llvm-6502/lib/Target/R600/AMDILISelDAGToDAG.cpp
Tom Stellard 9f7818d9bd R600: rework handling of the constants
Remove Cxxx registers, add new special register - "ALU_CONST" and new
operand for each alu src - "sel". ALU_CONST is used to designate that the
new operand contains the value to override src.sel, src.kc_bank, src.chan
for constants in the driver.

Patch by: Vadim Girlin

Vincent Lejeune:
  - Use pointers for constants
  - Fold CONST_ADDRESS when possible

Tom Stellard:
  - Give CONSTANT_BUFFER_0 its own address space
  - Use integer types for constant loads

Reviewed-by: Tom Stellard <thomas.stellard@amd.com>

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@173222 91177308-0d34-0410-b5e6-96231b3b80d8
2013-01-23 02:09:06 +00:00

568 lines
18 KiB
C++

//===-- AMDILISelDAGToDAG.cpp - A dag to dag inst selector for AMDIL ------===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//==-----------------------------------------------------------------------===//
//
/// \file
/// \brief Defines an instruction selector for the AMDGPU target.
//
//===----------------------------------------------------------------------===//
#include "AMDGPUInstrInfo.h"
#include "AMDGPUISelLowering.h" // For AMDGPUISD
#include "AMDGPURegisterInfo.h"
#include "AMDILDevices.h"
#include "R600InstrInfo.h"
#include "llvm/ADT/ValueMap.h"
#include "llvm/CodeGen/PseudoSourceValue.h"
#include "llvm/CodeGen/SelectionDAGISel.h"
#include "llvm/Support/Compiler.h"
#include "llvm/CodeGen/SelectionDAG.h"
#include <list>
#include <queue>
using namespace llvm;
//===----------------------------------------------------------------------===//
// Instruction Selector Implementation
//===----------------------------------------------------------------------===//
namespace {
/// AMDGPU specific code to select AMDGPU machine instructions for
/// SelectionDAG operations.
class AMDGPUDAGToDAGISel : public SelectionDAGISel {
// Subtarget - Keep a pointer to the AMDGPU Subtarget around so that we can
// make the right decision when generating code for different targets.
const AMDGPUSubtarget &Subtarget;
public:
AMDGPUDAGToDAGISel(TargetMachine &TM);
virtual ~AMDGPUDAGToDAGISel();
SDNode *Select(SDNode *N);
virtual const char *getPassName() const;
private:
inline SDValue getSmallIPtrImm(unsigned Imm);
bool FoldOperands(unsigned, const R600InstrInfo *, std::vector<SDValue> &);
// Complex pattern selectors
bool SelectADDRParam(SDValue Addr, SDValue& R1, SDValue& R2);
bool SelectADDR(SDValue N, SDValue &R1, SDValue &R2);
bool SelectADDR64(SDValue N, SDValue &R1, SDValue &R2);
static bool checkType(const Value *ptr, unsigned int addrspace);
static const Value *getBasePointerValue(const Value *V);
static bool isGlobalStore(const StoreSDNode *N);
static bool isPrivateStore(const StoreSDNode *N);
static bool isLocalStore(const StoreSDNode *N);
static bool isRegionStore(const StoreSDNode *N);
static bool isCPLoad(const LoadSDNode *N);
static bool isConstantLoad(const LoadSDNode *N, int cbID);
static bool isGlobalLoad(const LoadSDNode *N);
static bool isParamLoad(const LoadSDNode *N);
static bool isPrivateLoad(const LoadSDNode *N);
static bool isLocalLoad(const LoadSDNode *N);
static bool isRegionLoad(const LoadSDNode *N);
bool SelectGlobalValueConstantOffset(SDValue Addr, SDValue& IntPtr);
bool SelectGlobalValueVariableOffset(SDValue Addr,
SDValue &BaseReg, SDValue& Offset);
bool SelectADDR8BitOffset(SDValue Addr, SDValue& Base, SDValue& Offset);
bool SelectADDRReg(SDValue Addr, SDValue& Base, SDValue& Offset);
bool SelectADDRVTX_READ(SDValue Addr, SDValue &Base, SDValue &Offset);
// Include the pieces autogenerated from the target description.
#include "AMDGPUGenDAGISel.inc"
};
} // end anonymous namespace
/// \brief This pass converts a legalized DAG into a AMDGPU-specific
// DAG, ready for instruction scheduling.
FunctionPass *llvm::createAMDGPUISelDag(TargetMachine &TM
) {
return new AMDGPUDAGToDAGISel(TM);
}
AMDGPUDAGToDAGISel::AMDGPUDAGToDAGISel(TargetMachine &TM
)
: SelectionDAGISel(TM), Subtarget(TM.getSubtarget<AMDGPUSubtarget>()) {
}
AMDGPUDAGToDAGISel::~AMDGPUDAGToDAGISel() {
}
SDValue AMDGPUDAGToDAGISel::getSmallIPtrImm(unsigned int Imm) {
return CurDAG->getTargetConstant(Imm, MVT::i32);
}
bool AMDGPUDAGToDAGISel::SelectADDRParam(
SDValue Addr, SDValue& R1, SDValue& R2) {
if (Addr.getOpcode() == ISD::FrameIndex) {
if (FrameIndexSDNode *FIN = dyn_cast<FrameIndexSDNode>(Addr)) {
R1 = CurDAG->getTargetFrameIndex(FIN->getIndex(), MVT::i32);
R2 = CurDAG->getTargetConstant(0, MVT::i32);
} else {
R1 = Addr;
R2 = CurDAG->getTargetConstant(0, MVT::i32);
}
} else if (Addr.getOpcode() == ISD::ADD) {
R1 = Addr.getOperand(0);
R2 = Addr.getOperand(1);
} else {
R1 = Addr;
R2 = CurDAG->getTargetConstant(0, MVT::i32);
}
return true;
}
bool AMDGPUDAGToDAGISel::SelectADDR(SDValue Addr, SDValue& R1, SDValue& R2) {
if (Addr.getOpcode() == ISD::TargetExternalSymbol ||
Addr.getOpcode() == ISD::TargetGlobalAddress) {
return false;
}
return SelectADDRParam(Addr, R1, R2);
}
bool AMDGPUDAGToDAGISel::SelectADDR64(SDValue Addr, SDValue& R1, SDValue& R2) {
if (Addr.getOpcode() == ISD::TargetExternalSymbol ||
Addr.getOpcode() == ISD::TargetGlobalAddress) {
return false;
}
if (Addr.getOpcode() == ISD::FrameIndex) {
if (FrameIndexSDNode *FIN = dyn_cast<FrameIndexSDNode>(Addr)) {
R1 = CurDAG->getTargetFrameIndex(FIN->getIndex(), MVT::i64);
R2 = CurDAG->getTargetConstant(0, MVT::i64);
} else {
R1 = Addr;
R2 = CurDAG->getTargetConstant(0, MVT::i64);
}
} else if (Addr.getOpcode() == ISD::ADD) {
R1 = Addr.getOperand(0);
R2 = Addr.getOperand(1);
} else {
R1 = Addr;
R2 = CurDAG->getTargetConstant(0, MVT::i64);
}
return true;
}
SDNode *AMDGPUDAGToDAGISel::Select(SDNode *N) {
unsigned int Opc = N->getOpcode();
if (N->isMachineOpcode()) {
return NULL; // Already selected.
}
switch (Opc) {
default: break;
case ISD::FrameIndex: {
if (FrameIndexSDNode *FIN = dyn_cast<FrameIndexSDNode>(N)) {
unsigned int FI = FIN->getIndex();
EVT OpVT = N->getValueType(0);
unsigned int NewOpc = AMDGPU::COPY;
SDValue TFI = CurDAG->getTargetFrameIndex(FI, MVT::i32);
return CurDAG->SelectNodeTo(N, NewOpc, OpVT, TFI);
}
break;
}
case ISD::ConstantFP:
case ISD::Constant: {
const AMDGPUSubtarget &ST = TM.getSubtarget<AMDGPUSubtarget>();
// XXX: Custom immediate lowering not implemented yet. Instead we use
// pseudo instructions defined in SIInstructions.td
if (ST.device()->getGeneration() > AMDGPUDeviceInfo::HD6XXX) {
break;
}
const R600InstrInfo *TII = static_cast<const R600InstrInfo*>(TM.getInstrInfo());
uint64_t ImmValue = 0;
unsigned ImmReg = AMDGPU::ALU_LITERAL_X;
if (N->getOpcode() == ISD::ConstantFP) {
// XXX: 64-bit Immediates not supported yet
assert(N->getValueType(0) != MVT::f64);
ConstantFPSDNode *C = dyn_cast<ConstantFPSDNode>(N);
APFloat Value = C->getValueAPF();
float FloatValue = Value.convertToFloat();
if (FloatValue == 0.0) {
ImmReg = AMDGPU::ZERO;
} else if (FloatValue == 0.5) {
ImmReg = AMDGPU::HALF;
} else if (FloatValue == 1.0) {
ImmReg = AMDGPU::ONE;
} else {
ImmValue = Value.bitcastToAPInt().getZExtValue();
}
} else {
// XXX: 64-bit Immediates not supported yet
assert(N->getValueType(0) != MVT::i64);
ConstantSDNode *C = dyn_cast<ConstantSDNode>(N);
if (C->getZExtValue() == 0) {
ImmReg = AMDGPU::ZERO;
} else if (C->getZExtValue() == 1) {
ImmReg = AMDGPU::ONE_INT;
} else {
ImmValue = C->getZExtValue();
}
}
for (SDNode::use_iterator Use = N->use_begin(), Next = llvm::next(Use);
Use != SDNode::use_end(); Use = Next) {
Next = llvm::next(Use);
std::vector<SDValue> Ops;
for (unsigned i = 0; i < Use->getNumOperands(); ++i) {
Ops.push_back(Use->getOperand(i));
}
if (!Use->isMachineOpcode()) {
if (ImmReg == AMDGPU::ALU_LITERAL_X) {
// We can only use literal constants (e.g. AMDGPU::ZERO,
// AMDGPU::ONE, etc) in machine opcodes.
continue;
}
} else {
if (!TII->isALUInstr(Use->getMachineOpcode())) {
continue;
}
int ImmIdx = TII->getOperandIdx(Use->getMachineOpcode(), R600Operands::IMM);
assert(ImmIdx != -1);
// subtract one from ImmIdx, because the DST operand is usually index
// 0 for MachineInstrs, but we have no DST in the Ops vector.
ImmIdx--;
// Check that we aren't already using an immediate.
// XXX: It's possible for an instruction to have more than one
// immediate operand, but this is not supported yet.
if (ImmReg == AMDGPU::ALU_LITERAL_X) {
ConstantSDNode *C = dyn_cast<ConstantSDNode>(Use->getOperand(ImmIdx));
assert(C);
if (C->getZExtValue() != 0) {
// This instruction is already using an immediate.
continue;
}
// Set the immediate value
Ops[ImmIdx] = CurDAG->getTargetConstant(ImmValue, MVT::i32);
}
}
// Set the immediate register
Ops[Use.getOperandNo()] = CurDAG->getRegister(ImmReg, MVT::i32);
CurDAG->UpdateNodeOperands(*Use, Ops.data(), Use->getNumOperands());
}
break;
}
}
SDNode *Result = SelectCode(N);
// Fold operands of selected node
const AMDGPUSubtarget &ST = TM.getSubtarget<AMDGPUSubtarget>();
if (ST.device()->getGeneration() <= AMDGPUDeviceInfo::HD6XXX) {
const R600InstrInfo *TII =
static_cast<const R600InstrInfo*>(TM.getInstrInfo());
if (Result && TII->isALUInstr(Result->getMachineOpcode())) {
bool IsModified = false;
do {
std::vector<SDValue> Ops;
for(SDNode::op_iterator I = Result->op_begin(), E = Result->op_end();
I != E; ++I)
Ops.push_back(*I);
IsModified = FoldOperands(Result->getMachineOpcode(), TII, Ops);
if (IsModified) {
Result = CurDAG->MorphNodeTo(Result, Result->getOpcode(),
Result->getVTList(), Ops.data(), Ops.size());
}
} while (IsModified);
}
}
return Result;
}
bool AMDGPUDAGToDAGISel::FoldOperands(unsigned Opcode,
const R600InstrInfo *TII, std::vector<SDValue> &Ops) {
int OperandIdx[] = {
TII->getOperandIdx(Opcode, R600Operands::SRC0),
TII->getOperandIdx(Opcode, R600Operands::SRC1),
TII->getOperandIdx(Opcode, R600Operands::SRC2)
};
int SelIdx[] = {
TII->getOperandIdx(Opcode, R600Operands::SRC0_SEL),
TII->getOperandIdx(Opcode, R600Operands::SRC1_SEL),
TII->getOperandIdx(Opcode, R600Operands::SRC2_SEL)
};
for (unsigned i = 0; i < 3; i++) {
if (OperandIdx[i] < 0)
return false;
SDValue Operand = Ops[OperandIdx[i] - 1];
switch (Operand.getOpcode()) {
case AMDGPUISD::CONST_ADDRESS: {
SDValue CstOffset;
if (!Operand.getValueType().isVector() &&
SelectGlobalValueConstantOffset(Operand.getOperand(0), CstOffset)) {
Ops[OperandIdx[i] - 1] = CurDAG->getRegister(AMDGPU::ALU_CONST, MVT::f32);
Ops[SelIdx[i] - 1] = CstOffset;
return true;
}
}
break;
default:
break;
}
}
return false;
}
bool AMDGPUDAGToDAGISel::checkType(const Value *ptr, unsigned int addrspace) {
if (!ptr) {
return false;
}
Type *ptrType = ptr->getType();
return dyn_cast<PointerType>(ptrType)->getAddressSpace() == addrspace;
}
const Value * AMDGPUDAGToDAGISel::getBasePointerValue(const Value *V) {
if (!V) {
return NULL;
}
const Value *ret = NULL;
ValueMap<const Value *, bool> ValueBitMap;
std::queue<const Value *, std::list<const Value *> > ValueQueue;
ValueQueue.push(V);
while (!ValueQueue.empty()) {
V = ValueQueue.front();
if (ValueBitMap.find(V) == ValueBitMap.end()) {
ValueBitMap[V] = true;
if (dyn_cast<Argument>(V) && dyn_cast<PointerType>(V->getType())) {
ret = V;
break;
} else if (dyn_cast<GlobalVariable>(V)) {
ret = V;
break;
} else if (dyn_cast<Constant>(V)) {
const ConstantExpr *CE = dyn_cast<ConstantExpr>(V);
if (CE) {
ValueQueue.push(CE->getOperand(0));
}
} else if (const AllocaInst *AI = dyn_cast<AllocaInst>(V)) {
ret = AI;
break;
} else if (const Instruction *I = dyn_cast<Instruction>(V)) {
uint32_t numOps = I->getNumOperands();
for (uint32_t x = 0; x < numOps; ++x) {
ValueQueue.push(I->getOperand(x));
}
} else {
assert(!"Found a Value that we didn't know how to handle!");
}
}
ValueQueue.pop();
}
return ret;
}
bool AMDGPUDAGToDAGISel::isGlobalStore(const StoreSDNode *N) {
return checkType(N->getSrcValue(), AMDGPUAS::GLOBAL_ADDRESS);
}
bool AMDGPUDAGToDAGISel::isPrivateStore(const StoreSDNode *N) {
return (!checkType(N->getSrcValue(), AMDGPUAS::LOCAL_ADDRESS)
&& !checkType(N->getSrcValue(), AMDGPUAS::GLOBAL_ADDRESS)
&& !checkType(N->getSrcValue(), AMDGPUAS::REGION_ADDRESS));
}
bool AMDGPUDAGToDAGISel::isLocalStore(const StoreSDNode *N) {
return checkType(N->getSrcValue(), AMDGPUAS::LOCAL_ADDRESS);
}
bool AMDGPUDAGToDAGISel::isRegionStore(const StoreSDNode *N) {
return checkType(N->getSrcValue(), AMDGPUAS::REGION_ADDRESS);
}
bool AMDGPUDAGToDAGISel::isConstantLoad(const LoadSDNode *N, int cbID) {
if (checkType(N->getSrcValue(), AMDGPUAS::CONSTANT_ADDRESS)) {
return true;
}
MachineMemOperand *MMO = N->getMemOperand();
const Value *V = MMO->getValue();
const Value *BV = getBasePointerValue(V);
if (MMO
&& MMO->getValue()
&& ((V && dyn_cast<GlobalValue>(V))
|| (BV && dyn_cast<GlobalValue>(
getBasePointerValue(MMO->getValue()))))) {
return checkType(N->getSrcValue(), AMDGPUAS::PRIVATE_ADDRESS);
} else {
return false;
}
}
bool AMDGPUDAGToDAGISel::isGlobalLoad(const LoadSDNode *N) {
return checkType(N->getSrcValue(), AMDGPUAS::GLOBAL_ADDRESS);
}
bool AMDGPUDAGToDAGISel::isParamLoad(const LoadSDNode *N) {
return checkType(N->getSrcValue(), AMDGPUAS::PARAM_I_ADDRESS);
}
bool AMDGPUDAGToDAGISel::isLocalLoad(const LoadSDNode *N) {
return checkType(N->getSrcValue(), AMDGPUAS::LOCAL_ADDRESS);
}
bool AMDGPUDAGToDAGISel::isRegionLoad(const LoadSDNode *N) {
return checkType(N->getSrcValue(), AMDGPUAS::REGION_ADDRESS);
}
bool AMDGPUDAGToDAGISel::isCPLoad(const LoadSDNode *N) {
MachineMemOperand *MMO = N->getMemOperand();
if (checkType(N->getSrcValue(), AMDGPUAS::PRIVATE_ADDRESS)) {
if (MMO) {
const Value *V = MMO->getValue();
const PseudoSourceValue *PSV = dyn_cast<PseudoSourceValue>(V);
if (PSV && PSV == PseudoSourceValue::getConstantPool()) {
return true;
}
}
}
return false;
}
bool AMDGPUDAGToDAGISel::isPrivateLoad(const LoadSDNode *N) {
if (checkType(N->getSrcValue(), AMDGPUAS::PRIVATE_ADDRESS)) {
// Check to make sure we are not a constant pool load or a constant load
// that is marked as a private load
if (isCPLoad(N) || isConstantLoad(N, -1)) {
return false;
}
}
if (!checkType(N->getSrcValue(), AMDGPUAS::LOCAL_ADDRESS)
&& !checkType(N->getSrcValue(), AMDGPUAS::GLOBAL_ADDRESS)
&& !checkType(N->getSrcValue(), AMDGPUAS::REGION_ADDRESS)
&& !checkType(N->getSrcValue(), AMDGPUAS::CONSTANT_ADDRESS)
&& !checkType(N->getSrcValue(), AMDGPUAS::PARAM_D_ADDRESS)
&& !checkType(N->getSrcValue(), AMDGPUAS::PARAM_I_ADDRESS)) {
return true;
}
return false;
}
const char *AMDGPUDAGToDAGISel::getPassName() const {
return "AMDGPU DAG->DAG Pattern Instruction Selection";
}
#ifdef DEBUGTMP
#undef INT64_C
#endif
#undef DEBUGTMP
///==== AMDGPU Functions ====///
bool AMDGPUDAGToDAGISel::SelectGlobalValueConstantOffset(SDValue Addr,
SDValue& IntPtr) {
if (ConstantSDNode *Cst = dyn_cast<ConstantSDNode>(Addr)) {
IntPtr = CurDAG->getIntPtrConstant(Cst->getZExtValue() / 4, true);
return true;
}
return false;
}
bool AMDGPUDAGToDAGISel::SelectGlobalValueVariableOffset(SDValue Addr,
SDValue& BaseReg, SDValue &Offset) {
if (!dyn_cast<ConstantSDNode>(Addr)) {
BaseReg = Addr;
Offset = CurDAG->getIntPtrConstant(0, true);
return true;
}
return false;
}
bool AMDGPUDAGToDAGISel::SelectADDR8BitOffset(SDValue Addr, SDValue& Base,
SDValue& Offset) {
if (Addr.getOpcode() == ISD::TargetExternalSymbol ||
Addr.getOpcode() == ISD::TargetGlobalAddress) {
return false;
}
if (Addr.getOpcode() == ISD::ADD) {
bool Match = false;
// Find the base ptr and the offset
for (unsigned i = 0; i < Addr.getNumOperands(); i++) {
SDValue Arg = Addr.getOperand(i);
ConstantSDNode * OffsetNode = dyn_cast<ConstantSDNode>(Arg);
// This arg isn't a constant so it must be the base PTR.
if (!OffsetNode) {
Base = Addr.getOperand(i);
continue;
}
// Check if the constant argument fits in 8-bits. The offset is in bytes
// so we need to convert it to dwords.
if (isUInt<8>(OffsetNode->getZExtValue() >> 2)) {
Match = true;
Offset = CurDAG->getTargetConstant(OffsetNode->getZExtValue() >> 2,
MVT::i32);
}
}
return Match;
}
// Default case, no offset
Base = Addr;
Offset = CurDAG->getTargetConstant(0, MVT::i32);
return true;
}
bool AMDGPUDAGToDAGISel::SelectADDRVTX_READ(SDValue Addr, SDValue &Base,
SDValue &Offset) {
ConstantSDNode * IMMOffset;
if (Addr.getOpcode() == ISD::ADD
&& (IMMOffset = dyn_cast<ConstantSDNode>(Addr.getOperand(1)))
&& isInt<16>(IMMOffset->getZExtValue())) {
Base = Addr.getOperand(0);
Offset = CurDAG->getTargetConstant(IMMOffset->getZExtValue(), MVT::i32);
return true;
// If the pointer address is constant, we can move it to the offset field.
} else if ((IMMOffset = dyn_cast<ConstantSDNode>(Addr))
&& isInt<16>(IMMOffset->getZExtValue())) {
Base = CurDAG->getCopyFromReg(CurDAG->getEntryNode(),
CurDAG->getEntryNode().getDebugLoc(),
AMDGPU::ZERO, MVT::i32);
Offset = CurDAG->getTargetConstant(IMMOffset->getZExtValue(), MVT::i32);
return true;
}
// Default case, no offset
Base = Addr;
Offset = CurDAG->getTargetConstant(0, MVT::i32);
return true;
}
bool AMDGPUDAGToDAGISel::SelectADDRReg(SDValue Addr, SDValue& Base,
SDValue& Offset) {
if (Addr.getOpcode() == ISD::TargetExternalSymbol ||
Addr.getOpcode() == ISD::TargetGlobalAddress ||
Addr.getOpcode() != ISD::ADD) {
return false;
}
Base = Addr.getOperand(0);
Offset = Addr.getOperand(1);
return true;
}