Register Asm backend. Add functions to MipsAsmBackend.

Patch by Reed Kotler at Mips Technologies.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@140886 91177308-0d34-0410-b5e6-96231b3b80d8

lib/Target/Mips/MCTargetDesc/MipsAsmBackend.cpp

@@ -33,6 +33,44 @@ public:
   unsigned getNumFixupKinds() const {
     return 1;   //tbd
   }
+
+  /// ApplyFixup - Apply the \arg Value for given \arg Fixup into the provided
+  /// data fragment, at the offset specified by the fixup and following the
+  /// fixup kind as appropriate.
+  void ApplyFixup(const MCFixup &Fixup, char *Data, unsigned DataSize,
+                  uint64_t Value) const {
+  }
+
+  /// @name Target Relaxation Interfaces
+  /// @{
+
+  /// MayNeedRelaxation - Check whether the given instruction may need
+  /// relaxation.
+  ///
+  /// \param Inst - The instruction to test.
+  bool MayNeedRelaxation(const MCInst &Inst) const {
+    return false;
+  }
+
+  /// RelaxInstruction - Relax the instruction in the given fragment to the next
+  /// wider instruction.
+  ///
+  /// \param Inst - The instruction to relax, which may be the same as the
+  /// output.
+  /// \parm Res [output] - On return, the relaxed instruction.
+  void RelaxInstruction(const MCInst &Inst, MCInst &Res) const {
+  }
+  
+  /// @}
+
+  /// WriteNopData - Write an (optimal) nop sequence of Count bytes to the given
+  /// output. If the target cannot generate such a sequence, it should return an
+  /// error.
+  ///
+  /// \return - True on success.
+  bool WriteNopData(uint64_t Count, MCObjectWriter *OW) const {
+    return false;
+  }
 };
 
 class MipsEB_AsmBackend : public MipsAsmBackend {
@@ -69,3 +107,11 @@ public:
   }
 };
 }
+
+MCAsmBackend *llvm::createMipsAsmBackend(const Target &T, StringRef TT) {
+  Triple TheTriple(TT);
+
+  // just return little endian for now
+  //
+  return new MipsEL_AsmBackend(T, Triple(TT).getOS());
+}

lib/Target/Mips/MCTargetDesc/MipsMCTargetDesc.cpp

@@ -116,6 +116,12 @@ extern "C" void LLVMInitializeMipsTargetMC() {
   TargetRegistry::RegisterMCCodeEmitter(TheMips64elTarget,
                                         createMipsMCCodeEmitter);
 
+  // Register the asm backend.
+  TargetRegistry::RegisterMCAsmBackend(TheMipsTarget, createMipsAsmBackend);
+  TargetRegistry::RegisterMCAsmBackend(TheMipselTarget, createMipsAsmBackend);
+  TargetRegistry::RegisterMCAsmBackend(TheMips64Target, createMipsAsmBackend);
+  TargetRegistry::RegisterMCAsmBackend(TheMips64elTarget, createMipsAsmBackend);
+
   // Register the MC subtarget info.
   TargetRegistry::RegisterMCSubtargetInfo(TheMipsTarget,
                                           createMipsMCSubtargetInfo);

lib/Target/Mips/MCTargetDesc/MipsMCTargetDesc.h

@@ -15,6 +15,7 @@
 #define MIPSMCTARGETDESC_H
 
 namespace llvm {
+class MCAsmBackend;
 class MCInstrInfo;
 class MCCodeEmitter;
 class MCContext;
@@ -30,6 +31,8 @@ extern Target TheMips64elTarget;
 MCCodeEmitter *createMipsMCCodeEmitter(const MCInstrInfo &MCII,
                                        const MCSubtargetInfo &STI,
                                        MCContext &Ctx);
+
+MCAsmBackend *createMipsAsmBackend(const Target &T, StringRef TT);
 } // End llvm namespace
 
 // Defines symbolic names for Mips registers.  This defines a mapping from