llvm-6502/lib/Target/Alpha/AlphaISelDAGToDAG.cpp
Andrew Lenharth 4e62951282 Let's see if we can break things.
Lower GOT relative addresses to Lo and HI.
Update both ISels to select them when they can.
Saves instructions here and there.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@25001 91177308-0d34-0410-b5e6-96231b3b80d8
2005-12-24 05:36:33 +00:00

476 lines
18 KiB
C++

//===-- AlphaISelDAGToDAG.cpp - Alpha pattern matching inst selector ------===//
//
// The LLVM Compiler Infrastructure
//
// This file was developed by Andrew Lenharth and is distributed under
// the University of Illinois Open Source License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file defines a pattern matching instruction selector for Alpha,
// converting from a legalized dag to a Alpha dag.
//
//===----------------------------------------------------------------------===//
#include "Alpha.h"
#include "AlphaTargetMachine.h"
#include "AlphaISelLowering.h"
#include "llvm/CodeGen/MachineInstrBuilder.h"
#include "llvm/CodeGen/MachineFrameInfo.h"
#include "llvm/CodeGen/MachineFunction.h"
#include "llvm/CodeGen/SSARegMap.h"
#include "llvm/CodeGen/SelectionDAG.h"
#include "llvm/CodeGen/SelectionDAGISel.h"
#include "llvm/Target/TargetOptions.h"
#include "llvm/ADT/Statistic.h"
#include "llvm/Constants.h"
#include "llvm/GlobalValue.h"
#include "llvm/Support/Debug.h"
#include "llvm/Support/MathExtras.h"
#include <algorithm>
using namespace llvm;
namespace {
//===--------------------------------------------------------------------===//
/// AlphaDAGToDAGISel - Alpha specific code to select Alpha machine
/// instructions for SelectionDAG operations.
class AlphaDAGToDAGISel : public SelectionDAGISel {
AlphaTargetLowering AlphaLowering;
static const int IMM_LOW = -32768;
static const int IMM_HIGH = 32767;
static const int IMM_MULT = 65536;
public:
AlphaDAGToDAGISel(TargetMachine &TM)
: SelectionDAGISel(AlphaLowering), AlphaLowering(TM) {}
/// getI64Imm - Return a target constant with the specified value, of type
/// i64.
inline SDOperand getI64Imm(int64_t Imm) {
return CurDAG->getTargetConstant(Imm, MVT::i64);
}
// Select - Convert the specified operand from a target-independent to a
// target-specific node if it hasn't already been changed.
SDOperand Select(SDOperand Op);
/// InstructionSelectBasicBlock - This callback is invoked by
/// SelectionDAGISel when it has created a SelectionDAG for us to codegen.
virtual void InstructionSelectBasicBlock(SelectionDAG &DAG);
virtual const char *getPassName() const {
return "Alpha DAG->DAG Pattern Instruction Selection";
}
// Include the pieces autogenerated from the target description.
#include "AlphaGenDAGISel.inc"
private:
SDOperand getGlobalBaseReg();
SDOperand getRASaveReg();
SDOperand SelectCALL(SDOperand Op);
};
}
/// getGlobalBaseReg - Output the instructions required to put the
/// GOT address into a register.
///
SDOperand AlphaDAGToDAGISel::getGlobalBaseReg() {
return CurDAG->getCopyFromReg(CurDAG->getEntryNode(),
AlphaLowering.getVRegGP(),
MVT::i64);
}
/// getRASaveReg - Grab the return address
///
SDOperand AlphaDAGToDAGISel::getRASaveReg() {
return CurDAG->getCopyFromReg(CurDAG->getEntryNode(),
AlphaLowering.getVRegRA(),
MVT::i64);
}
/// InstructionSelectBasicBlock - This callback is invoked by
/// SelectionDAGISel when it has created a SelectionDAG for us to codegen.
void AlphaDAGToDAGISel::InstructionSelectBasicBlock(SelectionDAG &DAG) {
DEBUG(BB->dump());
// Select target instructions for the DAG.
DAG.setRoot(Select(DAG.getRoot()));
CodeGenMap.clear();
DAG.RemoveDeadNodes();
// Emit machine code to BB.
ScheduleAndEmitDAG(DAG);
}
// Select - Convert the specified operand from a target-independent to a
// target-specific node if it hasn't already been changed.
SDOperand AlphaDAGToDAGISel::Select(SDOperand Op) {
SDNode *N = Op.Val;
if (N->getOpcode() >= ISD::BUILTIN_OP_END &&
N->getOpcode() < AlphaISD::FIRST_NUMBER)
return Op; // Already selected.
// If this has already been converted, use it.
std::map<SDOperand, SDOperand>::iterator CGMI = CodeGenMap.find(Op);
if (CGMI != CodeGenMap.end()) return CGMI->second;
switch (N->getOpcode()) {
default: break;
case ISD::TAILCALL:
case ISD::CALL: return SelectCALL(Op);
case ISD::DYNAMIC_STACKALLOC: {
if (!isa<ConstantSDNode>(N->getOperand(2)) ||
cast<ConstantSDNode>(N->getOperand(2))->getValue() != 0) {
std::cerr << "Cannot allocate stack object with greater alignment than"
<< " the stack alignment yet!";
abort();
}
SDOperand Chain = Select(N->getOperand(0));
SDOperand Amt = Select(N->getOperand(1));
SDOperand Reg = CurDAG->getRegister(Alpha::R30, MVT::i64);
SDOperand Val = CurDAG->getCopyFromReg(Chain, Alpha::R30, MVT::i64);
Chain = Val.getValue(1);
// Subtract the amount (guaranteed to be a multiple of the stack alignment)
// from the stack pointer, giving us the result pointer.
SDOperand Result = CurDAG->getTargetNode(Alpha::SUBQ, MVT::i64, Val, Amt);
// Copy this result back into R30.
Chain = CurDAG->getNode(ISD::CopyToReg, MVT::Other, Chain, Reg, Result);
// Copy this result back out of R30 to make sure we're not using the stack
// space without decrementing the stack pointer.
Result = CurDAG->getCopyFromReg(Chain, Alpha::R30, MVT::i64);
// Finally, replace the DYNAMIC_STACKALLOC with the copyfromreg.
CodeGenMap[Op.getValue(0)] = Result;
CodeGenMap[Op.getValue(1)] = Result.getValue(1);
return SDOperand(Result.Val, Op.ResNo);
}
case ISD::BRCOND: {
if (N->getOperand(1).getOpcode() == ISD::SETCC &&
MVT::isFloatingPoint(N->getOperand(1).getOperand(0).getValueType())) {
SDOperand Chain = Select(N->getOperand(0));
SDOperand CC1 = Select(N->getOperand(1).getOperand(0));
SDOperand CC2 = Select(N->getOperand(1).getOperand(1));
ISD::CondCode cCode= cast<CondCodeSDNode>(N->getOperand(1).getOperand(2))->get();
bool rev = false;
bool isNE = false;
unsigned Opc = Alpha::WTF;
switch(cCode) {
default: N->dump(); assert(0 && "Unknown FP comparison!");
case ISD::SETEQ: Opc = Alpha::CMPTEQ; break;
case ISD::SETLT: Opc = Alpha::CMPTLT; break;
case ISD::SETLE: Opc = Alpha::CMPTLE; break;
case ISD::SETGT: Opc = Alpha::CMPTLT; rev = true; break;
case ISD::SETGE: Opc = Alpha::CMPTLE; rev = true; break;
case ISD::SETNE: Opc = Alpha::CMPTEQ; isNE = true; break;
};
SDOperand cmp = CurDAG->getTargetNode(Opc, MVT::f64,
rev?CC2:CC1,
rev?CC1:CC2);
MachineBasicBlock *Dest =
cast<BasicBlockSDNode>(N->getOperand(2))->getBasicBlock();
if(isNE)
return CurDAG->SelectNodeTo(N, Alpha::FBEQ, MVT::Other, cmp,
CurDAG->getBasicBlock(Dest), Chain);
else
return CurDAG->SelectNodeTo(N, Alpha::FBNE, MVT::Other, cmp,
CurDAG->getBasicBlock(Dest), Chain);
}
SDOperand Chain = Select(N->getOperand(0));
SDOperand CC = Select(N->getOperand(1));
MachineBasicBlock *Dest =
cast<BasicBlockSDNode>(N->getOperand(2))->getBasicBlock();
return CurDAG->SelectNodeTo(N, Alpha::BNE, MVT::Other, CC,
CurDAG->getBasicBlock(Dest), Chain);
}
case ISD::BR:
return CurDAG->SelectNodeTo(N, Alpha::BR_DAG, MVT::Other, N->getOperand(1),
Select(N->getOperand(0)));
case ISD::FrameIndex: {
int FI = cast<FrameIndexSDNode>(N)->getIndex();
return CurDAG->SelectNodeTo(N, Alpha::LDA, MVT::i64,
CurDAG->getTargetFrameIndex(FI, MVT::i32),
getI64Imm(0));
}
case AlphaISD::GlobalBaseReg:
return getGlobalBaseReg();
case ISD::TargetConstantPool: {
Constant *C = cast<ConstantPoolSDNode>(N)->get();
SDOperand Tmp, CPI = CurDAG->getTargetConstantPool(C, MVT::i64);
Tmp = CurDAG->getTargetNode(Alpha::LDAHr, MVT::i64, CPI, getGlobalBaseReg());
return CurDAG->SelectNodeTo(N, Alpha::LDAr, MVT::i64, CPI, Tmp);
}
case ISD::TargetGlobalAddress: {
GlobalValue *GV = cast<GlobalAddressSDNode>(N)->getGlobal();
SDOperand GA = CurDAG->getTargetGlobalAddress(GV, MVT::i64);
return CurDAG->SelectNodeTo(N, Alpha::LDQl, MVT::i64, GA,
getGlobalBaseReg());
}
case ISD::ExternalSymbol:
return CurDAG->SelectNodeTo(N, Alpha::LDQl, MVT::i64,
CurDAG->getTargetExternalSymbol(cast<ExternalSymbolSDNode>(N)->getSymbol(), MVT::i64),
getGlobalBaseReg());
case ISD::RET: {
SDOperand Chain = Select(N->getOperand(0)); // Token chain.
SDOperand InFlag;
if (N->getNumOperands() == 2) {
SDOperand Val = Select(N->getOperand(1));
if (N->getOperand(1).getValueType() == MVT::i64) {
Chain = CurDAG->getCopyToReg(Chain, Alpha::R0, Val, InFlag);
InFlag = Chain.getValue(1);
} else if (N->getOperand(1).getValueType() == MVT::f64 ||
N->getOperand(1).getValueType() == MVT::f32) {
Chain = CurDAG->getCopyToReg(Chain, Alpha::F0, Val, InFlag);
InFlag = Chain.getValue(1);
}
}
Chain = CurDAG->getCopyToReg(Chain, Alpha::R26, getRASaveReg(), InFlag);
InFlag = Chain.getValue(1);
// Finally, select this to a ret instruction.
return CurDAG->SelectNodeTo(N, Alpha::RETDAG, MVT::Other, Chain, InFlag);
}
case ISD::Constant: {
int64_t val = (int64_t)cast<ConstantSDNode>(N)->getValue();
if (val > (int64_t)IMM_HIGH +(int64_t)IMM_HIGH* (int64_t)IMM_MULT ||
val < (int64_t)IMM_LOW + (int64_t)IMM_LOW * (int64_t)IMM_MULT) {
MachineConstantPool *CP = BB->getParent()->getConstantPool();
ConstantUInt *C =
ConstantUInt::get(Type::getPrimitiveType(Type::ULongTyID) , val);
SDOperand Tmp, CPI = CurDAG->getTargetConstantPool(C, MVT::i64);
Tmp = CurDAG->getTargetNode(Alpha::LDAHr, MVT::i64, CPI, getGlobalBaseReg());
return CurDAG->SelectNodeTo(N, Alpha::LDQr, MVT::i64, CPI, Tmp);
}
break;
}
case ISD::ConstantFP:
if (ConstantFPSDNode *CN = dyn_cast<ConstantFPSDNode>(N)) {
bool isDouble = N->getValueType(0) == MVT::f64;
MVT::ValueType T = isDouble ? MVT::f64 : MVT::f32;
if (CN->isExactlyValue(+0.0)) {
return CurDAG->SelectNodeTo(N, isDouble ? Alpha::CPYST : Alpha::CPYSS,
T, CurDAG->getRegister(Alpha::F31, T),
CurDAG->getRegister(Alpha::F31, T));
} else if ( CN->isExactlyValue(-0.0)) {
return CurDAG->SelectNodeTo(N, isDouble ? Alpha::CPYSNT : Alpha::CPYSNS,
T, CurDAG->getRegister(Alpha::F31, T),
CurDAG->getRegister(Alpha::F31, T));
} else {
abort();
}
break;
}
case ISD::SDIV:
case ISD::UDIV:
case ISD::UREM:
case ISD::SREM:
if (MVT::isInteger(N->getValueType(0))) {
const char* opstr = 0;
switch(N->getOpcode()) {
case ISD::UREM: opstr = "__remqu"; break;
case ISD::SREM: opstr = "__remq"; break;
case ISD::UDIV: opstr = "__divqu"; break;
case ISD::SDIV: opstr = "__divq"; break;
}
SDOperand Tmp1 = Select(N->getOperand(0)),
Tmp2 = Select(N->getOperand(1)),
Addr = Select(CurDAG->getExternalSymbol(opstr,
AlphaLowering.getPointerTy()));
SDOperand Chain;
Chain = CurDAG->getCopyToReg(CurDAG->getEntryNode(), Alpha::R24, Tmp1,
SDOperand(0,0));
Chain = CurDAG->getCopyToReg(Chain, Alpha::R25, Tmp2, Chain.getValue(1));
Chain = CurDAG->getCopyToReg(Chain, Alpha::R27, Addr, Chain.getValue(1));
Chain = CurDAG->getTargetNode(Alpha::JSRsDAG, MVT::Other, MVT::Flag,
Chain, Chain.getValue(1));
return CurDAG->getCopyFromReg(Chain, Alpha::R27, MVT::i64,
Chain.getValue(1));
}
break;
case ISD::SETCC:
if (MVT::isFloatingPoint(N->getOperand(0).Val->getValueType(0))) {
unsigned Opc = Alpha::WTF;
ISD::CondCode CC = cast<CondCodeSDNode>(N->getOperand(2))->get();
bool rev = false;
bool isNE = false;
switch(CC) {
default: N->dump(); assert(0 && "Unknown FP comparison!");
case ISD::SETEQ: Opc = Alpha::CMPTEQ; break;
case ISD::SETLT: Opc = Alpha::CMPTLT; break;
case ISD::SETLE: Opc = Alpha::CMPTLE; break;
case ISD::SETGT: Opc = Alpha::CMPTLT; rev = true; break;
case ISD::SETGE: Opc = Alpha::CMPTLE; rev = true; break;
case ISD::SETNE: Opc = Alpha::CMPTEQ; isNE = true; break;
};
SDOperand tmp1 = Select(N->getOperand(0)),
tmp2 = Select(N->getOperand(1));
SDOperand cmp = CurDAG->getTargetNode(Opc, MVT::f64,
rev?tmp2:tmp1,
rev?tmp1:tmp2);
if (isNE)
cmp = CurDAG->getTargetNode(Alpha::CMPTEQ, MVT::f64, cmp,
CurDAG->getRegister(Alpha::F31, MVT::f64));
SDOperand LD;
if (AlphaLowering.hasITOF()) {
LD = CurDAG->getNode(AlphaISD::FTOIT_, MVT::i64, cmp);
} else {
int FrameIdx =
CurDAG->getMachineFunction().getFrameInfo()->CreateStackObject(8, 8);
SDOperand FI = CurDAG->getFrameIndex(FrameIdx, MVT::i64);
SDOperand ST = CurDAG->getTargetNode(Alpha::STT, MVT::Other,
cmp, FI, CurDAG->getRegister(Alpha::R31, MVT::i64));
LD = CurDAG->getTargetNode(Alpha::LDQ, MVT::i64, FI,
CurDAG->getRegister(Alpha::R31, MVT::i64),
ST);
}
SDOperand FP = CurDAG->getTargetNode(Alpha::CMPULT, MVT::i64,
CurDAG->getRegister(Alpha::R31, MVT::i64),
LD);
return FP;
}
break;
case ISD::SELECT:
if (MVT::isFloatingPoint(N->getValueType(0)) &&
(N->getOperand(0).getOpcode() != ISD::SETCC ||
!MVT::isFloatingPoint(N->getOperand(0).getOperand(1).getValueType()))) {
//This should be the condition not covered by the Patterns
//FIXME: Don't have SelectCode die, but rather return something testable
// so that things like this can be caught in fall though code
//move int to fp
bool isDouble = N->getValueType(0) == MVT::f64;
SDOperand LD,
cond = Select(N->getOperand(0)),
TV = Select(N->getOperand(1)),
FV = Select(N->getOperand(2));
if (AlphaLowering.hasITOF()) {
LD = CurDAG->getNode(AlphaISD::ITOFT_, MVT::f64, cond);
} else {
int FrameIdx =
CurDAG->getMachineFunction().getFrameInfo()->CreateStackObject(8, 8);
SDOperand FI = CurDAG->getFrameIndex(FrameIdx, MVT::i64);
SDOperand ST = CurDAG->getTargetNode(Alpha::STQ, MVT::Other,
cond, FI, CurDAG->getRegister(Alpha::R31, MVT::i64));
LD = CurDAG->getTargetNode(Alpha::LDT, MVT::f64, FI,
CurDAG->getRegister(Alpha::R31, MVT::i64),
ST);
}
SDOperand FP = CurDAG->getTargetNode(isDouble?Alpha::FCMOVNET:Alpha::FCMOVNES,
MVT::f64, FV, TV, LD);
return FP;
}
break;
}
return SelectCode(Op);
}
SDOperand AlphaDAGToDAGISel::SelectCALL(SDOperand Op) {
//TODO: add flag stuff to prevent nondeturministic breakage!
SDNode *N = Op.Val;
SDOperand Chain = Select(N->getOperand(0));
SDOperand Addr = Select(N->getOperand(1));
SDOperand InFlag; // Null incoming flag value.
std::vector<SDOperand> CallOperands;
std::vector<MVT::ValueType> TypeOperands;
//grab the arguments
for(int i = 2, e = N->getNumOperands(); i < e; ++i) {
TypeOperands.push_back(N->getOperand(i).getValueType());
CallOperands.push_back(Select(N->getOperand(i)));
}
int count = N->getNumOperands() - 2;
static const unsigned args_int[] = {Alpha::R16, Alpha::R17, Alpha::R18,
Alpha::R19, Alpha::R20, Alpha::R21};
static const unsigned args_float[] = {Alpha::F16, Alpha::F17, Alpha::F18,
Alpha::F19, Alpha::F20, Alpha::F21};
for (int i = 6; i < count; ++i) {
unsigned Opc = Alpha::WTF;
if (MVT::isInteger(TypeOperands[i])) {
Opc = Alpha::STQ;
} else if (TypeOperands[i] == MVT::f32) {
Opc = Alpha::STS;
} else if (TypeOperands[i] == MVT::f64) {
Opc = Alpha::STT;
} else
assert(0 && "Unknown operand");
Chain = CurDAG->getTargetNode(Opc, MVT::Other, CallOperands[i],
getI64Imm((i - 6) * 8),
CurDAG->getCopyFromReg(Chain, Alpha::R30, MVT::i64),
Chain);
}
for (int i = 0; i < std::min(6, count); ++i) {
if (MVT::isInteger(TypeOperands[i])) {
Chain = CurDAG->getCopyToReg(Chain, args_int[i], CallOperands[i], InFlag);
InFlag = Chain.getValue(1);
} else if (TypeOperands[i] == MVT::f32 || TypeOperands[i] == MVT::f64) {
Chain = CurDAG->getCopyToReg(Chain, args_float[i], CallOperands[i], InFlag);
InFlag = Chain.getValue(1);
} else
assert(0 && "Unknown operand");
}
Chain = CurDAG->getCopyToReg(Chain, Alpha::R27, Addr, InFlag);
InFlag = Chain.getValue(1);
// Finally, once everything is in registers to pass to the call, emit the
// call itself.
Chain = CurDAG->getTargetNode(Alpha::JSRDAG, MVT::Other, MVT::Flag,
Chain, InFlag );
InFlag = Chain.getValue(1);
std::vector<SDOperand> CallResults;
switch (N->getValueType(0)) {
default: assert(0 && "Unexpected ret value!");
case MVT::Other: break;
case MVT::i64:
Chain = CurDAG->getCopyFromReg(Chain, Alpha::R0, MVT::i64, InFlag).getValue(1);
CallResults.push_back(Chain.getValue(0));
break;
case MVT::f32:
Chain = CurDAG->getCopyFromReg(Chain, Alpha::F0, MVT::f32, InFlag).getValue(1);
CallResults.push_back(Chain.getValue(0));
break;
case MVT::f64:
Chain = CurDAG->getCopyFromReg(Chain, Alpha::F0, MVT::f64, InFlag).getValue(1);
CallResults.push_back(Chain.getValue(0));
break;
}
CallResults.push_back(Chain);
for (unsigned i = 0, e = CallResults.size(); i != e; ++i)
CodeGenMap[Op.getValue(i)] = CallResults[i];
return CallResults[Op.ResNo];
}
/// createAlphaISelDag - This pass converts a legalized DAG into a
/// Alpha-specific DAG, ready for instruction scheduling.
///
FunctionPass *llvm::createAlphaISelDag(TargetMachine &TM) {
return new AlphaDAGToDAGISel(TM);
}