R600: Handle fnearbyint

The difference from rint isn't really relevant here,
so treat them as equivalent. OpenCL doesn't have nearbyint,
so this is sort of pointless other than for completeness.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@211229 91177308-0d34-0410-b5e6-96231b3b80d8

lib/Target/R600/AMDGPUISelLowering.cpp

@@ -325,6 +325,7 @@ AMDGPUTargetLowering::AMDGPUTargetLowering(TargetMachine &TM) :
     setOperationAction(ISD::FTRUNC, VT, Expand);
     setOperationAction(ISD::FMUL, VT, Expand);
     setOperationAction(ISD::FRINT, VT, Expand);
+    setOperationAction(ISD::FNEARBYINT, VT, Expand);
     setOperationAction(ISD::FSQRT, VT, Expand);
     setOperationAction(ISD::FSIN, VT, Expand);
     setOperationAction(ISD::FSUB, VT, Expand);
@@ -334,6 +335,9 @@ AMDGPUTargetLowering::AMDGPUTargetLowering(TargetMachine &TM) :
     setOperationAction(ISD::FCOPYSIGN, VT, Expand);
   }
 
+  setOperationAction(ISD::FNEARBYINT, MVT::f32, Custom);
+  setOperationAction(ISD::FNEARBYINT, MVT::f64, Custom);
+
   setTargetDAGCombine(ISD::MUL);
   setTargetDAGCombine(ISD::SELECT_CC);
 
@@ -501,6 +505,7 @@ SDValue AMDGPUTargetLowering::LowerOperation(SDValue Op,
   case ISD::FCEIL: return LowerFCEIL(Op, DAG);
   case ISD::FTRUNC: return LowerFTRUNC(Op, DAG);
   case ISD::FRINT: return LowerFRINT(Op, DAG);
+  case ISD::FNEARBYINT: return LowerFNEARBYINT(Op, DAG);
   case ISD::FFLOOR: return LowerFFLOOR(Op, DAG);
   case ISD::UINT_TO_FP: return LowerUINT_TO_FP(Op, DAG);
 
@@ -1683,6 +1688,13 @@ SDValue AMDGPUTargetLowering::LowerFRINT(SDValue Op, SelectionDAG &DAG) const {
   return DAG.getSelect(SL, MVT::f64, Cond, Src, Tmp2);
 }
 
+SDValue AMDGPUTargetLowering::LowerFNEARBYINT(SDValue Op, SelectionDAG &DAG) const {
+  // FNEARBYINT and FRINT are the same, except in their handling of FP
+  // exceptions. Those aren't really meaningful for us, and OpenCL only has
+  // rint, so just treat them as equivalent.
+  return DAG.getNode(ISD::FRINT, SDLoc(Op), Op.getValueType(), Op.getOperand(0));
+}
+
 SDValue AMDGPUTargetLowering::LowerFFLOOR(SDValue Op, SelectionDAG &DAG) const {
   SDLoc SL(Op);
   SDValue Src = Op.getOperand(0);

lib/Target/R600/AMDGPUISelLowering.h

@@ -54,6 +54,7 @@ private:
   SDValue LowerFCEIL(SDValue Op, SelectionDAG &DAG) const;
   SDValue LowerFTRUNC(SDValue Op, SelectionDAG &DAG) const;
   SDValue LowerFRINT(SDValue Op, SelectionDAG &DAG) const;
+  SDValue LowerFNEARBYINT(SDValue Op, SelectionDAG &DAG) const;
   SDValue LowerFFLOOR(SDValue Op, SelectionDAG &DAG) const;
 
   SDValue LowerUINT_TO_FP(SDValue Op, SelectionDAG &DAG) const;

test/CodeGen/R600/fnearbyint.ll

@@ -0,0 +1,57 @@
+; RUN: llc -march=r600 -mcpu=SI -verify-machineinstrs < %s
+; RUN: llc -march=r600 -mcpu=bonaire -verify-machineinstrs < %s
+
+; This should have the exactly the same output as the test for rint,
+; so no need to check anything.
+
+declare float @llvm.nearbyint.f32(float) #0
+declare <2 x float> @llvm.nearbyint.v2f32(<2 x float>) #0
+declare <4 x float> @llvm.nearbyint.v4f32(<4 x float>) #0
+declare double @llvm.nearbyint.f64(double) #0
+declare <2 x double> @llvm.nearbyint.v2f64(<2 x double>) #0
+declare <4 x double> @llvm.nearbyint.v4f64(<4 x double>) #0
+
+
+define void @fnearbyint_f32(float addrspace(1)* %out, float %in) #1 {
+entry:
+  %0 = call float @llvm.nearbyint.f32(float %in)
+  store float %0, float addrspace(1)* %out
+  ret void
+}
+
+define void @fnearbyint_v2f32(<2 x float> addrspace(1)* %out, <2 x float> %in) #1 {
+entry:
+  %0 = call <2 x float> @llvm.nearbyint.v2f32(<2 x float> %in)
+  store <2 x float> %0, <2 x float> addrspace(1)* %out
+  ret void
+}
+
+define void @fnearbyint_v4f32(<4 x float> addrspace(1)* %out, <4 x float> %in) #1 {
+entry:
+  %0 = call <4 x float> @llvm.nearbyint.v4f32(<4 x float> %in)
+  store <4 x float> %0, <4 x float> addrspace(1)* %out
+  ret void
+}
+
+define void @nearbyint_f64(double addrspace(1)* %out, double %in) {
+entry:
+  %0 = call double @llvm.nearbyint.f64(double %in)
+  store double %0, double addrspace(1)* %out
+  ret void
+}
+define void @nearbyint_v2f64(<2 x double> addrspace(1)* %out, <2 x double> %in) {
+entry:
+  %0 = call <2 x double> @llvm.nearbyint.v2f64(<2 x double> %in)
+  store <2 x double> %0, <2 x double> addrspace(1)* %out
+  ret void
+}
+
+define void @nearbyint_v4f64(<4 x double> addrspace(1)* %out, <4 x double> %in) {
+entry:
+  %0 = call <4 x double> @llvm.nearbyint.v4f64(<4 x double> %in)
+  store <4 x double> %0, <4 x double> addrspace(1)* %out
+  ret void
+}
+
+attributes #0 = { nounwind readonly }
+attributes #1 = { nounwind }