TTI: Estimate @llvm.fmuladd cost as fmul + fadd when FMA's aren't legal on the target.
llvm-svn: 208115
diff --git a/llvm/lib/CodeGen/BasicTargetTransformInfo.cpp b/llvm/lib/CodeGen/BasicTargetTransformInfo.cpp
index 6ad1f28..4b89509 100644
--- a/llvm/lib/CodeGen/BasicTargetTransformInfo.cpp
+++ b/llvm/lib/CodeGen/BasicTargetTransformInfo.cpp
@@ -487,7 +487,7 @@
case Intrinsic::round: ISD = ISD::FROUND; break;
case Intrinsic::pow: ISD = ISD::FPOW; break;
case Intrinsic::fma: ISD = ISD::FMA; break;
- case Intrinsic::fmuladd: ISD = ISD::FMA; break; // FIXME: mul + add?
+ case Intrinsic::fmuladd: ISD = ISD::FMA; break;
case Intrinsic::lifetime_start:
case Intrinsic::lifetime_end:
return 0;
@@ -512,6 +512,12 @@
return LT.first * 2;
}
+ // If we can't lower fmuladd into an FMA estimate the cost as a floating
+ // point mul followed by an add.
+ if (IID == Intrinsic::fmuladd)
+ return TopTTI->getArithmeticInstrCost(BinaryOperator::FMul, RetTy) +
+ TopTTI->getArithmeticInstrCost(BinaryOperator::FAdd, RetTy);
+
// Else, assume that we need to scalarize this intrinsic. For math builtins
// this will emit a costly libcall, adding call overhead and spills. Make it
// very expensive.