Remove redundant power of 2 case

Author: spaits

llvm/lib/Transforms/InstCombine/InstCombineCalls.cpp

@@ -3779,17 +3779,7 @@ Instruction *InstCombinerImpl::visitCallInst(CallInst &CI) {
           unsigned VectorSize = ReducedVectorElementCount.getFixedValue();
           Type *SplatType = Splat->getType();
           unsigned SplatTypeWidth = SplatType->getIntegerBitWidth();
-          Value *Res;
-          // Power of two is a special case. We can just use a left shif here.
-          if (isPowerOf2_32(VectorSize)) {
-            unsigned Pow2 = Log2_32(VectorSize);
-            Res = Builder.CreateShl(
-                Splat, Constant::getIntegerValue(SplatType,
-                                                 APInt(SplatTypeWidth, Pow2)));
-            return replaceInstUsesWith(CI, Res);
-          }
-          // Otherwise just multiply.
-          Res = Builder.CreateMul(
+          Value *Res = Builder.CreateMul(
               Splat, Constant::getIntegerValue(
                          SplatType, APInt(SplatTypeWidth, VectorSize)));
           return replaceInstUsesWith(CI, Res);