lib/Target/TargetMachine.cpp

   1 //===-- TargetMachine.cpp - General Target Information ---------------------==//
   2 //
   3 //                     The LLVM Compiler Infrastructure
   4 //
   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.
   7 //
   8 //===----------------------------------------------------------------------===//
   9 //
  10 // This file describes the general parts of a Target machine.
  11 //
  12 //===----------------------------------------------------------------------===//
  13
  14 #include "llvm/Target/TargetAsmInfo.h"
  15 #include "llvm/Target/TargetMachine.h"
  16 #include "llvm/Target/TargetOptions.h"
  17 #include "llvm/Support/CommandLine.h"
  18 using namespace llvm;
  19
  20 //---------------------------------------------------------------------------
  21 // Command-line options that tend to be useful on more than one back-end.
  22 //
  23
  24 namespace llvm {
  25   bool PrintMachineCode;
  26   bool NoFramePointerElim;
  27   bool NoExcessFPPrecision;
  28   bool UnsafeFPMath;
  29   bool FiniteOnlyFPMathOption;
  30   bool HonorSignDependentRoundingFPMathOption;
  31   bool UseSoftFloat;
  32   bool NoZerosInBSS;
  33   bool ExceptionHandling;
  34   bool NewCCModeling;
  35   Reloc::Model RelocationModel;
  36   CodeModel::Model CMModel;
  37 }
  38 namespace {
  39   cl::opt<bool, true> PrintCode("print-machineinstrs",
  40     cl::desc("Print generated machine code"),
  41     cl::location(PrintMachineCode), cl::init(false));
  42
  43   cl::opt<bool, true>
  44     DisableFPElim("disable-fp-elim",
  45                   cl::desc("Disable frame pointer elimination optimization"),
  46                   cl::location(NoFramePointerElim),
  47                   cl::init(false));
  48   cl::opt<bool, true>
  49   DisableExcessPrecision("disable-excess-fp-precision",
  50                cl::desc("Disable optimizations that may increase FP precision"),
  51                cl::location(NoExcessFPPrecision),
  52                cl::init(false));
  53   cl::opt<bool, true>
  54   EnableUnsafeFPMath("enable-unsafe-fp-math",
  55                cl::desc("Enable optimizations that may decrease FP precision"),
  56                cl::location(UnsafeFPMath),
  57                cl::init(false));
  58   cl::opt<bool, true>
  59   EnableFiniteOnlyFPMath("enable-finite-only-fp-math",
  60                cl::desc("Enable optimizations that assumes non- NaNs / +-Infs"),
  61                cl::location(FiniteOnlyFPMathOption),
  62                cl::init(false));
  63   cl::opt<bool, true>
  64   EnableHonorSignDependentRoundingFPMath(cl::Hidden,
  65                "enable-sign-dependent-rounding-fp-math",
  66        cl::desc("Force codegen to assume rounding mode can change dynamically"),
  67                cl::location(HonorSignDependentRoundingFPMathOption),
  68                cl::init(false));
  69
  70   cl::opt<bool, true>
  71   GenerateSoftFloatCalls("soft-float",
  72                cl::desc("Generate software floating point library calls"),
  73                cl::location(UseSoftFloat),
  74                cl::init(false));
  75   cl::opt<bool, true>
  76   DontPlaceZerosInBSS("nozero-initialized-in-bss",
  77               cl::desc("Don't place zero-initialized symbols into bss section"),
  78               cl::location(NoZerosInBSS),
  79               cl::init(false));
  80   cl::opt<bool, true>
  81   EnableExceptionHandling("enable-eh",
  82                cl::desc("Exception handling should be emitted."),
  83                cl::location(ExceptionHandling),
  84                cl::init(false));
  85
  86   cl::opt<llvm::Reloc::Model, true>
  87   DefRelocationModel(
  88     "relocation-model",
  89     cl::desc("Choose relocation model"),
  90     cl::location(RelocationModel),
  91     cl::init(Reloc::Default),
  92     cl::values(
  93       clEnumValN(Reloc::Default, "default",
  94                  "  Target default relocation model"),
  95       clEnumValN(Reloc::Static, "static",
  96                  "  Non-relocatable code"),
  97       clEnumValN(Reloc::PIC_, "pic",
  98                  "  Fully relocatable, position independent code"),
  99       clEnumValN(Reloc::DynamicNoPIC, "dynamic-no-pic",
 100                  "  Relocatable external references, non-relocatable code"),
 101       clEnumValEnd));
 102   cl::opt<llvm::CodeModel::Model, true>
 103   DefCodeModel(
 104     "code-model",
 105     cl::desc("Choose code model"),
 106     cl::location(CMModel),
 107     cl::init(CodeModel::Default),
 108     cl::values(
 109       clEnumValN(CodeModel::Default, "default",
 110                  "  Target default code model"),
 111       clEnumValN(CodeModel::Small, "small",
 112                  "  Small code model"),
 113       clEnumValN(CodeModel::Kernel, "kernel",
 114                  "  Kernel code model"),
 115       clEnumValN(CodeModel::Medium, "medium",
 116                  "  Medium code model"),
 117       clEnumValN(CodeModel::Large, "large",
 118                  "  Large code model"),
 119       clEnumValEnd));
 120   cl::opt<bool, true>
 121   EnableNewCCModeling("new-cc-modeling-scheme",
 122                       cl::desc("New CC modeling scheme."),
 123                       cl::location(NewCCModeling),
 124                       cl::init(false));
 125 }
 126
 127 //---------------------------------------------------------------------------
 128 // TargetMachine Class
 129 //
 130
 131 TargetMachine::~TargetMachine() {
 132   delete AsmInfo;
 133 }
 134
 135 /// getRelocationModel - Returns the code generation relocation model. The
 136 /// choices are static, PIC, and dynamic-no-pic, and target default.
 137 Reloc::Model TargetMachine::getRelocationModel() {
 138   return RelocationModel;
 139 }
 140
 141 /// setRelocationModel - Sets the code generation relocation model.
 142 void TargetMachine::setRelocationModel(Reloc::Model Model) {
 143   RelocationModel = Model;
 144 }
 145
 146 /// getCodeModel - Returns the code model. The choices are small, kernel,
 147 /// medium, large, and target default.
 148 CodeModel::Model TargetMachine::getCodeModel() {
 149   return CMModel;
 150 }
 151
 152 /// setCodeModel - Sets the code model.
 153 void TargetMachine::setCodeModel(CodeModel::Model Model) {
 154   CMModel = Model;
 155 }
 156
 157 namespace llvm {
 158   /// FiniteOnlyFPMath - This returns true when the -enable-finite-only-fp-math
 159   /// option is specified on the command line. If this returns false (default),
 160   /// the code generator is not allowed to assume that FP arithmetic arguments
 161   /// and results are never NaNs or +-Infs.
 162   bool FiniteOnlyFPMath() { return UnsafeFPMath || FiniteOnlyFPMathOption; }
 163
 164   /// HonorSignDependentRoundingFPMath - Return true if the codegen must assume
 165   /// that the rounding mode of the FPU can change from its default.
 166   bool HonorSignDependentRoundingFPMath() {
 167     return !UnsafeFPMath && HonorSignDependentRoundingFPMathOption;
 168   }
 169 }
 170