/*
 *  dabusiness.h
 *
 *  Written by Eliot Miranda 11/07.
 *	Updated 5/2011 to cope with Cog stack direction.
 *
 * Body of the various callIA32XXXReturn functions.
 * Call a foreign function according to IA32-ish ABI rules.
 * N.B. In Cog Stack and Cogit VMs numArgs is negative to access args from
 * the downward-growing stack.
 */
	long i, size;
	sqInt funcAlien, resultMaybeAlien;
	char *argvec;
#if STACK_ALIGN_BYTES
	char *argstart;
#endif

#if STACKVM /* Need to access args downwards from first arg */
  if (numArgs < 0)
	for (i = size = 0; --i >= numArgs;) {
		sqInt arg = argVector[i+1];
		if (objIsAlien(arg) && sizeField(arg))
			size += moduloPOT(sizeof(long),abs(sizeField(arg)));
		else if (interpreterProxy->isFloatObject(arg))
			size += sizeof(double);
		else /* assume an integer or pointer.  check below. */
			size += sizeof(long);
	}
  else
#endif /* STACKVM */
	for (i = numArgs, size = 0; --i >= 0;) {
		sqInt arg = argVector[i];
		if (objIsAlien(arg) && sizeField(arg))
			size += moduloPOT(sizeof(long),abs(sizeField(arg)));
		else if (interpreterProxy->isFloatObject(arg))
			size += sizeof(double);
		else /* assume an integer or pointer.  check below. */
			size += sizeof(long);
	}

#if STACK_ALIGN_BYTES
	/* At point of call stack must be aligned to STACK_ALIGN_BYTES.  So alloca
	 * at least enough for this plus the argvector, and start writing argvector
	 * at aligned point.  Then just prior to call cut-back stack to aligned.
	 */
	argvec = alloca(STACK_ALIGN_BYTES + moduloPOT(STACK_ALIGN_BYTES,size));
	argvec = alignModuloPOT(STACK_ALIGN_BYTES, argvec);
	argstart = argvec;
#else
	argvec = alloca(moduloPOT(sizeof(long),size));
# if defined(__MINGW32__) && (__GNUC__ >= 3)
	/*
	 * cygwin & MinGW's gcc 3.4.x's alloca is a library routine that answers
	 * %esp + 4, so the outgoing stack is offset by one word if uncorrected.
	 * Grab the actual stack pointer to correct.
	 */
	argvec = getsp();
# endif
#endif

#if STACKVM /* Need to access args downwards from first arg */
  if (numArgs < 0)
	for (i = size = 0; --i >= numArgs;) {
		sqInt arg = argVector[i+1];
		if (isSmallInt(arg)) {
			*(long *)argvec = intVal(arg);
			argvec += sizeof(long);
		}
		else if (objIsAlien(arg)) {
			long  argByteSize;

			if (!(size = sizeField(arg)))
				size = argByteSize = sizeof(void *);
			else
				argByteSize = abs(size);
			memcpy(argvec, startOfDataWithSize(arg,size), argByteSize);
			argvec += moduloPOT(sizeof(long), argByteSize);
		}
		else if (objIsUnsafeAlien(arg)) {
			sqInt bitsObj = interpreterProxy->fetchPointerofObject(0,arg);
			void *v = interpreterProxy->firstIndexableField(bitsObj);
			*(void **)argvec = v;
			argvec += sizeof(long);
		}
		else if (interpreterProxy->isFloatObject(arg)) {
			double d = interpreterProxy->floatValueOf(arg);
			*(double *)argvec = d;
			argvec += sizeof(double);
		}
		else {
			long v = interpreterProxy->signed32BitValueOf(arg);
			if (interpreterProxy->failed()) {
				interpreterProxy->primitiveFailFor(0);
				v = interpreterProxy->positive32BitValueOf(arg);
				if (interpreterProxy->failed())
					return PrimErrBadArgument;
			}
			*(long *)argvec = v;
			argvec += sizeof(long);
		}
	}
  else
#endif /* STACKVM */
	for (i = 0; i < numArgs; i++) {
		sqInt arg = argVector[i];
		if (isSmallInt(arg)) {
			*(long *)argvec = intVal(arg);
			argvec += sizeof(long);
		}
		else if (objIsAlien(arg)) {
			long  argByteSize;

			if (!(size = sizeField(arg)))
				size = argByteSize = sizeof(void *);
			else
				argByteSize = abs(size);
			memcpy(argvec, startOfDataWithSize(arg,size), argByteSize);
			argvec += moduloPOT(sizeof(long), argByteSize);
		}
		else if (objIsUnsafeAlien(arg)) {
			sqInt bitsObj = interpreterProxy->fetchPointerofObject(0,arg);
			void *v = interpreterProxy->firstIndexableField(bitsObj);
			*(void **)argvec = v;
			argvec += sizeof(long);
		}
		else if (interpreterProxy->isFloatObject(arg)) {
			double d = interpreterProxy->floatValueOf(arg);
			*(double *)argvec = d;
			argvec += sizeof(double);
		}
		else {
			long v = interpreterProxy->signed32BitValueOf(arg);
			if (interpreterProxy->failed()) {
				interpreterProxy->primitiveFailFor(0);
				v = interpreterProxy->positive32BitValueOf(arg);
				if (interpreterProxy->failed())
					return PrimErrBadArgument;
			}
			*(long *)argvec = v;
			argvec += sizeof(long);
		}
	}

	funcAlien = interpreterProxy->stackValue(funcOffset);
	f = *(void **)startOfParameterData(funcAlien);
#if STACK_ALIGN_BYTES
	/* cut stack back to start of aligned args */
	setsp(argstart);
#endif
	r = f();
	/* post call need to refresh stack pointer in case of call-back and GC. */
	resultMaybeAlien = interpreterProxy->stackValue(resultOffset);
	if (objIsAlien(resultMaybeAlien)) {
		if (!(size = sizeField(resultMaybeAlien)))
			size = sizeof(void *);
		memcpy(startOfDataWithSize(resultMaybeAlien,size),
				&r,
				min((unsigned)abs(size), sizeof(r)));
	}

	return PrimNoErr;