R600: Custom lower frem

[arsenm]

r217553

lib/Target/R600/AMDGPUISelLowering.h

   /// \returns The resulting chain.
 
   SDValue LowerUDIVREM(SDValue Op, SelectionDAG &DAG) const;
+  SDValue LowerFREM(SDValue Op, SelectionDAG &DAG) const;
   SDValue LowerFCEIL(SDValue Op, SelectionDAG &DAG) const;
   SDValue LowerFTRUNC(SDValue Op, SelectionDAG &DAG) const;
   SDValue LowerFRINT(SDValue Op, SelectionDAG &DAG) const;

lib/Target/R600/AMDGPUISelLowering.cpp

   setOperationAction(ISD::FROUND, MVT::f32, Legal);
   setOperationAction(ISD::FTRUNC, MVT::f32, Legal);
 
+  setOperationAction(ISD::FREM, MVT::f32, Custom);
+  setOperationAction(ISD::FREM, MVT::f64, Custom);
+
   // Lower floating point store/load to integer store/load to reduce the number
   // of patterns in tablegen.
   setOperationAction(ISD::STORE, MVT::f32, Promote);

     setOperationAction(ISD::FDIV, VT, Expand);
     setOperationAction(ISD::FEXP2, VT, Expand);
     setOperationAction(ISD::FLOG2, VT, Expand);
+    setOperationAction(ISD::FREM, VT, Expand);
     setOperationAction(ISD::FPOW, VT, Expand);
     setOperationAction(ISD::FFLOOR, VT, Expand);
     setOperationAction(ISD::FTRUNC, VT, Expand);

   case ISD::INTRINSIC_WO_CHAIN: return LowerINTRINSIC_WO_CHAIN(Op, DAG);
   case ISD::UDIVREM: return LowerUDIVREM(Op, DAG);
   case ISD::SDIVREM: return LowerSDIVREM(Op, DAG);
+  case ISD::FREM: return LowerFREM(Op, DAG);
   case ISD::FCEIL: return LowerFCEIL(Op, DAG);
   case ISD::FTRUNC: return LowerFTRUNC(Op, DAG);
   case ISD::FRINT: return LowerFRINT(Op, DAG);

   return DAG.getMergeValues(Res, DL);
 }
 
+// (frem x, y) -> (sub x, (mul (floor (div x, y)), y))
+SDValue AMDGPUTargetLowering::LowerFREM(SDValue Op, SelectionDAG &DAG) const {
+  SDLoc SL(Op);
+  EVT VT = Op.getValueType();
+  SDValue X = Op.getOperand(0);
+  SDValue Y = Op.getOperand(1);
+
+  SDValue Div = DAG.getNode(ISD::FDIV, SL, VT, X, Y);
+  SDValue Floor = DAG.getNode(ISD::FTRUNC, SL, VT, Div);
+  SDValue Mul = DAG.getNode(ISD::FMUL, SL, VT, Floor, Y);
+
+  return DAG.getNode(ISD::FSUB, SL, VT, X, Mul);
+}
+
 SDValue AMDGPUTargetLowering::LowerFCEIL(SDValue Op, SelectionDAG &DAG) const {
   SDLoc SL(Op);
   SDValue Src = Op.getOperand(0);

test/CodeGen/R600/frem.ll

+; RUN: llc -march=r600 -mcpu=SI -enable-misched < %s | FileCheck -check-prefix=SI -check-prefix=FUNC %s
+
+; FUNC-LABEL: @frem_f32:
+; SI-DAG: BUFFER_LOAD_DWORD [[X:v[0-9]+]], {{.*$}}
+; SI-DAG: BUFFER_LOAD_DWORD [[Y:v[0-9]+]], {{.*}} offset:0x10
+; SI-DAG: V_CMP
+; SI-DAG: V_MUL_F32
+; SI: V_RCP_F32_e32
+; SI: V_MUL_F32_e32
+; SI: V_MUL_F32_e32
+; SI: V_TRUNC_F32_e32
+; SI: V_MAD_F32
+; SI: S_ENDPGM
+define void @frem_f32(float addrspace(1)* %out, float addrspace(1)* %in1,
+                      float addrspace(1)* %in2) #0 {
+   %gep2 = getelementptr float addrspace(1)* %in2, i32 4
+   %r0 = load float addrspace(1)* %in1, align 4
+   %r1 = load float addrspace(1)* %gep2, align 4
+   %r2 = frem float %r0, %r1
+   store float %r2, float addrspace(1)* %out, align 4
+   ret void
+}
+
+; FUNC-LABEL: @unsafe_frem_f32:
+; SI: BUFFER_LOAD_DWORD [[Y:v[0-9]+]], {{.*}} offset:0x10
+; SI: BUFFER_LOAD_DWORD [[X:v[0-9]+]], {{.*}}
+; SI: V_RCP_F32_e32 [[INVY:v[0-9]+]], [[Y]]
+; SI: V_MUL_F32_e32 [[DIV:v[0-9]+]], [[INVY]], [[X]]
+; SI: V_TRUNC_F32_e32 [[TRUNC:v[0-9]+]], [[DIV]]
+; SI: V_MAD_F32 [[RESULT:v[0-9]+]], -[[TRUNC]], [[Y]], [[X]],
+; SI: BUFFER_STORE_DWORD [[RESULT]]
+; SI: S_ENDPGM
+define void @unsafe_frem_f32(float addrspace(1)* %out, float addrspace(1)* %in1,
+                             float addrspace(1)* %in2) #1 {
+   %gep2 = getelementptr float addrspace(1)* %in2, i32 4
+   %r0 = load float addrspace(1)* %in1, align 4
+   %r1 = load float addrspace(1)* %gep2, align 4
+   %r2 = frem float %r0, %r1
+   store float %r2, float addrspace(1)* %out, align 4
+   ret void
+}
+
+; TODO: This should check something when f64 fdiv is implemented
+; correctly
+
+; FUNC-LABEL: @frem_f64:
+; SI: S_ENDPGM
+define void @frem_f64(double addrspace(1)* %out, double addrspace(1)* %in1,
+                      double addrspace(1)* %in2) #0 {
+   %r0 = load double addrspace(1)* %in1, align 8
+   %r1 = load double addrspace(1)* %in2, align 8
+   %r2 = frem double %r0, %r1
+   store double %r2, double addrspace(1)* %out, align 8
+   ret void
+}
+
+; FUNC-LABEL: @unsafe_frem_f64:
+; SI: V_RCP_F64_e32
+; SI: V_MUL_F64
+; SI: V_BFE_I32
+; SI: V_FMA_F64
+; SI: S_ENDPGM
+define void @unsafe_frem_f64(double addrspace(1)* %out, double addrspace(1)* %in1,
+                             double addrspace(1)* %in2) #1 {
+   %r0 = load double addrspace(1)* %in1, align 8
+   %r1 = load double addrspace(1)* %in2, align 8
+   %r2 = frem double %r0, %r1
+   store double %r2, double addrspace(1)* %out, align 8
+   ret void
+}
+
+define void @frem_v2f32(<2 x float> addrspace(1)* %out, <2 x float> addrspace(1)* %in1,
+                        <2 x float> addrspace(1)* %in2) #0 {
+   %gep2 = getelementptr <2 x float> addrspace(1)* %in2, i32 4
+   %r0 = load <2 x float> addrspace(1)* %in1, align 8
+   %r1 = load <2 x float> addrspace(1)* %gep2, align 8
+   %r2 = frem <2 x float> %r0, %r1
+   store <2 x float> %r2, <2 x float> addrspace(1)* %out, align 8
+   ret void
+}
+
+define void @frem_v4f32(<4 x float> addrspace(1)* %out, <4 x float> addrspace(1)* %in1,
+                        <4 x float> addrspace(1)* %in2) #0 {
+   %gep2 = getelementptr <4 x float> addrspace(1)* %in2, i32 4
+   %r0 = load <4 x float> addrspace(1)* %in1, align 16
+   %r1 = load <4 x float> addrspace(1)* %gep2, align 16
+   %r2 = frem <4 x float> %r0, %r1
+   store <4 x float> %r2, <4 x float> addrspace(1)* %out, align 16
+   ret void
+}
+
+define void @frem_v2f64(<2 x double> addrspace(1)* %out, <2 x double> addrspace(1)* %in1,
+                        <2 x double> addrspace(1)* %in2) #0 {
+   %gep2 = getelementptr <2 x double> addrspace(1)* %in2, i32 4
+   %r0 = load <2 x double> addrspace(1)* %in1, align 16
+   %r1 = load <2 x double> addrspace(1)* %gep2, align 16
+   %r2 = frem <2 x double> %r0, %r1
+   store <2 x double> %r2, <2 x double> addrspace(1)* %out, align 16
+   ret void
+}
+
+attributes #0 = { nounwind "unsafe-fp-math"="false" }
+attributes #1 = { nounwind "unsafe-fp-math"="true" }