lib/Target/Mips/MipsTargetMachine.cpp

   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 }