mirror of
https://github.com/RPCS3/llvm-mirror.git
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728e4fbd59
llvm-svn: 4908
103 lines
3.0 KiB
C++
103 lines
3.0 KiB
C++
//===-- jello.cpp - LLVM Just in Time Compiler ----------------------------===//
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//
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// This tool implements a just-in-time compiler for LLVM, allowing direct
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// execution of LLVM bytecode in an efficient manner.
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//
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//===----------------------------------------------------------------------===//
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#include "VM.h"
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#include "llvm/Target/TargetMachine.h"
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#include "llvm/CodeGen/MachineCodeEmitter.h"
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#include "llvm/Function.h"
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#include <iostream>
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#include <dlfcn.h> // dlsym access
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VM::~VM() {
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delete MCE;
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}
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/// setupPassManager - Initialize the VM PassManager object with all of the
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/// passes needed for the target to generate code.
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///
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void VM::setupPassManager() {
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// Compile LLVM Code down to machine code in the intermediate representation
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if (TM.addPassesToJITCompile(PM)) {
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std::cerr << ExeName << ": target '" << TM.getName()
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<< "' doesn't support JIT compilation!\n";
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abort();
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}
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// Turn the machine code intermediate representation into bytes in memory that
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// may be executed.
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//
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if (TM.addPassesToEmitMachineCode(PM, *MCE)) {
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std::cerr << ExeName << ": target '" << TM.getName()
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<< "' doesn't support machine code emission!\n";
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abort();
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}
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}
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int VM::run(Function *F) {
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int(*PF)() = (int(*)())getPointerToFunction(F);
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assert(PF != 0 && "Null pointer to function?");
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return PF();
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}
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void *VM::resolveFunctionReference(void *RefAddr) {
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Function *F = FunctionRefs[RefAddr];
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assert(F && "Reference address not known!");
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void *Addr = getPointerToFunction(F);
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assert(Addr && "Pointer to function unknown!");
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FunctionRefs.erase(RefAddr);
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return Addr;
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}
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const std::string &VM::getFunctionReferencedName(void *RefAddr) {
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return FunctionRefs[RefAddr]->getName();
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}
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// getPointerToGlobal - This returns the address of the specified global
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// value. This may involve code generation if it's a function.
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//
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void *VM::getPointerToGlobal(GlobalValue *GV) {
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if (Function *F = dyn_cast<Function>(GV))
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return getPointerToFunction(F);
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assert(GlobalAddress[GV] && "Global hasn't had an address allocated yet?");
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return GlobalAddress[GV];
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}
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static void NoopFn() {}
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/// getPointerToFunction - This method is used to get the address of the
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/// specified function, compiling it if neccesary.
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///
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void *VM::getPointerToFunction(Function *F) {
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void *&Addr = GlobalAddress[F]; // Function already code gen'd
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if (Addr) return Addr;
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if (F->isExternal()) {
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// If it's an external function, look it up in the process image...
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void *Ptr = dlsym(0, F->getName().c_str());
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if (Ptr == 0) {
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std::cerr << "WARNING: Cannot resolve fn '" << F->getName()
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<< "' using a dummy noop function instead!\n";
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Ptr = (void*)NoopFn;
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}
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return Addr = Ptr;
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}
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// JIT all of the functions in the module. Eventually this will JIT functions
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// on demand. This has the effect of populating all of the non-external
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// functions into the GlobalAddress table.
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PM.run(M);
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assert(Addr && "Code generation didn't add function to GlobalAddress table!");
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return Addr;
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}
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