llvm-project/llvm/lib/Target/Alpha/AlphaCodeEmitter.cpp

249 lines
8.2 KiB
C++

//===-- Alpha/AlphaCodeEmitter.cpp - Convert Alpha code to machine code ---===//
//
// The LLVM Compiler Infrastructure
//
// This file was developed by the LLVM research group and is distributed under
// the University of Illinois Open Source License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file contains the pass that transforms the Alpha machine instructions
// into relocatable machine code.
//
//===----------------------------------------------------------------------===//
#include "AlphaTargetMachine.h"
#include "AlphaRelocations.h"
#include "Alpha.h"
#include "llvm/PassManager.h"
#include "llvm/CodeGen/MachineCodeEmitter.h"
#include "llvm/CodeGen/MachineFunctionPass.h"
#include "llvm/CodeGen/MachineInstr.h"
#include "llvm/CodeGen/Passes.h"
#include "llvm/Function.h"
#include "llvm/Support/Debug.h"
#include "llvm/ADT/Statistic.h"
#include <iostream>
using namespace llvm;
namespace {
Statistic<>
NumEmitted("alpha-emitter", "Number of machine instructions emitted");
}
namespace {
class AlphaCodeEmitter : public MachineFunctionPass {
const AlphaInstrInfo *II;
MachineCodeEmitter &MCE;
std::map<const MachineBasicBlock*, unsigned*> BasicBlockAddrs;
std::vector<std::pair<const MachineBasicBlock *, unsigned*> > BBRefs;
/// getMachineOpValue - evaluates the MachineOperand of a given MachineInstr
///
int getMachineOpValue(MachineInstr &MI, MachineOperand &MO);
public:
explicit AlphaCodeEmitter(MachineCodeEmitter &mce) : II(0), MCE(mce) {}
AlphaCodeEmitter(MachineCodeEmitter &mce, const AlphaInstrInfo& ii)
: II(&ii), MCE(mce) {}
bool runOnMachineFunction(MachineFunction &MF);
virtual const char *getPassName() const {
return "Alpha Machine Code Emitter";
}
void emitInstruction(const MachineInstr &MI);
/// emitWord - write a 32-bit word to memory at the current PC
///
void emitWord(unsigned w) { MCE.emitWord(w); }
/// getBinaryCodeForInstr - This function, generated by the
/// CodeEmitterGenerator using TableGen, produces the binary encoding for
/// machine instructions.
///
unsigned getBinaryCodeForInstr(MachineInstr &MI);
private:
void emitBasicBlock(MachineBasicBlock &MBB);
};
}
/// createAlphaCodeEmitterPass - Return a pass that emits the collected Alpha code
/// to the specified MCE object.
FunctionPass *llvm::createAlphaCodeEmitterPass(MachineCodeEmitter &MCE) {
return new AlphaCodeEmitter(MCE);
}
bool AlphaCodeEmitter::runOnMachineFunction(MachineFunction &MF) {
II = ((AlphaTargetMachine&)MF.getTarget()).getInstrInfo();
MCE.startFunction(MF);
MCE.emitConstantPool(MF.getConstantPool());
for (MachineFunction::iterator I = MF.begin(), E = MF.end(); I != E; ++I)
emitBasicBlock(*I);
MCE.finishFunction(MF);
// Resolve all forward branches now...
for (unsigned i = 0, e = BBRefs.size(); i != e; ++i) {
unsigned* Location = (unsigned*)BasicBlockAddrs[BBRefs[i].first];
unsigned* Ref = (unsigned*)BBRefs[i].second;
intptr_t BranchTargetDisp =
(((unsigned char*)Location - (unsigned char*)Ref) >> 2) - 1;
DEBUG(std::cerr << "Fixup @ " << (void*)Ref << " to " << (void*)Location
<< " Disp " << BranchTargetDisp
<< " using " << (BranchTargetDisp & ((1 << 22)-1)) << "\n");
*Ref |= (BranchTargetDisp & ((1 << 21)-1));
}
BBRefs.clear();
BasicBlockAddrs.clear();
return false;
}
void AlphaCodeEmitter::emitBasicBlock(MachineBasicBlock &MBB) {
uintptr_t Addr = MCE.getCurrentPCValue();
BasicBlockAddrs[&MBB] = (unsigned*)Addr;
for (MachineBasicBlock::iterator I = MBB.begin(), E = MBB.end();
I != E; ++I) {
MachineInstr &MI = *I;
unsigned Opcode = MI.getOpcode();
switch(MI.getOpcode()) {
default:
emitWord(getBinaryCodeForInstr(*I));
break;
case Alpha::ALTENT:
case Alpha::PCLABEL:
case Alpha::MEMLABEL:
case Alpha::IDEF_I:
case Alpha::IDEF_F32:
case Alpha::IDEF_F64:
break; //skip these
}
}
}
static unsigned getAlphaRegNumber(unsigned Reg) {
switch (Reg) {
case Alpha::R0 : case Alpha::F0 : return 0;
case Alpha::R1 : case Alpha::F1 : return 1;
case Alpha::R2 : case Alpha::F2 : return 2;
case Alpha::R3 : case Alpha::F3 : return 3;
case Alpha::R4 : case Alpha::F4 : return 4;
case Alpha::R5 : case Alpha::F5 : return 5;
case Alpha::R6 : case Alpha::F6 : return 6;
case Alpha::R7 : case Alpha::F7 : return 7;
case Alpha::R8 : case Alpha::F8 : return 8;
case Alpha::R9 : case Alpha::F9 : return 9;
case Alpha::R10 : case Alpha::F10 : return 10;
case Alpha::R11 : case Alpha::F11 : return 11;
case Alpha::R12 : case Alpha::F12 : return 12;
case Alpha::R13 : case Alpha::F13 : return 13;
case Alpha::R14 : case Alpha::F14 : return 14;
case Alpha::R15 : case Alpha::F15 : return 15;
case Alpha::R16 : case Alpha::F16 : return 16;
case Alpha::R17 : case Alpha::F17 : return 17;
case Alpha::R18 : case Alpha::F18 : return 18;
case Alpha::R19 : case Alpha::F19 : return 19;
case Alpha::R20 : case Alpha::F20 : return 20;
case Alpha::R21 : case Alpha::F21 : return 21;
case Alpha::R22 : case Alpha::F22 : return 22;
case Alpha::R23 : case Alpha::F23 : return 23;
case Alpha::R24 : case Alpha::F24 : return 24;
case Alpha::R25 : case Alpha::F25 : return 25;
case Alpha::R26 : case Alpha::F26 : return 26;
case Alpha::R27 : case Alpha::F27 : return 27;
case Alpha::R28 : case Alpha::F28 : return 28;
case Alpha::R29 : case Alpha::F29 : return 29;
case Alpha::R30 : case Alpha::F30 : return 30;
case Alpha::R31 : case Alpha::F31 : return 31;
default:
assert(0 && "Unhandled reg");
abort();
}
}
int AlphaCodeEmitter::getMachineOpValue(MachineInstr &MI, MachineOperand &MO) {
int rv = 0; // Return value; defaults to 0 for unhandled cases
// or things that get fixed up later by the JIT.
if (MO.isRegister()) {
rv = getAlphaRegNumber(MO.getReg());
} else if (MO.isImmediate()) {
rv = MO.getImmedValue();
} else if (MO.isGlobalAddress() || MO.isExternalSymbol()
|| MO.isConstantPoolIndex()) {
DEBUG(std::cerr << MO << " is a relocated op for " << MI << "\n";);
bool isExternal = MO.isExternalSymbol() ||
(MO.isGlobalAddress() &&
( MO.getGlobal()->hasWeakLinkage() ||
MO.getGlobal()->isExternal()) );
unsigned Reloc = 0;
int Offset = 0;
bool useGOT = false;
switch (MI.getOpcode()) {
case Alpha::BSR:
Reloc = Alpha::reloc_bsr;
break;
case Alpha::LDLr:
case Alpha::LDQr:
case Alpha::LDBUr:
case Alpha::LDWUr:
case Alpha::LDSr:
case Alpha::LDTr:
case Alpha::LDAr:
case Alpha::STQr:
case Alpha::STLr:
case Alpha::STWr:
case Alpha::STBr:
case Alpha::STSr:
case Alpha::STTr:
Reloc = Alpha::reloc_gprellow;
break;
case Alpha::LDAHr:
Reloc = Alpha::reloc_gprelhigh;
break;
case Alpha::LDQl:
Reloc = Alpha::reloc_literal;
useGOT = true;
break;
case Alpha::LDAg:
case Alpha::LDAHg:
Reloc = Alpha::reloc_gpdist;
Offset = MI.getOperand(3).getImmedValue();
break;
default:
assert(0 && "unknown relocatable instruction");
abort();
}
if (MO.isGlobalAddress())
MCE.addRelocation(MachineRelocation((unsigned)MCE.getCurrentPCOffset(),
Reloc, MO.getGlobal(), Offset,
false, useGOT));
else if (MO.isExternalSymbol())
MCE.addRelocation(MachineRelocation((unsigned)MCE.getCurrentPCOffset(),
Reloc, MO.getSymbolName(), Offset,
true));
else
MCE.addRelocation(MachineRelocation((unsigned)MCE.getCurrentPCOffset(),
Reloc, MO.getConstantPoolIndex(),
Offset));
} else if (MO.isMachineBasicBlock()) {
unsigned* CurrPC = (unsigned*)(intptr_t)MCE.getCurrentPCValue();
BBRefs.push_back(std::make_pair(MO.getMachineBasicBlock(), CurrPC));
}else {
std::cerr << "ERROR: Unknown type of MachineOperand: " << MO << "\n";
abort();
}
return rv;
}
#include "AlphaGenCodeEmitter.inc"