Teach DAGCombine the same multiply-by-1.0 folding trick when doing FMAs, just like it now knows for FMULs.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@156029 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/SelectionDAG/DAGCombiner.cpp b/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
index b8f08bf..c2b7f6c 100644
--- a/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
+++ b/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
@@ -215,6 +215,7 @@
SDValue visitFADD(SDNode *N);
SDValue visitFSUB(SDNode *N);
SDValue visitFMUL(SDNode *N);
+ SDValue visitFMA(SDNode *N);
SDValue visitFDIV(SDNode *N);
SDValue visitFREM(SDNode *N);
SDValue visitFCOPYSIGN(SDNode *N);
@@ -1126,6 +1127,7 @@
case ISD::FADD: return visitFADD(N);
case ISD::FSUB: return visitFSUB(N);
case ISD::FMUL: return visitFMUL(N);
+ case ISD::FMA: return visitFMA(N);
case ISD::FDIV: return visitFDIV(N);
case ISD::FREM: return visitFREM(N);
case ISD::FCOPYSIGN: return visitFCOPYSIGN(N);
@@ -5751,6 +5753,22 @@
return SDValue();
}
+SDValue DAGCombiner::visitFMA(SDNode *N) {
+ SDValue N0 = N->getOperand(0);
+ SDValue N1 = N->getOperand(1);
+ SDValue N2 = N->getOperand(2);
+ ConstantFPSDNode *N0CFP = dyn_cast<ConstantFPSDNode>(N0);
+ ConstantFPSDNode *N1CFP = dyn_cast<ConstantFPSDNode>(N1);
+ EVT VT = N->getValueType(0);
+
+ if (N0CFP && N0CFP->isExactlyValue(1.0))
+ return DAG.getNode(ISD::FADD, N->getDebugLoc(), VT, N1, N2);
+ if (N1CFP && N1CFP->isExactlyValue(1.0))
+ return DAG.getNode(ISD::FADD, N->getDebugLoc(), VT, N0, N2);
+
+ return SDValue();
+}
+
SDValue DAGCombiner::visitFDIV(SDNode *N) {
SDValue N0 = N->getOperand(0);
SDValue N1 = N->getOperand(1);