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 #if !defined(ENABLE_X86_JIT) && !defined(ENABLE_SPARC_JIT)
25 #define NO_JITS_ENABLED
29 enum ArchName { x86, Sparc };
31 #ifndef NO_JITS_ENABLED
33 Arch("march", cl::desc("Architecture to JIT to:"), cl::Prefix,
36 clEnumVal(x86, " IA-32 (Pentium and above)"),
38 #ifdef ENABLE_SPARC_JIT
39 clEnumValN(Sparc, "sparc", " Sparc-V9"),
42 #if defined(ENABLE_X86_JIT)
44 #elif defined(ENABLE_SPARC_JIT)
48 #endif /* NO_JITS_ENABLED */
51 /// create - Create an return a new JIT compiler if there is one available
52 /// for the current target. Otherwise, return null.
54 ExecutionEngine *VM::create(ModuleProvider *MP) {
55 TargetMachine* (*TargetMachineAllocator)(const Module &) = 0;
57 // Allow a command-line switch to override what *should* be the default target
58 // machine for this platform. This allows for debugging a Sparc JIT on X86 --
59 // our X86 machines are much faster at recompiling LLVM and linking LLI.
60 #ifndef NO_JITS_ENABLED
65 TargetMachineAllocator = allocateX86TargetMachine;
68 #ifdef ENABLE_SPARC_JIT
70 TargetMachineAllocator = allocateSparcTargetMachine;
74 assert(0 && "-march flag not supported on this host!");
80 // Allocate a target...
81 TargetMachine *Target = TargetMachineAllocator(*MP->getModule());
82 assert(Target && "Could not allocate target machine!");
84 // If the target supports JIT code generation, return a new JIT now.
85 if (TargetJITInfo *TJ = Target->getJITInfo())
86 return new VM(MP, *Target, *TJ);
90 VM::VM(ModuleProvider *MP, TargetMachine &tm, TargetJITInfo &tji)
91 : ExecutionEngine(MP), TM(tm), TJI(tji), PM(MP) {
92 setTargetData(TM.getTargetData());
95 MCE = createEmitter(*this);
102 /// run - Start execution with the specified function and arguments.
104 GenericValue VM::run(Function *F, const std::vector<GenericValue> &ArgValues)
106 assert (F && "Function *F was null at entry to run()");
108 int (*PF)(int, char **, const char **) =
109 (int(*)(int, char **, const char **))getPointerToFunction(F);
110 assert(PF != 0 && "Pointer to fn's code was null after getPointerToFunction");
112 // Call the function.
113 int ExitCode = PF(ArgValues[0].IntVal, (char **) GVTOP (ArgValues[1]),
114 (const char **) GVTOP (ArgValues[2]));
116 // Run any atexit handlers now!
120 rv.IntVal = ExitCode;