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/PassManager.h"
18 #include "llvm/Target/TargetRegistry.h"
19 using namespace llvm;
20 
21 extern "C" void LLVMInitializeMipsTarget() {
22   // Register the target.
23   RegisterTargetMachine<MipsTargetMachine> X(TheMipsTarget);
24   RegisterTargetMachine<MipselTargetMachine> Y(TheMipselTarget);
25 }
26 
27 const TargetAsmInfo *MipsTargetMachine::
28 createTargetAsmInfo() const
29 {
30   return new MipsTargetAsmInfo(*this);
31 }
32 
33 // DataLayout --> Big-endian, 32-bit pointer/ABI/alignment
34 // The stack is always 8 byte aligned
35 // On function prologue, the stack is created by decrementing
36 // its pointer. Once decremented, all references are done with positive
37 // offset from the stack/frame pointer, using StackGrowsUp enables
38 // an easier handling.
39 // Using CodeModel::Large enables different CALL behavior.
40 MipsTargetMachine::
41 MipsTargetMachine(const Target &T, const std::string &TT, const std::string &FS,
42                   bool isLittle=false):
43   LLVMTargetMachine(T),
44   Subtarget(TT, FS, isLittle),
45   DataLayout(isLittle ? std::string("e-p:32:32:32-i8:8:32-i16:16:32") :
46                         std::string("E-p:32:32:32-i8:8:32-i16:16:32")),
47   InstrInfo(*this),
48   FrameInfo(TargetFrameInfo::StackGrowsUp, 8, 0),
49   TLInfo(*this)
50 {
51   // Abicall enables PIC by default
52   if (getRelocationModel() == Reloc::Default) {
53     if (Subtarget.isABI_O32())
54       setRelocationModel(Reloc::PIC_);
55     else
56       setRelocationModel(Reloc::Static);
57   }
58 
59   // TODO: create an option to enable long calls, like -mlong-calls,
60   // that would be our CodeModel::Large. It must not work with Abicall.
61   if (getCodeModel() == CodeModel::Default)
62     setCodeModel(CodeModel::Small);
63 }
64 
65 MipselTargetMachine::
66 MipselTargetMachine(const Target &T, const std::string &TT,
67                     const std::string &FS) :
68   MipsTargetMachine(T, TT, FS, true) {}
69 
70 // Install an instruction selector pass using
71 // the ISelDag to gen Mips code.
72 bool MipsTargetMachine::
73 addInstSelector(PassManagerBase &PM, CodeGenOpt::Level OptLevel)
74 {
75   PM.add(createMipsISelDag(*this));
76   return false;
77 }
78 
79 // Implemented by targets that want to run passes immediately before
80 // machine code is emitted. return true if -print-machineinstrs should
81 // print out the code after the passes.
82 bool MipsTargetMachine::
83 addPreEmitPass(PassManagerBase &PM, CodeGenOpt::Level OptLevel)
84 {
85   PM.add(createMipsDelaySlotFillerPass(*this));
86   return true;
87 }
88