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