path: root/lib/ExecutionEngine/Interpreter/Execution.cpp

//===-- Execution.cpp - Implement code to simulate the program ------------===//
// 
//  This file contains the actual instruction interpreter.
//
//===----------------------------------------------------------------------===//

#include "Interpreter.h"
#include "ExecutionAnnotations.h"
#include "llvm/Module.h"
#include "llvm/Instructions.h"
#include "llvm/DerivedTypes.h"
#include "llvm/Constants.h"
#include "llvm/Assembly/Writer.h"
#include "Support/CommandLine.h"
#include "Support/Statistic.h"
#include <cmath>  // For fmod

Interpreter *TheEE = 0;

namespace {
  Statistic<> NumDynamicInsts("lli", "Number of dynamic instructions executed");

  cl::opt<bool>
  QuietMode("quiet", cl::desc("Do not emit any non-program output"),
	    cl::init(true));

  cl::alias 
  QuietModeA("q", cl::desc("Alias for -quiet"), cl::aliasopt(QuietMode));

  cl::opt<bool>
  ArrayChecksEnabled("array-checks", cl::desc("Enable array bound checks"));
}

// Create a TargetData structure to handle memory addressing and size/alignment
// computations
//
CachedWriter CW;     // Object to accelerate printing of LLVM


//===----------------------------------------------------------------------===//
//                     Value Manipulation code
//===----------------------------------------------------------------------===//

static unsigned getOperandSlot(Value *V) {
  SlotNumber *SN = (SlotNumber*)V->getAnnotation(SlotNumberAID);
  assert(SN && "Operand does not have a slot number annotation!");
  return SN->SlotNum;
}

// Operations used by constant expr implementations...
static GenericValue executeCastOperation(Value *Src, const Type *DestTy,
                                         ExecutionContext &SF);
static GenericValue executeAddInst(GenericValue Src1, GenericValue Src2, 
				   const Type *Ty);


GenericValue Interpreter::getOperandValue(Value *V, ExecutionContext &SF) {
  if (ConstantExpr *CE = dyn_cast<ConstantExpr>(V)) {
    switch (CE->getOpcode()) {
    case Instruction::Cast:
      return executeCastOperation(CE->getOperand(0), CE->getType(), SF);
    case Instruction::GetElementPtr:
      return TheEE->executeGEPOperation(CE->getOperand(0), CE->op_begin()+1,
					CE->op_end(), SF);
    case Instruction::Add:
      return executeAddInst(getOperandValue(CE->getOperand(0), SF),
                            getOperandValue(CE->getOperand(1), SF),
                            CE->getType());
    default:
      std::cerr << "Unhandled ConstantExpr: " << CE << "\n";
      abort();
      return GenericValue();
    }
  } else if (Constant *CPV = dyn_cast<Constant>(V)) {
    return TheEE->getConstantValue(CPV);
  } else if (GlobalValue *GV = dyn_cast<GlobalValue>(V)) {
    return PTOGV(TheEE->getPointerToGlobal(GV));
  } else {
    unsigned TyP = V->getType()->getUniqueID();   // TypePlane for value
    unsigned OpSlot = getOperandSlot(V);
    assert(TyP < SF.Values.size() && 
           OpSlot < SF.Values[TyP].size() && "Value out of range!");
    return SF.Values[TyP][getOperandSlot(V)];
  }
}

static void SetValue(Value *V, GenericValue Val, ExecutionContext &SF) {
  unsigned TyP = V->getType()->getUniqueID();   // TypePlane for value

  //std::cout << "Setting value: " << &SF.Values[TyP][getOperandSlot(V)]<< "\n";
  SF.Values[TyP][getOperandSlot(V)] = Val;
}

//===----------------------------------------------------------------------===//
//                    Annotation Wrangling code
//===----------------------------------------------------------------------===//

void Interpreter::initializeExecutionEngine() {
  TheEE = this;
}

//===----------------------------------------------------------------------===//
//                    Binary Instruction Implementations
//===----------------------------------------------------------------------===//

#define IMPLEMENT_BINARY_OPERATOR(OP, TY) \
   case Type::TY##TyID: Dest.TY##Val = Src1.TY##Val OP Src2.TY##Val; break

static GenericValue executeAddInst(GenericValue Src1, GenericValue Src2, 
				   const Type *Ty) {
  GenericValue Dest;
  switch (Ty->getPrimitiveID()) {
    IMPLEMENT_BINARY_OPERATOR(+, UByte);
    IMPLEMENT_BINARY_OPERATOR(