llvm-6502/lib/Target/PTX/PTXISelLowering.cpp
Justin Holewinski 7c9dd62441 PTX: Remove physical register defs
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@140310 91177308-0d34-0410-b5e6-96231b3b80d8
2011-09-22 16:45:48 +00:00

465 lines
15 KiB
C++

//===-- PTXISelLowering.cpp - PTX DAG Lowering Implementation -------------===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file implements the PTXTargetLowering class.
//
//===----------------------------------------------------------------------===//
#include "PTX.h"
#include "PTXISelLowering.h"
#include "PTXMachineFunctionInfo.h"
#include "PTXRegisterInfo.h"
#include "PTXSubtarget.h"
#include "llvm/Support/ErrorHandling.h"
#include "llvm/CodeGen/CallingConvLower.h"
#include "llvm/CodeGen/MachineFunction.h"
#include "llvm/CodeGen/MachineRegisterInfo.h"
#include "llvm/CodeGen/SelectionDAG.h"
#include "llvm/CodeGen/TargetLoweringObjectFileImpl.h"
#include "llvm/Support/Debug.h"
#include "llvm/Support/raw_ostream.h"
using namespace llvm;
//===----------------------------------------------------------------------===//
// TargetLowering Implementation
//===----------------------------------------------------------------------===//
PTXTargetLowering::PTXTargetLowering(TargetMachine &TM)
: TargetLowering(TM, new TargetLoweringObjectFileELF()) {
// Set up the register classes.
addRegisterClass(MVT::i1, PTX::RegPredRegisterClass);
addRegisterClass(MVT::i16, PTX::RegI16RegisterClass);
addRegisterClass(MVT::i32, PTX::RegI32RegisterClass);
addRegisterClass(MVT::i64, PTX::RegI64RegisterClass);
addRegisterClass(MVT::f32, PTX::RegF32RegisterClass);
addRegisterClass(MVT::f64, PTX::RegF64RegisterClass);
setBooleanContents(ZeroOrOneBooleanContent);
setBooleanVectorContents(ZeroOrOneBooleanContent); // FIXME: Is this correct?
setMinFunctionAlignment(2);
////////////////////////////////////
/////////// Expansion //////////////
////////////////////////////////////
// (any/zero/sign) extload => load + (any/zero/sign) extend
setLoadExtAction(ISD::EXTLOAD, MVT::i16, Expand);
setLoadExtAction(ISD::ZEXTLOAD, MVT::i16, Expand);
setLoadExtAction(ISD::SEXTLOAD, MVT::i16, Expand);
// f32 extload => load + fextend
setLoadExtAction(ISD::EXTLOAD, MVT::f32, Expand);
// f64 truncstore => trunc + store
setTruncStoreAction(MVT::f64, MVT::f32, Expand);
// sign_extend_inreg => sign_extend
setOperationAction(ISD::SIGN_EXTEND_INREG, MVT::i1, Expand);
// br_cc => brcond
setOperationAction(ISD::BR_CC, MVT::Other, Expand);
// select_cc => setcc
setOperationAction(ISD::SELECT_CC, MVT::Other, Expand);
setOperationAction(ISD::SELECT_CC, MVT::f32, Expand);
setOperationAction(ISD::SELECT_CC, MVT::f64, Expand);
////////////////////////////////////
//////////// Legal /////////////////
////////////////////////////////////
setOperationAction(ISD::ConstantFP, MVT::f32, Legal);
setOperationAction(ISD::ConstantFP, MVT::f64, Legal);
////////////////////////////////////
//////////// Custom ////////////////
////////////////////////////////////
// customise setcc to use bitwise logic if possible
setOperationAction(ISD::SETCC, MVT::i1, Custom);
// customize translation of memory addresses
setOperationAction(ISD::GlobalAddress, MVT::i32, Custom);
setOperationAction(ISD::GlobalAddress, MVT::i64, Custom);
// Compute derived properties from the register classes
computeRegisterProperties();
}
EVT PTXTargetLowering::getSetCCResultType(EVT VT) const {
return MVT::i1;
}
SDValue PTXTargetLowering::LowerOperation(SDValue Op, SelectionDAG &DAG) const {
switch (Op.getOpcode()) {
default:
llvm_unreachable("Unimplemented operand");
case ISD::SETCC:
return LowerSETCC(Op, DAG);
case ISD::GlobalAddress:
return LowerGlobalAddress(Op, DAG);
}
}
const char *PTXTargetLowering::getTargetNodeName(unsigned Opcode) const {
switch (Opcode) {
default:
llvm_unreachable("Unknown opcode");
case PTXISD::COPY_ADDRESS:
return "PTXISD::COPY_ADDRESS";
case PTXISD::LOAD_PARAM:
return "PTXISD::LOAD_PARAM";
case PTXISD::STORE_PARAM:
return "PTXISD::STORE_PARAM";
case PTXISD::READ_PARAM:
return "PTXISD::READ_PARAM";
case PTXISD::WRITE_PARAM:
return "PTXISD::WRITE_PARAM";
case PTXISD::EXIT:
return "PTXISD::EXIT";
case PTXISD::RET:
return "PTXISD::RET";
case PTXISD::CALL:
return "PTXISD::CALL";
}
}
//===----------------------------------------------------------------------===//
// Custom Lower Operation
//===----------------------------------------------------------------------===//
SDValue PTXTargetLowering::LowerSETCC(SDValue Op, SelectionDAG &DAG) const {
assert(Op.getValueType() == MVT::i1 && "SetCC type must be 1-bit integer");
SDValue Op0 = Op.getOperand(0);
SDValue Op1 = Op.getOperand(1);
SDValue Op2 = Op.getOperand(2);
DebugLoc dl = Op.getDebugLoc();
ISD::CondCode CC = cast<CondCodeSDNode>(Op.getOperand(2))->get();
// Look for X == 0, X == 1, X != 0, or X != 1
// We can simplify these to bitwise logic
if (Op1.getOpcode() == ISD::Constant &&
(cast<ConstantSDNode>(Op1)->getZExtValue() == 1 ||
cast<ConstantSDNode>(Op1)->isNullValue()) &&
(CC == ISD::SETEQ || CC == ISD::SETNE)) {
return DAG.getNode(ISD::AND, dl, MVT::i1, Op0, Op1);
}
return DAG.getNode(ISD::SETCC, dl, MVT::i1, Op0, Op1, Op2);
}
SDValue PTXTargetLowering::
LowerGlobalAddress(SDValue Op, SelectionDAG &DAG) const {
EVT PtrVT = getPointerTy();
DebugLoc dl = Op.getDebugLoc();
const GlobalValue *GV = cast<GlobalAddressSDNode>(Op)->getGlobal();
assert(PtrVT.isSimple() && "Pointer must be to primitive type.");
SDValue targetGlobal = DAG.getTargetGlobalAddress(GV, dl, PtrVT);
SDValue movInstr = DAG.getNode(PTXISD::COPY_ADDRESS,
dl,
PtrVT.getSimpleVT(),
targetGlobal);
return movInstr;
}
//===----------------------------------------------------------------------===//
// Calling Convention Implementation
//===----------------------------------------------------------------------===//
SDValue PTXTargetLowering::
LowerFormalArguments(SDValue Chain,
CallingConv::ID CallConv,
bool isVarArg,
const SmallVectorImpl<ISD::InputArg> &Ins,
DebugLoc dl,
SelectionDAG &DAG,
SmallVectorImpl<SDValue> &InVals) const {
if (isVarArg) llvm_unreachable("PTX does not support varargs");
MachineFunction &MF = DAG.getMachineFunction();
const PTXSubtarget& ST = getTargetMachine().getSubtarget<PTXSubtarget>();
PTXMachineFunctionInfo *MFI = MF.getInfo<PTXMachineFunctionInfo>();
switch (CallConv) {
default:
llvm_unreachable("Unsupported calling convention");
break;
case CallingConv::PTX_Kernel:
MFI->setKernel(true);
break;
case CallingConv::PTX_Device:
MFI->setKernel(false);
break;
}
// We do one of two things here:
// IsKernel || SM >= 2.0 -> Use param space for arguments
// SM < 2.0 -> Use registers for arguments
if (MFI->isKernel() || ST.useParamSpaceForDeviceArgs()) {
// We just need to emit the proper LOAD_PARAM ISDs
for (unsigned i = 0, e = Ins.size(); i != e; ++i) {
assert((!MFI->isKernel() || Ins[i].VT != MVT::i1) &&
"Kernels cannot take pred operands");
SDValue ArgValue = DAG.getNode(PTXISD::LOAD_PARAM, dl, Ins[i].VT, Chain,
DAG.getTargetConstant(i, MVT::i32));
InVals.push_back(ArgValue);
// Instead of storing a physical register in our argument list, we just
// store the total size of the parameter, in bits. The ASM printer
// knows how to process this.
MFI->addArgParam(Ins[i].VT.getStoreSizeInBits());
}
}
else {
// For device functions, we use the PTX calling convention to do register
// assignments then create CopyFromReg ISDs for the allocated registers
//SmallVector<CCValAssign, 16> ArgLocs;
//CCState CCInfo(CallConv, isVarArg, MF, getTargetMachine(), ArgLocs,
// *DAG.getContext());
//CCInfo.AnalyzeFormalArguments(Ins, CC_PTX);
//for (unsigned i = 0, e = ArgLocs.size(); i != e; ++i) {
for (unsigned i = 0, e = Ins.size(); i != e; ++i) {
EVT RegVT = Ins[i].VT;
TargetRegisterClass* TRC = 0;
int OpCode;
//assert(VA.isRegLoc() && "CCValAssign must be RegLoc");
// Determine which register class we need
if (RegVT == MVT::i1) {
TRC = PTX::RegPredRegisterClass;
OpCode = PTX::READPARAMPRED;
}
else if (RegVT == MVT::i16) {
TRC = PTX::RegI16RegisterClass;
OpCode = PTX::READPARAMI16;
}
else if (RegVT == MVT::i32) {
TRC = PTX::RegI32RegisterClass;
OpCode = PTX::READPARAMI32;
}
else if (RegVT == MVT::i64) {
TRC = PTX::RegI64RegisterClass;
OpCode = PTX::READPARAMI64;
}
else if (RegVT == MVT::f32) {
TRC = PTX::RegF32RegisterClass;
OpCode = PTX::READPARAMF32;
}
else if (RegVT == MVT::f64) {
TRC = PTX::RegF64RegisterClass;
OpCode = PTX::READPARAMF64;
}
else {
llvm_unreachable("Unknown parameter type");
}
// Use a unique index in the instruction to prevent instruction folding.
// Yes, this is a hack.
SDValue Index = DAG.getTargetConstant(i, MVT::i32);
unsigned Reg = MF.getRegInfo().createVirtualRegister(TRC);
SDValue ArgValue = DAG.getNode(PTXISD::READ_PARAM, dl, RegVT, Chain,
Index);
SDValue Flag = ArgValue.getValue(1);
SDValue Copy = DAG.getCopyFromReg(Chain, dl, Reg, RegVT);
SDValue RegValue = DAG.getRegister(Reg, RegVT);
InVals.push_back(ArgValue);
MFI->addArgReg(Reg);
}
}
return Chain;
}
SDValue PTXTargetLowering::
LowerReturn(SDValue Chain,
CallingConv::ID CallConv,
bool isVarArg,
const SmallVectorImpl<ISD::OutputArg> &Outs,
const SmallVectorImpl<SDValue> &OutVals,
DebugLoc dl,
SelectionDAG &DAG) const {
if (isVarArg) llvm_unreachable("PTX does not support varargs");
switch (CallConv) {
default:
llvm_unreachable("Unsupported calling convention.");
case CallingConv::PTX_Kernel:
assert(Outs.size() == 0 && "Kernel must return void.");
return DAG.getNode(PTXISD::EXIT, dl, MVT::Other, Chain);
case CallingConv::PTX_Device:
assert(Outs.size() <= 1 && "Can at most return one value.");
break;
}
MachineFunction& MF = DAG.getMachineFunction();
PTXMachineFunctionInfo *MFI = MF.getInfo<PTXMachineFunctionInfo>();
SDValue Flag;
// Even though we could use the .param space for return arguments for
// device functions if SM >= 2.0 and the number of return arguments is
// only 1, we just always use registers since this makes the codegen
// easier.
const PTXSubtarget& ST = getTargetMachine().getSubtarget<PTXSubtarget>();
if (ST.useParamSpaceForDeviceArgs()) {
assert(Outs.size() < 2 && "Device functions can return at most one value");
if (Outs.size() == 1) {
unsigned Size = OutVals[0].getValueType().getSizeInBits();
SDValue Index = DAG.getTargetConstant(MFI->getNextParam(Size), MVT::i32);
Chain = DAG.getNode(PTXISD::STORE_PARAM, dl, MVT::Other, Chain,
Index, OutVals[0]);
//Flag = Chain.getValue(1);
MFI->setRetParamSize(Outs[0].VT.getStoreSizeInBits());
}
} else {
//SmallVector<CCValAssign, 16> RVLocs;
//CCState CCInfo(CallConv, isVarArg, DAG.getMachineFunction(),
//getTargetMachine(), RVLocs, *DAG.getContext());
//CCInfo.AnalyzeReturn(Outs, RetCC_PTX);
//for (unsigned i = 0, e = RVLocs.size(); i != e; ++i) {
//CCValAssign& VA = RVLocs[i];
for (unsigned i = 0, e = Outs.size(); i != e; ++i) {
//assert(VA.isRegLoc() && "CCValAssign must be RegLoc");
//unsigned Reg = VA.getLocReg();
EVT RegVT = Outs[i].VT;
TargetRegisterClass* TRC = 0;
// Determine which register class we need
if (RegVT == MVT::i1) {
TRC = PTX::RegPredRegisterClass;
}
else if (RegVT == MVT::i16) {
TRC = PTX::RegI16RegisterClass;
}
else if (RegVT == MVT::i32) {
TRC = PTX::RegI32RegisterClass;
}
else if (RegVT == MVT::i64) {
TRC = PTX::RegI64RegisterClass;
}
else if (RegVT == MVT::f32) {
TRC = PTX::RegF32RegisterClass;
}
else if (RegVT == MVT::f64) {
TRC = PTX::RegF64RegisterClass;
}
else {
llvm_unreachable("Unknown parameter type");
}
unsigned Reg = MF.getRegInfo().createVirtualRegister(TRC);
//DAG.getMachineFunction().getRegInfo().addLiveOut(Reg);
//Chain = DAG.getCopyToReg(Chain, dl, Reg, OutVals[i], Flag);
//SDValue Copy = DAG.getCopyToReg(Chain, dl, Reg, OutVals[i]/*, Flag*/);
// Guarantee that all emitted copies are stuck together,
// avoiding something bad
//Flag = Chain.getValue(1);
SDValue Copy = DAG.getCopyToReg(Chain, dl, Reg, OutVals[i]/*, Flag*/);
SDValue OutReg = DAG.getRegister(Reg, RegVT);
Chain = DAG.getNode(PTXISD::WRITE_PARAM, dl, MVT::Other, Copy, OutReg);
//Flag = Chain.getValue(1);
MFI->addRetReg(Reg);
//MFI->addRetReg(Reg);
}
}
if (Flag.getNode() == 0) {
return DAG.getNode(PTXISD::RET, dl, MVT::Other, Chain);
}
else {
return DAG.getNode(PTXISD::RET, dl, MVT::Other, Chain, Flag);
}
}
SDValue
PTXTargetLowering::LowerCall(SDValue Chain, SDValue Callee,
CallingConv::ID CallConv, bool isVarArg,
bool &isTailCall,
const SmallVectorImpl<ISD::OutputArg> &Outs,
const SmallVectorImpl<SDValue> &OutVals,
const SmallVectorImpl<ISD::InputArg> &Ins,
DebugLoc dl, SelectionDAG &DAG,
SmallVectorImpl<SDValue> &InVals) const {
MachineFunction& MF = DAG.getMachineFunction();
PTXMachineFunctionInfo *MFI = MF.getInfo<PTXMachineFunctionInfo>();
assert(getTargetMachine().getSubtarget<PTXSubtarget>().callsAreHandled() &&
"Calls are not handled for the target device");
// Is there a more "LLVM"-way to create a variable-length array of values?
SDValue* ops = new SDValue[OutVals.size() + 2];
ops[0] = Chain;
if (GlobalAddressSDNode *G = dyn_cast<GlobalAddressSDNode>(Callee)) {
const GlobalValue *GV = G->getGlobal();
Callee = DAG.getTargetGlobalAddress(GV, dl, getPointerTy());
ops[1] = Callee;
} else {
assert(false && "Function must be a GlobalAddressSDNode");
}
for (unsigned i = 0; i != OutVals.size(); ++i) {
unsigned Size = OutVals[i].getValueType().getSizeInBits();
SDValue Index = DAG.getTargetConstant(MFI->getNextParam(Size), MVT::i32);
Chain = DAG.getNode(PTXISD::STORE_PARAM, dl, MVT::Other, Chain,
Index, OutVals[i]);
ops[i+2] = Index;
}
ops[0] = Chain;
Chain = DAG.getNode(PTXISD::CALL, dl, MVT::Other, ops, OutVals.size()+2);
delete [] ops;
return Chain;
}