LLVM API Documentation

X86TargetMachine.cpp

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00001 //===-- X86TargetMachine.cpp - Define TargetMachine for the X86 -----------===//
00002 //
00003 //                     The LLVM Compiler Infrastructure
00004 //
00005 // This file was developed by the LLVM research group and is distributed under
00006 // the University of Illinois Open Source License. See LICENSE.TXT for details.
00007 //
00008 //===----------------------------------------------------------------------===//
00009 //
00010 // This file defines the X86 specific subclass of TargetMachine.
00011 //
00012 //===----------------------------------------------------------------------===//
00013 
00014 #include "X86TargetMachine.h"
00015 #include "X86.h"
00016 #include "llvm/Module.h"
00017 #include "llvm/PassManager.h"
00018 #include "llvm/CodeGen/MachineFunction.h"
00019 #include "llvm/CodeGen/Passes.h"
00020 #include "llvm/Target/TargetOptions.h"
00021 #include "llvm/Target/TargetMachineRegistry.h"
00022 #include "llvm/Transforms/Scalar.h"
00023 #include "llvm/Support/CommandLine.h"
00024 #include "llvm/ADT/Statistic.h"
00025 #include <iostream>
00026 using namespace llvm;
00027 
00028 /// X86TargetMachineModule - Note that this is used on hosts that cannot link
00029 /// in a library unless there are references into the library.  In particular,
00030 /// it seems that it is not possible to get things to work on Win32 without
00031 /// this.  Though it is unused, do not remove it.
00032 extern "C" int X86TargetMachineModule;
00033 int X86TargetMachineModule = 0;
00034 
00035 namespace {
00036   cl::opt<bool> DisableOutput("disable-x86-llc-output", cl::Hidden,
00037                               cl::desc("Disable the X86 asm printer, for use "
00038                                        "when profiling the code generator."));
00039   // Register the target.
00040   RegisterTarget<X86TargetMachine> X("x86", "  IA-32 (Pentium and above)");
00041 }
00042 
00043 unsigned X86TargetMachine::getJITMatchQuality() {
00044 #if defined(i386) || defined(__i386__) || defined(__x86__) || defined(_M_IX86)
00045   return 10;
00046 #else
00047   return 0;
00048 #endif
00049 }
00050 
00051 unsigned X86TargetMachine::getModuleMatchQuality(const Module &M) {
00052   // We strongly match "i[3-9]86-*".
00053   std::string TT = M.getTargetTriple();
00054   if (TT.size() >= 5 && TT[0] == 'i' && TT[2] == '8' && TT[3] == '6' &&
00055       TT[4] == '-' && TT[1] - '3' < 6)
00056     return 20;
00057 
00058   if (M.getEndianness()  == Module::LittleEndian &&
00059       M.getPointerSize() == Module::Pointer32)
00060     return 10;                                   // Weak match
00061   else if (M.getEndianness() != Module::AnyEndianness ||
00062            M.getPointerSize() != Module::AnyPointerSize)
00063     return 0;                                    // Match for some other target
00064 
00065   return getJITMatchQuality()/2;
00066 }
00067 
00068 /// X86TargetMachine ctor - Create an ILP32 architecture model
00069 ///
00070 X86TargetMachine::X86TargetMachine(const Module &M, const std::string &FS)
00071   : TargetMachine("X86"),
00072     Subtarget(M, FS),
00073     DataLayout("e-p:32:32-d:32-l:32"),
00074     FrameInfo(TargetFrameInfo::StackGrowsDown,
00075               Subtarget.getStackAlignment(), -4),
00076     InstrInfo(*this), JITInfo(*this), TLInfo(*this) {
00077   if (getRelocationModel() == Reloc::Default)
00078     if (Subtarget.isTargetDarwin())
00079       setRelocationModel(Reloc::DynamicNoPIC);
00080     else
00081       setRelocationModel(Reloc::PIC_);
00082 }
00083 
00084 
00085 // addPassesToEmitFile - We currently use all of the same passes as the JIT
00086 // does to emit statically compiled machine code.
00087 bool X86TargetMachine::addPassesToEmitFile(PassManager &PM, std::ostream &Out,
00088                                            CodeGenFileType FileType,
00089                                            bool Fast) {
00090   if (FileType != TargetMachine::AssemblyFile &&
00091       FileType != TargetMachine::ObjectFile) return true;
00092 
00093   // Run loop strength reduction before anything else.
00094   PM.add(createLoopStrengthReducePass(&TLInfo));
00095 
00096   // FIXME: Implement efficient support for garbage collection intrinsics.
00097   PM.add(createLowerGCPass());
00098 
00099   // FIXME: Implement the invoke/unwind instructions!
00100   PM.add(createLowerInvokePass());
00101 
00102   // Make sure that no unreachable blocks are instruction selected.
00103   PM.add(createUnreachableBlockEliminationPass());
00104 
00105   // Install an instruction selector.
00106   PM.add(createX86ISelDag(*this));
00107 
00108   // Print the instruction selected machine code...
00109   if (PrintMachineCode)
00110     PM.add(createMachineFunctionPrinterPass(&std::cerr));
00111 
00112   // Perform register allocation to convert to a concrete x86 representation
00113   PM.add(createRegisterAllocator());
00114 
00115   if (PrintMachineCode)
00116     PM.add(createMachineFunctionPrinterPass(&std::cerr));
00117 
00118   PM.add(createX86FloatingPointStackifierPass());
00119 
00120   if (PrintMachineCode)
00121     PM.add(createMachineFunctionPrinterPass(&std::cerr));
00122 
00123   // Insert prolog/epilog code.  Eliminate abstract frame index references...
00124   PM.add(createPrologEpilogCodeInserter());
00125 
00126   if (PrintMachineCode)  // Print the register-allocated code
00127     PM.add(createX86CodePrinterPass(std::cerr, *this));
00128 
00129   if (!DisableOutput)
00130     switch (FileType) {
00131     default:
00132       assert(0 && "Unexpected filetype here!");
00133     case TargetMachine::AssemblyFile:
00134       PM.add(createX86CodePrinterPass(Out, *this));
00135       break;
00136     case TargetMachine::ObjectFile:
00137       // FIXME: We only support emission of ELF files for now, this should check
00138       // the target triple and decide on the format to write (e.g. COFF on
00139       // win32).
00140       addX86ELFObjectWriterPass(PM, Out, *this);
00141       break;
00142     }
00143 
00144   // Delete machine code for this function
00145   PM.add(createMachineCodeDeleter());
00146 
00147   return false; // success!
00148 }
00149 
00150 /// addPassesToJITCompile - Add passes to the specified pass manager to
00151 /// implement a fast dynamic compiler for this target.  Return true if this is
00152 /// not supported for this target.
00153 ///
00154 void X86JITInfo::addPassesToJITCompile(FunctionPassManager &PM) {
00155   // The JIT should use static relocation model.
00156   TM.setRelocationModel(Reloc::Static);
00157 
00158   // Run loop strength reduction before anything else.
00159   PM.add(createLoopStrengthReducePass(TM.getTargetLowering()));
00160 
00161   // FIXME: Implement efficient support for garbage collection intrinsics.
00162   PM.add(createLowerGCPass());
00163 
00164   // FIXME: Implement the invoke/unwind instructions!
00165   PM.add(createLowerInvokePass());
00166 
00167   // Make sure that no unreachable blocks are instruction selected.
00168   PM.add(createUnreachableBlockEliminationPass());
00169 
00170   // Install an instruction selector.
00171   PM.add(createX86ISelDag(TM));
00172 
00173   // Print the instruction selected machine code...
00174   if (PrintMachineCode)
00175     PM.add(createMachineFunctionPrinterPass(&std::cerr));
00176 
00177   // Perform register allocation to convert to a concrete x86 representation
00178   PM.add(createRegisterAllocator());
00179 
00180   if (PrintMachineCode)
00181     PM.add(createMachineFunctionPrinterPass(&std::cerr));
00182 
00183   PM.add(createX86FloatingPointStackifierPass());
00184 
00185   if (PrintMachineCode)
00186     PM.add(createMachineFunctionPrinterPass(&std::cerr));
00187 
00188   // Insert prolog/epilog code.  Eliminate abstract frame index references...
00189   PM.add(createPrologEpilogCodeInserter());
00190 
00191   if (PrintMachineCode)  // Print the register-allocated code
00192     PM.add(createX86CodePrinterPass(std::cerr, TM));
00193 }
00194 
00195 bool X86TargetMachine::addPassesToEmitMachineCode(FunctionPassManager &PM,
00196                                                   MachineCodeEmitter &MCE) {
00197   PM.add(createX86CodeEmitterPass(*this, MCE));
00198   // Delete machine code for this function
00199   PM.add(createMachineCodeDeleter());
00200   return false;
00201 }