AMDGPU/GlobalISel: Legalize sin/cos

llvm-svn: 370402

Author: arsenm

llvm/lib/Target/AMDGPU/AMDGPULegalizerInfo.cpp

@@ -275,12 +275,16 @@ AMDGPULegalizerInfo::AMDGPULegalizerInfo(const GCNSubtarget &ST_,
   auto &FPOpActions = getActionDefinitionsBuilder(
     { G_FADD, G_FMUL, G_FNEG, G_FABS, G_FMA, G_FCANONICALIZE})
     .legalFor({S32, S64});
+  auto &TrigActions = getActionDefinitionsBuilder({G_FSIN, G_FCOS})
+    .customFor({S32, S64});
 
   if (ST.has16BitInsts()) {
     if (ST.hasVOP3PInsts())
       FPOpActions.legalFor({S16, V2S16});
     else
       FPOpActions.legalFor({S16});
+
+    TrigActions.customFor({S16});
   }
 
   auto &MinNumMaxNum = getActionDefinitionsBuilder({
@@ -306,10 +310,15 @@ AMDGPULegalizerInfo::AMDGPULegalizerInfo(const GCNSubtarget &ST_,
 
   if (ST.hasVOP3PInsts())
     FPOpActions.clampMaxNumElements(0, S16, 2);
+
   FPOpActions
     .scalarize(0)
     .clampScalar(0, ST.has16BitInsts() ? S16 : S32, S64);
 
+  TrigActions
+    .scalarize(0)
+    .clampScalar(0, ST.has16BitInsts() ? S16 : S32, S64);
+
   if (ST.has16BitInsts()) {
     getActionDefinitionsBuilder(G_FSQRT)
       .legalFor({S32, S64, S16})
@@ -816,6 +825,9 @@ bool AMDGPULegalizerInfo::legalizeCustom(MachineInstr &MI,
     return legalizeExtractVectorElt(MI, MRI, MIRBuilder);
   case TargetOpcode::G_INSERT_VECTOR_ELT:
     return legalizeInsertVectorElt(MI, MRI, MIRBuilder);
+  case TargetOpcode::G_FSIN:
+  case TargetOpcode::G_FCOS:
+    return legalizeSinCos(MI, MRI, MIRBuilder);
   default:
     return false;
   }
@@ -1231,6 +1243,35 @@ bool AMDGPULegalizerInfo::legalizeInsertVectorElt(
   return true;
 }
 
+bool AMDGPULegalizerInfo::legalizeSinCos(
+  MachineInstr &MI, MachineRegisterInfo &MRI,
+  MachineIRBuilder &B) const {
+  B.setInstr(MI);
+
+  Register DstReg = MI.getOperand(0).getReg();
+  Register SrcReg = MI.getOperand(1).getReg();
+  LLT Ty = MRI.getType(DstReg);
+  unsigned Flags = MI.getFlags();
+
+  Register TrigVal;
+  auto OneOver2Pi = B.buildFConstant(Ty, 0.5 / M_PI);
+  if (ST.hasTrigReducedRange()) {
+    auto MulVal = B.buildFMul(Ty, SrcReg, OneOver2Pi, Flags);
+    TrigVal = B.buildIntrinsic(Intrinsic::amdgcn_fract, {Ty}, false)
+      .addUse(MulVal.getReg(0))
+      .setMIFlags(Flags).getReg(0);
+  } else
+    TrigVal = B.buildFMul(Ty, SrcReg, OneOver2Pi, Flags).getReg(0);
+
+  Intrinsic::ID TrigIntrin = MI.getOpcode() == AMDGPU::G_FSIN ?
+    Intrinsic::amdgcn_sin : Intrinsic::amdgcn_cos;
+  B.buildIntrinsic(TrigIntrin, makeArrayRef<Register>(DstReg), false)
+    .addUse(TrigVal)
+    .setMIFlags(Flags);
+  MI.eraseFromParent();
+  return true;
+}
+
 // Return the use branch instruction, otherwise null if the usage is invalid.
 static MachineInstr *verifyCFIntrinsic(MachineInstr &MI,
                                        MachineRegisterInfo &MRI) {

llvm/lib/Target/AMDGPU/AMDGPULegalizerInfo.h

@@ -55,6 +55,8 @@ class AMDGPULegalizerInfo : public LegalizerInfo {
                                 MachineIRBuilder &MIRBuilder) const;
   bool legalizeInsertVectorElt(MachineInstr &MI, MachineRegisterInfo &MRI,
                                MachineIRBuilder &MIRBuilder) const;
+  bool legalizeSinCos(MachineInstr &MI, MachineRegisterInfo &MRI,
+                      MachineIRBuilder &MIRBuilder) const;
 
   Register getLiveInRegister(MachineRegisterInfo &MRI,
                              Register Reg, LLT Ty) const;