llvm-6502/tools/jello/GlobalVars.cpp
2002-12-13 13:15:36 +00:00

108 lines
3.8 KiB
C++

//===-- GlobalVars.cpp - Code to emit global variables to memory ----------===//
//
// This file contains the code to generate global variables to memory.
//
//===----------------------------------------------------------------------===//
#include "llvm/Module.h"
#include "llvm/DerivedTypes.h"
#include "llvm/Constants.h"
#include "llvm/Target/TargetMachine.h"
#include "Support/Statistic.h"
#include "VM.h"
#include <iostream>
/// EmitGlobals - Emit all of the global variables to memory, storing their
/// addresses into GlobalAddress. This must make sure to copy the contents of
/// their initializers into the memory.
///
void VM::emitGlobals() {
const TargetData &TD = TM.getTargetData();
// Loop over all of the global variables in the program, allocating the memory
// to hold them.
for (Module::giterator I = M.gbegin(), E = M.gend(); I != E; ++I)
if (!I->isExternal()) {
// Get the type of the global...
const Type *Ty = I->getType()->getElementType();
// Allocate some memory for it!
GlobalAddress[I] = new char[TD.getTypeSize(Ty)];
DEBUG(std::cerr << "Allocated global '" << I->getName()
<< "' to addr 0x" << std::hex << GlobalAddress[I] << std::dec
<< "\n");
} else {
assert(0 && "References to external globals not handled yet!");
}
// Now that all of the globals are set up in memory, loop through them all and
// initialize their contents.
for (Module::giterator I = M.gbegin(), E = M.gend(); I != E; ++I)
if (!I->isExternal())
emitConstantToMemory(I->getInitializer(), GlobalAddress[I]);
}
/// emitConstantToMemory - Use the specified LLVM constant to initialize the
/// specified region of memory.
///
void VM::emitConstantToMemory(Constant *Init, void *Addr) {
const TargetData &TD = TM.getTargetData();
if (ConstantIntegral *CI = dyn_cast<ConstantIntegral>(Init)) {
switch (CI->getType()->getPrimitiveID()) {
case Type::BoolTyID:
*(char*)Addr = cast<ConstantBool>(CI)->getValue();
return;
case Type::UByteTyID:
*(unsigned char*)Addr = cast<ConstantUInt>(CI)->getValue();
return;
case Type::SByteTyID:
*( signed char*)Addr = cast<ConstantSInt>(CI)->getValue();
return;
case Type::UShortTyID:
*(unsigned short*)Addr = cast<ConstantUInt>(CI)->getValue();
return;
case Type::ShortTyID:
*( signed short*)Addr = cast<ConstantSInt>(CI)->getValue();
return;
case Type::UIntTyID:
*(unsigned int*)Addr = cast<ConstantUInt>(CI)->getValue();
return;
case Type::IntTyID:
*( signed int*)Addr = cast<ConstantSInt>(CI)->getValue();
return;
case Type::ULongTyID:
*(uint64_t*)Addr = cast<ConstantUInt>(CI)->getValue();
return;
case Type::LongTyID:
*(int64_t*)Addr = cast<ConstantSInt>(CI)->getValue();
return;
default: break;
}
} else if (ConstantFP *CF = dyn_cast <ConstantFP> (Init)) {
switch (CF->getType ()->getPrimitiveID ()) {
case Type::FloatTyID:
*(float*)Addr = CF->getValue ();
return;
case Type::DoubleTyID:
*(double*)Addr = CF->getValue ();
return;
default: break;
}
} else if (ConstantPointerNull *CP = dyn_cast <ConstantPointerNull> (Init)) {
// Fill the space with a NULL pointer.
*(void **)Addr = NULL;
return;
} else if (ConstantArray *CA = dyn_cast<ConstantArray>(Init)) {
unsigned ElementSize = TD.getTypeSize(CA->getType()->getElementType());
for (unsigned i = 0, e = CA->getType()->getNumElements(); i != e; ++i) {
emitConstantToMemory(cast<Constant>(CA->getOperand(i)), Addr);
Addr = (char*)Addr+ElementSize;
}
return;
}
std::cerr << "Offending constant: " << Init << "\n";
assert(0 && "Don't know how to emit this constant to memory!");
}