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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/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;
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:
assert(0 && "You want these too?");
case ISD::BRCOND: {
SDOperand Chain = Select(N->getOperand(0));
SDOperand CC = Select(N->getOperand(1));
CurDAG->SelectNodeTo(N, Alpha::BNE, MVT::Other, CC, Chain);
return SDOperand(N, 0);
}
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;
}
CurDAG->SelectNodeTo(N, Opc, N->getValueType(0), MVT::Other,
getI64Imm(0), Address, Chain);
return SDOperand(N, Op.ResNo);
}
case ISD::BR: {
CurDAG->SelectNodeTo(N, Alpha::BR_DAG, MVT::Other, N->getOperand(1),
Select(N->getOperand(0)));
return SDOperand(N, 0);
}
case ISD::UNDEF:
if (N->getValueType(0) == MVT::i64)
CurDAG->SelectNodeTo(N, Alpha::IDEF, MVT::i64);
// else if (N->getValueType(0) == MVT::f32)
// CurDAG->SelectNodeTo(N, PPC::IMPLICIT_DEF_F4, MVT::f32);
// else
// CurDAG->SelectNodeTo(N, PPC::IMPLICIT_DEF_F8, MVT::f64);
return SDOperand(N, 0);
case ISD::FrameIndex: {
// int FI = cast<FrameIndexSDNode>(N)->getIndex();
// CurDAG->SelectNodeTo(N, Alpha::LDA, MVT::i64,
// CurDAG->getTargetFrameIndex(FI, MVT::i32),
// getI32Imm(0));
// return SDOperand(N, 0);
assert(0 && "Frame?, you are suppose to look through the window, not at the frame!");
}
case ISD::ConstantPool: {
// Constant *C = cast<ConstantPoolSDNode>(N)->get();
// SDOperand Tmp, CPI = CurDAG->getTargetConstantPool(C, MVT::i32);
// if (PICEnabled)
// Tmp = CurDAG->getTargetNode(PPC::ADDIS, MVT::i32, getGlobalBaseReg(),CPI);
// else
// Tmp = CurDAG->getTargetNode(PPC::LIS, MVT::i32, CPI);
// CurDAG->SelectNodeTo(N, PPC::LA, MVT::i32, Tmp, CPI);
// return SDOperand(N, 0);
assert(0 && "Constants are overrated");
}
case ISD::GlobalAddress: {
GlobalValue *GV = cast<GlobalAddressSDNode>(N)->getGlobal();
SDOperand GA = CurDAG->getTargetGlobalAddress(GV, MVT::i64);
CurDAG->SelectNodeTo(N, Alpha::LDQl, MVT::i64, GA, getGlobalBaseReg());
return SDOperand(N, 0);
}
case ISD::ExternalSymbol:
CurDAG->SelectNodeTo(N, Alpha::LDQl, MVT::i64,
CurDAG->getTargetExternalSymbol(cast<ExternalSymbolSDNode>(N)->getSymbol(), MVT::i64),
CurDAG->getRegister(AlphaLowering.getVRegGP(), MVT::i64));
return SDOperand(N, 0);
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;
CurDAG->SelectNodeTo(N, Opc, MVT::Other,
getI64Imm(Amt), Select(N->getOperand(0)));
return SDOperand(N, 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.
CurDAG->SelectNodeTo(N, Alpha::RETDAG, MVT::Other, Chain);
return SDOperand(N, 0);
}
}
return SelectCode(Op);
}
SDOperand AlphaDAGToDAGISel::SelectCALL(SDOperand Op) {
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 {
assert(0 && "No FP support yet");
}
}
assert(CallOperands.size() <= 6 && "Too big a call");
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;
}
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);
}