src/npymath/ieee754.c.src File Reference

#include "npy_math_common.h"
#include "npy_math_private.h"
#include "_signbit.c"

Functions
double	npy_copysign (double x, double y)
int	_npy_signbit_f (float x)
int	_npy_signbit_ld (long double x)
double	_next (double x, int p)
float	_nextf (float x, int p)
npy_longdouble	_nextl (npy_longdouble x, int p)
double	npy_nextafter (double x, double y)
float	npy_nextafterf (float x, float y)
npy_longdouble	npy_nextafterl (npy_longdouble x, npy_longdouble y)
type npy_spacing	suff (@type @x)
void	npy_set_floatstatus_divbyzero (void)
void	npy_set_floatstatus_overflow (void)
void	npy_set_floatstatus_underflow (void)
void	npy_set_floatstatus_invalid (void)
Variables
static volatile double	_npy_floatstatus_x
static volatile double	_npy_floatstatus_zero = 0.0
static volatile double	_npy_floatstatus_big = 1e300
static volatile double	_npy_floatstatus_small = 1e-300
static volatile double	_npy_floatstatus_inf

---

Function Documentation

double _next	(	double	x,
		int	p
	)

FIXME: There is a lot of redundancy between _next* and npy_nextafter*. refactor this at some point

p >= 0, returnx x + nulp p < 0, returnx x - nulp

<

|x|

Docutils System Messages

System Message: ERROR/3 (<string>, line 1); backlink Undefined substitution referenced: "x".

<

x is nan

<

x == 0

<

return +minsubnormal

<

return -minsubnormal

<

raise underflow flag

<

x -= ulp

<

x += ulp

<

overflow

<

underflow

<

raise underflow flag

References EXTRACT_WORDS, and INSERT_WORDS.

float _nextf	(	float	x,
		int	p
	)

<

|x|

Docutils System Messages

System Message: ERROR/3 (<string>, line 1); backlink Undefined substitution referenced: "x".

<

x is nan

<

x == 0

<

return +minsubnormal

<

return -minsubnormal

<

raise underflow flag

<

x -= ulp

<

x += ulp

<

overflow

<

underflow

<

raise underflow flag

npy_longdouble _nextl	(	npy_longdouble	x,
		int	p
	)

<

x is nan

<

return +-minsubnormal

<

raise underflow flag

<

x -= ulp

<

x += ulp

<

overflow

<

underflow

<

raise underflow flag

References SET_FLOAT_WORD.

int _npy_signbit_f

(

float

x

)

References _npy_signbit_d().

int _npy_signbit_ld

(

long double

x

)

References _npy_signbit_d().

double npy_copysign	(	double	x,
		double	y
	)

vim:syntax=c

Low-level routines related to IEEE-754 format

References GET_HIGH_WORD, and SET_HIGH_WORD.

Referenced by c().

double npy_nextafter	(	double	x,
		double	y
	)

nextafter code taken from BSD math lib, the code contains the following notice:

System Message: SEVERE/4 (<string>, line 4)

Missing matching underline for section title overline.

====================================================
Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.

Developed at SunPro, a Sun Microsystems, Inc. business. Permission to use, copy, modify, and distribute this software is freely granted, provided that this notice is preserved. ====================================================

<

|x|

Docutils System Messages

System Message: ERROR/3 (<string>, line 1); backlink Undefined substitution referenced: "x".

<

|y|

Docutils System Messages

System Message: ERROR/3 (<string>, line 1); backlink Undefined substitution referenced: "y".

<

x is nan

<

y is nan

<

x=y, return y

<

x == 0

<

return +-minsubnormal

<

raise underflow flag

<

x > 0

<

x > y, x -= ulp

<

x < y, x += ulp

<

x < 0

<

x < y, x -= ulp

<

x > y, x += ulp

<

overflow

<

underflow

<

raise underflow flag

Referenced by TIMEDELTA_md_m_multiply().

float npy_nextafterf	(	float	x,
		float	y
	)

<

|x|

Docutils System Messages

System Message: ERROR/3 (<string>, line 1); backlink Undefined substitution referenced: "x".

<

|y|

Docutils System Messages

System Message: ERROR/3 (<string>, line 1); backlink Undefined substitution referenced: "y".

<

x is nan

<

y is nan

<

x=y, return y

<

x == 0

<

return +-minsubnormal

<

raise underflow flag

<

x > 0

<

x > y, x -= ulp

<

x < y, x += ulp

<

x < 0

<

x < y, x -= ulp

<

x > y, x += ulp

<

overflow

<

underflow

<

raise underflow flag

References _npy_floatstatus_zero.

npy_longdouble npy_nextafterl	(	npy_longdouble	x,
		npy_longdouble	y
	)

<

x or y is nan

<

x=y, return y

<

return +-minsubnormal

<

raise underflow flag

<

x -= ulp

<

x += ulp

<

overflow

<

underflow

<

raise underflow flag

void npy_set_floatstatus_divbyzero

(

void

)

Functions that set the floating point error status word.

Referenced by _logical_not().

void npy_set_floatstatus_invalid

(

void

)

Referenced by npy_half_spacing().

void npy_set_floatstatus_overflow

(

void

)

Referenced by npy_half_spacing().

void npy_set_floatstatus_underflow

(

void

)

Referenced by npy_floatbits_to_halfbits().

type npy_spacing suff

(

@type @

x

)

begin repeat

suff = f,,l# #SUFF = F,,L# type = float, double, npy_longdouble#

XXX: npy isnan/isinf may be optimized by bit twiddling

Referenced by OBJECT_fill(), and suff().

---

Variable Documentation

volatile double _npy_floatstatus_big = 1e300

volatile double _npy_floatstatus_inf

volatile double _npy_floatstatus_small = 1e-300

volatile double _npy_floatstatus_x [static]

end repeat*

Decorate all the math functions which are available on the current platform

Functions to set the floating point status word.

By using a volatile floating point value, the compiler is forced to actually do the requested operations because of potential concurrency.

We shouldn't write multiple values to a single global here, because that would cause a race condition.

volatile double _npy_floatstatus_zero = 0.0

Referenced by npy_nextafterf().