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/* GSL - Generic Sound Layer
* Copyright (C) 1999, 2001 Tim Janik
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General
* Public License along with this library; if not, write to the
* Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
* Boston, MA 02110-1301, USA.
*/
#ifndef __GSL_IEEE754_H__
#define __GSL_IEEE754_H__
#include <gsl/gsldefs.h>
#ifdef __cplusplus
extern "C" {
#endif /* __cplusplus */
/* IEEE 754 single precision floating point layout:
* 31 30 23 22 0
* +--------+---------------+---------------+
* | s 1bit | e[30:23] 8bit | f[22:0] 23bit |
* +--------+---------------+---------------+
* B0------------------->B1------->B2-->B3-->
*
* IEEE 754 double precision floating point layout:
* 63 62 52 51 32 31 0
* +--------+----------------+----------------+ +---------------+
* | s 1bit | e[62:52] 11bit | f[51:32] 20bit | | f[31:0] 32bit |
* +--------+----------------+----------------+ +---------------+
* B0--------------->B1---------->B2--->B3----> B4->B5->B6->B7->
*/
/* floating point type related constants */
#define GSL_FLOAT_BIAS (127)
#define GSL_FLOAT_MAX_NORMAL (3.40282347e+38) /* 7f7fffff */
#define GSL_FLOAT_MIN_NORMAL (1.17549435e-38) /* 00800000 */
#define GSL_FLOAT_MAX_SUBNORMAL (1.17549421e-38) /* 007fffff */
#define GSL_FLOAT_MIN_SUBNORMAL (1.40129846e-45) /* 00000001 */
#define GSL_DOUBLE_BIAS (1023)
#define GSL_DOUBLE_MAX_NORMAL (1.7976931348623157e+308) /* 7fefffff ffffffff */
#define GSL_DOUBLE_MIN_NORMAL (2.2250738585072014e-308) /* 00100000 00000000 */
#define GSL_DOUBLE_MAX_SUBNORMAL (2.2250738585072009e-308) /* 000fffff ffffffff */
#define GSL_DOUBLE_MIN_SUBNORMAL (4.9406564584124654e-324) /* 00000000 00000001 */
#define GSL_DOUBLE_INF (_gsl_dinf_union.d)
#define GSL_DOUBLE_NAN (_gsl_dnan_union.d)
#define GSL_FLOAT_INF (_gsl_finf_union.f)
#define GSL_FLOAT_NAN (_gsl_fnan_union.f)
/* multiply with base2 exponent to get base10 exponent (for nomal numbers) */
#define GSL_LOG_2_BASE_10 (0.30102999566398119521)
/* the following macros work only on variables
* and evaluate arguments multiple times
*/
/* single precision value checks */
#define GSL_FLOAT_IS_ZERO(f) ((f) == 0.0) /* compiler knows this one */
#define GSL_FLOAT_IS_NORMAL(f) (GSL_FLOAT_PARTS (f).mpn.biased_exponent > 0 && \
GSL_FLOAT_PARTS (f).mpn.biased_exponent < 255)
#define GSL_FLOAT_IS_SUBNORMAL(f) (GSL_FLOAT_PARTS (f).mpn.biased_exponent == 0 && \
GSL_FLOAT_PARTS (f).mpn.mantissa != 0)
#define GSL_FLOAT_IS_NANINF(f) (GSL_FLOAT_PARTS (f).mpn.biased_exponent == 255)
#define GSL_FLOAT_IS_NAN(f) (GSL_FLOAT_IS_NANINF (f) && GSL_FLOAT_PARTS (f).mpn.mantissa != 0)
#define GSL_FLOAT_IS_INF(f) (GSL_FLOAT_IS_NANINF (f) && GSL_FLOAT_PARTS (f).mpn.mantissa == 0)
#define GSL_FLOAT_IS_INF_POSITIVE(f) (GSL_FLOAT_IS_INF (f) && GSL_FLOAT_PARTS (f).mpn.sign == 0)
#define GSL_FLOAT_IS_INF_NEGATIVE(f) (GSL_FLOAT_IS_INF (f) && GSL_FLOAT_PARTS (f).mpn.sign == 1)
#define GSL_FLOAT_SIGN(f) (GSL_FLOAT_PARTS (f).mpn.sign)
/* double precision value checks */
#define GSL_DOUBLE_IS_ZERO(d) ((d) == 0.0) /* compiler knows this one */
#define GSL_DOUBLE_IS_NORMAL(d) (GSL_DOUBLE_PARTS (d).mpn.biased_exponent > 0 && \
GSL_DOUBLE_PARTS (d).mpn.biased_exponent < 2047)
#define GSL_DOUBLE_IS_SUBNORMAL(d) (GSL_DOUBLE_PARTS (d).mpn.biased_exponent == 0 && \
(GSL_DOUBLE_PARTS (d).mpn.mantissa_low != 0 || \
GSL_DOUBLE_PARTS (d).mpn.mantissa_high != 0))
#define GSL_DOUBLE_IS_NANINF(d) (GSL_DOUBLE_PARTS (d).mpn.biased_exponent == 2047)
#define GSL_DOUBLE_IS_NAN(d) (GSL_DOUBLE_IS_NANINF (d) && \
(GSL_DOUBLE_PARTS (d).mpn.mantissa_low != 0 || \
GSL_DOUBLE_PARTS (d).mpn.mantissa_high != 0))
#define GSL_DOUBLE_IS_INF(d) (GSL_DOUBLE_IS_NANINF (d) && \
GSL_DOUBLE_PARTS (d).mpn.mantissa_low == 0 && \
GSL_DOUBLE_PARTS (d).mpn.mantissa_high == 0)
#define GSL_DOUBLE_IS_INF_POSITIVE(d) (GSL_DOUBLE_IS_INF (d) && GSL_DOUBLE_PARTS (d).mpn.sign == 0)
#define GSL_DOUBLE_IS_INF_NEGATIVE(d) (GSL_DOUBLE_IS_INF (d) && GSL_DOUBLE_PARTS (d).mpn.sign == 1)
#define GSL_DOUBLE_SIGN(d) (GSL_DOUBLE_PARTS (d).mpn.sign)
/* get structured parts of floating point numbers */
#define GSL_FLOAT_PARTS(f) (*((GslFloatIEEE754*) &(f)))
#define GSL_DOUBLE_PARTS(d) (*((GslDoubleIEEE754*) &(d)))
/* --- rounding --- */
typedef unsigned short int GslFpuState;
#if defined (__i386__) && defined (__GNUC__)
/* setting/restoring rounding mode shouldn't actually
* be necessary as round-to-nearest is the hardware
* default (can be checked with gsl_fpu_okround()).
*/
static inline void gsl_fpu_setround (GslFpuState *cw);
static inline int gsl_fpu_okround (void);
static inline void gsl_fpu_restore (GslFpuState cv);
static inline int gsl_ftoi /* nearest */ (register float f) G_GNUC_CONST;
static inline int gsl_dtoi /* nearest */ (register double f) G_GNUC_CONST;
/* fallbacks for the !386 case are below */
#endif
/* --- implementation bits --- */
#if G_BYTE_ORDER == G_LITTLE_ENDIAN
typedef union
{
float v_float;
struct {
unsigned int mantissa : 23;
unsigned int biased_exponent : 8;
unsigned int sign : 1;
} mpn;
} GslFloatIEEE754;
typedef union
{
double v_double;
struct {
unsigned int mantissa_low : 32;
unsigned int mantissa_high : 20;
unsigned int biased_exponent : 11;
unsigned int sign : 1;
} mpn;
} GslDoubleIEEE754;
#define _GSL_DOUBLE_INF_BYTES { 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0xf0, 0x7f }
#define _GSL_DOUBLE_NAN_BYTES { 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0xf8, 0x7f }
#define _GSL_FLOAT_INF_BYTES { 0x00, 0x00, 0x80, 0x7f }
#define _GSL_FLOAT_NAN_BYTES { 0x00, 0x00, 0xc0, 0x7f }
#elif G_BYTE_ORDER == G_BIG_ENDIAN
typedef union
{
float v_float;
struct {
unsigned int sign : 1;
unsigned int biased_exponent : 8;
unsigned int mantissa : 23;
} mpn;
} GslFloatIEEE754;
typedef union
{
double v_double;
struct {
unsigned int sign : 1;
unsigned int biased_exponent : 11;
unsigned int mantissa_high : 20;
unsigned int mantissa_low : 32;
} mpn;
} GslDoubleIEEE754;
#define _GSL_DOUBLE_INF_BYTES { 0x7f, 0xf0, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 }
#define _GSL_DOUBLE_NAN_BYTES { 0x7f, 0xf8, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 }
#define _GSL_FLOAT_INF_BYTES { 0x7f, 0x80, 0x00, 0x00 }
#define _GSL_FLOAT_NAN_BYTES { 0x7f, 0xc0, 0x00, 0x00 }
#else /* !G_LITTLE_ENDIAN && !G_BIG_ENDIAN */
#error unknown ENDIAN type
#endif /* !G_LITTLE_ENDIAN && !G_BIG_ENDIAN */
static const union { unsigned char c[8]; double d; } _gsl_dnan_union = { _GSL_DOUBLE_NAN_BYTES };
static const union { unsigned char c[8]; double d; } _gsl_dinf_union = { _GSL_DOUBLE_INF_BYTES };
static const union { unsigned char c[4]; float f; } _gsl_fnan_union = { _GSL_FLOAT_NAN_BYTES };
static const union { unsigned char c[4]; float f; } _gsl_finf_union = { _GSL_FLOAT_INF_BYTES };
#if defined (__i386__) && defined (__GNUC__)
static inline void
gsl_fpu_setround (GslFpuState *cw)
{
GslFpuState cv;
__asm__ ("fnstcw %0"
: "=m" (*&cv));
*cw = cv;
cv &= ~0x0c00;
__asm__ ("fldcw %0"
:
: "m" (*&cv));
}
static inline int
gsl_fpu_okround (void)
{
GslFpuState cv;
__asm__ ("fnstcw %0"
: "=m" (*&cv));
return !(cv & 0x0c00);
}
static inline void
gsl_fpu_restore (GslFpuState cv)
{
__asm__ ("fldcw %0"
:
: "m" (*&cv));
}
static inline int G_GNUC_CONST
gsl_ftoi (register float f)
{
int r;
__asm__ ("fistl %0"
: "=m" (r)
: "t" (f));
return r;
}
static inline int G_GNUC_CONST
gsl_dtoi (register double f)
{
int r;
__asm__ ("fistl %0"
: "=m" (r)
: "t" (f));
return r;
}
#else /* !386 */
# define gsl_fpu_setround(p) ((void) (p));
# define gsl_fpu_okround() (1)
# define gsl_fpu_restore(x) /* nop */
static inline int G_GNUC_CONST
gsl_ftoi (register float v)
{
return v < -0.0 ? v - 0.5 : v + 0.5;
}
static inline int G_GNUC_CONST
gsl_dtoi (register double v)
{
return v < -0.0 ? v - 0.5 : v + 0.5;
}
#endif
#ifdef __cplusplus
}
#endif /* __cplusplus */
#endif /* __GSL_IEEE754_H__ */ /* vim: set ts=8 sw=2 sts=2: */
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