MipsSubtarget.cpp revision 615a279f81e08e9c63fd5e411b33d39bfe593314
1//===-- MipsSubtarget.cpp - Mips Subtarget Information --------------------===// 2// 3// The LLVM Compiler Infrastructure 4// 5// This file is distributed under the University of Illinois Open Source 6// License. See LICENSE.TXT for details. 7// 8//===----------------------------------------------------------------------===// 9// 10// This file implements the Mips specific subclass of TargetSubtargetInfo. 11// 12//===----------------------------------------------------------------------===// 13 14#define DEBUG_TYPE "mips-subtarget" 15 16#include "MipsMachineFunction.h" 17#include "MipsSubtarget.h" 18#include "MipsTargetMachine.h" 19#include "Mips.h" 20#include "MipsRegisterInfo.h" 21#include "llvm/IR/Attributes.h" 22#include "llvm/IR/Function.h" 23#include "llvm/Support/CommandLine.h" 24#include "llvm/Support/Debug.h" 25#include "llvm/Support/TargetRegistry.h" 26#include "llvm/Support/raw_ostream.h" 27 28#define GET_SUBTARGETINFO_TARGET_DESC 29#define GET_SUBTARGETINFO_CTOR 30#include "MipsGenSubtargetInfo.inc" 31 32 33using namespace llvm; 34 35// FIXME: Maybe this should be on by default when Mips16 is specified 36// 37static cl::opt<bool> Mixed16_32( 38 "mips-mixed-16-32", 39 cl::init(false), 40 cl::desc("Allow for a mixture of Mips16 " 41 "and Mips32 code in a single source file"), 42 cl::Hidden); 43 44static cl::opt<bool> Mips_Os16( 45 "mips-os16", 46 cl::init(false), 47 cl::desc("Compile all functions that don' use " 48 "floating point as Mips 16"), 49 cl::Hidden); 50 51static cl::opt<bool> 52Mips16HardFloat("mips16-hard-float", cl::NotHidden, 53 cl::desc("MIPS: mips16 hard float enable."), 54 cl::init(false)); 55 56static cl::opt<bool> 57Mips16ConstantIslands( 58 "mips16-constant-islands", cl::Hidden, 59 cl::desc("MIPS: mips16 constant islands enable. experimental feature"), 60 cl::init(false)); 61 62void MipsSubtarget::anchor() { } 63 64MipsSubtarget::MipsSubtarget(const std::string &TT, const std::string &CPU, 65 const std::string &FS, bool little, 66 Reloc::Model _RM, MipsTargetMachine *_TM) : 67 MipsGenSubtargetInfo(TT, CPU, FS), 68 MipsArchVersion(Mips32), MipsABI(UnknownABI), IsLittle(little), 69 IsSingleFloat(false), IsFP64bit(false), IsGP64bit(false), HasVFPU(false), 70 IsLinux(true), HasSEInReg(false), HasCondMov(false), HasSwap(false), 71 HasBitCount(false), HasFPIdx(false), 72 InMips16Mode(false), InMips16HardFloat(Mips16HardFloat), 73 InMicroMipsMode(false), HasDSP(false), HasDSPR2(false), 74 AllowMixed16_32(Mixed16_32 | Mips_Os16), Os16(Mips_Os16), HasMSA(false), 75 StackAlignment(8), RM(_RM), OverrideMode(NoOverride), TM(_TM) 76{ 77 std::string CPUName = CPU; 78 if (CPUName.empty()) 79 CPUName = "mips32"; 80 81 // Parse features string. 82 ParseSubtargetFeatures(CPUName, FS); 83 84 PreviousInMips16Mode = InMips16Mode; 85 86 // Initialize scheduling itinerary for the specified CPU. 87 InstrItins = getInstrItineraryForCPU(CPUName); 88 89 // Set MipsABI if it hasn't been set yet. 90 if (MipsABI == UnknownABI) 91 MipsABI = hasMips64() ? N64 : O32; 92 93 // Check if Architecture and ABI are compatible. 94 assert(((!hasMips64() && (isABI_O32() || isABI_EABI())) || 95 (hasMips64() && (isABI_N32() || isABI_N64()))) && 96 "Invalid Arch & ABI pair."); 97 98 if (hasMSA() && !isFP64bit()) 99 report_fatal_error("MSA requires a 64-bit FPU register file (FR=1 mode). " 100 "See -mattr=+fp64.", 101 false); 102 103 // Is the target system Linux ? 104 if (TT.find("linux") == std::string::npos) 105 IsLinux = false; 106 107 // Set UseSmallSection. 108 UseSmallSection = !IsLinux && (RM == Reloc::Static); 109 // set some subtarget specific features 110 if (inMips16Mode()) 111 HasBitCount=false; 112} 113 114bool 115MipsSubtarget::enablePostRAScheduler(CodeGenOpt::Level OptLevel, 116 TargetSubtargetInfo::AntiDepBreakMode &Mode, 117 RegClassVector &CriticalPathRCs) const { 118 Mode = TargetSubtargetInfo::ANTIDEP_NONE; 119 CriticalPathRCs.clear(); 120 CriticalPathRCs.push_back(hasMips64() ? 121 &Mips::GPR64RegClass : &Mips::GPR32RegClass); 122 return OptLevel >= CodeGenOpt::Aggressive; 123} 124 125//FIXME: This logic for reseting the subtarget along with 126// the helper classes can probably be simplified but there are a lot of 127// cases so we will defer rewriting this to later. 128// 129void MipsSubtarget::resetSubtarget(MachineFunction *MF) { 130 bool ChangeToMips16 = false, ChangeToNoMips16 = false; 131 DEBUG(dbgs() << "resetSubtargetFeatures" << "\n"); 132 AttributeSet FnAttrs = MF->getFunction()->getAttributes(); 133 ChangeToMips16 = FnAttrs.hasAttribute(AttributeSet::FunctionIndex, 134 "mips16"); 135 ChangeToNoMips16 = FnAttrs.hasAttribute(AttributeSet::FunctionIndex, 136 "nomips16"); 137 assert (!(ChangeToMips16 & ChangeToNoMips16) && 138 "mips16 and nomips16 specified on the same function"); 139 if (ChangeToMips16) { 140 if (PreviousInMips16Mode) 141 return; 142 OverrideMode = Mips16Override; 143 PreviousInMips16Mode = true; 144 TM->setHelperClassesMips16(); 145 return; 146 } else if (ChangeToNoMips16) { 147 if (!PreviousInMips16Mode) 148 return; 149 OverrideMode = NoMips16Override; 150 PreviousInMips16Mode = false; 151 TM->setHelperClassesMipsSE(); 152 return; 153 } else { 154 if (OverrideMode == NoOverride) 155 return; 156 OverrideMode = NoOverride; 157 DEBUG(dbgs() << "back to default" << "\n"); 158 if (inMips16Mode() && !PreviousInMips16Mode) { 159 TM->setHelperClassesMips16(); 160 PreviousInMips16Mode = true; 161 } else if (!inMips16Mode() && PreviousInMips16Mode) { 162 TM->setHelperClassesMipsSE(); 163 PreviousInMips16Mode = false; 164 } 165 return; 166 } 167} 168 169bool MipsSubtarget::mipsSEUsesSoftFloat() const { 170 return TM->Options.UseSoftFloat && !InMips16HardFloat; 171} 172 173bool MipsSubtarget::useConstantIslands() { 174 DEBUG(dbgs() << "use constant islands " << Mips16ConstantIslands << "\n"); 175 return Mips16ConstantIslands; 176} 177