R600: Use DAG lowering pass to handle fcos/fsin

NOTE: This is a candidate for the stable branch.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@185940 91177308-0d34-0410-b5e6-96231b3b80d8

lib/Target/R600/AMDGPUISelLowering.h

@@ -121,6 +121,8 @@ enum {
   // End AMDIL ISD Opcodes
   DWORDADDR,
   FRACT,
+  COS_HW,
+  SIN_HW,
   FMAX,
   SMAX,
   UMAX,

lib/Target/R600/R600ISelLowering.cpp

@@ -26,7 +26,8 @@
 using namespace llvm;
 
 R600TargetLowering::R600TargetLowering(TargetMachine &TM) :
-    AMDGPUTargetLowering(TM) {
+    AMDGPUTargetLowering(TM),
+    Gen(TM.getSubtarget<AMDGPUSubtarget>().getGeneration()) {
   addRegisterClass(MVT::v4f32, &AMDGPU::R600_Reg128RegClass);
   addRegisterClass(MVT::f32, &AMDGPU::R600_Reg32RegClass);
   addRegisterClass(MVT::v4i32, &AMDGPU::R600_Reg128RegClass);
@@ -38,6 +39,9 @@ R600TargetLowering::R600TargetLowering(TargetMachine &TM) :
   setOperationAction(ISD::FDIV, MVT::v4f32, Expand);
   setOperationAction(ISD::FSUB, MVT::v4f32, Expand);
 
+  setOperationAction(ISD::FCOS, MVT::f32, Custom);
+  setOperationAction(ISD::FSIN, MVT::f32, Custom);
+
   setOperationAction(ISD::FP_TO_SINT, MVT::v4i32, Expand);
   setOperationAction(ISD::FP_TO_UINT, MVT::v4i32, Expand);
   setOperationAction(ISD::SINT_TO_FP, MVT::v4i32, Expand);
@@ -473,6 +477,8 @@ SDValue R600TargetLowering::LowerOperation(SDValue Op, SelectionDAG &DAG) const
   R600MachineFunctionInfo *MFI = MF.getInfo<R600MachineFunctionInfo>();
   switch (Op.getOpcode()) {
   default: return AMDGPUTargetLowering::LowerOperation(Op, DAG);
+  case ISD::FCOS:
+  case ISD::FSIN: return LowerTrig(Op, DAG);
   case ISD::SELECT_CC: return LowerSELECT_CC(Op, DAG);
   case ISD::SELECT: return LowerSELECT(Op, DAG);
   case ISD::STORE: return LowerSTORE(Op, DAG);
@@ -723,6 +729,37 @@ void R600TargetLowering::ReplaceNodeResults(SDNode *N,
   }
 }
 
+SDValue R600TargetLowering::LowerTrig(SDValue Op, SelectionDAG &DAG) const {
+  // On hw >= R700, COS/SIN input must be between -1. and 1.
+  // Thus we lower them to TRIG ( FRACT ( x / 2Pi + 0.5) - 0.5)
+  EVT VT = Op.getValueType();
+  SDValue Arg = Op.getOperand(0);
+  SDValue FractPart = DAG.getNode(AMDGPUISD::FRACT, SDLoc(Op), VT,
+      DAG.getNode(ISD::FADD, SDLoc(Op), VT,
+        DAG.getNode(ISD::FMUL, SDLoc(Op), VT, Arg,
+          DAG.getConstantFP(0.15915494309, MVT::f32)),
+        DAG.getConstantFP(0.5, MVT::f32)));
+  unsigned TrigNode;
+  switch (Op.getOpcode()) {
+  case ISD::FCOS:
+    TrigNode = AMDGPUISD::COS_HW;
+    break;
+  case ISD::FSIN:
+    TrigNode = AMDGPUISD::SIN_HW;
+    break;
+  default:
+    llvm_unreachable("Wrong trig opcode");
+  }
+  SDValue TrigVal = DAG.getNode(TrigNode, SDLoc(Op), VT,
+      DAG.getNode(ISD::FADD, SDLoc(Op), VT, FractPart,
+        DAG.getConstantFP(-0.5, MVT::f32)));
+  if (Gen >= AMDGPUSubtarget::R700)
+    return TrigVal;
+  // On R600 hw, COS/SIN input must be between -Pi and Pi.
+  return DAG.getNode(ISD::FMUL, SDLoc(Op), VT, TrigVal,
+      DAG.getConstantFP(3.14159265359, MVT::f32));
+}
+
 SDValue R600TargetLowering::LowerFPTOUINT(SDValue Op, SelectionDAG &DAG) const {
   return DAG.getNode(
       ISD::SETCC,

lib/Target/R600/R600ISelLowering.h

@@ -40,6 +40,7 @@ public:
                                       SmallVectorImpl<SDValue> &InVals) const;
   virtual EVT getSetCCResultType(LLVMContext &, EVT VT) const;
 private:
+  unsigned Gen;
   /// Each OpenCL kernel has nine implicit parameters that are stored in the
   /// first nine dwords of a Vertex Buffer.  These implicit parameters are
   /// lowered to load instructions which retreive the values from the Vertex
@@ -60,6 +61,7 @@ private:
   SDValue LowerFPTOUINT(SDValue Op, SelectionDAG &DAG) const;
   SDValue LowerLOAD(SDValue Op, SelectionDAG &DAG) const;
   SDValue LowerFrameIndex(SDValue Op, SelectionDAG &DAG) const;
+  SDValue LowerTrig(SDValue Op, SelectionDAG &DAG) const;
 
   SDValue stackPtrToRegIndex(SDValue Ptr, unsigned StackWidth,
                                           SelectionDAG &DAG) const;

lib/Target/R600/R600Instructions.td

@@ -364,6 +364,14 @@ def DOT4 : SDNode<"AMDGPUISD::DOT4",
   []
 >;
 
+def COS_HW : SDNode<"AMDGPUISD::COS_HW",
+  SDTypeProfile<1, 1, [SDTCisFP<0>, SDTCisFP<1>]>
+>;
+
+def SIN_HW : SDNode<"AMDGPUISD::SIN_HW",
+  SDTypeProfile<1, 1, [SDTCisFP<0>, SDTCisFP<1>]>
+>;
+
 def TEXTURE_FETCH_Type : SDTypeProfile<1, 19, [SDTCisFP<0>]>;
 
 def TEXTURE_FETCH: SDNode<"AMDGPUISD::TEXTURE_FETCH", TEXTURE_FETCH_Type, []>;
@@ -1080,14 +1088,14 @@ class RECIPSQRT_IEEE_Common <bits<11> inst> : R600_1OP <
 }
 
 class SIN_Common <bits<11> inst> : R600_1OP <
-  inst, "SIN", []>{
+  inst, "SIN", [(set f32:$dst, (SIN_HW f32:$src0))]>{
   let Trig = 1;
   let TransOnly = 1;
   let Itinerary = TransALU;
 }
 
 class COS_Common <bits<11> inst> : R600_1OP <
-  inst, "COS", []> {
+  inst, "COS", [(set f32:$dst, (COS_HW f32:$src0))]> {
   let Trig = 1;
   let TransOnly = 1;
   let Itinerary = TransALU;
@@ -1228,18 +1236,6 @@ let Predicates = [isR600] in {
 
 }
 
-// Helper pattern for normalizing inputs to triginomic instructions for R700+
-// cards.
-class COS_PAT <InstR600 trig> : Pat<
-  (fcos f32:$src),
-  (trig (MUL_IEEE (MOV_IMM_I32 CONST.TWO_PI_INV), $src))
->;
-
-class SIN_PAT <InstR600 trig> : Pat<
-  (fsin f32:$src),
-  (trig (MUL_IEEE (MOV_IMM_I32 CONST.TWO_PI_INV), $src))
->;
-
 //===----------------------------------------------------------------------===//
 // R700 Only instructions
 //===----------------------------------------------------------------------===//
@@ -1247,10 +1243,6 @@ class SIN_PAT <InstR600 trig> : Pat<
 let Predicates = [isR700] in {
   def SIN_r700 : SIN_Common<0x6E>;
   def COS_r700 : COS_Common<0x6F>;
-
-  // R700 normalizes inputs to SIN/COS the same as EG
-  def : SIN_PAT <SIN_r700>;
-  def : COS_PAT <COS_r700>;
 }
 
 //===----------------------------------------------------------------------===//
@@ -1276,8 +1268,6 @@ def SIN_eg : SIN_Common<0x8D>;
 def COS_eg : COS_Common<0x8E>;
 
 def : POW_Common <LOG_IEEE_eg, EXP_IEEE_eg, MUL>;
-def : SIN_PAT <SIN_eg>;
-def : COS_PAT <COS_eg>;
 def : Pat<(fsqrt f32:$src), (MUL $src, (RECIPSQRT_CLAMPED_eg $src))>;
 
 //===----------------------------------------------------------------------===//
@@ -1726,8 +1716,6 @@ def COS_cm : COS_Common<0x8E>;
 } // End isVector = 1
 
 def : POW_Common <LOG_IEEE_cm, EXP_IEEE_cm, MUL>;
-def : SIN_PAT <SIN_cm>;
-def : COS_PAT <COS_cm>;
 
 defm DIV_cm : DIV_Common<RECIP_IEEE_cm>;
 

test/CodeGen/R600/llvm.cos.ll

@@ -1,5 +1,8 @@
 ;RUN: llc < %s -march=r600 -mcpu=redwood | FileCheck %s
 
+;CHECK: MULADD_IEEE *
+;CHECK: FRACT *
+;CHECK: ADD *
 ;CHECK: COS * T{{[0-9]+\.[XYZW], PV\.[XYZW]}}
 
 define void @test() {

test/CodeGen/R600/llvm.sin.ll

@@ -1,5 +1,8 @@
 ;RUN: llc < %s -march=r600 -mcpu=redwood | FileCheck %s
 
+;CHECK: MULADD_IEEE *
+;CHECK: FRACT *
+;CHECK: ADD *
 ;CHECK: SIN * T{{[0-9]+\.[XYZW], PV\.[XYZW]}}
 
 define void @test() {