// cl_I_to_L().

// General includes.
#include "cl_sysdep.h"

// Specification.
#include "cln/integer.h"


// Implementation.

#include "cln/number.h"
#include "cl_I.h"
#include "cl_DS.h"
#include "cln/io.h"
#include "cln/integer_io.h"
#include "cln/abort.h"

namespace cln {

sint32 cl_I_to_L (const cl_I& obj)
{
	if (fixnump(obj))
		// Fixnum
		return FN_to_L(obj);
    {	// Bignum
	var cl_heap_bignum* bn = TheBignum(obj);
	var uintC len = bn->length;
	if ((sintD)mspref(arrayMSDptr(bn->data,len),0) >= 0) {
		// Bignum > 0
		#define IF_LENGTH(i)  \
		  if (bn_minlength <= i) /* genau i Digits überhaupt möglich? */\
		    if (len == i) /* genau i Digits? */				\
		      /* 2^((i-1)*intDsize-1) <= obj < 2^(i*intDsize-1) */	\
		      if ( (i*intDsize > 32)					\
		           && ( ((i-1)*intDsize >= 32)				\
		                || (mspref(arrayMSDptr(bn->data,len),0) >= (uintD)bitc(31-(i-1)*intDsize)) \
		         )    )							\
		        goto bad;						\
			else
		IF_LENGTH(1)
			return get_uint1D_Dptr(arrayLSDptr(bn->data,1));
		IF_LENGTH(2)
			return get_uint2D_Dptr(arrayLSDptr(bn->data,2));
		IF_LENGTH(3)
			return get_uint3D_Dptr(arrayLSDptr(bn->data,3));
		IF_LENGTH(4)
			return get_uint4D_Dptr(arrayLSDptr(bn->data,4));
		#undef IF_LENGTH
	} else {
		// Bignum < 0
		#define IF_LENGTH(i)  \
		  if (bn_minlength <= i) /* genau i Digits überhaupt möglich? */\
		    if (len == i) /* genau i Digits? */				\
		      /* - 2^(i*intDsize-1) <= obj < - 2^((i-1)*intDsize-1) */	\
		      if ( (i*intDsize > 32)					\
		           && ( ((i-1)*intDsize >= 32)				\
		                || (mspref(arrayMSDptr(bn->data,len),0) < (uintD)(-bitc(31-(i-1)*intDsize))) \
		         )    )							\
		        goto bad;						\
			else
		IF_LENGTH(1)
			return get_sint1D_Dptr(arrayLSDptr(bn->data,1));
		IF_LENGTH(2)
			return get_sint2D_Dptr(arrayLSDptr(bn->data,2));
		IF_LENGTH(3)
			return get_sint3D_Dptr(arrayLSDptr(bn->data,3));
		IF_LENGTH(4)
			return get_sint4D_Dptr(arrayLSDptr(bn->data,4));
		#undef IF_LENGTH
	}
	bad: // unpassendes Objekt
	fprint(std::cerr, "Not a 32-bit integer: ");
	fprint(std::cerr, obj);
	fprint(std::cerr, "\n");
	cl_abort();
    }
}

}  // namespace cln