Initial Mips support, here we go! =)
- Modifications from the last patch included
  (issues pointed by Evan Cheng are now fixed).
- Added more MipsI instructions.
- Added more patterns to match branch instructions.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@37461 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Target/Mips/MipsTargetMachine.cpp b/lib/Target/Mips/MipsTargetMachine.cpp
new file mode 100644
index 0000000..de30284
--- /dev/null
+++ b/lib/Target/Mips/MipsTargetMachine.cpp
@@ -0,0 +1,81 @@
+//===-- MipsTargetMachine.cpp - Define TargetMachine for Mips -------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file was developed by Bruno Cardoso Lopes and is distributed under the
+// University of Illinois Open Source License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// Implements the info about Mips target spec.
+//
+//===----------------------------------------------------------------------===//
+
+#include "Mips.h"
+#include "MipsTargetAsmInfo.h"
+#include "MipsTargetMachine.h"
+#include "llvm/Module.h"
+#include "llvm/PassManager.h"
+#include "llvm/Target/TargetMachineRegistry.h"
+using namespace llvm;
+
+namespace {
+  // Register the target.
+  RegisterTarget<MipsTargetMachine> X("mips", "  Mips");
+}
+
+const TargetAsmInfo *MipsTargetMachine::
+createTargetAsmInfo() const 
+{
+  return new MipsTargetAsmInfo(*this);
+}
+
+// DataLayout --> Big-endian, 32-bit pointer/ABI/alignment
+// FrameInfo  --> StackGrowsDown, 8 bytes aligned, LOA : -4 (Ra : 0)
+MipsTargetMachine::
+MipsTargetMachine(const Module &M, const std::string &FS): 
+  Subtarget(*this, M, FS), DataLayout("E-p:32:32:32"), 
+  InstrInfo(*this), FrameInfo(TargetFrameInfo::StackGrowsDown, 8, -4),
+  TLInfo(*this) {}
+
+// return 0 and must specify -march to gen MIPS code.
+unsigned MipsTargetMachine::
+getModuleMatchQuality(const Module &M) 
+{
+  // We strongly match "mips-*".
+  std::string TT = M.getTargetTriple();
+  if (TT.size() >= 5 && std::string(TT.begin(), TT.begin()+5) == "mips-")
+    return 20;
+  
+  return 0;
+}
+
+// Install an instruction selector pass using 
+// the ISelDag to gen Mips code.
+bool MipsTargetMachine::
+addInstSelector(FunctionPassManager &PM, bool Fast) 
+{
+  PM.add(createMipsISelDag(*this));
+  return false;
+}
+
+// Implemented by targets that want to run passes immediately before 
+// machine code is emitted. return true if -print-machineinstrs should 
+// print out the code after the passes.
+// TODO: Delay slot must be implemented here.
+bool MipsTargetMachine::
+addPreEmitPass(FunctionPassManager &PM, bool Fast) 
+{
+  return false;
+}
+
+// Implements the AssemblyEmitter for the target. Must return
+// true if AssemblyEmitter is supported
+bool MipsTargetMachine::
+addAssemblyEmitter(FunctionPassManager &PM, bool Fast, 
+                   std::ostream &Out) 
+{
+  // Output assembly language.
+  PM.add(createMipsCodePrinterPass(Out, *this));
+  return false;
+}