src/llvm/lib/Target/Mips/MipsOs16.cpp

   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 "MipsOs16.h"
  15 #include "llvm/IR/Module.h"
  16 #include "llvm/Support/CommandLine.h"
  17 #include "llvm/Support/Debug.h"
  18 #include "llvm/Support/raw_ostream.h"
  19
  20 #define DEBUG_TYPE "mips-os16"
  21
  22
  23 static cl::opt<std::string> Mips32FunctionMask(
  24   "mips32-function-mask",
  25   cl::init(""),
  26   cl::desc("Force function to be mips32"),
  27   cl::Hidden);
  28
  29 namespace {
  30
  31   // Figure out if we need float point based on the function signature.
  32   // We need to move variables in and/or out of floating point
  33   // registers because of the ABI
  34   //
  35   bool needsFPFromSig(Function &F) {
  36     Type* RetType = F.getReturnType();
  37     switch (RetType->getTypeID()) {
  38     case Type::FloatTyID:
  39     case Type::DoubleTyID:
  40       return true;
  41     default:
  42       ;
  43     }
  44     if (F.arg_size() >=1) {
  45       Argument &Arg = F.getArgumentList().front();
  46       switch (Arg.getType()->getTypeID()) {
  47         case Type::FloatTyID:
  48         case Type::DoubleTyID:
  49           return true;
  50         default:
  51           ;
  52       }
  53     }
  54     return false;
  55   }
  56
  57   // Figure out if the function will need floating point operations
  58   //
  59   bool needsFP(Function &F) {
  60     if (needsFPFromSig(F))
  61       return true;
  62     for (Function::const_iterator BB = F.begin(), E = F.end(); BB != E; ++BB)
  63       for (BasicBlock::const_iterator I = BB->begin(), E = BB->end();
  64          I != E; ++I) {
  65         const Instruction &Inst = *I;
  66         switch (Inst.getOpcode()) {
  67         case Instruction::FAdd:
  68         case Instruction::FSub:
  69         case Instruction::FMul:
  70         case Instruction::FDiv:
  71         case Instruction::FRem:
  72         case Instruction::FPToUI:
  73         case Instruction::FPToSI:
  74         case Instruction::UIToFP:
  75         case Instruction::SIToFP:
  76         case Instruction::FPTrunc:
  77         case Instruction::FPExt:
  78         case Instruction::FCmp:
  79           return true;
  80         default:
  81           ;
  82         }
  83         if (const CallInst *CI = dyn_cast<CallInst>(I)) {
  84           DEBUG(dbgs() << "Working on call" << "\n");
  85           Function &F_ =  *CI->getCalledFunction();
  86           if (needsFPFromSig(F_))
  87             return true;
  88         }
  89       }
  90     return false;
  91   }
  92 }
  93 namespace llvm {
  94
  95
  96 bool MipsOs16::runOnModule(Module &M) {
  97   bool usingMask = Mips32FunctionMask.length() > 0;
  98   bool doneUsingMask = false; // this will make it stop repeating
  99   DEBUG(dbgs() << "Run on Module MipsOs16 \n" << Mips32FunctionMask << "\n");
 100   if (usingMask)
 101     DEBUG(dbgs() << "using mask \n" << Mips32FunctionMask << "\n");
 102   unsigned int functionIndex = 0;
 103   bool modified = false;
 104   for (Module::iterator F = M.begin(), E = M.end(); F != E; ++F) {
 105     if (F->isDeclaration()) continue;
 106     DEBUG(dbgs() << "Working on " << F->getName() << "\n");
 107     if (usingMask) {
 108       if (!doneUsingMask) {
 109         if (functionIndex == Mips32FunctionMask.length())
 110           functionIndex = 0;
 111         switch (Mips32FunctionMask[functionIndex]) {
 112         case '1':
 113           DEBUG(dbgs() << "mask forced mips32: " << F->getName() << "\n");
 114           F->addFnAttr("nomips16");
 115           break;
 116         case '.':
 117           doneUsingMask = true;
 118           break;
 119         default:
 120           break;
 121         }
 122         functionIndex++;
 123       }
 124     }
 125     else {
 126       if (needsFP(*F)) {
 127         DEBUG(dbgs() << "os16 forced mips32: " << F->getName() << "\n");
 128         F->addFnAttr("nomips16");
 129       }
 130       else {
 131         DEBUG(dbgs() << "os16 forced mips16: " << F->getName() << "\n");
 132         F->addFnAttr("mips16");
 133       }
 134     }
 135   }
 136   return modified;
 137 }
 138
 139 char MipsOs16::ID = 0;
 140
 141 }
 142
 143 ModulePass *llvm::createMipsOs16(MipsTargetMachine &TM) {
 144   return new MipsOs16;
 145 }
 146
 147