Enable roundeven.

Add support for roundeven and implement appropriate tests.

Reviewed By: arsenm

Differential Revision: https://reviews.llvm.org/D137954

Author: Leon Clark

llvm/lib/Target/AMDGPU/AMDGPUISelLowering.cpp

@@ -332,6 +332,8 @@ AMDGPUTargetLowering::AMDGPUTargetLowering(const TargetMachine &TM,
 
   setOperationAction(ISD::FNEARBYINT, {MVT::f16, MVT::f32, MVT::f64}, Custom);
 
+  setOperationAction(ISD::FROUNDEVEN, {MVT::f16, MVT::f32, MVT::f64}, Custom);
+
   setOperationAction(ISD::FREM, {MVT::f16, MVT::f32, MVT::f64}, Custom);
 
   if (Subtarget->has16BitInsts())
@@ -1252,6 +1254,8 @@ SDValue AMDGPUTargetLowering::LowerOperation(SDValue Op,
   case ISD::FTRUNC: return LowerFTRUNC(Op, DAG);
   case ISD::FRINT: return LowerFRINT(Op, DAG);
   case ISD::FNEARBYINT: return LowerFNEARBYINT(Op, DAG);
+  case ISD::FROUNDEVEN:
+    return LowerFROUNDEVEN(Op, DAG);
   case ISD::FROUND: return LowerFROUND(Op, DAG);
   case ISD::FFLOOR: return LowerFFLOOR(Op, DAG);
   case ISD::FLOG:
@@ -2244,6 +2248,13 @@ SDValue AMDGPUTargetLowering::LowerFNEARBYINT(SDValue Op, SelectionDAG &DAG) con
   return DAG.getNode(ISD::FRINT, SDLoc(Op), Op.getValueType(), Op.getOperand(0));
 }
 
+SDValue AMDGPUTargetLowering::LowerFROUNDEVEN(SDValue Op,
+                                              SelectionDAG &DAG) const {
+  auto VT = Op.getValueType();
+  auto Arg = Op.getOperand(0u);
+  return DAG.getNode(ISD::FRINT, SDLoc(Op), VT, Arg);
+}
+
 // XXX - May require not supporting f32 denormals?
 
 // Don't handle v2f16. The extra instructions to scalarize and repack around the

llvm/lib/Target/AMDGPU/AMDGPUISelLowering.h

@@ -57,6 +57,7 @@ class AMDGPUTargetLowering : public TargetLowering {
   SDValue LowerFRINT(SDValue Op, SelectionDAG &DAG) const;
   SDValue LowerFNEARBYINT(SDValue Op, SelectionDAG &DAG) const;
 
+  SDValue LowerFROUNDEVEN(SDValue Op, SelectionDAG &DAG) const;
   SDValue LowerFROUND(SDValue Op, SelectionDAG &DAG) const;
   SDValue LowerFFLOOR(SDValue Op, SelectionDAG &DAG) const;
   SDValue LowerFLOG(SDValue Op, SelectionDAG &DAG,