// float_epsilon().

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

CL_PROVIDE(cl_F_epspos)

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

// Implementation.

#include "cl_F.h"
#include "cl_SF.h"
#include "cl_FF.h"
#include "cl_DF.h"
#include "cl_LF.h"
#include "cl_LF_impl.h"

namespace cln {

// Bei Floats mit d Bits (incl. Hiddem Bit, also d = ?F_mant_len+1)
// ist ?F_epsilon = 2^-d*(1+2^(1-d)), d.h. Mantisse 10...01, Vorzeichen +.

static const cl_SF SF_epsilon =
	make_SF(0,SF_exp_mid-SF_mant_len,bit(SF_mant_len)+1);

static const cl_FF FF_epsilon =
	encode_FF(0,-FF_mant_len,bit(FF_mant_len)+1);

static const cl_DF DF_epsilon =
	#if (cl_word_size==64)
	  encode_DF(0,-DF_mant_len,bit(DF_mant_len)+1);
	#else
	  encode_DF(0,-DF_mant_len,bit(DF_mant_len-32),1);
	#endif

inline const cl_LF LF_epsilon (uintC len)
{
	var Lfloat erg = allocate_lfloat(len,LF_exp_mid+1-intDsize*len,0);
	var uintD* ptr = &TheLfloat(erg)->data[0];
	#if CL_DS_BIG_ENDIAN_P
	  *ptr++ = bit(intDsize-1);
	  ptr = clear_loop_up(ptr,len-2);
	  *ptr = bit(0);
	#else
	  *ptr++ = bit(0);
	  ptr = clear_loop_up(ptr,len-2);
	  *ptr = bit(intDsize-1);
	#endif
	return erg;
}

const cl_F float_epsilon (float_format_t f)
{
	floatformatcase((uintC)f
	,	return SF_epsilon;
	,	return FF_epsilon;
	,	return DF_epsilon;
	,	return LF_epsilon(len);
	);
}

}  // namespace cln

CL_PROVIDE_END(cl_F_epspos)