Rename Emitter.cpp -> JITEmitter.cpp

llvm-svn: 18132

1 files changed, 0 insertions, 425 deletions

diff --git a/llvm/lib/ExecutionEngine/JIT/Emitter.cpp b/llvm/lib/ExecutionEngine/JIT/Emitter.cpp
deleted file mode 100644
index 50ec2e11d25..00000000000
--- a/llvm/lib/ExecutionEngine/JIT/Emitter.cpp
+++ /dev/null
@@ -1,425 +0,0 @@
-//===-- Emitter.cpp - Write machine code to executable memory -------------===//
-// 
-//                     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 defines a MachineCodeEmitter object that is used by the JIT to
-// write machine code to memory and remember where relocatable values are.
-//
-//===----------------------------------------------------------------------===//
-
-#define DEBUG_TYPE "jit"
-#include "JIT.h"
-#include "llvm/Constant.h"
-#include "llvm/Module.h"
-#include "llvm/CodeGen/MachineCodeEmitter.h"
-#include "llvm/CodeGen/MachineFunction.h"
-#include "llvm/CodeGen/MachineConstantPool.h"
-#include "llvm/CodeGen/MachineRelocation.h"
-#include "llvm/Target/TargetData.h"
-#include "llvm/Target/TargetJITInfo.h"
-#include "llvm/Support/Debug.h"
-#include "llvm/ADT/Statistic.h"
-#include "llvm/System/Memory.h"
-using namespace llvm;
-
-namespace {
-  Statistic<> NumBytes("jit", "Number of bytes of machine code compiled");
-  JIT *TheJIT = 0;
-}
-
-
-//===----------------------------------------------------------------------===//
-// JITMemoryManager code.
-//
-namespace {
-  /// JITMemoryManager - Manage memory for the JIT code generation in a logical,
-  /// sane way.  This splits a large block of MAP_NORESERVE'd memory into two
-  /// sections, one for function stubs, one for the functions themselves.  We
-  /// have to do this because we may need to emit a function stub while in the
-  /// middle of emitting a function, and we don't know how large the function we
-  /// are emitting is.  This never bothers to release the memory, because when
-  /// we are ready to destroy the JIT, the program exits.
-  class JITMemoryManager {
-    sys::MemoryBlock  MemBlock;  // Virtual memory block allocated RWX
-    unsigned char *MemBase;      // Base of block of memory, start of stub mem
-    unsigned char *FunctionBase; // Start of the function body area
-    unsigned char *CurStubPtr, *CurFunctionPtr;
-  public:
-    JITMemoryManager();
-    
-    inline unsigned char *allocateStub(unsigned StubSize);
-    inline unsigned char *startFunctionBody();
-    inline void endFunctionBody(unsigned char *FunctionEnd);    
-  };
-}
-
-JITMemoryManager::JITMemoryManager() {
-  // Allocate a 16M block of memory...
-  MemBlock = sys::Memory::AllocateRWX((16 << 20));
-  MemBase = reinterpret_cast<unsigned char*>(MemBlock.base());
-  FunctionBase = MemBase + 512*1024; // Use 512k for stubs
-
-  // Allocate stubs backwards from the function base, allocate functions forward
-  // from the function base.
-  CurStubPtr = CurFunctionPtr = FunctionBase;
-}
-
-unsigned char *JITMemoryManager::allocateStub(unsigned StubSize) {
-  CurStubPtr -= StubSize;
-  if (CurStubPtr < MemBase) {
-    std::cerr << "JIT ran out of memory for function stubs!\n";
-    abort();
-  }
-  return CurStubPtr;
-}
-
-unsigned char *JITMemoryManager::startFunctionBody() {
-  // Round up to an even multiple of 8 bytes, this should eventually be target
-  // specific.
-  return (unsigned char*)(((intptr_t)CurFunctionPtr + 7) & ~7);
-}
-
-void JITMemoryManager::endFunctionBody(unsigned char *FunctionEnd) {
-  assert(FunctionEnd > CurFunctionPtr);
-  CurFunctionPtr = FunctionEnd;
-}
-
-//===----------------------------------------------------------------------===//
-// JIT lazy compilation code.
-//
-namespace {
-  /// JITResolver - Keep track of, and resolve, call sites for functions that
-  /// have not yet been compiled.
-  class JITResolver {
-    /// MCE - The MachineCodeEmitter to use to emit stubs with.
-    MachineCodeEmitter &MCE;
-
-    /// LazyResolverFn - The target lazy resolver function that we actually
-    /// rewrite instructions to use.
-    TargetJITInfo::LazyResolverFn LazyResolverFn;
-
-    // FunctionToStubMap - Keep track of the stub created for a particular
-    // function so that we can reuse them if necessary.
-    std::map<Function*, void*> FunctionToStubMap;
-
-    // StubToFunctionMap - Keep track of the function that each stub corresponds
-    // to.
-    std::map<void*, Function*> StubToFunctionMap;
-
-  public:
-    JITResolver(MachineCodeEmitter &mce) : MCE(mce) {
-      LazyResolverFn =
-        TheJIT->getJITInfo().getLazyResolverFunction(JITCompilerFn);
-    }
-
-    /// getFunctionStub - This returns a pointer to a function stub, creating
-    /// one on demand as needed.
-    void *getFunctionStub(Function *F);
-
-    /// AddCallbackAtLocation - If the target is capable of rewriting an
-    /// instruction without the use of a stub, record the location of the use so
-    /// we know which function is being used at the location.
-    void *AddCallbackAtLocation(Function *F, void *Location) {
-      /// Get the target-specific JIT resolver function.
-      StubToFunctionMap[Location] = F;
-      return (void*)LazyResolverFn;
-    }
-
-    /// JITCompilerFn - This function is called to resolve a stub to a compiled
-    /// address.  If the LLVM Function corresponding to the stub has not yet
-    /// been compiled, this function compiles it first.
-    static void *JITCompilerFn(void *Stub);
-  };
-}
-
-/// getJITResolver - This function returns the one instance of the JIT resolver.
-///
-static JITResolver &getJITResolver(MachineCodeEmitter *MCE = 0) {
-  static JITResolver TheJITResolver(*MCE);
-  return TheJITResolver;
-}
-
-/// getFunctionStub - This returns a pointer to a function stub, creating
-/// one on demand as needed.
-void *JITResolver::getFunctionStub(Function *F) {
-  // If we already have a stub for this function, recycle it.
-  void *&Stub = FunctionToStubMap[F];
-  if (Stub) return Stub;
-
-  // Call the lazy resolver function unless we already KNOW it is an external
-  // function, in which case we just skip the lazy resolution step.
-  void *Actual = (void*)LazyResolverFn;
-  if (F->hasExternalLinkage())
-    Actual = TheJIT->getPointerToFunction(F);
-    
-  // Otherwise, codegen a new stub.  For now, the stub will call the lazy
-  // resolver function.
-  Stub = TheJIT->getJITInfo().emitFunctionStub(Actual, MCE);
-
-  if (F->hasExternalLinkage()) {
-    // If we are getting the stub for an external function, we really want the
-    // address of the stub in the GlobalAddressMap for the JIT, not the address
-    // of the external function.
-    TheJIT->updateGlobalMapping(F, Stub);
-  }
-
-  DEBUG(std::cerr << "JIT: Stub emitted at [" << Stub << "] for function '"
-                  << F->getName() << "'\n");
-
-  // Finally, keep track of the stub-to-Function mapping so that the
-  // JITCompilerFn knows which function to compile!
-  StubToFunctionMap[Stub] = F;
-  return Stub;
-}
-
-/// JITCompilerFn - This function is called when a lazy compilation stub has
-/// been entered.  It looks up which function this stub corresponds to, compiles
-/// it if necessary, then returns the resultant function pointer.
-void *JITResolver::JITCompilerFn(void *Stub) {
-  JITResolver &JR = getJITResolver();
-  
-  // The address given to us for the stub may not be exactly right, it might be
-  // a little bit after the stub.  As such, use upper_bound to find it.
-  std::map<void*, Function*>::iterator I =
-    JR.StubToFunctionMap.upper_bound(Stub);
-  assert(I != JR.StubToFunctionMap.begin() && "This is not a known stub!");
-  Function *F = (--I)->second;
-
-  // The target function will rewrite the stub so that the compilation callback
-  // function is no longer called from this stub.
-  JR.StubToFunctionMap.erase(I);
-
-  DEBUG(std::cerr << "JIT: Lazily resolving function '" << F->getName()
-                  << "' In stub ptr = " << Stub << " actual ptr = "
-                  << I->first << "\n");
-
-  void *Result = TheJIT->getPointerToFunction(F);
-
-  // We don't need to reuse this stub in the future, as F is now compiled.
-  JR.FunctionToStubMap.erase(F);
-
-  // FIXME: We could rewrite all references to this stub if we knew them.
-  return Result;
-}
-
-
-//===----------------------------------------------------------------------===//
-// JIT MachineCodeEmitter code.
-//
-namespace {
-  /// Emitter - The JIT implementation of the MachineCodeEmitter, which is used
-  /// to output functions to memory for execution.
-  class Emitter : public MachineCodeEmitter {
-    JITMemoryManager MemMgr;
-
-    // CurBlock - The start of the current block of memory.  CurByte - The
-    // current byte being emitted to.
-    unsigned char *CurBlock, *CurByte;
-
-    // When outputting a function stub in the context of some other function, we
-    // save CurBlock and CurByte here.
-    unsigned char *SavedCurBlock, *SavedCurByte;
-
-    // ConstantPoolAddresses - Contains the location for each entry in the
-    // constant pool.
-    std::vector<void*> ConstantPoolAddresses;
-
-    /// Relocations - These are the relocations that the function needs, as
-    /// emitted.
-    std::vector<MachineRelocation> Relocations;
-  public:
-    Emitter(JIT &jit) { TheJIT = &jit; }
-
-    virtual void startFunction(MachineFunction &F);
-    virtual void finishFunction(MachineFunction &F);
-    virtual void emitConstantPool(MachineConstantPool *MCP);
-    virtual void startFunctionStub(unsigned StubSize);
-    virtual void* finishFunctionStub(const Function *F);
-    virtual void emitByte(unsigned char B);
-    virtual void emitWord(unsigned W);
-    virtual void emitWordAt(unsigned W, unsigned *Ptr);
-
-    virtual void addRelocation(const MachineRelocation &MR) {
-      Relocations.push_back(MR);
-    }
-
-    virtual uint64_t getCurrentPCValue();
-    virtual uint64_t getCurrentPCOffset();
-    virtual uint64_t getConstantPoolEntryAddress(unsigned Entry);
-
-  private:
-    void *getPointerToGlobal(GlobalValue *GV, void *Reference, bool NoNeedStub);
-  };
-}
-
-MachineCodeEmitter *JIT::createEmitter(JIT &jit) {
-  return new Emitter(jit);
-}
-
-void *Emitter::getPointerToGlobal(GlobalValue *V, void *Reference,
-                                  bool DoesntNeedStub) {
-  if (GlobalVariable *GV = dyn_cast<GlobalVariable>(V)) {
-    /// FIXME: If we straightened things out, this could actually emit the
-    /// global immediately instead of queuing it for codegen later!
-    GlobalVariable *GV = cast<GlobalVariable>(V);
-    return TheJIT->getOrEmitGlobalVariable(GV);
-  }
-
-  // If we have already compiled the function, return a pointer to its body.
-  Function *F = cast<Function>(V);
-  void *ResultPtr = TheJIT->getPointerToGlobalIfAvailable(F);
-  if (ResultPtr) return ResultPtr;
-
-  if (F->hasExternalLinkage()) {
-    // If this is an external function pointer, we can force the JIT to
-    // 'compile' it, which really just adds it to the map.
-    if (DoesntNeedStub)
-      return TheJIT->getPointerToFunction(F);
-
-    return getJITResolver(this).getFunctionStub(F);
-  }
-
-  // Okay, the function has not been compiled yet, if the target callback
-  // mechanism is capable of rewriting the instruction directly, prefer to do
-  // that instead of emitting a stub.
-  if (DoesntNeedStub)
-    return getJITResolver(this).AddCallbackAtLocation(F, Reference);
-
-  // Otherwise, we have to emit a lazy resolving stub.
-  return getJITResolver(this).getFunctionStub(F);
-}
-
-void Emitter::startFunction(MachineFunction &F) {
-  CurByte = CurBlock = MemMgr.startFunctionBody();
-  TheJIT->addGlobalMapping(F.getFunction(), CurBlock);
-}
-
-void Emitter::finishFunction(MachineFunction &F) {
-  MemMgr.endFunctionBody(CurByte);
-  ConstantPoolAddresses.clear();
-  NumBytes += CurByte-CurBlock;
-
-  if (!Relocations.empty()) {
-    // Resolve the relocations to concrete pointers.
-    for (unsigned i = 0, e = Relocations.size(); i != e; ++i) {
-      MachineRelocation &MR = Relocations[i];
-      void *ResultPtr;
-      if (MR.isString())
-        ResultPtr = TheJIT->getPointerToNamedFunction(MR.getString());
-      else
-        ResultPtr = getPointerToGlobal(MR.getGlobalValue(),
-                                       CurBlock+MR.getMachineCodeOffset(),
-                                       MR.doesntNeedFunctionStub());
-      MR.setResultPointer(ResultPtr);
-    }
-
-    TheJIT->getJITInfo().relocate(CurBlock, &Relocations[0],
-                                  Relocations.size());
-  }
-
-  DEBUG(std::cerr << "JIT: Finished CodeGen of [" << (void*)CurBlock
-                  << "] Function: " << F.getFunction()->getName()
-                  << ": " << CurByte-CurBlock << " bytes of text, "
-                  << Relocations.size() << " relocations\n");
-  Relocations.clear();
-}
-
-void Emitter::emitConstantPool(MachineConstantPool *MCP) {
-  const std::vector<Constant*> &Constants = MCP->getConstants();
-  if (Constants.empty()) return;
-
-  std::vector<unsigned> ConstantOffset;
-  ConstantOffset.reserve(Constants.size());
-
-  // Calculate how much space we will need for all the constants, and the offset
-  // each one will live in.
-  unsigned TotalSize = 0;
-  for (unsigned i = 0, e = Constants.size(); i != e; ++i) {
-    const Type *Ty = Constants[i]->getType();
-    unsigned Size      = TheJIT->getTargetData().getTypeSize(Ty);
-    unsigned Alignment = TheJIT->getTargetData().getTypeAlignment(Ty);
-    // Make sure to take into account the alignment requirements of the type.
-    TotalSize = (TotalSize + Alignment-1) & ~(Alignment-1);
-
-    // Remember the offset this element lives at.
-    ConstantOffset.push_back(TotalSize);
-    TotalSize += Size;   // Reserve space for the constant.
-  }
-
-  // Now that we know how much memory to allocate, do so.
-  char *Pool = new char[TotalSize];
-
-  // Actually output all of the constants, and remember their addresses.
-  for (unsigned i = 0, e = Constants.size(); i != e; ++i) {
-    void *Addr = Pool + ConstantOffset[i];
-    TheJIT->InitializeMemory(Constants[i], Addr);
-    ConstantPoolAddresses.push_back(Addr);
-  }
-}
-
-void Emitter::startFunctionStub(unsigned StubSize) {
-  SavedCurBlock = CurBlock;  SavedCurByte = CurByte;
-  CurByte = CurBlock = MemMgr.allocateStub(StubSize);
-}
-
-void *Emitter::finishFunctionStub(const Function *F) {
-  NumBytes += CurByte-CurBlock;
-  std::swap(CurBlock, SavedCurBlock);
-  CurByte = SavedCurByte;
-  return SavedCurBlock;
-}
-
-void Emitter::emitByte(unsigned char B) {
-  *CurByte++ = B;   // Write the byte to memory
-}
-
-void Emitter::emitWord(unsigned W) {
-  // This won't work if the endianness of the host and target don't agree!  (For
-  // a JIT this can't happen though.  :)
-  *(unsigned*)CurByte = W;
-  CurByte += sizeof(unsigned);
-}
-
-void Emitter::emitWordAt(unsigned W, unsigned *Ptr) {
-  *Ptr = W;
-}
-
-// getConstantPoolEntryAddress - Return the address of the 'ConstantNum' entry
-// in the constant pool that was last emitted with the 'emitConstantPool'
-// method.
-//
-uint64_t Emitter::getConstantPoolEntryAddress(unsigned ConstantNum) {
-  assert(ConstantNum < ConstantPoolAddresses.size() &&
-	 "Invalid ConstantPoolIndex!");
-  return (intptr_t)ConstantPoolAddresses[ConstantNum];
-}
-
-// getCurrentPCValue - This returns the address that the next emitted byte
-// will be output to.
-//
-uint64_t Emitter::getCurrentPCValue() {
-  return (intptr_t)CurByte;
-}
-
-uint64_t Emitter::getCurrentPCOffset() {
-  return (intptr_t)CurByte-(intptr_t)CurBlock;
-}
-
-// getPointerToNamedFunction - This function is used as a global wrapper to
-// JIT::getPointerToNamedFunction for the purpose of resolving symbols when
-// bugpoint is debugging the JIT. In that scenario, we are loading an .so and
-// need to resolve function(s) that are being mis-codegenerated, so we need to
-// resolve their addresses at runtime, and this is the way to do it.
-extern "C" {
-  void *getPointerToNamedFunction(const char *Name) {
-    Module &M = TheJIT->getModule();
-    if (Function *F = M.getNamedFunction(Name))
-      return TheJIT->getPointerToFunction(F);
-    return TheJIT->getPointerToNamedFunction(Name);
-  }
-}