1 //===-- JIT.cpp - LLVM Just in Time Compiler ------------------------------===//
3 // The LLVM Compiler Infrastructure
5 // This file was developed by the LLVM research group and is distributed under
6 // the University of Illinois Open Source License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 // This file implements the top-level support for creating a Just-In-Time
11 // compiler for the current architecture.
13 //===----------------------------------------------------------------------===//
16 #include "llvm/Module.h"
17 #include "llvm/ModuleProvider.h"
18 #include "llvm/ExecutionEngine/GenericValue.h"
19 #include "llvm/Target/TargetMachine.h"
20 #include "llvm/Target/TargetMachineImpls.h"
21 #include "Support/CommandLine.h"
24 #include "llvm/PassManager.h"
26 #if !defined(ENABLE_X86_JIT) && !defined(ENABLE_SPARC_JIT)
27 #define NO_JITS_ENABLED
31 enum ArchName { x86, Sparc };
33 #ifndef NO_JITS_ENABLED
35 Arch("march", cl::desc("Architecture to JIT to:"), cl::Prefix,
38 clEnumVal(x86, " IA-32 (Pentium and above)"),
40 #ifdef ENABLE_SPARC_JIT
41 clEnumValN(Sparc, "sparc", " Sparc-V9"),
44 #if defined(ENABLE_X86_JIT)
46 #elif defined(ENABLE_SPARC_JIT)
50 #endif /* NO_JITS_ENABLED */
53 /// create - Create an return a new JIT compiler if there is one available
54 /// for the current target. Otherwise, return null.
56 ExecutionEngine *VM::create(ModuleProvider *MP) {
57 TargetMachine* (*TargetMachineAllocator)(const Module &) = 0;
59 // Allow a command-line switch to override what *should* be the default target
60 // machine for this platform. This allows for debugging a Sparc JIT on X86 --
61 // our X86 machines are much faster at recompiling LLVM and linking LLI.
62 #ifdef NO_JITS_ENABLED
69 TargetMachineAllocator = allocateX86TargetMachine;
72 #ifdef ENABLE_SPARC_JIT
74 TargetMachineAllocator = allocateSparcTargetMachine;
78 assert(0 && "-march flag not supported on this host!");
81 // Allocate a target...
82 TargetMachine *Target = TargetMachineAllocator(*MP->getModule());
83 assert(Target && "Could not allocate target machine!");
85 // Create the virtual machine object...
86 return new VM(MP, Target);
89 VM::VM(ModuleProvider *MP, TargetMachine *tm) : ExecutionEngine(MP), TM(*tm),
92 setTargetData(TM.getTargetData());
95 MCE = createEmitter(*this);
99 #ifdef ENABLE_SPARC_JIT
100 // THIS GOES BEYOND UGLY HACKS
101 if (TM.getName() == "UltraSparc-Native") {
102 extern Pass *createPreSelectionPass(TargetMachine &TM);
104 // Specialize LLVM code for this target machine and then
105 // run basic dataflow optimizations on LLVM code.
106 PM.add(createPreSelectionPass(TM));
107 // We cannot utilize function-at-a-time loading here because PreSelection
109 MP->materializeModule();
110 PM.run(*MP->getModule());
117 /// run - Start execution with the specified function and arguments.
119 GenericValue VM::run(Function *F, const std::vector<GenericValue> &ArgValues)
121 assert (F && "Function *F was null at entry to run()");
123 int (*PF)(int, char **, const char **) =
124 (int(*)(int, char **, const char **))getPointerToFunction(F);
125 assert(PF != 0 && "Pointer to fn's code was null after getPointerToFunction");
127 // Call the function.
128 int ExitCode = PF(ArgValues[0].IntVal, (char **) GVTOP (ArgValues[1]),
129 (const char **) GVTOP (ArgValues[2]));
131 // Run any atexit handlers now!
135 rv.IntVal = ExitCode;