llvm-6502/lib/Target/TargetMachine.cpp
Arnold Schwaighofer c85e1716f0 Added tail call optimization to the x86 back end. It can be
enabled by passing -tailcallopt to llc.  The optimization is
performed if the following conditions are satisfied:
* caller/callee are fastcc
* elf/pic is disabled OR
  elf/pic enabled + callee is in module + callee has
  visibility protected or hidden


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@42870 91177308-0d34-0410-b5e6-96231b3b80d8
2007-10-11 19:40:01 +00:00

172 lines
6.2 KiB
C++

//===-- TargetMachine.cpp - General Target Information ---------------------==//
//
// The LLVM Compiler Infrastructure
//
// This file was developed by the LLVM research group and 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/Target/TargetAsmInfo.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 PrintMachineCode;
bool NoFramePointerElim;
bool NoExcessFPPrecision;
bool UnsafeFPMath;
bool FiniteOnlyFPMathOption;
bool HonorSignDependentRoundingFPMathOption;
bool UseSoftFloat;
bool NoZerosInBSS;
bool ExceptionHandling;
Reloc::Model RelocationModel;
CodeModel::Model CMModel;
bool PerformTailCallOpt;
}
namespace {
cl::opt<bool, true> PrintCode("print-machineinstrs",
cl::desc("Print generated machine code"),
cl::location(PrintMachineCode), cl::init(false));
cl::opt<bool, true>
DisableFPElim("disable-fp-elim",
cl::desc("Disable frame pointer elimination optimization"),
cl::location(NoFramePointerElim),
cl::init(false));
cl::opt<bool, true>
DisableExcessPrecision("disable-excess-fp-precision",
cl::desc("Disable optimizations that may increase FP precision"),
cl::location(NoExcessFPPrecision),
cl::init(false));
cl::opt<bool, true>
EnableUnsafeFPMath("enable-unsafe-fp-math",
cl::desc("Enable optimizations that may decrease FP precision"),
cl::location(UnsafeFPMath),
cl::init(false));
cl::opt<bool, true>
EnableFiniteOnlyFPMath("enable-finite-only-fp-math",
cl::desc("Enable optimizations that assumes non- NaNs / +-Infs"),
cl::location(FiniteOnlyFPMathOption),
cl::init(false));
cl::opt<bool, true>
EnableHonorSignDependentRoundingFPMath(cl::Hidden,
"enable-sign-dependent-rounding-fp-math",
cl::desc("Force codegen to assume rounding mode can change dynamically"),
cl::location(HonorSignDependentRoundingFPMathOption),
cl::init(false));
cl::opt<bool, true>
GenerateSoftFloatCalls("soft-float",
cl::desc("Generate software floating point library calls"),
cl::location(UseSoftFloat),
cl::init(false));
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));
cl::opt<bool, true>
EnableExceptionHandling("enable-eh",
cl::desc("Exception handling should be emitted."),
cl::location(ExceptionHandling),
cl::init(false));
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));
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));
cl::opt<bool, true>
EnablePerformTailCallOpt("tailcallopt",
cl::desc("Turn on tail call optimization."),
cl::location(PerformTailCallOpt),
cl::init(false));
}
//---------------------------------------------------------------------------
// TargetMachine Class
//
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;
}
namespace llvm {
/// FiniteOnlyFPMath - This returns true when the -enable-finite-only-fp-math
/// option is specified on the command line. If this returns false (default),
/// the code generator is not allowed to assume that FP arithmetic arguments
/// and results are never NaNs or +-Infs.
bool FiniteOnlyFPMath() { return UnsafeFPMath || FiniteOnlyFPMathOption; }
/// 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;
}
}