Add a new intrinsic: llvm.fmuladd. This intrinsic represents a multiply-add
expression (a * b + c) that can be implemented as a fused multiply-add (fma)
if the target determines that this will be more efficient. This intrinsic
will be used to implement FP_CONTRACT support and an aggressive FMA formation
mode.
If your target has a fast FMA instruction you should override the
isFMAFasterThanMulAndAdd method in TargetLowering to return true.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@158014 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp b/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
index ab3ce48..4152aa1 100644
--- a/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
+++ b/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
@@ -4932,6 +4932,27 @@
getValue(I.getArgOperand(1)),
getValue(I.getArgOperand(2))));
return 0;
+ case Intrinsic::fmuladd: {
+ EVT VT = TLI.getValueType(I.getType());
+ if (TLI.isOperationLegal(ISD::FMA, VT) && TLI.isFMAFasterThanMulAndAdd(VT)){
+ setValue(&I, DAG.getNode(ISD::FMA, dl,
+ getValue(I.getArgOperand(0)).getValueType(),
+ getValue(I.getArgOperand(0)),
+ getValue(I.getArgOperand(1)),
+ getValue(I.getArgOperand(2))));
+ } else {
+ SDValue Mul = DAG.getNode(ISD::FMUL, dl,
+ getValue(I.getArgOperand(0)).getValueType(),
+ getValue(I.getArgOperand(0)),
+ getValue(I.getArgOperand(1)));
+ SDValue Add = DAG.getNode(ISD::FADD, dl,
+ getValue(I.getArgOperand(0)).getValueType(),
+ Mul,
+ getValue(I.getArgOperand(2)));
+ setValue(&I, Add);
+ }
+ return 0;
+ }
case Intrinsic::convert_to_fp16:
setValue(&I, DAG.getNode(ISD::FP32_TO_FP16, dl,
MVT::i16, getValue(I.getArgOperand(0))));