llvm-6502/lib/ExecutionEngine/JIT/JIT.cpp

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//===-- JIT.cpp - LLVM Just in Time Compiler ------------------------------===//
//
// 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 tool implements a just-in-time compiler for LLVM, allowing direct
// execution of LLVM bytecode in an efficient manner.
//
//===----------------------------------------------------------------------===//
#include "JIT.h"
#include "llvm/Constants.h"
#include "llvm/DerivedTypes.h"
#include "llvm/Function.h"
#include "llvm/GlobalVariable.h"
#include "llvm/Instructions.h"
#include "llvm/ModuleProvider.h"
#include "llvm/CodeGen/MachineCodeEmitter.h"
#include "llvm/CodeGen/MachineFunction.h"
#include "llvm/ExecutionEngine/GenericValue.h"
#include "llvm/System/DynamicLibrary.h"
#include "llvm/Target/TargetMachine.h"
#include "llvm/Target/TargetJITInfo.h"
#include <iostream>
using namespace llvm;
JIT::JIT(ModuleProvider *MP, TargetMachine &tm, TargetJITInfo &tji)
: ExecutionEngine(MP), TM(tm), TJI(tji), PM(MP) {
setTargetData(TM.getTargetData());
// Initialize MCE
MCE = createEmitter(*this);
// Add target data
PM.add(new TargetData(TM.getTargetData()));
// Compile LLVM Code down to machine code in the intermediate representation
TJI.addPassesToJITCompile(PM);
// Turn the machine code intermediate representation into bytes in memory that
// may be executed.
if (TM.addPassesToEmitMachineCode(PM, *MCE)) {
std::cerr << "Target '" << TM.getName()
<< "' doesn't support machine code emission!\n";
abort();
}
}
JIT::~JIT() {
delete MCE;
delete &TM;
}
/// run - Start execution with the specified function and arguments.
///
GenericValue JIT::runFunction(Function *F,
const std::vector<GenericValue> &ArgValues) {
assert(F && "Function *F was null at entry to run()");
void *FPtr = getPointerToFunction(F);
assert(FPtr && "Pointer to fn's code was null after getPointerToFunction");
const FunctionType *FTy = F->getFunctionType();
const Type *RetTy = FTy->getReturnType();
assert((FTy->getNumParams() <= ArgValues.size() || FTy->isVarArg()) &&
"Too many arguments passed into function!");
assert(FTy->getNumParams() == ArgValues.size() &&
"This doesn't support passing arguments through varargs (yet)!");
// Handle some common cases first. These cases correspond to common `main'
// prototypes.
if (RetTy == Type::IntTy || RetTy == Type::UIntTy || RetTy == Type::VoidTy) {
switch (ArgValues.size()) {
case 3:
if ((FTy->getParamType(0) == Type::IntTy ||
FTy->getParamType(0) == Type::UIntTy) &&
isa<PointerType>(FTy->getParamType(1)) &&
isa<PointerType>(FTy->getParamType(2))) {
int (*PF)(int, char **, const char **) =
(int(*)(int, char **, const char **))FPtr;
// Call the function.
GenericValue rv;
rv.IntVal = PF(ArgValues[0].IntVal, (char **)GVTOP(ArgValues[1]),
(const char **)GVTOP(ArgValues[2]));
return rv;
}
break;
case 2:
if ((FTy->getParamType(0) == Type::IntTy ||
FTy->getParamType(0) == Type::UIntTy) &&
isa<PointerType>(FTy->getParamType(1))) {
int (*PF)(int, char **) = (int(*)(int, char **))FPtr;
// Call the function.
GenericValue rv;
rv.IntVal = PF(ArgValues[0].IntVal, (char **)GVTOP(ArgValues[1]));
return rv;
}
break;
case 1:
if (FTy->getNumParams() == 1 &&
(FTy->getParamType(0) == Type::IntTy ||
FTy->getParamType(0) == Type::UIntTy)) {
GenericValue rv;
int (*PF)(int) = (int(*)(int))FPtr;
rv.IntVal = PF(ArgValues[0].IntVal);
return rv;
}
break;
}
}
// Handle cases where no arguments are passed first.
if (ArgValues.empty()) {
GenericValue rv;
switch (RetTy->getTypeID()) {
default: assert(0 && "Unknown return type for function call!");
case Type::BoolTyID:
rv.BoolVal = ((bool(*)())FPtr)();
return rv;
case Type::SByteTyID:
case Type::UByteTyID:
rv.SByteVal = ((char(*)())FPtr)();
return rv;
case Type::ShortTyID:
case Type::UShortTyID:
rv.ShortVal = ((short(*)())FPtr)();
return rv;
case Type::VoidTyID:
case Type::IntTyID:
case Type::UIntTyID:
rv.IntVal = ((int(*)())FPtr)();
return rv;
case Type::LongTyID:
case Type::ULongTyID:
rv.LongVal = ((int64_t(*)())FPtr)();
return rv;
case Type::FloatTyID:
rv.FloatVal = ((float(*)())FPtr)();
return rv;
case Type::DoubleTyID:
rv.DoubleVal = ((double(*)())FPtr)();
return rv;
case Type::PointerTyID:
return PTOGV(((void*(*)())FPtr)());
}
}
// Okay, this is not one of our quick and easy cases. Because we don't have a
// full FFI, we have to codegen a nullary stub function that just calls the
// function we are interested in, passing in constants for all of the
// arguments. Make this function and return.
// First, create the function.
FunctionType *STy=FunctionType::get(RetTy, std::vector<const Type*>(), false);
Function *Stub = new Function(STy, Function::InternalLinkage, "",
F->getParent());
// Insert a basic block.
BasicBlock *StubBB = new BasicBlock("", Stub);
// Convert all of the GenericValue arguments over to constants. Note that we
// currently don't support varargs.
std::vector<Value*> Args;
for (unsigned i = 0, e = ArgValues.size(); i != e; ++i) {
Constant *C = 0;
const Type *ArgTy = FTy->getParamType(i);
const GenericValue &AV = ArgValues[i];
switch (ArgTy->getTypeID()) {
default: assert(0 && "Unknown argument type for function call!");
case Type::BoolTyID: C = ConstantBool::get(AV.BoolVal); break;
case Type::SByteTyID: C = ConstantSInt::get(ArgTy, AV.SByteVal); break;
case Type::UByteTyID: C = ConstantUInt::get(ArgTy, AV.UByteVal); break;
case Type::ShortTyID: C = ConstantSInt::get(ArgTy, AV.ShortVal); break;
case Type::UShortTyID: C = ConstantUInt::get(ArgTy, AV.UShortVal); break;
case Type::IntTyID: C = ConstantSInt::get(ArgTy, AV.IntVal); break;
case Type::UIntTyID: C = ConstantUInt::get(ArgTy, AV.UIntVal); break;
case Type::LongTyID: C = ConstantSInt::get(ArgTy, AV.LongVal); break;
case Type::ULongTyID: C = ConstantUInt::get(ArgTy, AV.ULongVal); break;
case Type::FloatTyID: C = ConstantFP ::get(ArgTy, AV.FloatVal); break;
case Type::DoubleTyID: C = ConstantFP ::get(ArgTy, AV.DoubleVal); break;
case Type::PointerTyID:
void *ArgPtr = GVTOP(AV);
if (sizeof(void*) == 4) {
C = ConstantSInt::get(Type::IntTy, (int)(intptr_t)ArgPtr);
} else {
C = ConstantSInt::get(Type::LongTy, (intptr_t)ArgPtr);
}
C = ConstantExpr::getCast(C, ArgTy); // Cast the integer to pointer
break;
}
Args.push_back(C);
}
Value *TheCall = new CallInst(F, Args, "", StubBB);
if (TheCall->getType() != Type::VoidTy)
new ReturnInst(TheCall, StubBB); // Return result of the call.
else
new ReturnInst(StubBB); // Just return void.
// Finally, return the value returned by our nullary stub function.
return runFunction(Stub, std::vector<GenericValue>());
}
/// runJITOnFunction - Run the FunctionPassManager full of
/// just-in-time compilation passes on F, hopefully filling in
/// GlobalAddress[F] with the address of F's machine code.
///
void JIT::runJITOnFunction(Function *F) {
static bool isAlreadyCodeGenerating = false;
assert(!isAlreadyCodeGenerating && "Error: Recursive compilation detected!");
// JIT the function
isAlreadyCodeGenerating = true;
PM.run(*F);
isAlreadyCodeGenerating = false;
// If the function referred to a global variable that had not yet been
// emitted, it allocates memory for the global, but doesn't emit it yet. Emit
// all of these globals now.
while (!PendingGlobals.empty()) {
const GlobalVariable *GV = PendingGlobals.back();
PendingGlobals.pop_back();
EmitGlobalVariable(GV);
}
}
/// getPointerToFunction - This method is used to get the address of the
/// specified function, compiling it if neccesary.
///
void *JIT::getPointerToFunction(Function *F) {
if (void *Addr = getPointerToGlobalIfAvailable(F))
return Addr; // Check if function already code gen'd
// Make sure we read in the function if it exists in this Module
if (F->hasNotBeenReadFromBytecode())
try {
MP->materializeFunction(F);
} catch ( std::string& errmsg ) {
std::cerr << "Error reading function '" << F->getName()
<< "' from bytecode file: " << errmsg << "\n";
abort();
} catch (...) {
std::cerr << "Error reading function '" << F->getName()
<< "from bytecode file!\n";
abort();
}
if (F->isExternal()) {
void *Addr = getPointerToNamedFunction(F->getName());
addGlobalMapping(F, Addr);
return Addr;
}
runJITOnFunction(F);
void *Addr = getPointerToGlobalIfAvailable(F);
assert(Addr && "Code generation didn't add function to GlobalAddress table!");
return Addr;
}
/// getOrEmitGlobalVariable - Return the address of the specified global
/// variable, possibly emitting it to memory if needed. This is used by the
/// Emitter.
void *JIT::getOrEmitGlobalVariable(const GlobalVariable *GV) {
void *Ptr = getPointerToGlobalIfAvailable(GV);
if (Ptr) return Ptr;
// If the global is external, just remember the address.
if (GV->isExternal()) {
Ptr = sys::DynamicLibrary::SearchForAddressOfSymbol(GV->getName().c_str());
if (Ptr == 0) {
std::cerr << "Could not resolve external global address: "
<< GV->getName() << "\n";
abort();
}
} else {
// If the global hasn't been emitted to memory yet, allocate space. We will
// actually initialize the global after current function has finished
// compilation.
uint64_t S = getTargetData().getTypeSize(GV->getType()->getElementType());
Ptr = new char[(size_t)S];
PendingGlobals.push_back(GV);
}
addGlobalMapping(GV, Ptr);
return Ptr;
}
/// recompileAndRelinkFunction - This method is used to force a function
/// which has already been compiled, to be compiled again, possibly
/// after it has been modified. Then the entry to the old copy is overwritten
/// with a branch to the new copy. If there was no old copy, this acts
/// just like JIT::getPointerToFunction().
///
void *JIT::recompileAndRelinkFunction(Function *F) {
void *OldAddr = getPointerToGlobalIfAvailable(F);
// If it's not already compiled there is no reason to patch it up.
if (OldAddr == 0) { return getPointerToFunction(F); }
// Delete the old function mapping.
addGlobalMapping(F, 0);
// Recodegen the function
runJITOnFunction(F);
// Update state, forward the old function to the new function.
void *Addr = getPointerToGlobalIfAvailable(F);
assert(Addr && "Code generation didn't add function to GlobalAddress table!");
TJI.replaceMachineCodeForFunction(OldAddr, Addr);
return Addr;
}
/// freeMachineCodeForFunction - release machine code memory for given Function
///
void JIT::freeMachineCodeForFunction(Function *F) {
// currently a no-op
}