lib/Transforms/InstCombine/InstCombineShifts.cpp
index 2495747da5f..2f91c204dbd 100644
--- a/llvm/lib/Transforms/InstCombine/InstCombineShifts.cpp
+++ b/llvm/lib/Transforms/InstCombine/InstCombineShifts.cpp
@@ -815,10 +815,5 @@ Instruction *InstCombiner::visitAShr(BinaryOperator &I) {
                         APInt::getSignBit(I.getType()->getScalarSizeInBits())))
     return BinaryOperator::CreateLShr(Op0, Op1);
 
-  // Arithmetic shifting an all-sign-bit value is a no-op.
-  unsigned NumSignBits = ComputeNumSignBits(Op0);
-  if (NumSignBits == Op0->getType()->getScalarSizeInBits())
-    return ReplaceInstUsesWith(I, Op0);
-
   return nullptr;
 }