LLVM  3.7.0
MipsOs16.cpp
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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"
18 #include "llvm/Support/Debug.h"
20 
21 using namespace llvm;
22 
23 #define DEBUG_TYPE "mips-os16"
24 
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 
36  MipsOs16() : ModulePass(ID) {}
37 
38  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 //
52 static 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 //
76 static 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 
111 bool MipsOs16::runOnModule(Module &M) {
112  bool usingMask = Mips32FunctionMask.length() > 0;
113  bool doneUsingMask = false; // this will make it stop repeating
114  DEBUG(dbgs() << "Run on Module MipsOs16 \n" << Mips32FunctionMask << "\n");
115  if (usingMask)
116  DEBUG(dbgs() << "using mask \n" << Mips32FunctionMask << "\n");
117  unsigned int functionIndex = 0;
118  bool modified = false;
119  for (Module::iterator F = M.begin(), E = M.end(); F != E; ++F) {
120  if (F->isDeclaration()) continue;
121  DEBUG(dbgs() << "Working on " << F->getName() << "\n");
122  if (usingMask) {
123  if (!doneUsingMask) {
124  if (functionIndex == Mips32FunctionMask.length())
125  functionIndex = 0;
126  switch (Mips32FunctionMask[functionIndex]) {
127  case '1':
128  DEBUG(dbgs() << "mask forced mips32: " << F->getName() << "\n");
129  F->addFnAttr("nomips16");
130  break;
131  case '.':
132  doneUsingMask = true;
133  break;
134  default:
135  break;
136  }
137  functionIndex++;
138  }
139  }
140  else {
141  if (needsFP(*F)) {
142  DEBUG(dbgs() << "os16 forced mips32: " << F->getName() << "\n");
143  F->addFnAttr("nomips16");
144  }
145  else {
146  DEBUG(dbgs() << "os16 forced mips16: " << F->getName() << "\n");
147  F->addFnAttr("mips16");
148  }
149  }
150  }
151  return modified;
152 }
153 
155  return new MipsOs16;
156 }
LLVM Argument representation.
Definition: Argument.h:35
A Module instance is used to store all the information related to an LLVM module. ...
Definition: Module.h:114
2: 32-bit floating point type
Definition: Type.h:58
iterator end()
Definition: Function.h:459
CallInst - This class represents a function call, abstracting a target machine's calling convention...
Type * getReturnType() const
Definition: Function.cpp:233
F(f)
size_t arg_size() const
Definition: Function.cpp:301
static cl::opt< std::string > Mips32FunctionMask("mips32-function-mask", cl::init(""), cl::desc("Force function to be mips32"), cl::Hidden)
static bool needsFPFromSig(Function &F)
Definition: MipsOs16.cpp:52
static bool needsFP(Function &F)
Definition: MipsOs16.cpp:76
TypeID getTypeID() const
getTypeID - Return the type id for the type.
Definition: Type.h:134
iterator begin()
Definition: Function.h:457
initializer< Ty > init(const Ty &Val)
Definition: CommandLine.h:325
The instances of the Type class are immutable: once they are created, they are never changed...
Definition: Type.h:45
Module.h This file contains the declarations for the Module class.
Type * getType() const
All values are typed, get the type of this value.
Definition: Value.h:222
raw_ostream & dbgs()
dbgs() - This returns a reference to a raw_ostream for debugging messages.
Definition: Debug.cpp:123
reference front()
Definition: ilist.h:390
ModulePass * createMipsOs16Pass(MipsTargetMachine &TM)
Definition: MipsOs16.cpp:154
iterator end()
Definition: Module.h:571
#define I(x, y, z)
Definition: MD5.cpp:54
ModulePass class - This class is used to implement unstructured interprocedural optimizations and ana...
Definition: Pass.h:236
iterator begin()
Definition: Module.h:569
3: 64-bit floating point type
Definition: Type.h:59
unsigned getOpcode() const
getOpcode() returns a member of one of the enums like Instruction::Add.
Definition: Instruction.h:112
const ArgumentListType & getArgumentList() const
Get the underlying elements of the Function...
Definition: Function.h:424
#define DEBUG(X)
Definition: Debug.h:92