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 33 using namespace llvm; 34 35 // FIXME: Maybe this should be on by default when Mips16 is specified 36 // 37 static 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 44 static 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 51 static cl::opt<bool> 52 Mips16HardFloat("mips16-hard-float", cl::NotHidden, 53 cl::desc("MIPS: mips16 hard float enable."), 54 cl::init(false)); 55 56 static cl::opt<bool> 57 Mips16ConstantIslands( 58 "mips16-constant-islands", cl::NotHidden, 59 cl::desc("MIPS: mips16 constant islands enable."), 60 cl::init(true)); 61 62 void MipsSubtarget::anchor() { } 63 64 MipsSubtarget::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 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 if (InMips16Mode && !TM->Options.UseSoftFloat) { 85 // Hard float for mips16 means essentially to compile as soft float 86 // but to use a runtime library for soft float that is written with 87 // native mips32 floating point instructions (those runtime routines 88 // run in mips32 hard float mode). 89 TM->Options.UseSoftFloat = true; 90 TM->Options.FloatABIType = FloatABI::Soft; 91 InMips16HardFloat = true; 92 } 93 94 PreviousInMips16Mode = InMips16Mode; 95 96 // Initialize scheduling itinerary for the specified CPU. 97 InstrItins = getInstrItineraryForCPU(CPUName); 98 99 // Set MipsABI if it hasn't been set yet. 100 if (MipsABI == UnknownABI) 101 MipsABI = hasMips64() ? N64 : O32; 102 103 // Check if Architecture and ABI are compatible. 104 assert(((!hasMips64() && (isABI_O32() || isABI_EABI())) || 105 (hasMips64() && (isABI_N32() || isABI_N64()))) && 106 "Invalid Arch & ABI pair."); 107 108 if (hasMSA() && !isFP64bit()) 109 report_fatal_error("MSA requires a 64-bit FPU register file (FR=1 mode). " 110 "See -mattr=+fp64.", 111 false); 112 113 // Is the target system Linux ? 114 if (TT.find("linux") == std::string::npos) 115 IsLinux = false; 116 117 // Set UseSmallSection. 118 UseSmallSection = !IsLinux && (RM == Reloc::Static); 119 // set some subtarget specific features 120 if (inMips16Mode()) 121 HasBitCount=false; 122 } 123 124 bool 125 MipsSubtarget::enablePostRAScheduler(CodeGenOpt::Level OptLevel, 126 TargetSubtargetInfo::AntiDepBreakMode &Mode, 127 RegClassVector &CriticalPathRCs) const { 128 Mode = TargetSubtargetInfo::ANTIDEP_NONE; 129 CriticalPathRCs.clear(); 130 CriticalPathRCs.push_back(hasMips64() ? 131 &Mips::GPR64RegClass : &Mips::GPR32RegClass); 132 return OptLevel >= CodeGenOpt::Aggressive; 133 } 134 135 //FIXME: This logic for reseting the subtarget along with 136 // the helper classes can probably be simplified but there are a lot of 137 // cases so we will defer rewriting this to later. 138 // 139 void MipsSubtarget::resetSubtarget(MachineFunction *MF) { 140 bool ChangeToMips16 = false, ChangeToNoMips16 = false; 141 DEBUG(dbgs() << "resetSubtargetFeatures" << "\n"); 142 AttributeSet FnAttrs = MF->getFunction()->getAttributes(); 143 ChangeToMips16 = FnAttrs.hasAttribute(AttributeSet::FunctionIndex, 144 "mips16"); 145 ChangeToNoMips16 = FnAttrs.hasAttribute(AttributeSet::FunctionIndex, 146 "nomips16"); 147 assert (!(ChangeToMips16 & ChangeToNoMips16) && 148 "mips16 and nomips16 specified on the same function"); 149 if (ChangeToMips16) { 150 if (PreviousInMips16Mode) 151 return; 152 OverrideMode = Mips16Override; 153 PreviousInMips16Mode = true; 154 TM->setHelperClassesMips16(); 155 return; 156 } else if (ChangeToNoMips16) { 157 if (!PreviousInMips16Mode) 158 return; 159 OverrideMode = NoMips16Override; 160 PreviousInMips16Mode = false; 161 TM->setHelperClassesMipsSE(); 162 return; 163 } else { 164 if (OverrideMode == NoOverride) 165 return; 166 OverrideMode = NoOverride; 167 DEBUG(dbgs() << "back to default" << "\n"); 168 if (inMips16Mode() && !PreviousInMips16Mode) { 169 TM->setHelperClassesMips16(); 170 PreviousInMips16Mode = true; 171 } else if (!inMips16Mode() && PreviousInMips16Mode) { 172 TM->setHelperClassesMipsSE(); 173 PreviousInMips16Mode = false; 174 } 175 return; 176 } 177 } 178 179 bool MipsSubtarget::mipsSEUsesSoftFloat() const { 180 return TM->Options.UseSoftFloat && !InMips16HardFloat; 181 } 182 183 bool MipsSubtarget::useConstantIslands() { 184 DEBUG(dbgs() << "use constant islands " << Mips16ConstantIslands << "\n"); 185 return Mips16ConstantIslands; 186 } 187