1 //===---- MipsOs16.cpp for Mips Option -Os16 --------===// 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 defines an optimization phase for the MIPS target. 11 // 12 //===----------------------------------------------------------------------===// 13 14 #include "llvm/IR/Instructions.h" 15 #include "Mips.h" 16 #include "llvm/IR/Module.h" 17 #include "llvm/Support/CommandLine.h" 18 #include "llvm/Support/Debug.h" 19 #include "llvm/Support/raw_ostream.h" 20 21 using namespace llvm; 22 23 #define DEBUG_TYPE "mips-os16" 24 25 static cl::opt<std::string> Mips32FunctionMask( 26 "mips32-function-mask", 27 cl::init(""), 28 cl::desc("Force function to be mips32"), 29 cl::Hidden); 30 31 namespace { 32 class MipsOs16 : public ModulePass { 33 public: 34 static char ID; 35 MipsOs16()36 MipsOs16() : ModulePass(ID) {} 37 getPassName() const38 const char *getPassName() const override { 39 return "MIPS Os16 Optimization"; 40 } 41 42 bool runOnModule(Module &M) override; 43 }; 44 45 char MipsOs16::ID = 0; 46 } 47 48 // Figure out if we need float point based on the function signature. 49 // We need to move variables in and/or out of floating point 50 // registers because of the ABI 51 // needsFPFromSig(Function & F)52static bool needsFPFromSig(Function &F) { 53 Type* RetType = F.getReturnType(); 54 switch (RetType->getTypeID()) { 55 case Type::FloatTyID: 56 case Type::DoubleTyID: 57 return true; 58 default: 59 ; 60 } 61 if (F.arg_size() >=1) { 62 Argument &Arg = F.getArgumentList().front(); 63 switch (Arg.getType()->getTypeID()) { 64 case Type::FloatTyID: 65 case Type::DoubleTyID: 66 return true; 67 default: 68 ; 69 } 70 } 71 return false; 72 } 73 74 // Figure out if the function will need floating point operations 75 // needsFP(Function & F)76static bool needsFP(Function &F) { 77 if (needsFPFromSig(F)) 78 return true; 79 for (Function::const_iterator BB = F.begin(), E = F.end(); BB != E; ++BB) 80 for (BasicBlock::const_iterator I = BB->begin(), E = BB->end(); 81 I != E; ++I) { 82 const Instruction &Inst = *I; 83 switch (Inst.getOpcode()) { 84 case Instruction::FAdd: 85 case Instruction::FSub: 86 case Instruction::FMul: 87 case Instruction::FDiv: 88 case Instruction::FRem: 89 case Instruction::FPToUI: 90 case Instruction::FPToSI: 91 case Instruction::UIToFP: 92 case Instruction::SIToFP: 93 case Instruction::FPTrunc: 94 case Instruction::FPExt: 95 case Instruction::FCmp: 96 return true; 97 default: 98 ; 99 } 100 if (const CallInst *CI = dyn_cast<CallInst>(I)) { 101 DEBUG(dbgs() << "Working on call" << "\n"); 102 Function &F_ = *CI->getCalledFunction(); 103 if (needsFPFromSig(F_)) 104 return true; 105 } 106 } 107 return false; 108 } 109 110 runOnModule(Module & M)111bool MipsOs16::runOnModule(Module &M) { 112 bool usingMask = Mips32FunctionMask.length() > 0; 113 bool doneUsingMask = false; // this will make it stop repeating 114 115 DEBUG(dbgs() << "Run on Module MipsOs16 \n" << Mips32FunctionMask << "\n"); 116 if (usingMask) 117 DEBUG(dbgs() << "using mask \n" << Mips32FunctionMask << "\n"); 118 119 unsigned int functionIndex = 0; 120 bool modified = false; 121 122 for (auto &F : M) { 123 if (F.isDeclaration()) 124 continue; 125 126 DEBUG(dbgs() << "Working on " << F.getName() << "\n"); 127 if (usingMask) { 128 if (!doneUsingMask) { 129 if (functionIndex == Mips32FunctionMask.length()) 130 functionIndex = 0; 131 switch (Mips32FunctionMask[functionIndex]) { 132 case '1': 133 DEBUG(dbgs() << "mask forced mips32: " << F.getName() << "\n"); 134 F.addFnAttr("nomips16"); 135 break; 136 case '.': 137 doneUsingMask = true; 138 break; 139 default: 140 break; 141 } 142 functionIndex++; 143 } 144 } 145 else { 146 if (needsFP(F)) { 147 DEBUG(dbgs() << "os16 forced mips32: " << F.getName() << "\n"); 148 F.addFnAttr("nomips16"); 149 } 150 else { 151 DEBUG(dbgs() << "os16 forced mips16: " << F.getName() << "\n"); 152 F.addFnAttr("mips16"); 153 } 154 } 155 } 156 157 return modified; 158 } 159 createMipsOs16Pass(MipsTargetMachine & TM)160ModulePass *llvm::createMipsOs16Pass(MipsTargetMachine &TM) { 161 return new MipsOs16; 162 } 163