1 //===-- MipsTargetMachine.cpp - Define TargetMachine for Mips -------------===//
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 // Implements the info about Mips target spec.
11 //
12 //===----------------------------------------------------------------------===//
13 
14 #include "Mips.h"
15 #include "MipsTargetAsmInfo.h"
16 #include "MipsTargetMachine.h"
17 #include "llvm/Module.h"
18 #include "llvm/PassManager.h"
19 #include "llvm/Target/TargetMachineRegistry.h"
20 using namespace llvm;
21 
22 /// MipsTargetMachineModule - Note that this is used on hosts that
23 /// cannot link in a library unless there are references into the
24 /// library.  In particular, it seems that it is not possible to get
25 /// things to work on Win32 without this.  Though it is unused, do not
26 /// remove it.
27 extern "C" int MipsTargetMachineModule;
28 int MipsTargetMachineModule = 0;
29 
30 // Register the target.
31 static RegisterTarget<MipsTargetMachine>    X("mips", "Mips");
32 static RegisterTarget<MipselTargetMachine>  Y("mipsel", "Mipsel");
33 
34 MipsTargetMachine::AsmPrinterCtorFn MipsTargetMachine::AsmPrinterCtor = 0;
35 
36 
37 // Force static initialization.
38 extern "C" void LLVMInitializeMipsTarget() { }
39 
40 const TargetAsmInfo *MipsTargetMachine::
41 createTargetAsmInfo() const
42 {
43   return new MipsTargetAsmInfo(*this);
44 }
45 
46 // DataLayout --> Big-endian, 32-bit pointer/ABI/alignment
47 // The stack is always 8 byte aligned
48 // On function prologue, the stack is created by decrementing
49 // its pointer. Once decremented, all references are done with positive
50 // offset from the stack/frame pointer, using StackGrowsUp enables
51 // an easier handling.
52 // Using CodeModel::Large enables different CALL behavior.
53 MipsTargetMachine::
54 MipsTargetMachine(const Module &M, const std::string &FS, bool isLittle=false):
55   Subtarget(*this, M, FS, isLittle),
56   DataLayout(isLittle ? std::string("e-p:32:32:32-i8:8:32-i16:16:32") :
57                         std::string("E-p:32:32:32-i8:8:32-i16:16:32")),
58   InstrInfo(*this),
59   FrameInfo(TargetFrameInfo::StackGrowsUp, 8, 0),
60   TLInfo(*this)
61 {
62   // Abicall enables PIC by default
63   if (Subtarget.hasABICall())
64     setRelocationModel(Reloc::PIC_);
65 
66   // TODO: create an option to enable long calls, like -mlong-calls,
67   // that would be our CodeModel::Large. It must not work with Abicall.
68   if (getCodeModel() == CodeModel::Default)
69     setCodeModel(CodeModel::Small);
70 }
71 
72 MipselTargetMachine::
73 MipselTargetMachine(const Module &M, const std::string &FS) :
74   MipsTargetMachine(M, FS, true) {}
75 
76 // return 0 and must specify -march to gen MIPS code.
77 unsigned MipsTargetMachine::
78 getModuleMatchQuality(const Module &M)
79 {
80   // We strongly match "mips*-*".
81   std::string TT = M.getTargetTriple();
82   if (TT.size() >= 5 && std::string(TT.begin(), TT.begin()+5) == "mips-")
83     return 20;
84 
85   if (TT.size() >= 13 && std::string(TT.begin(),
86       TT.begin()+13) == "mipsallegrex-")
87     return 20;
88 
89   return 0;
90 }
91 
92 // return 0 and must specify -march to gen MIPSEL code.
93 unsigned MipselTargetMachine::
94 getModuleMatchQuality(const Module &M)
95 {
96   // We strongly match "mips*el-*".
97   std::string TT = M.getTargetTriple();
98   if (TT.size() >= 7 && std::string(TT.begin(), TT.begin()+7) == "mipsel-")
99     return 20;
100 
101   if (TT.size() >= 15 && std::string(TT.begin(),
102       TT.begin()+15) == "mipsallegrexel-")
103     return 20;
104 
105   if (TT.size() == 3 && std::string(TT.begin(), TT.begin()+3) == "psp")
106     return 20;
107 
108   return 0;
109 }
110 
111 // Install an instruction selector pass using
112 // the ISelDag to gen Mips code.
113 bool MipsTargetMachine::
114 addInstSelector(PassManagerBase &PM, CodeGenOpt::Level OptLevel)
115 {
116   PM.add(createMipsISelDag(*this));
117   return false;
118 }
119 
120 // Implemented by targets that want to run passes immediately before
121 // machine code is emitted. return true if -print-machineinstrs should
122 // print out the code after the passes.
123 bool MipsTargetMachine::
124 addPreEmitPass(PassManagerBase &PM, CodeGenOpt::Level OptLevel)
125 {
126   PM.add(createMipsDelaySlotFillerPass(*this));
127   return true;
128 }
129 
130 // Implements the AssemblyEmitter for the target. Must return
131 // true if AssemblyEmitter is supported
132 bool MipsTargetMachine::
133 addAssemblyEmitter(PassManagerBase &PM, CodeGenOpt::Level OptLevel,
134                    bool Verbose, raw_ostream &Out)  {
135   // Output assembly language.
136   assert(AsmPrinterCtor && "AsmPrinter was not linked in");
137   PM.add(AsmPrinterCtor(Out, *this, Verbose));
138   return false;
139 }
140