//===-- JIT.cpp - LLVM Just in Time Compiler ------------------------------===//
//
-// This file implements the top-level support for creating a Just-In-Time
-// compiler for the current architecture.
+// The LLVM Compiler Infrastructure
+//
+// This file 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 bitcode in an efficient manner.
//
//===----------------------------------------------------------------------===//
-#include "VM.h"
+#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/TargetMachineImpls.h"
-#include "llvm/Module.h"
-#include "Support/CommandLine.h"
+#include "llvm/Target/TargetJITInfo.h"
-// FIXME: REMOVE THIS
-#include "llvm/PassManager.h"
+#include "llvm/Config/config.h"
-#if !defined(ENABLE_X86_JIT) && !defined(ENABLE_SPARC_JIT)
-#define NO_JITS_ENABLED
-#endif
+using namespace llvm;
-namespace {
- enum ArchName { x86, Sparc };
-
-#ifndef NO_JITS_ENABLED
- cl::opt<ArchName>
- Arch("march", cl::desc("Architecture to JIT to:"), cl::Prefix,
- cl::values(
-#ifdef ENABLE_X86_JIT
- clEnumVal(x86, " IA-32 (Pentium and above)"),
-#endif
-#ifdef ENABLE_SPARC_JIT
- clEnumValN(Sparc, "sparc", " Sparc-V9"),
+#ifdef __APPLE__
+// 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.
+# 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))
+# ifndef HAVE___DSO_HANDLE
+# define HAVE___DSO_HANDLE 1
+# endif
+# endif
#endif
- 0),
-#if defined(ENABLE_X86_JIT)
- cl::init(x86)
-#elif defined(ENABLE_SPARC_JIT)
- cl::init(Sparc)
+
+#if HAVE___DSO_HANDLE
+extern void *__dso_handle __attribute__ ((__visibility__ ("hidden")));
#endif
- );
-#endif /* NO_JITS_ENABLED */
+
+namespace {
+
+static struct RegisterJIT {
+ RegisterJIT() { JIT::Register(); }
+} JITRegistrator;
+
}
-/// createJIT - Create an return a new JIT compiler if there is one available
-/// for the current target. Otherwise it returns null.
-///
-ExecutionEngine *ExecutionEngine::createJIT(Module *M, unsigned Config) {
-
- TargetMachine* (*TargetMachineAllocator)(unsigned) = 0;
+namespace llvm {
+ void LinkInJIT() {
+ }
+}
- // Allow a command-line switch to override what *should* be the default target
- // machine for this platform. This allows for debugging a Sparc JIT on X86 --
- // our X86 machines are much faster at recompiling LLVM and linking LLI.
-#ifdef NO_JITS_ENABLED
- return 0;
+#if defined (__GNUC__)
+extern "C" void __register_frame(void*);
#endif
- switch (Arch) {
-#ifdef ENABLE_X86_JIT
- case x86:
- TargetMachineAllocator = allocateX86TargetMachine;
- break;
-#endif
-#ifdef ENABLE_SPARC_JIT
- case Sparc:
- TargetMachineAllocator = allocateSparcTargetMachine;
- break;
+/// createJIT - This is the factory method for creating a JIT for the current
+/// machine, it does not fall back to the interpreter. This takes ownership
+/// of the module provider.
+ExecutionEngine *ExecutionEngine::createJIT(ModuleProvider *MP,
+ std::string *ErrorStr,
+ JITMemoryManager *JMM) {
+ ExecutionEngine *EE = JIT::createJIT(MP, ErrorStr, JMM);
+ if (!EE) return 0;
+
+ // Register routine for informing unwinding runtime about new EH frames
+#if defined(__GNUC__)
+ EE->InstallExceptionTableRegister(__register_frame);
#endif
- default:
- assert(0 && "-march flag not supported on this host!");
- }
- // Allocate a target...
- TargetMachine *Target = (*TargetMachineAllocator)(Config);
- assert(Target && "Could not allocate target machine!");
-
- // Create the virtual machine object...
- return new VM(M, Target);
+ // Make sure we can resolve symbols in the program as well. The zero arg
+ // to the function tells DynamicLibrary to load the program, not a library.
+ sys::DynamicLibrary::LoadLibraryPermanently(0, ErrorStr);
+ return EE;
}
-VM::VM(Module *M, TargetMachine *tm) : ExecutionEngine(M), TM(*tm) {
+JIT::JIT(ModuleProvider *MP, TargetMachine &tm, TargetJITInfo &tji,
+ JITMemoryManager *JMM)
+ : ExecutionEngine(MP), TM(tm), TJI(tji), jitstate(MP) {
setTargetData(TM.getTargetData());
// Initialize MCE
- MCE = createEmitter(*this);
-
- setupPassManager();
-
-#ifdef ENABLE_SPARC_JIT
- // THIS GOES BEYOND UGLY HACKS
- if (TM.getName() == "UltraSparc-Native") {
- extern Pass *createPreSelectionPass(TargetMachine &TM);
- PassManager PM;
- // Specialize LLVM code for this target machine and then
- // run basic dataflow optimizations on LLVM code.
- PM.add(createPreSelectionPass(TM));
- PM.run(*M);
+ MCE = createEmitter(*this, JMM);
+
+ // 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();
}
-#endif
+
+ // Initialize passes.
+ PM.doInitialization();
+}
- emitGlobals();
+JIT::~JIT() {
+ delete MCE;
+ delete &TM;
}
-/// VM::run - This method begins the execution of a program beginning at the
-/// specified function name. The function is called with the specified
-/// arguments and array of environment variables (a la main()).
+/// run - Start execution with the specified function and arguments.
///
-/// Inputs:
-/// FnName - The name of the function as a C++ string.
-/// Args - A vector of C++ strings containing the arguments.
-/// envp - An array of C strings containing the environment.
+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::VoidTy) {
+ switch (ArgValues.size()) {
+ case 3:
+ if (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 &&
+ 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) {
+ 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::X86_FP80TyID:
+ case Type::FP128TyID:
+ case Type::PPC_FP128TyID:
+ assert(0 && "long double not supported yet");
+ 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 = Function::Create(STy, Function::InternalLinkage, "",
+ F->getParent());
+
+ // Insert a basic block.
+ BasicBlock *StubBB = BasicBlock::Create("", 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(APFloat(AV.FloatVal));
+ break;
+ case Type::DoubleTyID:
+ C = ConstantFP::get(APFloat(AV.DoubleVal));
+ break;
+ case Type::PPC_FP128TyID:
+ case Type::X86_FP80TyID:
+ case Type::FP128TyID:
+ C = ConstantFP::get(APFloat(AV.IntVal));
+ 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 = CallInst::Create(F, Args.begin(), Args.end(),
+ "", StubBB);
+ TheCall->setTailCall();
+ if (TheCall->getType() != Type::VoidTy)
+ ReturnInst::Create(TheCall, StubBB); // Return result of the call.
+ else
+ ReturnInst::Create(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.
///
-/// Return value:
-/// 1 - An error occurred.
-/// Otherwise, the return value from the specified function is returned.
+void JIT::runJITOnFunction(Function *F) {
+ static bool isAlreadyCodeGenerating = false;
+
+ MutexGuard locked(lock);
+ assert(!isAlreadyCodeGenerating && "Error: Recursive compilation detected!");
+
+ // 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.
///
-int VM::run(const std::string &FnName, const std::vector<std::string> &Args,
- const char **envp) {
- Function *F = getModule().getNamedFunction(FnName);
- if (F == 0) {
- std::cerr << "Could not find function '" << FnName << "' in module!\n";
- return 1;
+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->hasNotBeenReadFromBitcode()) {
+ // 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 bitcode file: " << ErrorMsg << "\n";
+ abort();
+ }
+ }
+
+ if (void *Addr = getPointerToGlobalIfAvailable(F)) {
+ return Addr;
}
- int (*PF)(int, char**, const char**) =
- (int(*)(int, char**, const char**))getPointerToFunction(F);
- assert(PF != 0 && "Null pointer to function?");
+ MutexGuard locked(lock);
+
+ if (F->isDeclaration()) {
+ void *Addr = getPointerToNamedFunction(F->getName());
+ addGlobalMapping(F, Addr);
+ return Addr;
+ }
- // Build an argv vector...
- char **Argv = (char**)CreateArgv(Args);
+ runJITOnFunction(F);
+
+ void *Addr = getPointerToGlobalIfAvailable(F);
+ assert(Addr && "Code generation didn't add function to GlobalAddress table!");
+ return Addr;
+}
- // Call the main function...
- int Result = PF(Args.size(), Argv, envp);
+/// 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);
- // Run any atexit handlers now!
- runAtExitHandlers();
- return Result;
+ void *Ptr = getPointerToGlobalIfAvailable(GV);
+ if (Ptr) return Ptr;
+
+ // If the global is external, just remember the address.
+ if (GV->isDeclaration()) {
+#if HAVE___DSO_HANDLE
+ 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()->getABITypeSize(GlobalType);
+ size_t A = getTargetData()->getPreferredAlignment(GV);
+ 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;
+}
+