[CostModel] Add really basic support for being able to query the cost of the FNeg instruction.

Summary:
This reuses the getArithmeticInstrCost, but passes dummy values of the second
operand flags.

The X86 costs are wrong and can be improved in a follow up. I just wanted to
stop it from reporting an unknown cost first.

Reviewers: RKSimon, spatel, andrew.w.kaylor, cameron.mcinally

Reviewed By: spatel

Subscribers: hiraditya, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D62444

llvm-svn: 361788

1 files changed, 10 insertions, 0 deletions

diff --git a/llvm/lib/Analysis/TargetTransformInfo.cpp b/llvm/lib/Analysis/TargetTransformInfo.cpp
index 2f9f1e069f8..53dd2bf2304 100644
--- a/llvm/lib/Analysis/TargetTransformInfo.cpp
+++ b/llvm/lib/Analysis/TargetTransformInfo.cpp
@@ -1043,6 +1043,16 @@ int TargetTransformInfo::getInstructionThroughput(const Instruction *I) const {
     return getArithmeticInstrCost(I->getOpcode(), I->getType(), Op1VK, Op2VK,
                                   Op1VP, Op2VP, Operands);
   }
+  case Instruction::FNeg: {
+    TargetTransformInfo::OperandValueKind Op1VK, Op2VK;
+    TargetTransformInfo::OperandValueProperties Op1VP, Op2VP;
+    Op1VK = getOperandInfo(I->getOperand(0), Op1VP);
+    Op2VK = OK_AnyValue;
+    Op2VP = OP_None;
+    SmallVector<const Value *, 2> Operands(I->operand_values());
+    return getArithmeticInstrCost(I->getOpcode(), I->getType(), Op1VK, Op2VK,
+                                  Op1VP, Op2VP, Operands);
+  }
   case Instruction::Select: {
     const SelectInst *SI = cast<SelectInst>(I);
     Type *CondTy = SI->getCondition()->getType();