llvm-project/llvm/lib/Target/Mips/MipsSubtarget.cpp

304 lines
10 KiB
C++

//===-- MipsSubtarget.cpp - Mips Subtarget Information --------------------===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file implements the Mips specific subclass of TargetSubtargetInfo.
//
//===----------------------------------------------------------------------===//
#include "MipsMachineFunction.h"
#include "Mips.h"
#include "MipsRegisterInfo.h"
#include "MipsSubtarget.h"
#include "MipsTargetMachine.h"
#include "llvm/IR/Attributes.h"
#include "llvm/IR/Function.h"
#include "llvm/Support/CommandLine.h"
#include "llvm/Support/Debug.h"
#include "llvm/Support/TargetRegistry.h"
#include "llvm/Support/raw_ostream.h"
using namespace llvm;
#define DEBUG_TYPE "mips-subtarget"
#define GET_SUBTARGETINFO_TARGET_DESC
#define GET_SUBTARGETINFO_CTOR
#include "MipsGenSubtargetInfo.inc"
// FIXME: Maybe this should be on by default when Mips16 is specified
//
static cl::opt<bool> Mixed16_32(
"mips-mixed-16-32",
cl::init(false),
cl::desc("Allow for a mixture of Mips16 "
"and Mips32 code in a single source file"),
cl::Hidden);
static cl::opt<bool> Mips_Os16(
"mips-os16",
cl::init(false),
cl::desc("Compile all functions that don' use "
"floating point as Mips 16"),
cl::Hidden);
static cl::opt<bool>
Mips16HardFloat("mips16-hard-float", cl::NotHidden,
cl::desc("MIPS: mips16 hard float enable."),
cl::init(false));
static cl::opt<bool>
Mips16ConstantIslands(
"mips16-constant-islands", cl::NotHidden,
cl::desc("MIPS: mips16 constant islands enable."),
cl::init(true));
/// Select the Mips CPU for the given triple and cpu name.
/// FIXME: Merge with the copy in MipsMCTargetDesc.cpp
static StringRef selectMipsCPU(Triple TT, StringRef CPU) {
if (CPU.empty() || CPU == "generic") {
if (TT.getArch() == Triple::mips || TT.getArch() == Triple::mipsel)
CPU = "mips32";
else
CPU = "mips64";
}
return CPU;
}
void MipsSubtarget::anchor() { }
static std::string computeDataLayout(const MipsSubtarget &ST) {
std::string Ret = "";
// There are both little and big endian mips.
if (ST.isLittle())
Ret += "e";
else
Ret += "E";
Ret += "-m:m";
// Pointers are 32 bit on some ABIs.
if (!ST.isABI_N64())
Ret += "-p:32:32";
// 8 and 16 bit integers only need no have natural alignment, but try to
// align them to 32 bits. 64 bit integers have natural alignment.
Ret += "-i8:8:32-i16:16:32-i64:64";
// 32 bit registers are always available and the stack is at least 64 bit
// aligned. On N64 64 bit registers are also available and the stack is
// 128 bit aligned.
if (ST.isABI_N64() || ST.isABI_N32())
Ret += "-n32:64-S128";
else
Ret += "-n32-S64";
return Ret;
}
MipsSubtarget::MipsSubtarget(const std::string &TT, const std::string &CPU,
const std::string &FS, bool little,
Reloc::Model _RM, MipsTargetMachine *_TM)
: MipsGenSubtargetInfo(TT, CPU, FS), MipsArchVersion(Mips32),
MipsABI(UnknownABI), IsLittle(little), IsSingleFloat(false),
IsFPXX(false), IsFP64bit(false), UseOddSPReg(true), IsNaN2008bit(false),
IsGP64bit(false), HasVFPU(false), HasCnMips(false), IsLinux(true),
HasMips3_32(false), HasMips3_32r2(false), HasMips4_32(false),
HasMips4_32r2(false), HasMips5_32r2(false), InMips16Mode(false),
InMips16HardFloat(Mips16HardFloat), InMicroMipsMode(false), HasDSP(false),
HasDSPR2(false), AllowMixed16_32(Mixed16_32 | Mips_Os16), Os16(Mips_Os16),
HasMSA(false), RM(_RM), OverrideMode(NoOverride), TM(_TM),
TargetTriple(TT),
DL(computeDataLayout(initializeSubtargetDependencies(CPU, FS, TM))),
TSInfo(DL), JITInfo(), InstrInfo(MipsInstrInfo::create(*TM)),
FrameLowering(MipsFrameLowering::create(*TM, *this)),
TLInfo(MipsTargetLowering::create(*TM)) {
PreviousInMips16Mode = InMips16Mode;
// Don't even attempt to generate code for MIPS-I, MIPS-II, MIPS-III, and
// MIPS-V. They have not been tested and currently exist for the integrated
// assembler only.
if (MipsArchVersion == Mips1)
report_fatal_error("Code generation for MIPS-I is not implemented", false);
if (MipsArchVersion == Mips2)
report_fatal_error("Code generation for MIPS-II is not implemented", false);
if (MipsArchVersion == Mips3)
report_fatal_error("Code generation for MIPS-III is not implemented",
false);
if (MipsArchVersion == Mips5)
report_fatal_error("Code generation for MIPS-V is not implemented", false);
// Assert exactly one ABI was chosen.
assert(MipsABI != UnknownABI);
assert((((getFeatureBits() & Mips::FeatureO32) != 0) +
((getFeatureBits() & Mips::FeatureEABI) != 0) +
((getFeatureBits() & Mips::FeatureN32) != 0) +
((getFeatureBits() & Mips::FeatureN64) != 0)) == 1);
// Check if Architecture and ABI are compatible.
assert(((!isGP64bit() && (isABI_O32() || isABI_EABI())) ||
(isGP64bit() && (isABI_N32() || isABI_N64()))) &&
"Invalid Arch & ABI pair.");
if (hasMSA() && !isFP64bit())
report_fatal_error("MSA requires a 64-bit FPU register file (FR=1 mode). "
"See -mattr=+fp64.",
false);
if (!isABI_O32() && !useOddSPReg())
report_fatal_error("-mattr=+nooddspreg is not currently permitted for a "
"the O32 ABI.",
false);
if (IsFPXX && (isABI_N32() || isABI_N64()))
report_fatal_error("FPXX is not permitted for the N32/N64 ABI's.", false);
if (hasMips32r6()) {
StringRef ISA = hasMips64r6() ? "MIPS64r6" : "MIPS32r6";
assert(isFP64bit());
assert(isNaN2008());
if (hasDSP())
report_fatal_error(ISA + " is not compatible with the DSP ASE", false);
}
// Is the target system Linux ?
if (TT.find("linux") == std::string::npos)
IsLinux = false;
// Set UseSmallSection.
// TODO: Investigate the IsLinux check. I suspect it's really checking for
// bare-metal.
UseSmallSection = !IsLinux && (RM == Reloc::Static);
}
bool
MipsSubtarget::enablePostRAScheduler(CodeGenOpt::Level OptLevel,
TargetSubtargetInfo::AntiDepBreakMode &Mode,
RegClassVector &CriticalPathRCs) const {
Mode = TargetSubtargetInfo::ANTIDEP_NONE;
CriticalPathRCs.clear();
CriticalPathRCs.push_back(isGP64bit() ? &Mips::GPR64RegClass
: &Mips::GPR32RegClass);
return OptLevel >= CodeGenOpt::Aggressive;
}
MipsSubtarget &
MipsSubtarget::initializeSubtargetDependencies(StringRef CPU, StringRef FS,
const TargetMachine *TM) {
std::string CPUName = selectMipsCPU(TargetTriple, CPU);
// Parse features string.
ParseSubtargetFeatures(CPUName, FS);
// Initialize scheduling itinerary for the specified CPU.
InstrItins = getInstrItineraryForCPU(CPUName);
if (InMips16Mode && !TM->Options.UseSoftFloat) {
// Hard float for mips16 means essentially to compile as soft float
// but to use a runtime library for soft float that is written with
// native mips32 floating point instructions (those runtime routines
// run in mips32 hard float mode).
TM->Options.UseSoftFloat = true;
TM->Options.FloatABIType = FloatABI::Soft;
InMips16HardFloat = true;
}
return *this;
}
//FIXME: This logic for reseting the subtarget along with
// the helper classes can probably be simplified but there are a lot of
// cases so we will defer rewriting this to later.
//
void MipsSubtarget::resetSubtarget(MachineFunction *MF) {
bool ChangeToMips16 = false, ChangeToNoMips16 = false;
DEBUG(dbgs() << "resetSubtargetFeatures" << "\n");
AttributeSet FnAttrs = MF->getFunction()->getAttributes();
ChangeToMips16 = FnAttrs.hasAttribute(AttributeSet::FunctionIndex,
"mips16");
ChangeToNoMips16 = FnAttrs.hasAttribute(AttributeSet::FunctionIndex,
"nomips16");
assert (!(ChangeToMips16 & ChangeToNoMips16) &&
"mips16 and nomips16 specified on the same function");
if (ChangeToMips16) {
if (PreviousInMips16Mode)
return;
OverrideMode = Mips16Override;
PreviousInMips16Mode = true;
setHelperClassesMips16();
return;
} else if (ChangeToNoMips16) {
if (!PreviousInMips16Mode)
return;
OverrideMode = NoMips16Override;
PreviousInMips16Mode = false;
setHelperClassesMipsSE();
return;
} else {
if (OverrideMode == NoOverride)
return;
OverrideMode = NoOverride;
DEBUG(dbgs() << "back to default" << "\n");
if (inMips16Mode() && !PreviousInMips16Mode) {
setHelperClassesMips16();
PreviousInMips16Mode = true;
} else if (!inMips16Mode() && PreviousInMips16Mode) {
setHelperClassesMipsSE();
PreviousInMips16Mode = false;
}
return;
}
}
void MipsSubtarget::setHelperClassesMips16() {
InstrInfoSE.swap(InstrInfo);
FrameLoweringSE.swap(FrameLowering);
TLInfoSE.swap(TLInfo);
if (!InstrInfo16) {
InstrInfo.reset(MipsInstrInfo::create(*TM));
FrameLowering.reset(MipsFrameLowering::create(*TM, *this));
TLInfo.reset(MipsTargetLowering::create(*TM));
} else {
InstrInfo16.swap(InstrInfo);
FrameLowering16.swap(FrameLowering);
TLInfo16.swap(TLInfo);
}
assert(TLInfo && "null target lowering 16");
assert(InstrInfo && "null instr info 16");
assert(FrameLowering && "null frame lowering 16");
}
void MipsSubtarget::setHelperClassesMipsSE() {
InstrInfo16.swap(InstrInfo);
FrameLowering16.swap(FrameLowering);
TLInfo16.swap(TLInfo);
if (!InstrInfoSE) {
InstrInfo.reset(MipsInstrInfo::create(*TM));
FrameLowering.reset(MipsFrameLowering::create(*TM, *this));
TLInfo.reset(MipsTargetLowering::create(*TM));
} else {
InstrInfoSE.swap(InstrInfo);
FrameLoweringSE.swap(FrameLowering);
TLInfoSE.swap(TLInfo);
}
assert(TLInfo && "null target lowering in SE");
assert(InstrInfo && "null instr info SE");
assert(FrameLowering && "null frame lowering SE");
}
bool MipsSubtarget::mipsSEUsesSoftFloat() const {
return TM->Options.UseSoftFloat && !InMips16HardFloat;
}
bool MipsSubtarget::useConstantIslands() {
DEBUG(dbgs() << "use constant islands " << Mips16ConstantIslands << "\n");
return Mips16ConstantIslands;
}