llvm/lib/Target/Alpha/AlphaISelDAGToDAG.cpp

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//===-- 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 SelectCALL(SDOperand Op);
};
}
/// getGlobalBaseReg - Output the instructions required to put the
/// GOT address into a register.
///
SDOperand AlphaDAGToDAGISel::getGlobalBaseReg() {
return CurDAG->getRegister(AlphaLowering.getVRegGP(), 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: {
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::LOAD:
case ISD::EXTLOAD:
case ISD::ZEXTLOAD:
case ISD::SEXTLOAD: {
SDOperand Chain = Select(N->getOperand(0));
SDOperand Address = Select(N->getOperand(1));
unsigned opcode = N->getOpcode();
unsigned Opc = Alpha::WTF;
if (opcode == ISD::LOAD)
switch (N->getValueType(0)) {
default: N->dump(); assert(0 && "Bad load!");
case MVT::i64: Opc = Alpha::LDQ; break;
case MVT::f64: Opc = Alpha::LDT; break;
case MVT::f32: Opc = Alpha::LDS; break;
}
else
switch (cast<VTSDNode>(N->getOperand(3))->getVT()) {
default: N->dump(); assert(0 && "Bad sign extend!");
case MVT::i32: Opc = Alpha::LDL;
assert(opcode != ISD::ZEXTLOAD && "Not sext"); break;
case MVT::i16: Opc = Alpha::LDWU;
assert(opcode != ISD::SEXTLOAD && "Not zext"); break;
case MVT::i1: //FIXME: Treat i1 as i8 since there are problems otherwise
case MVT::i8: Opc = Alpha::LDBU;
assert(opcode != ISD::SEXTLOAD && "Not zext"); break;
}
return CurDAG->SelectNodeTo(N, Opc, N->getValueType(0), MVT::Other,
getI64Imm(0), Address,
Chain).getValue(Op.ResNo);
}
case ISD::STORE:
case ISD::TRUNCSTORE: {
SDOperand Chain = Select(N->getOperand(0));
SDOperand Value = Select(N->getOperand(1));
SDOperand Address = Select(N->getOperand(2));
unsigned Opc = Alpha::WTF;
if (N->getOpcode() == ISD::STORE) {
switch (N->getOperand(1).getValueType()) {
case MVT::i64: Opc = Alpha::STQ; break;
case MVT::f64: Opc = Alpha::STT; break;
case MVT::f32: Opc = Alpha::STS; break;
default: assert(0 && "Bad store!");
};
} else { //TRUNCSTORE
switch (cast<VTSDNode>(N->getOperand(4))->getVT()) {
case MVT::i32: Opc = Alpha::STL; break;
case MVT::i16: Opc = Alpha::STW; break;
case MVT::i8: Opc = Alpha::STB; break;
default: assert(0 && "Bad truncstore!");
};
}
return CurDAG->SelectNodeTo(N, Opc, MVT::Other, Value, getI64Imm(0),
Address, 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 ISD::ConstantPool: {
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::GlobalAddress: {
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),
CurDAG->getRegister(AlphaLowering.getVRegGP(), MVT::i64));
case ISD::CALLSEQ_START:
case ISD::CALLSEQ_END: {
unsigned Amt = cast<ConstantSDNode>(N->getOperand(1))->getValue();
unsigned Opc = N->getOpcode() == ISD::CALLSEQ_START ?
Alpha::ADJUSTSTACKDOWN : Alpha::ADJUSTSTACKUP;
return CurDAG->SelectNodeTo(N, Opc, MVT::Other,
getI64Imm(Amt), Select(N->getOperand(0)));
}
case ISD::RET: {
SDOperand Chain = Select(N->getOperand(0)); // Token chain.
if (N->getNumOperands() == 2) {
SDOperand Val = Select(N->getOperand(1));
if (N->getOperand(1).getValueType() == MVT::i64) {
Chain = CurDAG->getCopyToReg(Chain, Alpha::R0, Val);
}
}
//BuildMI(BB, Alpha::RET, 2, Alpha::R31).addReg(Alpha::R26).addImm(1);
// FIXME: add restoring of the RA to R26 to the chain
// Finally, select this to a ret instruction.
return CurDAG->SelectNodeTo(N, Alpha::RETDAG, MVT::Other, Chain);
}
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::LDAr, 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 = CurDAG->getExternalSymbol(opstr, AlphaLowering.getPointerTy());
SDOperand Tmp3 = Select(Addr);
SDOperand Chain = CurDAG->getCopyToReg(CurDAG->getRoot(), Alpha::R24,
Tmp1, SDOperand());
Chain = CurDAG->getCopyToReg(CurDAG->getRoot(), Alpha::R25,
Tmp2, Chain.getValue(1));
Chain = CurDAG->getCopyToReg(CurDAG->getRoot(), Alpha::R27,
Tmp3, Chain.getValue(1));
Chain = CurDAG->getTargetNode(Alpha::JSRs, MVT::i64, MVT::Flag,
CurDAG->getRegister(Alpha::R27, MVT::i64),
getI64Imm(0));
return CurDAG->getCopyFromReg(Chain.getValue(1), 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))) {
//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::FCMOVEQT:Alpha::FCMOVEQS,
MVT::f64, TV, FV, 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));
// unsigned CallOpcode;
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 = 0; i < std::min(6, count); ++i) {
if (MVT::isInteger(TypeOperands[i])) {
Chain = CurDAG->getCopyToReg(Chain, args_int[i], CallOperands[i]);
} else if (TypeOperands[i] == MVT::f32 || TypeOperands[i] == MVT::f64) {
Chain = CurDAG->getCopyToReg(Chain, args_float[i], CallOperands[i]);
} else
assert(0 && "Unknown operand");
}
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->getRegister(Alpha::R30, MVT::i64),
Chain);
}
Chain = CurDAG->getCopyToReg(Chain, Alpha::R27, Addr);
// Finally, once everything is in registers to pass to the call, emit the
// call itself.
Chain = CurDAG->getTargetNode(Alpha::JSRDAG, MVT::Other, Chain );
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).getValue(1);
CallResults.push_back(Chain.getValue(0));
break;
case MVT::f32:
Chain = CurDAG->getCopyFromReg(Chain, Alpha::F0, MVT::f32).getValue(1);
CallResults.push_back(Chain.getValue(0));
break;
case MVT::f64:
Chain = CurDAG->getCopyFromReg(Chain, Alpha::F0, MVT::f64).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);
}