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//===-- PPC32CodeEmitter.cpp - JIT Code Emitter for PowerPC32 -----*- C++ -*-=//
//
// 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 defines the PowerPC 32-bit CodeEmitter and associated machinery to
// JIT-compile bytecode to native PowerPC.
//
//===----------------------------------------------------------------------===//
#include "PPC32JITInfo.h"
#include "PPC32TargetMachine.h"
#include "PowerPC.h"
#include "llvm/Module.h"
#include "llvm/CodeGen/MachineCodeEmitter.h"
#include "llvm/CodeGen/MachineFunctionPass.h"
#include "llvm/CodeGen/Passes.h"
#include "llvm/Support/Debug.h"
namespace llvm {
namespace {
class JITResolver {
MachineCodeEmitter &MCE;
// LazyCodeGenMap - Keep track of call sites for functions that are to be
// lazily resolved.
std::map<unsigned, Function*> LazyCodeGenMap;
// LazyResolverMap - Keep track of the lazy resolver created for a
// particular function so that we can reuse them if necessary.
std::map<Function*, unsigned> LazyResolverMap;
public:
JITResolver(MachineCodeEmitter &mce) : MCE(mce) {}
unsigned getLazyResolver(Function *F);
unsigned addFunctionReference(unsigned Address, Function *F);
private:
unsigned emitStubForFunction(Function *F);
static void CompilationCallback();
unsigned resolveFunctionReference(unsigned RetAddr);
};
static JITResolver &getResolver(MachineCodeEmitter &MCE) {
static JITResolver *TheJITResolver = 0;
if (TheJITResolver == 0)
TheJITResolver = new JITResolver(MCE);
return *TheJITResolver;
}
}
unsigned JITResolver::getLazyResolver(Function *F) {
std::map<Function*, unsigned>::iterator I = LazyResolverMap.lower_bound(F);
if (I != LazyResolverMap.end() && I->first == F) return I->second;
unsigned Stub = emitStubForFunction(F);
LazyResolverMap.insert(I, std::make_pair(F, Stub));
return Stub;
}
/// addFunctionReference - This method is called when we need to emit the
/// address of a function that has not yet been emitted, so we don't know the
/// address. Instead, we emit a call to the CompilationCallback method, and
/// keep track of where we are.
///
unsigned JITResolver::addFunctionReference(unsigned Address, Function *F) {
LazyCodeGenMap[Address] = F;
return (intptr_t)&JITResolver::CompilationCallback;
}
unsigned JITResolver::resolveFunctionReference(unsigned RetAddr) {
std::map<unsigned, Function*>::iterator I = LazyCodeGenMap.find(RetAddr);
assert(I != LazyCodeGenMap.end() && "Not in map!");
Function *F = I->second;
LazyCodeGenMap.erase(I);
return MCE.forceCompilationOf(F);
}
/// emitStubForFunction - This method is used by the JIT when it needs to emit
/// the address of a function for a function whose code has not yet been
/// generated. In order to do this, it generates a stub which jumps to the lazy
/// function compiler, which will eventually get fixed to call the function
/// directly.
///
unsigned JITResolver::emitStubForFunction(Function *F) {
std::cerr << "PPC32CodeEmitter::emitStubForFunction() unimplemented!\n";
abort();
return 0;
}
void JITResolver::CompilationCallback() {
std::cerr << "PPC32CodeEmitter: CompilationCallback() unimplemented!";
abort();
}
namespace {
class PPC32CodeEmitter : public MachineFunctionPass {
TargetMachine &TM;
MachineCodeEmitter &MCE;
// Tracks which instruction references which BasicBlock
std::vector<std::pair<const BasicBlock*,
std::pair<unsigned*,MachineInstr*> > > BBRefs;
// Tracks where each BasicBlock starts
std::map<const BasicBlock*, long> BBLocations;
/// getMachineOpValue - evaluates the MachineOperand of a given MachineInstr
///
int64_t getMachineOpValue(MachineInstr &MI, MachineOperand &MO);
unsigned getAddressOfExternalFunction(Function *F);
public:
PPC32CodeEmitter(TargetMachine &T, MachineCodeEmitter &M)
: TM(T), MCE(M) {}
const char *getPassName() const { return "PowerPC Machine Code Emitter"; }
/// runOnMachineFunction - emits the given MachineFunction to memory
///
bool runOnMachineFunction(MachineFunction &MF);
/// emitBasicBlock - emits the given MachineBasicBlock to memory
///
void emitBasicBlock(MachineBasicBlock &MBB);
/// emitWord - write a 32-bit word to memory at the current PC
///
void emitWord(unsigned w) { MCE.emitWord(w); }
/// getValueBit - return the particular bit of Val
///
unsigned getValueBit(int64_t Val, unsigned bit) { return (Val >> bit) & 1; }
/// getBinaryCodeForInstr - This function, generated by the
/// CodeEmitterGenerator using TableGen, produces the binary encoding for
/// machine instructions.
///
unsigned getBinaryCodeForInstr(MachineInstr &MI);
};
}
/// addPassesToEmitMachineCode - Add passes to the specified pass manager to get
/// machine code emitted. This uses a MachineCodeEmitter object to handle
/// actually outputting the machine code and resolving things like the address
/// of functions. This method should returns true if machine code emission is
/// not supported.
///
bool PPC32TargetMachine::addPassesToEmitMachineCode(FunctionPassManager &PM,
MachineCodeEmitter &MCE) {
// Keep as `true' until this is a functional JIT to allow llvm-gcc to build
return true;
// Machine code emitter pass for PowerPC
PM.add(new PPC32CodeEmitter(*this, MCE));
// Delete machine code for this function after emitting it
PM.add(createMachineCodeDeleter());
return false;
}
bool PPC32CodeEmitter::runOnMachineFunction(MachineFunction &MF) {
MCE.startFunction(MF);
MCE.emitConstantPool(MF.getConstantPool());
for (MachineFunction::iterator BB = MF.begin(), E = MF.end(); BB != E; ++BB)
emitBasicBlock(*BB);
MCE.finishFunction(MF);
// Resolve branches to BasicBlocks for the entire function
for (unsigned i = 0, e = BBRefs.size(); i != e; ++i) {
long Location = BBLocations[BBRefs[i].first];
unsigned *Ref = BBRefs[i].second.first;
MachineInstr *MI = BBRefs[i].second.second;
DEBUG(std::cerr << "Fixup @ " << std::hex << Ref << " to 0x" << Location
<< " in instr: " << std::dec << *MI);
for (unsigned ii = 0, ee = MI->getNumOperands(); ii != ee; ++ii) {
MachineOperand &op = MI->getOperand(ii);
if (op.isPCRelativeDisp()) {
// the instruction's branch target is made such that it branches to
// PC + (branchTarget * 4), so undo that arithmetic here:
// Location is the target of the branch
// Ref is the location of the instruction, and hence the PC
int64_t branchTarget = (Location - (long)Ref) >> 2;
MI->SetMachineOperandConst(ii, MachineOperand::MO_SignExtendedImmed,
branchTarget);
unsigned fixedInstr = PPC32CodeEmitter::getBinaryCodeForInstr(*MI);
MCE.emitWordAt(fixedInstr, Ref);
break;
}
}
}
BBRefs.clear();
BBLocations.clear();
return false;
}
void PPC32CodeEmitter::emitBasicBlock(MachineBasicBlock &MBB) {
BBLocations[MBB.getBasicBlock()] = MCE.getCurrentPCValue();
for (MachineBasicBlock::iterator I = MBB.begin(), E = MBB.end(); I != E; ++I){
MachineInstr &MI = *I;
unsigned Opcode = MI.getOpcode();
if (Opcode == PPC::IMPLICIT_DEF) continue;
emitWord(getBinaryCodeForInstr(*I));
}
}
unsigned PPC32CodeEmitter::getAddressOfExternalFunction(Function *F) {
static std::map<Function*, unsigned> ExternalFn2Addr;
std::map<Function*, unsigned>::iterator Addr = ExternalFn2Addr.find(F);
if (Addr == ExternalFn2Addr.end())
ExternalFn2Addr[F] = MCE.forceCompilationOf(F);
return ExternalFn2Addr[F];
}
static unsigned enumRegToMachineReg(unsigned enumReg) {
switch (enumReg) {
case PPC::R0 : case PPC::F0 : return 0;
case PPC::R1 : case PPC::F1 : return 1;
case PPC::R2 : case PPC::F2 : return 2;
case PPC::R3 : case PPC::F3 : return 3;
case PPC::R4 : case PPC::F4 : return 4;
case PPC::R5 : case PPC::F5 : return 5;
case PPC::R6 : case PPC::F6 : return 6;
case PPC::R7 : case PPC::F7 : return 7;
case PPC::R8 : case PPC::F8 : return 8;
case PPC::R9 : case PPC::F9 : return 9;
case PPC::R10: case PPC::F10: return 10;
case PPC::R11: case PPC::F11: return 11;
case PPC::R12: case PPC::F12: return 12;
case PPC::R13: case PPC::F13: return 13;
case PPC::R14: case PPC::F14: return 14;
case PPC::R15: case PPC::F15: return 15;
case PPC::R16: case PPC::F16: return 16;
case PPC::R17: case PPC::F17: return 17;
case PPC::R18: case PPC::F18: return 18;
case PPC::R19: case PPC::F19: return 19;
case PPC::R20: case PPC::F20: return 20;
case PPC::R21: case PPC::F21: return 21;
case PPC::R22: case PPC::F22: return 22;
case PPC::R23: case PPC::F23: return 23;
case PPC::R24: case PPC::F24: return 24;
case PPC::R25: case PPC::F25: return 25;
case PPC::R26: case PPC::F26: return 26;
case PPC::R27: case PPC::F27: return 27;
case PPC::R28: case PPC::F28: return 28;
case PPC::R29: case PPC::F29: return 29;
case PPC::R30: case PPC::F30: return 30;
case PPC::R31: case PPC::F31: return 31;
default:
std::cerr << "Unhandled reg in enumRegToRealReg!\n";
abort();
}
}
int64_t PPC32CodeEmitter::getMachineOpValue(MachineInstr &MI,
MachineOperand &MO) {
int64_t rv = 0; // Return value; defaults to 0 for unhandled cases
// or things that get fixed up later by the JIT.
if (MO.isRegister()) {
rv = enumRegToMachineReg(MO.getReg());
} else if (MO.isImmediate()) {
rv = MO.getImmedValue();
} else if (MO.isGlobalAddress()) {
GlobalValue *GV = MO.getGlobal();
intptr_t Addr = (intptr_t)MCE.getGlobalValueAddress(GV);
if (Addr == 0) {
if (Function *F = dyn_cast<Function>(GV)) {
if (F->isExternal())
rv = getAddressOfExternalFunction(F);
else {
// Function has not yet been code generated!
getResolver(MCE).addFunctionReference(MCE.getCurrentPCValue(), F);
// Delayed resolution...
return (intptr_t)getResolver(MCE).getLazyResolver(F);
}
} else if (GlobalVariable *GVar = dyn_cast<GlobalVariable>(GV)) {
if (GVar->isExternal()) {
rv = MCE.getGlobalValueAddress(MO.getSymbolName());
if (!rv) {
std::cerr << "PPC32CodeEmitter: External global addr not found: "
<< *GVar;
abort();
}
} else {
std::cerr << "PPC32CodeEmitter: global addr not found: " << *GVar;
abort();
}
}
}
if (MO.isPCRelative()) { // Global variable reference
rv = (Addr - MCE.getCurrentPCValue()) >> 2;
}
} else if (MO.isMachineBasicBlock()) {
const BasicBlock *BB = MO.getMachineBasicBlock()->getBasicBlock();
unsigned* CurrPC = (unsigned*)(intptr_t)MCE.getCurrentPCValue();
BBRefs.push_back(std::make_pair(BB, std::make_pair(CurrPC, &MI)));
} else if (MO.isConstantPoolIndex()) {
unsigned index = MO.getConstantPoolIndex();
rv = MCE.getConstantPoolEntryAddress(index);
} else if (MO.isFrameIndex()) {
std::cerr << "PPC32CodeEmitter: error: Frame index unhandled!\n";
abort();
} else {
std::cerr << "ERROR: Unknown type of MachineOperand: " << MO << "\n";
abort();
}
// Special treatment for global symbols: constants and vars
if (MO.isConstantPoolIndex() || MO.isGlobalAddress()) {
unsigned Opcode = MI.getOpcode();
int64_t MBBLoc = BBLocations[MI.getParent()->getBasicBlock()];
if (Opcode == PPC::LOADHiAddr) {
// LoadHiAddr wants hi16(addr - mbb)
rv = (rv - MBBLoc) >> 16;
} else if (Opcode == PPC::LWZ || Opcode == PPC::LA ||
Opcode == PPC::LFS || Opcode == PPC::LFD) {
// These load opcodes want lo16(addr - mbb)
rv = (rv - MBBLoc) & 0xffff;
}
}
return rv;
}
void *PPC32JITInfo::getJITStubForFunction(Function *F, MachineCodeEmitter &MCE){
return (void*)((unsigned long)getResolver(MCE).getLazyResolver(F));
}
void PPC32JITInfo::replaceMachineCodeForFunction (void *Old, void *New) {
std::cerr << "PPC32JITInfo::replaceMachineCodeForFunction not implemented\n";
abort();
}
#include "PPC32GenCodeEmitter.inc"
} // end llvm namespace
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