llvm-6502/lib/Target/Mips/MipsSubtarget.cpp
Vasileios Kalintiris 328bc2f89e [mips] Add preliminary support for the MIPS II target.
Summary:
This patch enables code generation for the MIPS II target. Pre-Mips32
targets don't have the MUL instruction, so we add the correspondent
pattern that uses the MULT/MFLO combination in order to retrieve the
product.

This is WIP as we don't support code generation for select nodes due to
the lack of conditional-move instructions.

Reviewers: dsanders

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D6150

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@221686 91177308-0d34-0410-b5e6-96231b3b80d8
2014-11-11 11:43:55 +00:00

232 lines
7.6 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));
static cl::opt<bool>
GPOpt("mgpopt", cl::Hidden,
cl::desc("MIPS: Enable gp-relative addressing of small data items"));
/// 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,
const MipsTargetMachine *_TM)
: MipsGenSubtargetInfo(TT, CPU, FS), MipsArchVersion(MipsDefault),
ABI(MipsABIInfo::Unknown()), IsLittle(little), IsSingleFloat(false),
IsFPXX(false), NoABICalls(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), TM(_TM), TargetTriple(TT),
DL(computeDataLayout(initializeSubtargetDependencies(CPU, FS, TM))),
TSInfo(DL), InstrInfo(MipsInstrInfo::create(*this)),
FrameLowering(MipsFrameLowering::create(*this)),
TLInfo(MipsTargetLowering::create(*TM, *this)) {
PreviousInMips16Mode = InMips16Mode;
if (MipsArchVersion == MipsDefault)
MipsArchVersion = Mips32;
// Don't even attempt to generate code for MIPS-I, 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 == 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(ABI.IsKnown());
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 requires 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;
if (NoABICalls && TM->getRelocationModel() == Reloc::PIC_)
report_fatal_error("position-independent code requires '-mabicalls'");
// Set UseSmallSection.
UseSmallSection = GPOpt;
if (!NoABICalls && GPOpt) {
errs() << "warning: cannot use small-data accesses for '-mabicalls'"
<< "\n";
UseSmallSection = false;
}
}
/// This overrides the PostRAScheduler bit in the SchedModel for any CPU.
bool MipsSubtarget::enablePostMachineScheduler() const { return true; }
void MipsSubtarget::getCriticalPathRCs(RegClassVector &CriticalPathRCs) const {
CriticalPathRCs.clear();
CriticalPathRCs.push_back(isGP64bit() ?
&Mips::GPR64RegClass : &Mips::GPR32RegClass);
}
CodeGenOpt::Level MipsSubtarget::getOptLevelToEnablePostRAScheduler() const {
return 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)
InMips16HardFloat = true;
return *this;
}
bool MipsSubtarget::abiUsesSoftFloat() const {
return TM->Options.UseSoftFloat && !InMips16HardFloat;
}
bool MipsSubtarget::useConstantIslands() {
DEBUG(dbgs() << "use constant islands " << Mips16ConstantIslands << "\n");
return Mips16ConstantIslands;
}
Reloc::Model MipsSubtarget::getRelocationModel() const {
return TM->getRelocationModel();
}