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llvm-project/llvm/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/Support/MutexGuard.h"
#include "llvm/System/DynamicLibrary.h"
#include "llvm/Target/TargetData.h"
#include "llvm/Target/TargetMachine.h"
#include "llvm/Target/TargetJITInfo.h"
using namespace llvm;
#ifdef __APPLE__
#include <AvailabilityMacros.h>
#if defined(MAC_OS_X_VERSION_10_4) && \
((MAC_OS_X_VERSION_MIN_REQUIRED > MAC_OS_X_VERSION_10_4) || \
(MAC_OS_X_VERSION_MIN_REQUIRED == MAC_OS_X_VERSION_10_4 && \
__APPLE_CC__ >= 5330))
// __dso_handle is resolved by Mac OS X dynamic linker.
extern void *__dso_handle __attribute__ ((__visibility__ ("hidden")));
#endif
#endif
static struct RegisterJIT {
RegisterJIT() { JIT::Register(); }
} JITRegistrator;
namespace llvm {
void LinkInJIT() {
}
}
JIT::JIT(ModuleProvider *MP, TargetMachine &tm, TargetJITInfo &tji)
: ExecutionEngine(MP), TM(tm), TJI(tji), jitstate(MP) {
setTargetData(TM.getTargetData());
// Initialize MCE
MCE = createEmitter(*this);
// Add target data
MutexGuard locked(lock);
FunctionPassManager &PM = jitstate.getPM(locked);
PM.add(new TargetData(*TM.getTargetData()));
// Turn the machine code intermediate representation into bytes in memory that
// may be executed.
if (TM.addPassesToEmitMachineCode(PM, *MCE, false /*fast*/)) {
cerr << "Target does not support machine code emission!\n";
abort();
}
// Initialize passes.
PM.doInitialization();
}
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::Int32Ty || RetTy == Type::Int32Ty || RetTy == Type::VoidTy) {
switch (ArgValues.size()) {
case 3:
if ((FTy->getParamType(0) == Type::Int32Ty ||
FTy->getParamType(0) == Type::Int32Ty) &&
isa<PointerType>(FTy->getParamType(1)) &&
isa<PointerType>(FTy->getParamType(2))) {
int (*PF)(int, char **, const char **) =
(int(*)(int, char **, const char **))(intptr_t)FPtr;
// Call the function.
GenericValue rv;
rv.IntVal = APInt(32, PF(ArgValues[0].IntVal.getZExtValue(),
(char **)GVTOP(ArgValues[1]),
(const char **)GVTOP(ArgValues[2])));
return rv;
}
break;
case 2:
if ((FTy->getParamType(0) == Type::Int32Ty ||
FTy->getParamType(0) == Type::Int32Ty) &&
isa<PointerType>(FTy->getParamType(1))) {
int (*PF)(int, char **) = (int(*)(int, char **))(intptr_t)FPtr;
// Call the function.
GenericValue rv;
rv.IntVal = APInt(32, PF(ArgValues[0].IntVal.getZExtValue(),
(char **)GVTOP(ArgValues[1])));
return rv;
}
break;
case 1:
if (FTy->getNumParams() == 1 &&
(FTy->getParamType(0) == Type::Int32Ty ||
FTy->getParamType(0) == Type::Int32Ty)) {
GenericValue rv;
int (*PF)(int) = (int(*)(int))(intptr_t)FPtr;
rv.IntVal = APInt(32, PF(ArgValues[0].IntVal.getZExtValue()));
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::IntegerTyID: {
unsigned BitWidth = cast<IntegerType>(RetTy)->getBitWidth();
if (BitWidth == 1)
rv.IntVal = APInt(BitWidth, ((bool(*)())(intptr_t)FPtr)());
else if (BitWidth <= 8)
rv.IntVal = APInt(BitWidth, ((char(*)())(intptr_t)FPtr)());
else if (BitWidth <= 16)
rv.IntVal = APInt(BitWidth, ((short(*)())(intptr_t)FPtr)());
else if (BitWidth <= 32)
rv.IntVal = APInt(BitWidth, ((int(*)())(intptr_t)FPtr)());
else if (BitWidth <= 64)
rv.IntVal = APInt(BitWidth, ((int64_t(*)())(intptr_t)FPtr)());
else
assert(0 && "Integer types > 64 bits not supported");
return rv;
}
case Type::VoidTyID:
rv.IntVal = APInt(32, ((int(*)())(intptr_t)FPtr)());
return rv;
case Type::FloatTyID:
rv.FloatVal = ((float(*)())(intptr_t)FPtr)();
return rv;
case Type::DoubleTyID:
rv.DoubleVal = ((double(*)())(intptr_t)FPtr)();
return rv;
case Type::PointerTyID:
return PTOGV(((void*(*)())(intptr_t)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.
SmallVector<Value*, 8> 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::IntegerTyID: C = ConstantInt::get(AV.IntVal); 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 = ConstantInt::get(Type::Int32Ty, (int)(intptr_t)ArgPtr);
} else {
C = ConstantInt::get(Type::Int64Ty, (intptr_t)ArgPtr);
}
C = ConstantExpr::getIntToPtr(C, ArgTy); // Cast the integer to pointer
break;
}
Args.push_back(C);
}
CallInst *TheCall = new CallInst(F, &Args[0], Args.size(), "", StubBB);
TheCall->setTailCall();
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!");
MutexGuard locked(lock);
// JIT the function
isAlreadyCodeGenerating = true;
jitstate.getPM(locked).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 (!jitstate.getPendingGlobals(locked).empty()) {
const GlobalVariable *GV = jitstate.getPendingGlobals(locked).back();
jitstate.getPendingGlobals(locked).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) {
MutexGuard locked(lock);
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()) {
// Determine the module provider this function is provided by.
Module *M = F->getParent();
ModuleProvider *MP = 0;
for (unsigned i = 0, e = Modules.size(); i != e; ++i) {
if (Modules[i]->getModule() == M) {
MP = Modules[i];
break;
}
}
assert(MP && "Function isn't in a module we know about!");
std::string ErrorMsg;
if (MP->materializeFunction(F, &ErrorMsg)) {
cerr << "Error reading function '" << F->getName()
<< "' from bytecode file: " << ErrorMsg << "\n";
abort();
}
}
if (F->isDeclaration()) {
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) {
MutexGuard locked(lock);
void *Ptr = getPointerToGlobalIfAvailable(GV);
if (Ptr) return Ptr;
// If the global is external, just remember the address.
if (GV->isDeclaration()) {
#if defined(__APPLE__) && defined(MAC_OS_X_VERSION_10_4) && \
((MAC_OS_X_VERSION_MIN_REQUIRED > MAC_OS_X_VERSION_10_4) || \
(MAC_OS_X_VERSION_MIN_REQUIRED == MAC_OS_X_VERSION_10_4 && \
__APPLE_CC__ >= 5330))
// Apple gcc defaults to -fuse-cxa-atexit (i.e. calls __cxa_atexit instead
// of atexit). It passes the address of linker generated symbol __dso_handle
// to the function.
// This configuration change happened at version 5330.
if (GV->getName() == "__dso_handle")
return (void*)&__dso_handle;
#endif
Ptr = sys::DynamicLibrary::SearchForAddressOfSymbol(GV->getName().c_str());
if (Ptr == 0) {
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.
const Type *GlobalType = GV->getType()->getElementType();
size_t S = getTargetData()->getTypeSize(GlobalType);
size_t A = getTargetData()->getPrefTypeAlignment(GlobalType);
if (A <= 8) {
Ptr = malloc(S);
} else {
// Allocate S+A bytes of memory, then use an aligned pointer within that
// space.
Ptr = malloc(S+A);
unsigned MisAligned = ((intptr_t)Ptr & (A-1));
Ptr = (char*)Ptr + (MisAligned ? (A-MisAligned) : 0);
}
jitstate.getPendingGlobals(locked).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;
}
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