case Instruction::AShr:
case Instruction::And:
case Instruction::Or:
- case Instruction::Xor:
- return TTI.getArithmeticInstrCost(I->getOpcode(), VectorTy);
+ case Instruction::Xor: {
+ // Certain instructions can be cheaper to vectorize if they have a constant
+ // second vector operand. One example of this are shifts on x86.
+ TargetTransformInfo::OperandValueKind Op1VK =
+ TargetTransformInfo::OK_AnyValue;
+ TargetTransformInfo::OperandValueKind Op2VK =
+ TargetTransformInfo::OK_AnyValue;
+
+ if (isa<ConstantInt>(I->getOperand(1)))
+ Op2VK = TargetTransformInfo::OK_UniformConstantValue;
+
+ return TTI.getArithmeticInstrCost(I->getOpcode(), VectorTy, Op1VK, Op2VK);
+ }
case Instruction::Select: {
SelectInst *SI = cast<SelectInst>(I);
const SCEV *CondSCEV = SE->getSCEV(SI->getCondition());
--- /dev/null
+; RUN: opt -mtriple=x86_64-apple-darwin -mcpu=core2 -loop-vectorize -dce -instcombine -S < %s | FileCheck %s
+
+@B = common global [1024 x i32] zeroinitializer, align 16
+@A = common global [1024 x i32] zeroinitializer, align 16
+
+; We use to not vectorize this loop because the shift was deemed to expensive.
+; Now that we differentiate shift cost base on the operand value kind, we will
+; vectorize this loop.
+; CHECK: ashr <4 x i32>
+define void @f() {
+entry:
+ br label %for.body
+
+for.body:
+ %indvars.iv = phi i64 [ 0, %entry ], [ %indvars.iv.next, %for.body ]
+ %arrayidx = getelementptr inbounds [1024 x i32]* @B, i64 0, i64 %indvars.iv
+ %0 = load i32* %arrayidx, align 4
+ %shl = ashr i32 %0, 3
+ %arrayidx2 = getelementptr inbounds [1024 x i32]* @A, i64 0, i64 %indvars.iv
+ store i32 %shl, i32* %arrayidx2, align 4
+ %indvars.iv.next = add i64 %indvars.iv, 1
+ %lftr.wideiv = trunc i64 %indvars.iv.next to i32
+ %exitcond = icmp eq i32 %lftr.wideiv, 1024
+ br i1 %exitcond, label %for.end, label %for.body
+
+for.end:
+ ret void
+}