Move target specific code to target files. The new MachineCodeEmitter

class is actually target independent!


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@6517 91177308-0d34-0410-b5e6-96231b3b80d8

6 files changed, 80 insertions, 196 deletions

diff --git a/lib/ExecutionEngine/JIT/Callback.cpp b/lib/ExecutionEngine/JIT/Callback.cpp
deleted file mode 100644
index 0cb612c..0000000
--- a/lib/ExecutionEngine/JIT/Callback.cpp
+++ /dev/null
@@ -1,82 +0,0 @@
-//===-- Callback.cpp - Trap handler for function resolution ---------------===//
-//
-// This file defines the handler which is invoked when a reference to a
-// non-codegen'd function is found.  This file defines target specific code
-// which is used by the JIT.
-//
-//===----------------------------------------------------------------------===//
-
-#include "VM.h"
-#include "Support/Statistic.h"
-#include "llvm/CodeGen/MachineCodeEmitter.h"
-#include <iostream>
-
-static VM *TheVM = 0;
-
-// CompilationCallback - Invoked the first time that a call site is found,
-// which causes lazy compilation of the target function.
-// 
-void VM::CompilationCallback() {
-#if defined(i386) || defined(__i386__) || defined(__x86__)
-  unsigned *StackPtr = (unsigned*)__builtin_frame_address(0);
-  unsigned RetAddr = (unsigned)__builtin_return_address(0);
-
-  assert(StackPtr[1] == RetAddr &&
-         "Could not find return address on the stack!");
-  bool isStub = ((unsigned char*)RetAddr)[0] == 0xCD;  // Interrupt marker?
-
-  // The call instruction should have pushed the return value onto the stack...
-  RetAddr -= 4;  // Backtrack to the reference itself...
-
-  DEBUG(std::cerr << "In callback! Addr=0x" << std::hex << RetAddr
-                  << " ESP=0x" << (unsigned)StackPtr << std::dec
-                  << ": Resolving call to function: "
-                  << TheVM->getFunctionReferencedName((void*)RetAddr) << "\n");
-
-  // Sanity check to make sure this really is a call instruction...
-  assert(((unsigned char*)RetAddr)[-1] == 0xE8 && "Not a call instr!");
-  
-  unsigned NewVal = (unsigned)TheVM->resolveFunctionReference((void*)RetAddr);
-
-  // Rewrite the call target... so that we don't fault every time we execute
-  // the call.
-  *(unsigned*)RetAddr = NewVal-RetAddr-4;    
-
-  if (isStub) {
-    // If this is a stub, rewrite the call into an unconditional branch
-    // instruction so that two return addresses are not pushed onto the stack
-    // when the requested function finally gets called.  This also makes the
-    // 0xCD byte (interrupt) dead, so the marker doesn't effect anything.
-    ((unsigned char*)RetAddr)[-1] = 0xE9;
-  }
-
-  // Change the return address to reexecute the call instruction...
-  StackPtr[1] -= 5;
-#else
-  abort();
-#endif
-}
-
-/// emitStubForFunction - This virtual method is used by the JIT when it needs
-/// to emit the address of a function for a function whose code has not yet
-/// been generated.  In order to do this, it generates a stub which jumps to
-/// the lazy function compiler, which will eventually get fixed to call the
-/// function directly.
-///
-void *VM::emitStubForFunction(const Function &F) {
-#if defined(i386) || defined(__i386__) || defined(__x86__)
-  MCE->startFunctionStub(F, 6);
-  MCE->emitByte(0xE8);   // Call with 32 bit pc-rel destination...
-  MCE->emitGlobalAddress((GlobalValue*)&F, true);
-  MCE->emitByte(0xCD);   // Interrupt - Just a marker identifying the stub!
-  return MCE->finishFunctionStub(F);
-#else
-  abort();
-#endif
-}
-
-void VM::registerCallback() {
-  TheVM = this;
-}
-
-
diff --git a/lib/ExecutionEngine/JIT/JIT.cpp b/lib/ExecutionEngine/JIT/JIT.cpp
index 95d7331..b0b6dea 100644
--- a/lib/ExecutionEngine/JIT/JIT.cpp
+++ b/lib/ExecutionEngine/JIT/JIT.cpp
@@ -43,7 +43,7 @@ ExecutionEngine *ExecutionEngine::createJIT(Module *M, unsigned Config) {
   if (Arch == "x86") {
     TargetMachineAllocator = allocateX86TargetMachine;
   } else if (Arch == "sparc") {
-    TargetMachineAllocator = allocateSparcTargetMachine;
+    //TargetMachineAllocator = allocateSparcTargetMachine;
   }
 
   if (TargetMachineAllocator) {
@@ -65,11 +65,10 @@ VM::VM(Module *M, TargetMachine *tm) : ExecutionEngine(M), TM(*tm) {
   if (Arch == "x86") {
     MCE = createX86Emitter(*this);
   } else if (Arch == "sparc") {
-    MCE = createSparcEmitter(*this);
+    //MCE = createSparcEmitter(*this);
   }
 
   setupPassManager();
-  registerCallback();
   emitGlobals();
 }
 
diff --git a/lib/ExecutionEngine/JIT/JIT.h b/lib/ExecutionEngine/JIT/JIT.h
index 58b7a38..7c378c4 100644
--- a/lib/ExecutionEngine/JIT/JIT.h
+++ b/lib/ExecutionEngine/JIT/JIT.h
@@ -22,12 +22,6 @@ class VM : public ExecutionEngine {
   PassManager PM;          // Passes to compile a function
   MachineCodeEmitter *MCE; // MCE object
 
-  // FunctionRefs - A mapping between addresses that refer to unresolved
-  // functions and the LLVM function object itself.  This is used by the fault
-  // handler to lazily patch up references...
-  //
-  std::map<void*, Function*> FunctionRefs;
-
 public:
   VM(Module *M, TargetMachine *tm);
   ~VM();
@@ -37,14 +31,6 @@ public:
   virtual int run(const std::string &FnName,
 		  const std::vector<std::string> &Args);
 
-  void addFunctionRef(void *Ref, Function *F) {
-    FunctionRefs[Ref] = F;
-  }
-
-  const std::string &getFunctionReferencedName(void *RefAddr);
-
-  void *resolveFunctionReference(void *RefAddr);
-
   /// getPointerToNamedFunction - This method returns the address of the
   /// specified function by using the dlsym function call.  As such it is only
   /// useful for resolving library symbols, not code generated symbols.
@@ -61,21 +47,14 @@ public:
   ///
   static void runAtExitHandlers();
 
+  /// getPointerToFunction - This returns the address of the specified function,
+  /// compiling it if necessary.
+  void *getPointerToFunction(const Function *F);
+
 private:
   static MachineCodeEmitter *createX86Emitter(VM &V);
   static MachineCodeEmitter *createSparcEmitter(VM &V);
   void setupPassManager();
-  void *getPointerToFunction(const Function *F);
-
-  void registerCallback();
-
-  /// emitStubForFunction - This method is used by the JIT when it needs to emit
-  /// the address of a function for a function whose code has not yet been
-  /// generated.  In order to do this, it generates a stub which jumps to the
-  /// lazy function compiler, which will eventually get fixed to call the
-  /// function directly.
-  ///
-  void *emitStubForFunction(const Function &F);
 };
 
 #endif
diff --git a/lib/ExecutionEngine/JIT/JITEmitter.cpp b/lib/ExecutionEngine/JIT/JITEmitter.cpp
index e6fe09b..215e9eb 100644
--- a/lib/ExecutionEngine/JIT/JITEmitter.cpp
+++ b/lib/ExecutionEngine/JIT/JITEmitter.cpp
@@ -13,38 +13,45 @@
 #include "llvm/Function.h"
 #include "Support/Statistic.h"
 
+static VM *TheVM = 0;
+
 namespace {
   Statistic<> NumBytes("jello", "Number of bytes of machine code compiled");
 
   class Emitter : public MachineCodeEmitter {
-    VM &TheVM;
-
+    // 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;
-    
-    std::vector<std::pair<BasicBlock*, unsigned *> > BBRefs;
-    std::map<BasicBlock*, unsigned> BBLocations;
+
+    // ConstantPoolAddresses - Contains the location for each entry in the
+    // constant pool.
     std::vector<void*> ConstantPoolAddresses;
   public:
-    Emitter(VM &vm) : TheVM(vm) {}
+    Emitter(VM &vm) { TheVM = &vm; }
 
     virtual void startFunction(MachineFunction &F);
     virtual void finishFunction(MachineFunction &F);
     virtual void emitConstantPool(MachineConstantPool *MCP);
-    virtual void startBasicBlock(MachineBasicBlock &BB);
     virtual void startFunctionStub(const Function &F, unsigned StubSize);
     virtual void* finishFunctionStub(const Function &F);
     virtual void emitByte(unsigned char B);
-    virtual void emitPCRelativeDisp(Value *V);
-    virtual void emitGlobalAddress(GlobalValue *V, bool isPCRelative);
-    virtual void emitGlobalAddress(const std::string &Name, bool isPCRelative);
-    virtual void emitFunctionConstantValueAddress(unsigned ConstantNum,
-						  int Offset);
-  private:
-    void emitAddress(void *Addr, bool isPCRelative);
+    virtual void emitWord(unsigned W);
+
+    virtual uint64_t getGlobalValueAddress(GlobalValue *V);
+    virtual uint64_t getGlobalValueAddress(const std::string &Name);
+    virtual uint64_t getConstantPoolEntryAddress(unsigned Entry);
+    virtual uint64_t getCurrentPCValue();
+
+    // forceCompilationOf - Force the compilation of the specified function, and
+    // return its address, because we REALLY need the address now.
+    //
+    // FIXME: This is JIT specific!
+    //
+    virtual uint64_t forceCompilationOf(Function *F);
   };
 }
 
@@ -66,21 +73,13 @@ static void *getMemory(unsigned NumPages) {
 
 
 void Emitter::startFunction(MachineFunction &F) {
-  CurBlock = (unsigned char *)getMemory(8);
+  CurBlock = (unsigned char *)getMemory(16);
   CurByte = CurBlock;  // Start writing at the beginning of the fn.
-  TheVM.addGlobalMapping(F.getFunction(), CurBlock);
+  TheVM->addGlobalMapping(F.getFunction(), CurBlock);
 }
 
 void Emitter::finishFunction(MachineFunction &F) {
   ConstantPoolAddresses.clear();
-  for (unsigned i = 0, e = BBRefs.size(); i != e; ++i) {
-    unsigned Location = BBLocations[BBRefs[i].first];
-    unsigned *Ref = BBRefs[i].second;
-    *Ref = Location-(unsigned)(intptr_t)Ref-4;
-  }
-  BBRefs.clear();
-  BBLocations.clear();
-
   NumBytes += CurByte-CurBlock;
 
   DEBUG(std::cerr << "Finished CodeGen of [0x" << std::hex
@@ -95,18 +94,12 @@ void Emitter::emitConstantPool(MachineConstantPool *MCP) {
     // For now we just allocate some memory on the heap, this can be
     // dramatically improved.
     const Type *Ty = ((Value*)Constants[i])->getType();
-    void *Addr = malloc(TheVM.getTargetData().getTypeSize(Ty));
-    TheVM.InitializeMemory(Constants[i], Addr);
+    void *Addr = malloc(TheVM->getTargetData().getTypeSize(Ty));
+    TheVM->InitializeMemory(Constants[i], Addr);
     ConstantPoolAddresses.push_back(Addr);
   }
 }
 
-
-void Emitter::startBasicBlock(MachineBasicBlock &BB) {
-  BBLocations[BB.getBasicBlock()] = (unsigned)(intptr_t)CurByte;
-}
-
-
 void Emitter::startFunctionStub(const Function &F, unsigned StubSize) {
   SavedCurBlock = CurBlock;  SavedCurByte = CurByte;
   // FIXME: this is a huge waste of memory.
@@ -129,6 +122,46 @@ void Emitter::emitByte(unsigned char B) {
   *CurByte++ = B;   // Write the byte to memory
 }
 
+void Emitter::emitWord(unsigned W) {
+  // FIXME: 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);
+}
+
+
+uint64_t Emitter::getGlobalValueAddress(GlobalValue *V) {
+  // Try looking up the function to see if it is already compiled, if not return
+  // 0.
+  return (intptr_t)TheVM->getPointerToGlobalIfAvailable(V);
+}
+uint64_t Emitter::getGlobalValueAddress(const std::string &Name) {
+  return (intptr_t)TheVM->getPointerToNamedFunction(Name);
+}
+
+// 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::forceCompilationOf(Function *F) {
+  return (intptr_t)TheVM->getPointerToFunction(F);
+}
+
+#if 0
+
 
 // emitPCRelativeDisp - For functions, just output a displacement that will
 // cause a reference to the zero page, which will cause a seg-fault, causing
@@ -157,23 +190,19 @@ void Emitter::emitAddress(void *Addr, bool isPCRelative) {
 void Emitter::emitGlobalAddress(GlobalValue *V, bool isPCRelative) {
   if (isPCRelative) { // must be a call, this is a major hack!
     // Try looking up the function to see if it is already compiled!
-    if (void *Addr = TheVM.getPointerToGlobalIfAvailable(V)) {
+    if (void *Addr = TheVM->getPointerToGlobalIfAvailable(V)) {
       emitAddress(Addr, isPCRelative);
     } else {  // Function has not yet been code generated!
-      TheVM.addFunctionRef(CurByte, cast<Function>(V));
+      TheVM->addFunctionRef(CurByte, cast<Function>(V));
 
       // Delayed resolution...
       emitAddress((void*)VM::CompilationCallback, isPCRelative);
     }
   } else {
-    emitAddress(TheVM.getPointerToGlobal(V), isPCRelative);
+    emitAddress(TheVM->getPointerToGlobal(V), isPCRelative);
   }
 }
 
-void Emitter::emitGlobalAddress(const std::string &Name, bool isPCRelative) {
-  emitAddress(TheVM.getPointerToNamedFunction(Name), isPCRelative);
-}
-
 void Emitter::emitFunctionConstantValueAddress(unsigned ConstantNum,
 					       int Offset) {
   assert(ConstantNum < ConstantPoolAddresses.size() &&
@@ -181,3 +210,4 @@ void Emitter::emitFunctionConstantValueAddress(unsigned ConstantNum,
   *(void**)CurByte = (char*)ConstantPoolAddresses[ConstantNum]+Offset;
   CurByte += 4;
 }
+#endif
diff --git a/lib/ExecutionEngine/JIT/VM.cpp b/lib/ExecutionEngine/JIT/VM.cpp
index c6748fa..d5815e8 100644
--- a/lib/ExecutionEngine/JIT/VM.cpp
+++ b/lib/ExecutionEngine/JIT/VM.cpp
@@ -36,22 +36,6 @@ void VM::setupPassManager() {
   }
 }
 
-void *VM::resolveFunctionReference(void *RefAddr) {
-  Function *F = FunctionRefs[RefAddr];
-  assert(F && "Reference address not known!");
-
-  void *Addr = getPointerToFunction(F);
-  assert(Addr && "Pointer to function unknown!");
-
-  FunctionRefs.erase(RefAddr);
-  return Addr;
-}
-
-const std::string &VM::getFunctionReferencedName(void *RefAddr) {
-  assert(FunctionRefs[RefAddr] && "Function address unknown!");
-  return FunctionRefs[RefAddr]->getName();
-}
-
 /// getPointerToFunction - This method is used to get the address of the
 /// specified function, compiling it if neccesary.
 ///
@@ -63,12 +47,7 @@ void *VM::getPointerToFunction(const Function *F) {
     return Addr = getPointerToNamedFunction(F->getName());
 
   static bool isAlreadyCodeGenerating = false;
-  if (isAlreadyCodeGenerating) {
-    // Generate a function stub instead of reentering...
-    void *SAddr = emitStubForFunction(*F);
-    assert(SAddr && "Target machine doesn't support function stub generation!");
-    return SAddr;
-  }
+  assert(!isAlreadyCodeGenerating && "ERROR: RECURSIVE COMPILATION DETECTED!");
 
   // FIXME: JIT all of the functions in the module.  Eventually this will JIT
   // functions on demand.  This has the effect of populating all of the
diff --git a/lib/ExecutionEngine/JIT/VM.h b/lib/ExecutionEngine/JIT/VM.h
index 58b7a38..7c378c4 100644
--- a/lib/ExecutionEngine/JIT/VM.h
+++ b/lib/ExecutionEngine/JIT/VM.h
@@ -22,12 +22,6 @@ class VM : public ExecutionEngine {
   PassManager PM;          // Passes to compile a function
   MachineCodeEmitter *MCE; // MCE object
 
-  // FunctionRefs - A mapping between addresses that refer to unresolved
-  // functions and the LLVM function object itself.  This is used by the fault
-  // handler to lazily patch up references...
-  //
-  std::map<void*, Function*> FunctionRefs;
-
 public:
   VM(Module *M, TargetMachine *tm);
   ~VM();
@@ -37,14 +31,6 @@ public:
   virtual int run(const std::string &FnName,
 		  const std::vector<std::string> &Args);
 
-  void addFunctionRef(void *Ref, Function *F) {
-    FunctionRefs[Ref] = F;
-  }
-
-  const std::string &getFunctionReferencedName(void *RefAddr);
-
-  void *resolveFunctionReference(void *RefAddr);
-
   /// getPointerToNamedFunction - This method returns the address of the
   /// specified function by using the dlsym function call.  As such it is only
   /// useful for resolving library symbols, not code generated symbols.
@@ -61,21 +47,14 @@ public:
   ///
   static void runAtExitHandlers();
 
+  /// getPointerToFunction - This returns the address of the specified function,
+  /// compiling it if necessary.
+  void *getPointerToFunction(const Function *F);
+
 private:
   static MachineCodeEmitter *createX86Emitter(VM &V);
   static MachineCodeEmitter *createSparcEmitter(VM &V);
   void setupPassManager();
-  void *getPointerToFunction(const Function *F);
-
-  void registerCallback();
-
-  /// emitStubForFunction - This method is used by the JIT when it needs to emit
-  /// the address of a function for a function whose code has not yet been
-  /// generated.  In order to do this, it generates a stub which jumps to the
-  /// lazy function compiler, which will eventually get fixed to call the
-  /// function directly.
-  ///
-  void *emitStubForFunction(const Function &F);
 };
 
 #endif