llvm/lib/Target/TargetMachine.cpp
2011-06-23 18:15:47 +00:00

315 lines
10 KiB
C++

//===-- TargetMachine.cpp - General Target Information ---------------------==//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file describes the general parts of a Target machine.
//
//===----------------------------------------------------------------------===//
#include "llvm/CodeGen/MachineFunction.h"
#include "llvm/CodeGen/MachineFrameInfo.h"
#include "llvm/MC/MCAsmInfo.h"
#include "llvm/Target/TargetMachine.h"
#include "llvm/Target/TargetOptions.h"
#include "llvm/Support/CommandLine.h"
using namespace llvm;
//---------------------------------------------------------------------------
// Command-line options that tend to be useful on more than one back-end.
//
namespace llvm {
bool LessPreciseFPMADOption;
bool PrintMachineCode;
bool NoFramePointerElim;
bool NoFramePointerElimNonLeaf;
bool NoExcessFPPrecision;
bool UnsafeFPMath;
bool NoInfsFPMath;
bool NoNaNsFPMath;
bool HonorSignDependentRoundingFPMathOption;
bool UseSoftFloat;
FloatABI::ABIType FloatABIType;
bool NoImplicitFloat;
bool NoZerosInBSS;
bool JITExceptionHandling;
bool JITEmitDebugInfo;
bool JITEmitDebugInfoToDisk;
Reloc::Model RelocationModel;
CodeModel::Model CMModel;
bool GuaranteedTailCallOpt;
unsigned StackAlignmentOverride;
bool RealignStack;
bool DisableJumpTables;
bool StrongPHIElim;
bool HasDivModLibcall;
bool AsmVerbosityDefault(false);
}
static cl::opt<bool, true>
PrintCode("print-machineinstrs",
cl::desc("Print generated machine code"),
cl::location(PrintMachineCode), cl::init(false));
static cl::opt<bool, true>
DisableFPElim("disable-fp-elim",
cl::desc("Disable frame pointer elimination optimization"),
cl::location(NoFramePointerElim),
cl::init(false));
static cl::opt<bool, true>
DisableFPElimNonLeaf("disable-non-leaf-fp-elim",
cl::desc("Disable frame pointer elimination optimization for non-leaf funcs"),
cl::location(NoFramePointerElimNonLeaf),
cl::init(false));
static cl::opt<bool, true>
DisableExcessPrecision("disable-excess-fp-precision",
cl::desc("Disable optimizations that may increase FP precision"),
cl::location(NoExcessFPPrecision),
cl::init(false));
static cl::opt<bool, true>
EnableFPMAD("enable-fp-mad",
cl::desc("Enable less precise MAD instructions to be generated"),
cl::location(LessPreciseFPMADOption),
cl::init(false));
static cl::opt<bool, true>
EnableUnsafeFPMath("enable-unsafe-fp-math",
cl::desc("Enable optimizations that may decrease FP precision"),
cl::location(UnsafeFPMath),
cl::init(false));
static cl::opt<bool, true>
EnableNoInfsFPMath("enable-no-infs-fp-math",
cl::desc("Enable FP math optimizations that assume no +-Infs"),
cl::location(NoInfsFPMath),
cl::init(false));
static cl::opt<bool, true>
EnableNoNaNsFPMath("enable-no-nans-fp-math",
cl::desc("Enable FP math optimizations that assume no NaNs"),
cl::location(NoNaNsFPMath),
cl::init(false));
static cl::opt<bool, true>
EnableHonorSignDependentRoundingFPMath("enable-sign-dependent-rounding-fp-math",
cl::Hidden,
cl::desc("Force codegen to assume rounding mode can change dynamically"),
cl::location(HonorSignDependentRoundingFPMathOption),
cl::init(false));
static cl::opt<bool, true>
GenerateSoftFloatCalls("soft-float",
cl::desc("Generate software floating point library calls"),
cl::location(UseSoftFloat),
cl::init(false));
static cl::opt<llvm::FloatABI::ABIType, true>
FloatABIForCalls("float-abi",
cl::desc("Choose float ABI type"),
cl::location(FloatABIType),
cl::init(FloatABI::Default),
cl::values(
clEnumValN(FloatABI::Default, "default",
"Target default float ABI type"),
clEnumValN(FloatABI::Soft, "soft",
"Soft float ABI (implied by -soft-float)"),
clEnumValN(FloatABI::Hard, "hard",
"Hard float ABI (uses FP registers)"),
clEnumValEnd));
static cl::opt<bool, true>
DontPlaceZerosInBSS("nozero-initialized-in-bss",
cl::desc("Don't place zero-initialized symbols into bss section"),
cl::location(NoZerosInBSS),
cl::init(false));
static cl::opt<bool, true>
EnableJITExceptionHandling("jit-enable-eh",
cl::desc("Emit exception handling information"),
cl::location(JITExceptionHandling),
cl::init(false));
// In debug builds, make this default to true.
#ifdef NDEBUG
#define EMIT_DEBUG false
#else
#define EMIT_DEBUG true
#endif
static cl::opt<bool, true>
EmitJitDebugInfo("jit-emit-debug",
cl::desc("Emit debug information to debugger"),
cl::location(JITEmitDebugInfo),
cl::init(EMIT_DEBUG));
#undef EMIT_DEBUG
static cl::opt<bool, true>
EmitJitDebugInfoToDisk("jit-emit-debug-to-disk",
cl::Hidden,
cl::desc("Emit debug info objfiles to disk"),
cl::location(JITEmitDebugInfoToDisk),
cl::init(false));
static cl::opt<llvm::Reloc::Model, true>
DefRelocationModel("relocation-model",
cl::desc("Choose relocation model"),
cl::location(RelocationModel),
cl::init(Reloc::Default),
cl::values(
clEnumValN(Reloc::Default, "default",
"Target default relocation model"),
clEnumValN(Reloc::Static, "static",
"Non-relocatable code"),
clEnumValN(Reloc::PIC_, "pic",
"Fully relocatable, position independent code"),
clEnumValN(Reloc::DynamicNoPIC, "dynamic-no-pic",
"Relocatable external references, non-relocatable code"),
clEnumValEnd));
static cl::opt<llvm::CodeModel::Model, true>
DefCodeModel("code-model",
cl::desc("Choose code model"),
cl::location(CMModel),
cl::init(CodeModel::Default),
cl::values(
clEnumValN(CodeModel::Default, "default",
"Target default code model"),
clEnumValN(CodeModel::Small, "small",
"Small code model"),
clEnumValN(CodeModel::Kernel, "kernel",
"Kernel code model"),
clEnumValN(CodeModel::Medium, "medium",
"Medium code model"),
clEnumValN(CodeModel::Large, "large",
"Large code model"),
clEnumValEnd));
static cl::opt<bool, true>
EnableGuaranteedTailCallOpt("tailcallopt",
cl::desc("Turn fastcc calls into tail calls by (potentially) changing ABI."),
cl::location(GuaranteedTailCallOpt),
cl::init(false));
static cl::opt<unsigned, true>
OverrideStackAlignment("stack-alignment",
cl::desc("Override default stack alignment"),
cl::location(StackAlignmentOverride),
cl::init(0));
static cl::opt<bool, true>
EnableRealignStack("realign-stack",
cl::desc("Realign stack if needed"),
cl::location(RealignStack),
cl::init(true));
static cl::opt<bool, true>
DisableSwitchTables(cl::Hidden, "disable-jump-tables",
cl::desc("Do not generate jump tables."),
cl::location(DisableJumpTables),
cl::init(false));
static cl::opt<bool, true>
EnableStrongPHIElim(cl::Hidden, "strong-phi-elim",
cl::desc("Use strong PHI elimination."),
cl::location(StrongPHIElim),
cl::init(false));
static cl::opt<std::string>
TrapFuncName("trap-func", cl::Hidden,
cl::desc("Emit a call to trap function rather than a trap instruction"),
cl::init(""));
static cl::opt<bool>
DataSections("fdata-sections",
cl::desc("Emit data into separate sections"),
cl::init(false));
static cl::opt<bool>
FunctionSections("ffunction-sections",
cl::desc("Emit functions into separate sections"),
cl::init(false));
//---------------------------------------------------------------------------
// TargetMachine Class
//
TargetMachine::TargetMachine(const Target &T)
: TheTarget(T), AsmInfo(0),
MCRelaxAll(false),
MCNoExecStack(false),
MCSaveTempLabels(false),
MCUseLoc(true),
MCUseCFI(true) {
// Typically it will be subtargets that will adjust FloatABIType from Default
// to Soft or Hard.
if (UseSoftFloat)
FloatABIType = FloatABI::Soft;
}
TargetMachine::~TargetMachine() {
delete AsmInfo;
}
/// getRelocationModel - Returns the code generation relocation model. The
/// choices are static, PIC, and dynamic-no-pic, and target default.
Reloc::Model TargetMachine::getRelocationModel() {
return RelocationModel;
}
/// setRelocationModel - Sets the code generation relocation model.
void TargetMachine::setRelocationModel(Reloc::Model Model) {
RelocationModel = Model;
}
/// getCodeModel - Returns the code model. The choices are small, kernel,
/// medium, large, and target default.
CodeModel::Model TargetMachine::getCodeModel() {
return CMModel;
}
/// setCodeModel - Sets the code model.
void TargetMachine::setCodeModel(CodeModel::Model Model) {
CMModel = Model;
}
bool TargetMachine::getAsmVerbosityDefault() {
return AsmVerbosityDefault;
}
void TargetMachine::setAsmVerbosityDefault(bool V) {
AsmVerbosityDefault = V;
}
bool TargetMachine::getFunctionSections() {
return FunctionSections;
}
bool TargetMachine::getDataSections() {
return DataSections;
}
void TargetMachine::setFunctionSections(bool V) {
FunctionSections = V;
}
void TargetMachine::setDataSections(bool V) {
DataSections = V;
}
namespace llvm {
/// DisableFramePointerElim - This returns true if frame pointer elimination
/// optimization should be disabled for the given machine function.
bool DisableFramePointerElim(const MachineFunction &MF) {
// Check to see if we should eliminate non-leaf frame pointers and then
// check to see if we should eliminate all frame pointers.
if (NoFramePointerElimNonLeaf && !NoFramePointerElim) {
const MachineFrameInfo *MFI = MF.getFrameInfo();
return MFI->hasCalls();
}
return NoFramePointerElim;
}
/// LessPreciseFPMAD - This flag return true when -enable-fp-mad option
/// is specified on the command line. When this flag is off(default), the
/// code generator is not allowed to generate mad (multiply add) if the
/// result is "less precise" than doing those operations individually.
bool LessPreciseFPMAD() { return UnsafeFPMath || LessPreciseFPMADOption; }
/// HonorSignDependentRoundingFPMath - Return true if the codegen must assume
/// that the rounding mode of the FPU can change from its default.
bool HonorSignDependentRoundingFPMath() {
return !UnsafeFPMath && HonorSignDependentRoundingFPMathOption;
}
/// getTrapFunctionName - If this returns a non-empty string, this means isel
/// should lower Intrinsic::trap to a call to the specified function name
/// instead of an ISD::TRAP node.
StringRef getTrapFunctionName() {
return TrapFuncName;
}
}