AMDGPU: Use DAG patterns for div_fmas

[kerbowa]

LGTM

[arsenm]

cbf719b5681262e2be01646f97818d98818bdfd3

llvm/lib/Target/AMDGPU/AMDGPUISelDAGToDAG.cpp

private:
   SDValue getHi16Elt(SDValue In) const;
 
   SDValue getMaterializedScalarImm32(int64_t Val, const SDLoc &DL) const;
 
   void SelectADD_SUB_I64(SDNode *N);
   void SelectAddcSubb(SDNode *N);
   void SelectUADDO_USUBO(SDNode *N);
   void SelectDIV_SCALE(SDNode *N);
-  void SelectDIV_FMAS(SDNode *N);
   void SelectMAD_64_32(SDNode *N);
   void SelectFMA_W_CHAIN(SDNode *N);
   void SelectFMUL_W_CHAIN(SDNode *N);
 
   SDNode *getS_BFE(unsigned Opcode, const SDLoc &DL, SDValue Val,
                    uint32_t Offset, uint32_t Width);
   void SelectS_BFEFromShifts(SDNode *N);
   void SelectS_BFE(SDNode *N);
case AMDGPUISD::BFE_U32: {
     ReplaceNode(N, getS_BFE(Signed ? AMDGPU::S_BFE_I32 : AMDGPU::S_BFE_U32,
                             SDLoc(N), N->getOperand(0), OffsetVal, WidthVal));
     return;
   }
   case AMDGPUISD::DIV_SCALE: {
     SelectDIV_SCALE(N);
     return;
   }
-  case AMDGPUISD::DIV_FMAS: {
-    SelectDIV_FMAS(N);
-    return;
-  }
   case AMDGPUISD::MAD_I64_I32:
   case AMDGPUISD::MAD_U64_U32: {
     SelectMAD_64_32(N);
     return;
   }
   case ISD::CopyToReg: {
     const SITargetLowering& Lowering =
       *static_cast<const SITargetLowering*>(getTargetLowering());
void AMDGPUDAGToDAGISel::SelectDIV_SCALE(SDNode *N) {
 
   unsigned Opc
     = (VT == MVT::f64) ? AMDGPU::V_DIV_SCALE_F64 : AMDGPU::V_DIV_SCALE_F32;
 
   SDValue Ops[] = { N->getOperand(0), N->getOperand(1), N->getOperand(2) };
   CurDAG->SelectNodeTo(N, Opc, N->getVTList(), Ops);
 }
 
-void AMDGPUDAGToDAGISel::SelectDIV_FMAS(SDNode *N) {
-  const GCNSubtarget *ST = static_cast<const GCNSubtarget *>(Subtarget);
-  const SIRegisterInfo *TRI = ST->getRegisterInfo();
-
-  SDLoc SL(N);
-  EVT VT = N->getValueType(0);
-
-  assert(VT == MVT::f32 || VT == MVT::f64);
-
-  unsigned Opc
-    = (VT == MVT::f64) ? AMDGPU::V_DIV_FMAS_F64 : AMDGPU::V_DIV_FMAS_F32;
-
-  SDValue CarryIn = N->getOperand(3);
-  // V_DIV_FMAS implicitly reads VCC.
-  SDValue VCC = CurDAG->getCopyToReg(CurDAG->getEntryNode(), SL,
-                                     TRI->getVCC(), CarryIn, SDValue());
-
-  SDValue Ops[10];
-
-  SelectVOP3Mods0(N->getOperand(0), Ops[1], Ops[0], Ops[6], Ops[7]);
-  SelectVOP3Mods(N->getOperand(1), Ops[3], Ops[2]);
-  SelectVOP3Mods(N->getOperand(2), Ops[5], Ops[4]);
-
-  Ops[8] = VCC;
-  Ops[9] = VCC.getValue(1);
-
-  CurDAG->SelectNodeTo(N, Opc, N->getVTList(), Ops);
-}
-
 // We need to handle this here because tablegen doesn't support matching
 // instructions with multiple outputs.
 void AMDGPUDAGToDAGISel::SelectMAD_64_32(SDNode *N) {
   SDLoc SL(N);
   bool Signed = N->getOpcode() == AMDGPUISD::MAD_I64_I32;
   unsigned Opc = Signed ? AMDGPU::V_MAD_I64_I32 : AMDGPU::V_MAD_U64_U32;
 
   SDValue Clamp = CurDAG->getTargetConstant(0, SL, MVT::i1);

llvm/lib/Target/AMDGPU/VOP3Instructions.td

let SubtargetPredicate = isGFX10Plus in {
   def : PermlaneDiscardVDstIn<
     BoundControlOrFetchInvalidPermlane<int_amdgcn_permlane16>,
     V_PERMLANE16_B32>;
   def : PermlaneDiscardVDstIn<
     BoundControlOrFetchInvalidPermlane<int_amdgcn_permlanex16>,
     V_PERMLANEX16_B32>;
 } // End SubtargetPredicate = isGFX10Plus
 
+class DivFmasPat<ValueType vt, Instruction inst, Register CondReg> : GCNPat<
+  (AMDGPUdiv_fmas (vt (VOP3Mods vt:$src0, i32:$src0_modifiers)),
+                      (VOP3Mods vt:$src1, i32:$src1_modifiers),
+                      (VOP3Mods vt:$src2, i32:$src2_modifiers),
+                      (i1 CondReg)),
+  (inst $src0_modifiers, $src0, $src1_modifiers, $src1, $src2_modifiers, $src2)
+>;
+
+let WaveSizePredicate = isWave64 in {
+def : DivFmasPat<f32, V_DIV_FMAS_F32, VCC>;
+def : DivFmasPat<f64, V_DIV_FMAS_F64, VCC>;
+}
+
+let WaveSizePredicate = isWave32 in {
+def : DivFmasPat<f32, V_DIV_FMAS_F32, VCC_LO>;
+def : DivFmasPat<f64, V_DIV_FMAS_F64, VCC_LO>;
+}
+
 //===----------------------------------------------------------------------===//
 // Integer Clamp Patterns
 //===----------------------------------------------------------------------===//
 
 class getClampPat<VOPProfile P, SDPatternOperator node> {
   dag ret3 = (P.DstVT (node P.Src0VT:$src0, P.Src1VT:$src1, P.Src2VT:$src2));
   dag ret2 = (P.DstVT (node P.Src0VT:$src0, P.Src1VT:$src1));
   dag ret1 = (P.DstVT (node P.Src0VT:$src0));