It's not necessary to do rounding for alloca operations when the requested
alignment is equal to the stack alignment.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@40004 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/ExecutionEngine/JIT/Intercept.cpp b/lib/ExecutionEngine/JIT/Intercept.cpp
new file mode 100644
index 0000000..f370e5b
--- /dev/null
+++ b/lib/ExecutionEngine/JIT/Intercept.cpp
@@ -0,0 +1,121 @@
+//===-- Intercept.cpp - System function interception routines -------------===//
+//
+// 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.
+//
+//===----------------------------------------------------------------------===//
+//
+// If a function call occurs to an external function, the JIT is designed to use
+// the dynamic loader interface to find a function to call. This is useful for
+// calling system calls and library functions that are not available in LLVM.
+// Some system calls, however, need to be handled specially. For this reason,
+// we intercept some of them here and use our own stubs to handle them.
+//
+//===----------------------------------------------------------------------===//
+
+#include "JIT.h"
+#include "llvm/System/DynamicLibrary.h"
+#include "llvm/Config/config.h"
+using namespace llvm;
+
+// AtExitHandlers - List of functions to call when the program exits,
+// registered with the atexit() library function.
+static std::vector<void (*)()> AtExitHandlers;
+
+/// runAtExitHandlers - Run any functions registered by the program's
+/// calls to atexit(3), which we intercept and store in
+/// AtExitHandlers.
+///
+static void runAtExitHandlers() {
+ while (!AtExitHandlers.empty()) {
+ void (*Fn)() = AtExitHandlers.back();
+ AtExitHandlers.pop_back();
+ Fn();
+ }
+}
+
+//===----------------------------------------------------------------------===//
+// Function stubs that are invoked instead of certain library calls
+//===----------------------------------------------------------------------===//
+
+// Force the following functions to be linked in to anything that uses the
+// JIT. This is a hack designed to work around the all-too-clever Glibc
+// strategy of making these functions work differently when inlined vs. when
+// not inlined, and hiding their real definitions in a separate archive file
+// that the dynamic linker can't see. For more info, search for
+// 'libc_nonshared.a' on Google, or read http://llvm.org/PR274.
+#if defined(__linux__)
+#if defined(HAVE_SYS_STAT_H)
+#include <sys/stat.h>
+#endif
+void *FunctionPointers[] = {
+ (void *)(intptr_t) stat,
+ (void *)(intptr_t) fstat,
+ (void *)(intptr_t) lstat,
+ (void *)(intptr_t) stat64,
+ (void *)(intptr_t) fstat64,
+ (void *)(intptr_t) lstat64,
+ (void *)(intptr_t) atexit,
+ (void *)(intptr_t) mknod
+};
+#endif // __linux__
+
+// __mainFunc - If the program does not have a linked in __main function, allow
+// it to run, but print a warning.
+static void __mainFunc() {
+ fprintf(stderr, "WARNING: Program called __main but was not linked to "
+ "libcrtend.a.\nThis probably won't hurt anything unless the "
+ "program is written in C++.\n");
+}
+
+// jit_exit - Used to intercept the "exit" library call.
+static void jit_exit(int Status) {
+ runAtExitHandlers(); // Run atexit handlers...
+ exit(Status);
+}
+
+// jit_atexit - Used to intercept the "atexit" library call.
+static int jit_atexit(void (*Fn)(void)) {
+ AtExitHandlers.push_back(Fn); // Take note of atexit handler...
+ return 0; // Always successful
+}
+
+//===----------------------------------------------------------------------===//
+//
+/// getPointerToNamedFunction - This method returns the address of the specified
+/// function by using the dynamic loader interface. As such it is only useful
+/// for resolving library symbols, not code generated symbols.
+///
+void *JIT::getPointerToNamedFunction(const std::string &Name) {
+ // Check to see if this is one of the functions we want to intercept. Note,
+ // we cast to intptr_t here to silence a -pedantic warning that complains
+ // about casting a function pointer to a normal pointer.
+ if (Name == "exit") return (void*)(intptr_t)&jit_exit;
+ if (Name == "atexit") return (void*)(intptr_t)&jit_atexit;
+
+ // If the program does not have a linked in __main function, allow it to run,
+ // but print a warning.
+ if (Name == "__main") return (void*)(intptr_t)&__mainFunc;
+
+ const char *NameStr = Name.c_str();
+ // If this is an asm specifier, skip the sentinal.
+ if (NameStr[0] == 1) ++NameStr;
+
+ // If it's an external function, look it up in the process image...
+ void *Ptr = sys::DynamicLibrary::SearchForAddressOfSymbol(NameStr);
+ if (Ptr) return Ptr;
+
+ // If it wasn't found and if it starts with an underscore ('_') character, and
+ // has an asm specifier, try again without the underscore.
+ if (Name[0] == 1 && NameStr[0] == '_') {
+ Ptr = sys::DynamicLibrary::SearchForAddressOfSymbol(NameStr+1);
+ if (Ptr) return Ptr;
+ }
+
+ cerr << "ERROR: Program used external function '" << Name
+ << "' which could not be resolved!\n";
+ abort();
+ return 0;
+}
diff --git a/lib/ExecutionEngine/JIT/JIT.cpp b/lib/ExecutionEngine/JIT/JIT.cpp
new file mode 100644
index 0000000..603f8ec
--- /dev/null
+++ b/lib/ExecutionEngine/JIT/JIT.cpp
@@ -0,0 +1,369 @@
+//===-- 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 bitcode 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->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 (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;
+}
+
diff --git a/lib/ExecutionEngine/JIT/JIT.h b/lib/ExecutionEngine/JIT/JIT.h
new file mode 100644
index 0000000..5a3d661
--- /dev/null
+++ b/lib/ExecutionEngine/JIT/JIT.h
@@ -0,0 +1,130 @@
+//===-- JIT.h - Class definition for the JIT --------------------*- 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 top-level JIT data structure.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef JIT_H
+#define JIT_H
+
+#include "llvm/ExecutionEngine/ExecutionEngine.h"
+#include "llvm/PassManager.h"
+#include <map>
+
+namespace llvm {
+
+class Function;
+class GlobalValue;
+class Constant;
+class TargetMachine;
+class TargetJITInfo;
+class MachineCodeEmitter;
+
+class JITState {
+private:
+ FunctionPassManager PM; // Passes to compile a function
+
+ /// PendingGlobals - Global variables which have had memory allocated for them
+ /// while a function was code generated, but which have not been initialized
+ /// yet.
+ std::vector<const GlobalVariable*> PendingGlobals;
+
+public:
+ JITState(ModuleProvider *MP) : PM(MP) {}
+
+ FunctionPassManager &getPM(const MutexGuard &L) {
+ return PM;
+ }
+
+ std::vector<const GlobalVariable*> &getPendingGlobals(const MutexGuard &L) {
+ return PendingGlobals;
+ }
+};
+
+
+class JIT : public ExecutionEngine {
+ TargetMachine &TM; // The current target we are compiling to
+ TargetJITInfo &TJI; // The JITInfo for the target we are compiling to
+ MachineCodeEmitter *MCE; // MCE object
+
+ JITState jitstate;
+
+ JIT(ModuleProvider *MP, TargetMachine &tm, TargetJITInfo &tji);
+public:
+ ~JIT();
+
+ static void Register() {
+ JITCtor = create;
+ }
+
+ /// getJITInfo - Return the target JIT information structure.
+ ///
+ TargetJITInfo &getJITInfo() const { return TJI; }
+
+ /// create - Create an return a new JIT compiler if there is one available
+ /// for the current target. Otherwise, return null.
+ ///
+ static ExecutionEngine *create(ModuleProvider *MP, std::string* = 0);
+
+ /// run - Start execution with the specified function and arguments.
+ ///
+ virtual GenericValue runFunction(Function *F,
+ const std::vector<GenericValue> &ArgValues);
+
+ /// getPointerToNamedFunction - This method returns the address of the
+ /// specified function by using the dlsym function call. As such it is only
+ /// useful for resolving library symbols, not code generated symbols.
+ ///
+ void *getPointerToNamedFunction(const std::string &Name);
+
+ // CompilationCallback - Invoked the first time that a call site is found,
+ // which causes lazy compilation of the target function.
+ //
+ static void CompilationCallback();
+
+ /// getPointerToFunction - This returns the address of the specified function,
+ /// compiling it if necessary.
+ ///
+ void *getPointerToFunction(Function *F);
+
+ /// getOrEmitGlobalVariable - Return the address of the specified global
+ /// variable, possibly emitting it to memory if needed. This is used by the
+ /// Emitter.
+ void *getOrEmitGlobalVariable(const GlobalVariable *GV);
+
+ /// getPointerToFunctionOrStub - If the specified function has been
+ /// code-gen'd, return a pointer to the function. If not, compile it, or use
+ /// a stub to implement lazy compilation if available.
+ ///
+ void *getPointerToFunctionOrStub(Function *F);
+
+ /// 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 *recompileAndRelinkFunction(Function *F);
+
+ /// freeMachineCodeForFunction - deallocate memory used to code-generate this
+ /// Function.
+ ///
+ void freeMachineCodeForFunction(Function *F);
+
+ /// getCodeEmitter - Return the code emitter this JIT is emitting into.
+ MachineCodeEmitter *getCodeEmitter() const { return MCE; }
+private:
+ static MachineCodeEmitter *createEmitter(JIT &J);
+ void runJITOnFunction (Function *F);
+};
+
+} // End llvm namespace
+
+#endif
diff --git a/lib/ExecutionEngine/JIT/JITEmitter.cpp b/lib/ExecutionEngine/JIT/JITEmitter.cpp
new file mode 100644
index 0000000..484af48
--- /dev/null
+++ b/lib/ExecutionEngine/JIT/JITEmitter.cpp
@@ -0,0 +1,1067 @@
+//===-- JITEmitter.cpp - Write machine code to executable memory ----------===//
+//
+// 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 a MachineCodeEmitter object that is used by the JIT to
+// write machine code to memory and remember where relocatable values are.
+//
+//===----------------------------------------------------------------------===//
+
+#define DEBUG_TYPE "jit"
+#include "JIT.h"
+#include "llvm/Constant.h"
+#include "llvm/Module.h"
+#include "llvm/Type.h"
+#include "llvm/CodeGen/MachineCodeEmitter.h"
+#include "llvm/CodeGen/MachineFunction.h"
+#include "llvm/CodeGen/MachineConstantPool.h"
+#include "llvm/CodeGen/MachineJumpTableInfo.h"
+#include "llvm/CodeGen/MachineRelocation.h"
+#include "llvm/ExecutionEngine/GenericValue.h"
+#include "llvm/Target/TargetData.h"
+#include "llvm/Target/TargetJITInfo.h"
+#include "llvm/Target/TargetMachine.h"
+#include "llvm/Support/Debug.h"
+#include "llvm/Support/MutexGuard.h"
+#include "llvm/System/Disassembler.h"
+#include "llvm/ADT/Statistic.h"
+#include "llvm/System/Memory.h"
+#include <algorithm>
+using namespace llvm;
+
+STATISTIC(NumBytes, "Number of bytes of machine code compiled");
+STATISTIC(NumRelos, "Number of relocations applied");
+static JIT *TheJIT = 0;
+
+//===----------------------------------------------------------------------===//
+// JITMemoryManager code.
+//
+namespace {
+ /// MemoryRangeHeader - For a range of memory, this is the header that we put
+ /// on the block of memory. It is carefully crafted to be one word of memory.
+ /// Allocated blocks have just this header, free'd blocks have FreeRangeHeader
+ /// which starts with this.
+ struct FreeRangeHeader;
+ struct MemoryRangeHeader {
+ /// ThisAllocated - This is true if this block is currently allocated. If
+ /// not, this can be converted to a FreeRangeHeader.
+ intptr_t ThisAllocated : 1;
+
+ /// PrevAllocated - Keep track of whether the block immediately before us is
+ /// allocated. If not, the word immediately before this header is the size
+ /// of the previous block.
+ intptr_t PrevAllocated : 1;
+
+ /// BlockSize - This is the size in bytes of this memory block,
+ /// including this header.
+ uintptr_t BlockSize : (sizeof(intptr_t)*8 - 2);
+
+
+ /// getBlockAfter - Return the memory block immediately after this one.
+ ///
+ MemoryRangeHeader &getBlockAfter() const {
+ return *(MemoryRangeHeader*)((char*)this+BlockSize);
+ }
+
+ /// getFreeBlockBefore - If the block before this one is free, return it,
+ /// otherwise return null.
+ FreeRangeHeader *getFreeBlockBefore() const {
+ if (PrevAllocated) return 0;
+ intptr_t PrevSize = ((intptr_t *)this)[-1];
+ return (FreeRangeHeader*)((char*)this-PrevSize);
+ }
+
+ /// FreeBlock - Turn an allocated block into a free block, adjusting
+ /// bits in the object headers, and adding an end of region memory block.
+ FreeRangeHeader *FreeBlock(FreeRangeHeader *FreeList);
+
+ /// TrimAllocationToSize - If this allocated block is significantly larger
+ /// than NewSize, split it into two pieces (where the former is NewSize
+ /// bytes, including the header), and add the new block to the free list.
+ FreeRangeHeader *TrimAllocationToSize(FreeRangeHeader *FreeList,
+ uint64_t NewSize);
+ };
+
+ /// FreeRangeHeader - For a memory block that isn't already allocated, this
+ /// keeps track of the current block and has a pointer to the next free block.
+ /// Free blocks are kept on a circularly linked list.
+ struct FreeRangeHeader : public MemoryRangeHeader {
+ FreeRangeHeader *Prev;
+ FreeRangeHeader *Next;
+
+ /// getMinBlockSize - Get the minimum size for a memory block. Blocks
+ /// smaller than this size cannot be created.
+ static unsigned getMinBlockSize() {
+ return sizeof(FreeRangeHeader)+sizeof(intptr_t);
+ }
+
+ /// SetEndOfBlockSizeMarker - The word at the end of every free block is
+ /// known to be the size of the free block. Set it for this block.
+ void SetEndOfBlockSizeMarker() {
+ void *EndOfBlock = (char*)this + BlockSize;
+ ((intptr_t *)EndOfBlock)[-1] = BlockSize;
+ }
+
+ FreeRangeHeader *RemoveFromFreeList() {
+ assert(Next->Prev == this && Prev->Next == this && "Freelist broken!");
+ Next->Prev = Prev;
+ return Prev->Next = Next;
+ }
+
+ void AddToFreeList(FreeRangeHeader *FreeList) {
+ Next = FreeList;
+ Prev = FreeList->Prev;
+ Prev->Next = this;
+ Next->Prev = this;
+ }
+
+ /// GrowBlock - The block after this block just got deallocated. Merge it
+ /// into the current block.
+ void GrowBlock(uintptr_t NewSize);
+
+ /// AllocateBlock - Mark this entire block allocated, updating freelists
+ /// etc. This returns a pointer to the circular free-list.
+ FreeRangeHeader *AllocateBlock();
+ };
+}
+
+
+/// AllocateBlock - Mark this entire block allocated, updating freelists
+/// etc. This returns a pointer to the circular free-list.
+FreeRangeHeader *FreeRangeHeader::AllocateBlock() {
+ assert(!ThisAllocated && !getBlockAfter().PrevAllocated &&
+ "Cannot allocate an allocated block!");
+ // Mark this block allocated.
+ ThisAllocated = 1;
+ getBlockAfter().PrevAllocated = 1;
+
+ // Remove it from the free list.
+ return RemoveFromFreeList();
+}
+
+/// FreeBlock - Turn an allocated block into a free block, adjusting
+/// bits in the object headers, and adding an end of region memory block.
+/// If possible, coalesce this block with neighboring blocks. Return the
+/// FreeRangeHeader to allocate from.
+FreeRangeHeader *MemoryRangeHeader::FreeBlock(FreeRangeHeader *FreeList) {
+ MemoryRangeHeader *FollowingBlock = &getBlockAfter();
+ assert(ThisAllocated && "This block is already allocated!");
+ assert(FollowingBlock->PrevAllocated && "Flags out of sync!");
+
+ FreeRangeHeader *FreeListToReturn = FreeList;
+
+ // If the block after this one is free, merge it into this block.
+ if (!FollowingBlock->ThisAllocated) {
+ FreeRangeHeader &FollowingFreeBlock = *(FreeRangeHeader *)FollowingBlock;
+ // "FreeList" always needs to be a valid free block. If we're about to
+ // coalesce with it, update our notion of what the free list is.
+ if (&FollowingFreeBlock == FreeList) {
+ FreeList = FollowingFreeBlock.Next;
+ FreeListToReturn = 0;
+ assert(&FollowingFreeBlock != FreeList && "No tombstone block?");
+ }
+ FollowingFreeBlock.RemoveFromFreeList();
+
+ // Include the following block into this one.
+ BlockSize += FollowingFreeBlock.BlockSize;
+ FollowingBlock = &FollowingFreeBlock.getBlockAfter();
+
+ // Tell the block after the block we are coalescing that this block is
+ // allocated.
+ FollowingBlock->PrevAllocated = 1;
+ }
+
+ assert(FollowingBlock->ThisAllocated && "Missed coalescing?");
+
+ if (FreeRangeHeader *PrevFreeBlock = getFreeBlockBefore()) {
+ PrevFreeBlock->GrowBlock(PrevFreeBlock->BlockSize + BlockSize);
+ return FreeListToReturn ? FreeListToReturn : PrevFreeBlock;
+ }
+
+ // Otherwise, mark this block free.
+ FreeRangeHeader &FreeBlock = *(FreeRangeHeader*)this;
+ FollowingBlock->PrevAllocated = 0;
+ FreeBlock.ThisAllocated = 0;
+
+ // Link this into the linked list of free blocks.
+ FreeBlock.AddToFreeList(FreeList);
+
+ // Add a marker at the end of the block, indicating the size of this free
+ // block.
+ FreeBlock.SetEndOfBlockSizeMarker();
+ return FreeListToReturn ? FreeListToReturn : &FreeBlock;
+}
+
+/// GrowBlock - The block after this block just got deallocated. Merge it
+/// into the current block.
+void FreeRangeHeader::GrowBlock(uintptr_t NewSize) {
+ assert(NewSize > BlockSize && "Not growing block?");
+ BlockSize = NewSize;
+ SetEndOfBlockSizeMarker();
+ getBlockAfter().PrevAllocated = 0;
+}
+
+/// TrimAllocationToSize - If this allocated block is significantly larger
+/// than NewSize, split it into two pieces (where the former is NewSize
+/// bytes, including the header), and add the new block to the free list.
+FreeRangeHeader *MemoryRangeHeader::
+TrimAllocationToSize(FreeRangeHeader *FreeList, uint64_t NewSize) {
+ assert(ThisAllocated && getBlockAfter().PrevAllocated &&
+ "Cannot deallocate part of an allocated block!");
+
+ // Round up size for alignment of header.
+ unsigned HeaderAlign = __alignof(FreeRangeHeader);
+ NewSize = (NewSize+ (HeaderAlign-1)) & ~(HeaderAlign-1);
+
+ // Size is now the size of the block we will remove from the start of the
+ // current block.
+ assert(NewSize <= BlockSize &&
+ "Allocating more space from this block than exists!");
+
+ // If splitting this block will cause the remainder to be too small, do not
+ // split the block.
+ if (BlockSize <= NewSize+FreeRangeHeader::getMinBlockSize())
+ return FreeList;
+
+ // Otherwise, we splice the required number of bytes out of this block, form
+ // a new block immediately after it, then mark this block allocated.
+ MemoryRangeHeader &FormerNextBlock = getBlockAfter();
+
+ // Change the size of this block.
+ BlockSize = NewSize;
+
+ // Get the new block we just sliced out and turn it into a free block.
+ FreeRangeHeader &NewNextBlock = (FreeRangeHeader &)getBlockAfter();
+ NewNextBlock.BlockSize = (char*)&FormerNextBlock - (char*)&NewNextBlock;
+ NewNextBlock.ThisAllocated = 0;
+ NewNextBlock.PrevAllocated = 1;
+ NewNextBlock.SetEndOfBlockSizeMarker();
+ FormerNextBlock.PrevAllocated = 0;
+ NewNextBlock.AddToFreeList(FreeList);
+ return &NewNextBlock;
+}
+
+
+namespace {
+ /// JITMemoryManager - Manage memory for the JIT code generation in a logical,
+ /// sane way. This splits a large block of MAP_NORESERVE'd memory into two
+ /// sections, one for function stubs, one for the functions themselves. We
+ /// have to do this because we may need to emit a function stub while in the
+ /// middle of emitting a function, and we don't know how large the function we
+ /// are emitting is. This never bothers to release the memory, because when
+ /// we are ready to destroy the JIT, the program exits.
+ class JITMemoryManager {
+ std::vector<sys::MemoryBlock> Blocks; // Memory blocks allocated by the JIT
+ FreeRangeHeader *FreeMemoryList; // Circular list of free blocks.
+
+ // When emitting code into a memory block, this is the block.
+ MemoryRangeHeader *CurBlock;
+
+ unsigned char *CurStubPtr, *StubBase;
+ unsigned char *GOTBase; // Target Specific reserved memory
+
+ // Centralize memory block allocation.
+ sys::MemoryBlock getNewMemoryBlock(unsigned size);
+
+ std::map<const Function*, MemoryRangeHeader*> FunctionBlocks;
+ public:
+ JITMemoryManager(bool useGOT);
+ ~JITMemoryManager();
+
+ inline unsigned char *allocateStub(unsigned StubSize, unsigned Alignment);
+
+ /// startFunctionBody - When a function starts, allocate a block of free
+ /// executable memory, returning a pointer to it and its actual size.
+ unsigned char *startFunctionBody(uintptr_t &ActualSize) {
+ CurBlock = FreeMemoryList;
+
+ // Allocate the entire memory block.
+ FreeMemoryList = FreeMemoryList->AllocateBlock();
+ ActualSize = CurBlock->BlockSize-sizeof(MemoryRangeHeader);
+ return (unsigned char *)(CurBlock+1);
+ }
+
+ /// endFunctionBody - The function F is now allocated, and takes the memory
+ /// in the range [FunctionStart,FunctionEnd).
+ void endFunctionBody(const Function *F, unsigned char *FunctionStart,
+ unsigned char *FunctionEnd) {
+ assert(FunctionEnd > FunctionStart);
+ assert(FunctionStart == (unsigned char *)(CurBlock+1) &&
+ "Mismatched function start/end!");
+
+ uintptr_t BlockSize = FunctionEnd - (unsigned char *)CurBlock;
+ FunctionBlocks[F] = CurBlock;
+
+ // Release the memory at the end of this block that isn't needed.
+ FreeMemoryList =CurBlock->TrimAllocationToSize(FreeMemoryList, BlockSize);
+ }
+
+ unsigned char *getGOTBase() const {
+ return GOTBase;
+ }
+ bool isManagingGOT() const {
+ return GOTBase != NULL;
+ }
+
+ /// deallocateMemForFunction - Deallocate all memory for the specified
+ /// function body.
+ void deallocateMemForFunction(const Function *F) {
+ std::map<const Function*, MemoryRangeHeader*>::iterator
+ I = FunctionBlocks.find(F);
+ if (I == FunctionBlocks.end()) return;
+
+ // Find the block that is allocated for this function.
+ MemoryRangeHeader *MemRange = I->second;
+ assert(MemRange->ThisAllocated && "Block isn't allocated!");
+
+ // Fill the buffer with garbage!
+ DEBUG(memset(MemRange+1, 0xCD, MemRange->BlockSize-sizeof(*MemRange)));
+
+ // Free the memory.
+ FreeMemoryList = MemRange->FreeBlock(FreeMemoryList);
+
+ // Finally, remove this entry from FunctionBlocks.
+ FunctionBlocks.erase(I);
+ }
+ };
+}
+
+JITMemoryManager::JITMemoryManager(bool useGOT) {
+ // Allocate a 16M block of memory for functions.
+ sys::MemoryBlock MemBlock = getNewMemoryBlock(16 << 20);
+
+ unsigned char *MemBase = reinterpret_cast<unsigned char*>(MemBlock.base());
+
+ // Allocate stubs backwards from the base, allocate functions forward
+ // from the base.
+ StubBase = MemBase;
+ CurStubPtr = MemBase + 512*1024; // Use 512k for stubs, working backwards.
+
+ // We set up the memory chunk with 4 mem regions, like this:
+ // [ START
+ // [ Free #0 ] -> Large space to allocate functions from.
+ // [ Allocated #1 ] -> Tiny space to separate regions.
+ // [ Free #2 ] -> Tiny space so there is always at least 1 free block.
+ // [ Allocated #3 ] -> Tiny space to prevent looking past end of block.
+ // END ]
+ //
+ // The last three blocks are never deallocated or touched.
+
+ // Add MemoryRangeHeader to the end of the memory region, indicating that
+ // the space after the block of memory is allocated. This is block #3.
+ MemoryRangeHeader *Mem3 = (MemoryRangeHeader*)(MemBase+MemBlock.size())-1;
+ Mem3->ThisAllocated = 1;
+ Mem3->PrevAllocated = 0;
+ Mem3->BlockSize = 0;
+
+ /// Add a tiny free region so that the free list always has one entry.
+ FreeRangeHeader *Mem2 =
+ (FreeRangeHeader *)(((char*)Mem3)-FreeRangeHeader::getMinBlockSize());
+ Mem2->ThisAllocated = 0;
+ Mem2->PrevAllocated = 1;
+ Mem2->BlockSize = FreeRangeHeader::getMinBlockSize();
+ Mem2->SetEndOfBlockSizeMarker();
+ Mem2->Prev = Mem2; // Mem2 *is* the free list for now.
+ Mem2->Next = Mem2;
+
+ /// Add a tiny allocated region so that Mem2 is never coalesced away.
+ MemoryRangeHeader *Mem1 = (MemoryRangeHeader*)Mem2-1;
+ Mem1->ThisAllocated = 1;
+ Mem1->PrevAllocated = 0;
+ Mem1->BlockSize = (char*)Mem2 - (char*)Mem1;
+
+ // Add a FreeRangeHeader to the start of the function body region, indicating
+ // that the space is free. Mark the previous block allocated so we never look
+ // at it.
+ FreeRangeHeader *Mem0 = (FreeRangeHeader*)CurStubPtr;
+ Mem0->ThisAllocated = 0;
+ Mem0->PrevAllocated = 1;
+ Mem0->BlockSize = (char*)Mem1-(char*)Mem0;
+ Mem0->SetEndOfBlockSizeMarker();
+ Mem0->AddToFreeList(Mem2);
+
+ // Start out with the freelist pointing to Mem0.
+ FreeMemoryList = Mem0;
+
+ // Allocate the GOT.
+ GOTBase = NULL;
+ if (useGOT) GOTBase = new unsigned char[sizeof(void*) * 8192];
+}
+
+JITMemoryManager::~JITMemoryManager() {
+ for (unsigned i = 0, e = Blocks.size(); i != e; ++i)
+ sys::Memory::ReleaseRWX(Blocks[i]);
+
+ delete[] GOTBase;
+ Blocks.clear();
+}
+
+unsigned char *JITMemoryManager::allocateStub(unsigned StubSize,
+ unsigned Alignment) {
+ CurStubPtr -= StubSize;
+ CurStubPtr = (unsigned char*)(((intptr_t)CurStubPtr) &
+ ~(intptr_t)(Alignment-1));
+ if (CurStubPtr < StubBase) {
+ // FIXME: allocate a new block
+ cerr << "JIT ran out of memory for function stubs!\n";
+ abort();
+ }
+ return CurStubPtr;
+}
+
+sys::MemoryBlock JITMemoryManager::getNewMemoryBlock(unsigned size) {
+ // Allocate a new block close to the last one.
+ const sys::MemoryBlock *BOld = Blocks.empty() ? 0 : &Blocks.front();
+ std::string ErrMsg;
+ sys::MemoryBlock B = sys::Memory::AllocateRWX(size, BOld, &ErrMsg);
+ if (B.base() == 0) {
+ cerr << "Allocation failed when allocating new memory in the JIT\n";
+ cerr << ErrMsg << "\n";
+ abort();
+ }
+ Blocks.push_back(B);
+ return B;
+}
+
+//===----------------------------------------------------------------------===//
+// JIT lazy compilation code.
+//
+namespace {
+ class JITResolverState {
+ private:
+ /// FunctionToStubMap - Keep track of the stub created for a particular
+ /// function so that we can reuse them if necessary.
+ std::map<Function*, void*> FunctionToStubMap;
+
+ /// StubToFunctionMap - Keep track of the function that each stub
+ /// corresponds to.
+ std::map<void*, Function*> StubToFunctionMap;
+
+ public:
+ std::map<Function*, void*>& getFunctionToStubMap(const MutexGuard& locked) {
+ assert(locked.holds(TheJIT->lock));
+ return FunctionToStubMap;
+ }
+
+ std::map<void*, Function*>& getStubToFunctionMap(const MutexGuard& locked) {
+ assert(locked.holds(TheJIT->lock));
+ return StubToFunctionMap;
+ }
+ };
+
+ /// JITResolver - Keep track of, and resolve, call sites for functions that
+ /// have not yet been compiled.
+ class JITResolver {
+ /// LazyResolverFn - The target lazy resolver function that we actually
+ /// rewrite instructions to use.
+ TargetJITInfo::LazyResolverFn LazyResolverFn;
+
+ JITResolverState state;
+
+ /// ExternalFnToStubMap - This is the equivalent of FunctionToStubMap for
+ /// external functions.
+ std::map<void*, void*> ExternalFnToStubMap;
+
+ //map addresses to indexes in the GOT
+ std::map<void*, unsigned> revGOTMap;
+ unsigned nextGOTIndex;
+
+ static JITResolver *TheJITResolver;
+ public:
+ JITResolver(JIT &jit) : nextGOTIndex(0) {
+ TheJIT = &jit;
+
+ LazyResolverFn = jit.getJITInfo().getLazyResolverFunction(JITCompilerFn);
+ assert(TheJITResolver == 0 && "Multiple JIT resolvers?");
+ TheJITResolver = this;
+ }
+
+ ~JITResolver() {
+ TheJITResolver = 0;
+ }
+
+ /// getFunctionStub - This returns a pointer to a function stub, creating
+ /// one on demand as needed.
+ void *getFunctionStub(Function *F);
+
+ /// getExternalFunctionStub - Return a stub for the function at the
+ /// specified address, created lazily on demand.
+ void *getExternalFunctionStub(void *FnAddr);
+
+ /// AddCallbackAtLocation - If the target is capable of rewriting an
+ /// instruction without the use of a stub, record the location of the use so
+ /// we know which function is being used at the location.
+ void *AddCallbackAtLocation(Function *F, void *Location) {
+ MutexGuard locked(TheJIT->lock);
+ /// Get the target-specific JIT resolver function.
+ state.getStubToFunctionMap(locked)[Location] = F;
+ return (void*)(intptr_t)LazyResolverFn;
+ }
+
+ /// getGOTIndexForAddress - Return a new or existing index in the GOT for
+ /// and address. This function only manages slots, it does not manage the
+ /// contents of the slots or the memory associated with the GOT.
+ unsigned getGOTIndexForAddr(void* addr);
+
+ /// JITCompilerFn - This function is called to resolve a stub to a compiled
+ /// address. If the LLVM Function corresponding to the stub has not yet
+ /// been compiled, this function compiles it first.
+ static void *JITCompilerFn(void *Stub);
+ };
+}
+
+JITResolver *JITResolver::TheJITResolver = 0;
+
+#if (defined(__POWERPC__) || defined (__ppc__) || defined(_POWER)) && \
+ defined(__APPLE__)
+extern "C" void sys_icache_invalidate(const void *Addr, size_t len);
+#endif
+
+/// synchronizeICache - On some targets, the JIT emitted code must be
+/// explicitly refetched to ensure correct execution.
+static void synchronizeICache(const void *Addr, size_t len) {
+#if (defined(__POWERPC__) || defined (__ppc__) || defined(_POWER)) && \
+ defined(__APPLE__)
+ sys_icache_invalidate(Addr, len);
+#endif
+}
+
+/// getFunctionStub - This returns a pointer to a function stub, creating
+/// one on demand as needed.
+void *JITResolver::getFunctionStub(Function *F) {
+ MutexGuard locked(TheJIT->lock);
+
+ // If we already have a stub for this function, recycle it.
+ void *&Stub = state.getFunctionToStubMap(locked)[F];
+ if (Stub) return Stub;
+
+ // Call the lazy resolver function unless we already KNOW it is an external
+ // function, in which case we just skip the lazy resolution step.
+ void *Actual = (void*)(intptr_t)LazyResolverFn;
+ if (F->isDeclaration() && !F->hasNotBeenReadFromBitcode())
+ Actual = TheJIT->getPointerToFunction(F);
+
+ // Otherwise, codegen a new stub. For now, the stub will call the lazy
+ // resolver function.
+ Stub = TheJIT->getJITInfo().emitFunctionStub(Actual,
+ *TheJIT->getCodeEmitter());
+
+ if (Actual != (void*)(intptr_t)LazyResolverFn) {
+ // If we are getting the stub for an external function, we really want the
+ // address of the stub in the GlobalAddressMap for the JIT, not the address
+ // of the external function.
+ TheJIT->updateGlobalMapping(F, Stub);
+ }
+
+ // Invalidate the icache if necessary.
+ synchronizeICache(Stub, TheJIT->getCodeEmitter()->getCurrentPCValue() -
+ (intptr_t)Stub);
+
+ DOUT << "JIT: Stub emitted at [" << Stub << "] for function '"
+ << F->getName() << "'\n";
+
+ // Finally, keep track of the stub-to-Function mapping so that the
+ // JITCompilerFn knows which function to compile!
+ state.getStubToFunctionMap(locked)[Stub] = F;
+ return Stub;
+}
+
+/// getExternalFunctionStub - Return a stub for the function at the
+/// specified address, created lazily on demand.
+void *JITResolver::getExternalFunctionStub(void *FnAddr) {
+ // If we already have a stub for this function, recycle it.
+ void *&Stub = ExternalFnToStubMap[FnAddr];
+ if (Stub) return Stub;
+
+ Stub = TheJIT->getJITInfo().emitFunctionStub(FnAddr,
+ *TheJIT->getCodeEmitter());
+
+ // Invalidate the icache if necessary.
+ synchronizeICache(Stub, TheJIT->getCodeEmitter()->getCurrentPCValue() -
+ (intptr_t)Stub);
+
+ DOUT << "JIT: Stub emitted at [" << Stub
+ << "] for external function at '" << FnAddr << "'\n";
+ return Stub;
+}
+
+unsigned JITResolver::getGOTIndexForAddr(void* addr) {
+ unsigned idx = revGOTMap[addr];
+ if (!idx) {
+ idx = ++nextGOTIndex;
+ revGOTMap[addr] = idx;
+ DOUT << "Adding GOT entry " << idx
+ << " for addr " << addr << "\n";
+ // ((void**)MemMgr.getGOTBase())[idx] = addr;
+ }
+ return idx;
+}
+
+/// JITCompilerFn - This function is called when a lazy compilation stub has
+/// been entered. It looks up which function this stub corresponds to, compiles
+/// it if necessary, then returns the resultant function pointer.
+void *JITResolver::JITCompilerFn(void *Stub) {
+ JITResolver &JR = *TheJITResolver;
+
+ MutexGuard locked(TheJIT->lock);
+
+ // The address given to us for the stub may not be exactly right, it might be
+ // a little bit after the stub. As such, use upper_bound to find it.
+ std::map<void*, Function*>::iterator I =
+ JR.state.getStubToFunctionMap(locked).upper_bound(Stub);
+ assert(I != JR.state.getStubToFunctionMap(locked).begin() &&
+ "This is not a known stub!");
+ Function *F = (--I)->second;
+
+ // If we have already code generated the function, just return the address.
+ void *Result = TheJIT->getPointerToGlobalIfAvailable(F);
+
+ if (!Result) {
+ // Otherwise we don't have it, do lazy compilation now.
+
+ // If lazy compilation is disabled, emit a useful error message and abort.
+ if (TheJIT->isLazyCompilationDisabled()) {
+ cerr << "LLVM JIT requested to do lazy compilation of function '"
+ << F->getName() << "' when lazy compiles are disabled!\n";
+ abort();
+ }
+
+ // We might like to remove the stub from the StubToFunction map.
+ // We can't do that! Multiple threads could be stuck, waiting to acquire the
+ // lock above. As soon as the 1st function finishes compiling the function,
+ // the next one will be released, and needs to be able to find the function
+ // it needs to call.
+ //JR.state.getStubToFunctionMap(locked).erase(I);
+
+ DOUT << "JIT: Lazily resolving function '" << F->getName()
+ << "' In stub ptr = " << Stub << " actual ptr = "
+ << I->first << "\n";
+
+ Result = TheJIT->getPointerToFunction(F);
+ }
+
+ // We don't need to reuse this stub in the future, as F is now compiled.
+ JR.state.getFunctionToStubMap(locked).erase(F);
+
+ // FIXME: We could rewrite all references to this stub if we knew them.
+
+ // What we will do is set the compiled function address to map to the
+ // same GOT entry as the stub so that later clients may update the GOT
+ // if they see it still using the stub address.
+ // Note: this is done so the Resolver doesn't have to manage GOT memory
+ // Do this without allocating map space if the target isn't using a GOT
+ if(JR.revGOTMap.find(Stub) != JR.revGOTMap.end())
+ JR.revGOTMap[Result] = JR.revGOTMap[Stub];
+
+ return Result;
+}
+
+
+//===----------------------------------------------------------------------===//
+// JITEmitter code.
+//
+namespace {
+ /// JITEmitter - The JIT implementation of the MachineCodeEmitter, which is
+ /// used to output functions to memory for execution.
+ class JITEmitter : public MachineCodeEmitter {
+ JITMemoryManager MemMgr;
+
+ // When outputting a function stub in the context of some other function, we
+ // save BufferBegin/BufferEnd/CurBufferPtr here.
+ unsigned char *SavedBufferBegin, *SavedBufferEnd, *SavedCurBufferPtr;
+
+ /// Relocations - These are the relocations that the function needs, as
+ /// emitted.
+ std::vector<MachineRelocation> Relocations;
+
+ /// MBBLocations - This vector is a mapping from MBB ID's to their address.
+ /// It is filled in by the StartMachineBasicBlock callback and queried by
+ /// the getMachineBasicBlockAddress callback.
+ std::vector<intptr_t> MBBLocations;
+
+ /// ConstantPool - The constant pool for the current function.
+ ///
+ MachineConstantPool *ConstantPool;
+
+ /// ConstantPoolBase - A pointer to the first entry in the constant pool.
+ ///
+ void *ConstantPoolBase;
+
+ /// JumpTable - The jump tables for the current function.
+ ///
+ MachineJumpTableInfo *JumpTable;
+
+ /// JumpTableBase - A pointer to the first entry in the jump table.
+ ///
+ void *JumpTableBase;
+
+ /// Resolver - This contains info about the currently resolved functions.
+ JITResolver Resolver;
+ public:
+ JITEmitter(JIT &jit)
+ : MemMgr(jit.getJITInfo().needsGOT()), Resolver(jit) {
+ if (MemMgr.isManagingGOT()) DOUT << "JIT is managing a GOT\n";
+ }
+
+ JITResolver &getJITResolver() { return Resolver; }
+
+ virtual void startFunction(MachineFunction &F);
+ virtual bool finishFunction(MachineFunction &F);
+
+ void emitConstantPool(MachineConstantPool *MCP);
+ void initJumpTableInfo(MachineJumpTableInfo *MJTI);
+ void emitJumpTableInfo(MachineJumpTableInfo *MJTI);
+
+ virtual void startFunctionStub(unsigned StubSize, unsigned Alignment = 1);
+ virtual void* finishFunctionStub(const Function *F);
+
+ virtual void addRelocation(const MachineRelocation &MR) {
+ Relocations.push_back(MR);
+ }
+
+ virtual void StartMachineBasicBlock(MachineBasicBlock *MBB) {
+ if (MBBLocations.size() <= (unsigned)MBB->getNumber())
+ MBBLocations.resize((MBB->getNumber()+1)*2);
+ MBBLocations[MBB->getNumber()] = getCurrentPCValue();
+ }
+
+ virtual intptr_t getConstantPoolEntryAddress(unsigned Entry) const;
+ virtual intptr_t getJumpTableEntryAddress(unsigned Entry) const;
+
+ virtual intptr_t getMachineBasicBlockAddress(MachineBasicBlock *MBB) const {
+ assert(MBBLocations.size() > (unsigned)MBB->getNumber() &&
+ MBBLocations[MBB->getNumber()] && "MBB not emitted!");
+ return MBBLocations[MBB->getNumber()];
+ }
+
+ /// deallocateMemForFunction - Deallocate all memory for the specified
+ /// function body.
+ void deallocateMemForFunction(Function *F) {
+ MemMgr.deallocateMemForFunction(F);
+ }
+ private:
+ void *getPointerToGlobal(GlobalValue *GV, void *Reference, bool NoNeedStub);
+ };
+}
+
+void *JITEmitter::getPointerToGlobal(GlobalValue *V, void *Reference,
+ bool DoesntNeedStub) {
+ if (GlobalVariable *GV = dyn_cast<GlobalVariable>(V)) {
+ /// FIXME: If we straightened things out, this could actually emit the
+ /// global immediately instead of queuing it for codegen later!
+ return TheJIT->getOrEmitGlobalVariable(GV);
+ }
+
+ // If we have already compiled the function, return a pointer to its body.
+ Function *F = cast<Function>(V);
+ void *ResultPtr = TheJIT->getPointerToGlobalIfAvailable(F);
+ if (ResultPtr) return ResultPtr;
+
+ if (F->isDeclaration() && !F->hasNotBeenReadFromBitcode()) {
+ // If this is an external function pointer, we can force the JIT to
+ // 'compile' it, which really just adds it to the map.
+ if (DoesntNeedStub)
+ return TheJIT->getPointerToFunction(F);
+
+ return Resolver.getFunctionStub(F);
+ }
+
+ // Okay, the function has not been compiled yet, if the target callback
+ // mechanism is capable of rewriting the instruction directly, prefer to do
+ // that instead of emitting a stub.
+ if (DoesntNeedStub)
+ return Resolver.AddCallbackAtLocation(F, Reference);
+
+ // Otherwise, we have to emit a lazy resolving stub.
+ return Resolver.getFunctionStub(F);
+}
+
+void JITEmitter::startFunction(MachineFunction &F) {
+ uintptr_t ActualSize;
+ BufferBegin = CurBufferPtr = MemMgr.startFunctionBody(ActualSize);
+ BufferEnd = BufferBegin+ActualSize;
+
+ // Ensure the constant pool/jump table info is at least 4-byte aligned.
+ emitAlignment(16);
+
+ emitConstantPool(F.getConstantPool());
+ initJumpTableInfo(F.getJumpTableInfo());
+
+ // About to start emitting the machine code for the function.
+ emitAlignment(std::max(F.getFunction()->getAlignment(), 8U));
+ TheJIT->updateGlobalMapping(F.getFunction(), CurBufferPtr);
+
+ MBBLocations.clear();
+}
+
+bool JITEmitter::finishFunction(MachineFunction &F) {
+ if (CurBufferPtr == BufferEnd) {
+ // FIXME: Allocate more space, then try again.
+ cerr << "JIT: Ran out of space for generated machine code!\n";
+ abort();
+ }
+
+ emitJumpTableInfo(F.getJumpTableInfo());
+
+ // FnStart is the start of the text, not the start of the constant pool and
+ // other per-function data.
+ unsigned char *FnStart =
+ (unsigned char *)TheJIT->getPointerToGlobalIfAvailable(F.getFunction());
+ unsigned char *FnEnd = CurBufferPtr;
+
+ MemMgr.endFunctionBody(F.getFunction(), BufferBegin, FnEnd);
+ NumBytes += FnEnd-FnStart;
+
+ if (!Relocations.empty()) {
+ NumRelos += Relocations.size();
+
+ // Resolve the relocations to concrete pointers.
+ for (unsigned i = 0, e = Relocations.size(); i != e; ++i) {
+ MachineRelocation &MR = Relocations[i];
+ void *ResultPtr;
+ if (MR.isString()) {
+ ResultPtr = TheJIT->getPointerToNamedFunction(MR.getString());
+
+ // If the target REALLY wants a stub for this function, emit it now.
+ if (!MR.doesntNeedFunctionStub())
+ ResultPtr = Resolver.getExternalFunctionStub(ResultPtr);
+ } else if (MR.isGlobalValue()) {
+ ResultPtr = getPointerToGlobal(MR.getGlobalValue(),
+ BufferBegin+MR.getMachineCodeOffset(),
+ MR.doesntNeedFunctionStub());
+ } else if (MR.isBasicBlock()) {
+ ResultPtr = (void*)getMachineBasicBlockAddress(MR.getBasicBlock());
+ } else if (MR.isConstantPoolIndex()) {
+ ResultPtr=(void*)getConstantPoolEntryAddress(MR.getConstantPoolIndex());
+ } else {
+ assert(MR.isJumpTableIndex());
+ ResultPtr=(void*)getJumpTableEntryAddress(MR.getJumpTableIndex());
+ }
+
+ MR.setResultPointer(ResultPtr);
+
+ // if we are managing the GOT and the relocation wants an index,
+ // give it one
+ if (MemMgr.isManagingGOT() && MR.isGOTRelative()) {
+ unsigned idx = Resolver.getGOTIndexForAddr(ResultPtr);
+ MR.setGOTIndex(idx);
+ if (((void**)MemMgr.getGOTBase())[idx] != ResultPtr) {
+ DOUT << "GOT was out of date for " << ResultPtr
+ << " pointing at " << ((void**)MemMgr.getGOTBase())[idx]
+ << "\n";
+ ((void**)MemMgr.getGOTBase())[idx] = ResultPtr;
+ }
+ }
+ }
+
+ TheJIT->getJITInfo().relocate(BufferBegin, &Relocations[0],
+ Relocations.size(), MemMgr.getGOTBase());
+ }
+
+ // Update the GOT entry for F to point to the new code.
+ if (MemMgr.isManagingGOT()) {
+ unsigned idx = Resolver.getGOTIndexForAddr((void*)BufferBegin);
+ if (((void**)MemMgr.getGOTBase())[idx] != (void*)BufferBegin) {
+ DOUT << "GOT was out of date for " << (void*)BufferBegin
+ << " pointing at " << ((void**)MemMgr.getGOTBase())[idx] << "\n";
+ ((void**)MemMgr.getGOTBase())[idx] = (void*)BufferBegin;
+ }
+ }
+
+ // Invalidate the icache if necessary.
+ synchronizeICache(FnStart, FnEnd-FnStart);
+
+ DOUT << "JIT: Finished CodeGen of [" << (void*)FnStart
+ << "] Function: " << F.getFunction()->getName()
+ << ": " << (FnEnd-FnStart) << " bytes of text, "
+ << Relocations.size() << " relocations\n";
+ Relocations.clear();
+
+#ifndef NDEBUG
+ if (sys::hasDisassembler())
+ DOUT << "Disassembled code:\n"
+ << sys::disassembleBuffer(FnStart, FnEnd-FnStart, (uintptr_t)FnStart);
+#endif
+
+ return false;
+}
+
+void JITEmitter::emitConstantPool(MachineConstantPool *MCP) {
+ const std::vector<MachineConstantPoolEntry> &Constants = MCP->getConstants();
+ if (Constants.empty()) return;
+
+ MachineConstantPoolEntry CPE = Constants.back();
+ unsigned Size = CPE.Offset;
+ const Type *Ty = CPE.isMachineConstantPoolEntry()
+ ? CPE.Val.MachineCPVal->getType() : CPE.Val.ConstVal->getType();
+ Size += TheJIT->getTargetData()->getTypeSize(Ty);
+
+ ConstantPoolBase = allocateSpace(Size, 1 << MCP->getConstantPoolAlignment());
+ ConstantPool = MCP;
+
+ if (ConstantPoolBase == 0) return; // Buffer overflow.
+
+ // Initialize the memory for all of the constant pool entries.
+ for (unsigned i = 0, e = Constants.size(); i != e; ++i) {
+ void *CAddr = (char*)ConstantPoolBase+Constants[i].Offset;
+ if (Constants[i].isMachineConstantPoolEntry()) {
+ // FIXME: add support to lower machine constant pool values into bytes!
+ cerr << "Initialize memory with machine specific constant pool entry"
+ << " has not been implemented!\n";
+ abort();
+ }
+ TheJIT->InitializeMemory(Constants[i].Val.ConstVal, CAddr);
+ }
+}
+
+void JITEmitter::initJumpTableInfo(MachineJumpTableInfo *MJTI) {
+ const std::vector<MachineJumpTableEntry> &JT = MJTI->getJumpTables();
+ if (JT.empty()) return;
+
+ unsigned NumEntries = 0;
+ for (unsigned i = 0, e = JT.size(); i != e; ++i)
+ NumEntries += JT[i].MBBs.size();
+
+ unsigned EntrySize = MJTI->getEntrySize();
+
+ // Just allocate space for all the jump tables now. We will fix up the actual
+ // MBB entries in the tables after we emit the code for each block, since then
+ // we will know the final locations of the MBBs in memory.
+ JumpTable = MJTI;
+ JumpTableBase = allocateSpace(NumEntries * EntrySize, MJTI->getAlignment());
+}
+
+void JITEmitter::emitJumpTableInfo(MachineJumpTableInfo *MJTI) {
+ const std::vector<MachineJumpTableEntry> &JT = MJTI->getJumpTables();
+ if (JT.empty() || JumpTableBase == 0) return;
+
+ if (TargetMachine::getRelocationModel() == Reloc::PIC_) {
+ assert(MJTI->getEntrySize() == 4 && "Cross JIT'ing?");
+ // For each jump table, place the offset from the beginning of the table
+ // to the target address.
+ int *SlotPtr = (int*)JumpTableBase;
+
+ for (unsigned i = 0, e = JT.size(); i != e; ++i) {
+ const std::vector<MachineBasicBlock*> &MBBs = JT[i].MBBs;
+ // Store the offset of the basic block for this jump table slot in the
+ // memory we allocated for the jump table in 'initJumpTableInfo'
+ intptr_t Base = (intptr_t)SlotPtr;
+ for (unsigned mi = 0, me = MBBs.size(); mi != me; ++mi)
+ *SlotPtr++ = (intptr_t)getMachineBasicBlockAddress(MBBs[mi]) - Base;
+ }
+ } else {
+ assert(MJTI->getEntrySize() == sizeof(void*) && "Cross JIT'ing?");
+
+ // For each jump table, map each target in the jump table to the address of
+ // an emitted MachineBasicBlock.
+ intptr_t *SlotPtr = (intptr_t*)JumpTableBase;
+
+ for (unsigned i = 0, e = JT.size(); i != e; ++i) {
+ const std::vector<MachineBasicBlock*> &MBBs = JT[i].MBBs;
+ // Store the address of the basic block for this jump table slot in the
+ // memory we allocated for the jump table in 'initJumpTableInfo'
+ for (unsigned mi = 0, me = MBBs.size(); mi != me; ++mi)
+ *SlotPtr++ = getMachineBasicBlockAddress(MBBs[mi]);
+ }
+ }
+}
+
+void JITEmitter::startFunctionStub(unsigned StubSize, unsigned Alignment) {
+ SavedBufferBegin = BufferBegin;
+ SavedBufferEnd = BufferEnd;
+ SavedCurBufferPtr = CurBufferPtr;
+
+ BufferBegin = CurBufferPtr = MemMgr.allocateStub(StubSize, Alignment);
+ BufferEnd = BufferBegin+StubSize+1;
+}
+
+void *JITEmitter::finishFunctionStub(const Function *F) {
+ NumBytes += getCurrentPCOffset();
+ std::swap(SavedBufferBegin, BufferBegin);
+ BufferEnd = SavedBufferEnd;
+ CurBufferPtr = SavedCurBufferPtr;
+ return SavedBufferBegin;
+}
+
+// getConstantPoolEntryAddress - Return the address of the 'ConstantNum' entry
+// in the constant pool that was last emitted with the 'emitConstantPool'
+// method.
+//
+intptr_t JITEmitter::getConstantPoolEntryAddress(unsigned ConstantNum) const {
+ assert(ConstantNum < ConstantPool->getConstants().size() &&
+ "Invalid ConstantPoolIndex!");
+ return (intptr_t)ConstantPoolBase +
+ ConstantPool->getConstants()[ConstantNum].Offset;
+}
+
+// getJumpTableEntryAddress - Return the address of the JumpTable with index
+// 'Index' in the jumpp table that was last initialized with 'initJumpTableInfo'
+//
+intptr_t JITEmitter::getJumpTableEntryAddress(unsigned Index) const {
+ const std::vector<MachineJumpTableEntry> &JT = JumpTable->getJumpTables();
+ assert(Index < JT.size() && "Invalid jump table index!");
+
+ unsigned Offset = 0;
+ unsigned EntrySize = JumpTable->getEntrySize();
+
+ for (unsigned i = 0; i < Index; ++i)
+ Offset += JT[i].MBBs.size();
+
+ Offset *= EntrySize;
+
+ return (intptr_t)((char *)JumpTableBase + Offset);
+}
+
+//===----------------------------------------------------------------------===//
+// Public interface to this file
+//===----------------------------------------------------------------------===//
+
+MachineCodeEmitter *JIT::createEmitter(JIT &jit) {
+ return new JITEmitter(jit);
+}
+
+// getPointerToNamedFunction - This function is used as a global wrapper to
+// JIT::getPointerToNamedFunction for the purpose of resolving symbols when
+// bugpoint is debugging the JIT. In that scenario, we are loading an .so and
+// need to resolve function(s) that are being mis-codegenerated, so we need to
+// resolve their addresses at runtime, and this is the way to do it.
+extern "C" {
+ void *getPointerToNamedFunction(const char *Name) {
+ if (Function *F = TheJIT->FindFunctionNamed(Name))
+ return TheJIT->getPointerToFunction(F);
+ return TheJIT->getPointerToNamedFunction(Name);
+ }
+}
+
+// getPointerToFunctionOrStub - If the specified function has been
+// code-gen'd, return a pointer to the function. If not, compile it, or use
+// a stub to implement lazy compilation if available.
+//
+void *JIT::getPointerToFunctionOrStub(Function *F) {
+ // If we have already code generated the function, just return the address.
+ if (void *Addr = getPointerToGlobalIfAvailable(F))
+ return Addr;
+
+ // Get a stub if the target supports it.
+ assert(dynamic_cast<JITEmitter*>(MCE) && "Unexpected MCE?");
+ JITEmitter *JE = static_cast<JITEmitter*>(getCodeEmitter());
+ return JE->getJITResolver().getFunctionStub(F);
+}
+
+/// freeMachineCodeForFunction - release machine code memory for given Function.
+///
+void JIT::freeMachineCodeForFunction(Function *F) {
+ // Delete translation for this from the ExecutionEngine, so it will get
+ // retranslated next time it is used.
+ updateGlobalMapping(F, 0);
+
+ // Free the actual memory for the function body and related stuff.
+ assert(dynamic_cast<JITEmitter*>(MCE) && "Unexpected MCE?");
+ static_cast<JITEmitter*>(MCE)->deallocateMemForFunction(F);
+}
+
diff --git a/lib/ExecutionEngine/JIT/Makefile b/lib/ExecutionEngine/JIT/Makefile
new file mode 100644
index 0000000..ebbdc3f
--- /dev/null
+++ b/lib/ExecutionEngine/JIT/Makefile
@@ -0,0 +1,37 @@
+##===- lib/ExecutionEngine/JIT/Makefile --------------------*- Makefile -*-===##
+#
+# 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.
+#
+##===----------------------------------------------------------------------===##
+LEVEL = ../../..
+LIBRARYNAME = LLVMJIT
+
+# Get the $(ARCH) setting
+include $(LEVEL)/Makefile.config
+
+# Enable the X86 JIT if compiling on X86
+ifeq ($(ARCH), x86)
+ ENABLE_X86_JIT = 1
+endif
+
+# This flag can also be used on the command line to force inclusion
+# of the X86 JIT on non-X86 hosts
+ifdef ENABLE_X86_JIT
+ CPPFLAGS += -DENABLE_X86_JIT
+endif
+
+# Enable the Sparc JIT if compiling on Sparc
+ifeq ($(ARCH), Sparc)
+ ENABLE_SPARC_JIT = 1
+endif
+
+# This flag can also be used on the command line to force inclusion
+# of the Sparc JIT on non-Sparc hosts
+ifdef ENABLE_SPARC_JIT
+ CPPFLAGS += -DENABLE_SPARC_JIT
+endif
+
+include $(LEVEL)/Makefile.common
diff --git a/lib/ExecutionEngine/JIT/TargetSelect.cpp b/lib/ExecutionEngine/JIT/TargetSelect.cpp
new file mode 100644
index 0000000..bf968af
--- /dev/null
+++ b/lib/ExecutionEngine/JIT/TargetSelect.cpp
@@ -0,0 +1,78 @@
+//===-- TargetSelect.cpp - Target Chooser 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 just asks the TargetMachineRegistry for the appropriate JIT to use, and
+// allows the user to specify a specific one on the commandline with -march=x.
+//
+//===----------------------------------------------------------------------===//
+
+#include "JIT.h"
+#include "llvm/Module.h"
+#include "llvm/ModuleProvider.h"
+#include "llvm/Target/SubtargetFeature.h"
+#include "llvm/Target/TargetMachine.h"
+#include "llvm/Target/TargetMachineRegistry.h"
+using namespace llvm;
+
+static cl::opt<const TargetMachineRegistry::Entry*, false, TargetNameParser>
+MArch("march", cl::desc("Architecture to generate assembly for:"));
+
+static cl::opt<std::string>
+MCPU("mcpu",
+ cl::desc("Target a specific cpu type (-mcpu=help for details)"),
+ cl::value_desc("cpu-name"),
+ cl::init(""));
+
+static cl::list<std::string>
+MAttrs("mattr",
+ cl::CommaSeparated,
+ cl::desc("Target specific attributes (-mattr=help for details)"),
+ cl::value_desc("a1,+a2,-a3,..."));
+
+/// create - Create an return a new JIT compiler if there is one available
+/// for the current target. Otherwise, return null.
+///
+ExecutionEngine *JIT::create(ModuleProvider *MP, std::string *ErrorStr) {
+ const TargetMachineRegistry::Entry *TheArch = MArch;
+ if (TheArch == 0) {
+ std::string Error;
+ TheArch = TargetMachineRegistry::getClosestTargetForJIT(Error);
+ if (TheArch == 0) {
+ if (ErrorStr)
+ *ErrorStr = Error;
+ return 0;
+ }
+ } else if (TheArch->JITMatchQualityFn() == 0) {
+ cerr << "WARNING: This target JIT is not designed for the host you are"
+ << " running. If bad things happen, please choose a different "
+ << "-march switch.\n";
+ }
+
+ // Package up features to be passed to target/subtarget
+ std::string FeaturesStr;
+ if (MCPU.size() || MAttrs.size()) {
+ SubtargetFeatures Features;
+ Features.setCPU(MCPU);
+ for (unsigned i = 0; i != MAttrs.size(); ++i)
+ Features.AddFeature(MAttrs[i]);
+ FeaturesStr = Features.getString();
+ }
+
+ // Allocate a target...
+ TargetMachine *Target = TheArch->CtorFn(*MP->getModule(), FeaturesStr);
+ assert(Target && "Could not allocate target machine!");
+
+ // If the target supports JIT code generation, return a new JIT now.
+ if (TargetJITInfo *TJ = Target->getJITInfo())
+ return new JIT(MP, *Target, *TJ);
+
+ if (ErrorStr)
+ *ErrorStr = "target does not support JIT code generation";
+ return 0;
+}