path: root/lib/Target/SparcV9/SparcV9AsmPrinter.cpp

//===-- EmitAssembly.cpp - Emit Sparc Specific .s File ---------------------==//
// 
//                     The LLVM Compiler Infrastructure
//
// This file was developed by the LLVM research group and is distributed under
// the University of Illinois Open Source License. See LICENSE.TXT for details.
// 
//===----------------------------------------------------------------------===//
//
// This file implements all of the stuff necessary to output a .s file from
// LLVM.  The code in this file assumes that the specified module has already
// been compiled into the internal data structures of the Module.
//
// This code largely consists of two LLVM Pass's: a FunctionPass and a Pass.
// The FunctionPass is pipelined together with all of the rest of the code
// generation stages, and the Pass runs at the end to emit code for global
// variables and such.
//
//===----------------------------------------------------------------------===//

#include "llvm/CodeGen/MachineInstr.h"
#include "llvm/CodeGen/MachineFunction.h"
#include "llvm/CodeGen/MachineFunctionInfo.h"
#include "llvm/Constants.h"
#include "llvm/DerivedTypes.h"
#include "llvm/Module.h"
#include "llvm/SlotCalculator.h"
#include "llvm/Pass.h"
#include "llvm/Assembly/Writer.h"
#include "Support/StringExtras.h"
#include "Support/Statistic.h"
#include "SparcInternals.h"
#include <string>

namespace {

Statistic<> EmittedInsts("asm-printer", "Number of machine instrs printed");

class GlobalIdTable: public Annotation {
  static AnnotationID AnnotId;
  friend class AsmPrinter;              // give access to AnnotId
  
  typedef hash_map<const Value*, int> ValIdMap;
  typedef ValIdMap::const_iterator ValIdMapConstIterator;
  typedef ValIdMap::      iterator ValIdMapIterator;
public:
  SlotCalculator Table;    // map anonymous values to unique integer IDs
  ValIdMap valToIdMap;     // used for values not handled by SlotCalculator 
  
  GlobalIdTable(Module* M) : Annotation(AnnotId), Table(M, true) {}
};

AnnotationID GlobalIdTable::AnnotId =
  AnnotationManager::getID("ASM PRINTER GLOBAL TABLE ANNOT");
  
//===---------------------------------------------------------------------===//
//   Code Shared By the two printer passes, as a mixin
//===---------------------------------------------------------------------===//

class AsmPrinter {
  GlobalIdTable* idTable;
public:
  std::ostream &toAsm;
  const TargetMachine &Target;
  
  enum Sections {
    Unknown,
    Text,
    ReadOnlyData,
    InitRWData,
    ZeroInitRWData,
  } CurSection;

  AsmPrinter(std::ostream &os, const TargetMachine &T)
    : idTable(0), toAsm(os), Target(T), CurSection(Unknown) {}
  
  // (start|end)(Module|Function) - Callback methods to be invoked by subclasses
  void startModule(Module &M) {
    // Create the global id table if it does not already exist
    idTable = (GlobalIdTable*)M.getAnnotation(GlobalIdTable::AnnotId);
    if (idTable == NULL) {
      idTable = new GlobalIdTable(&M);
      M.addAnnotation(idTable);
    }
  }
  void startFunction(Function &F) {
    // Make sure the slot table has information about this function...
    idTable->Table.incorporateFunction(&F);
  }
  void endFunction(Function &) {
    idTable->Table.purgeFunction();  // Forget all about F
  }
  void endModule() {
  }

  // Check if a value is external or accessible from external code.
  bool isExternal(const Value* V) {
    const GlobalValue *GV = dyn_cast<GlobalValue>(V);
    return GV && GV->hasExternalLinkage();
  }
  
  // enterSection - Use this method to enter a different section of the output
  // executable.  This is used to only output necessary section transitions.
  //
  void enterSection(enum Sections S) {
    if (S == CurSection) return;        // Only switch section if necessary
    CurSection = S;

    toAsm << "\n\t.section ";
    switch (S)
      {
      default: assert(0 && "Bad section name!");
      case Text:         toAsm << "\".text\""; break;
      case ReadOnlyData: toAsm << "\".rodata\",#alloc"; break;
      case InitRWData:   toAsm << "\".data\",#alloc,#write"; break;
      case ZeroInitRWData: toAsm << "\".bss\",#alloc,#write"; break;
      }
    toAsm << "\n";
  }

  static std::string getValidSymbolName(const std::string &S) {
    std::string Result;
    
    // Symbol names in Sparc assembly language have these rules:
    // (a) Must match { letter | _ | . | $ } { letter | _ | . | $ | digit }*
    // (b) A name beginning in "." is treated as a local name.
    // 
    if (isdigit(S[0]))
      Result = "ll";
    
    for (unsigned i = 0; i < S.size(); ++i)
      {
        char C = S[i];
        if (C == '_' || C == '.' || C == '$' || isalpha(C) || isdigit(C))
          Result += C;
        else
          {
            Result