mingw-w64-crt/math/bsd_private_base.h

/*
* ====================================================
* 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.
* ====================================================
*/

#include <inttypes.h>
#include <float.h>

typedef unsigned int u_int32_t;

typedef union
{
    double value;
    struct
    {
        u_int32_t lsw;
        u_int32_t msw;
    } parts;
} ieee_double_shape_type;

typedef union {
    float value;
    u_int32_t word;
} ieee_float_shape_type;

/* Get two 32 bit ints from a double.  */

#define EXTRACT_WORDS(ix0,ix1,d)    \
do {                                \
    ieee_double_shape_type ew_u;    \
    ew_u.value = (d);               \
    (ix0) = ew_u.parts.msw;         \
    (ix1) = ew_u.parts.lsw;         \
} while (0)

/* Get the most significant 32 bit int from a double.  */

#define GET_HIGH_WORD(i,d)          \
do {                                \
    ieee_double_shape_type gh_u;    \
    gh_u.value = (d);               \
    (i) = gh_u.parts.msw;           \
} while (0)

/* Get the less significant 32 bit int from a double.  */

#define GET_LOW_WORD(i,d)           \
do {                                \
    ieee_double_shape_type gl_u;    \
    gl_u.value = (d);               \
    (i) = gl_u.parts.lsw;           \
} while (0)

/* Set a double from two 32 bit ints.  */

#define INSERT_WORDS(d,ix0,ix1)     \
do {                                \
    ieee_double_shape_type iw_u;    \
    iw_u.parts.msw = (ix0);         \
    iw_u.parts.lsw = (ix1);         \
    (d) = iw_u.value;               \
} while (0)

/* Set the more significant 32 bits of a double from an int.  */

#define SET_HIGH_WORD(d,v)          \
do {                                \
    ieee_double_shape_type sh_u;    \
    sh_u.value = (d);               \
    sh_u.parts.msw = (v);           \
    (d) = sh_u.value;               \
} while (0)

/* Set the less significant 32 bits of a double from an int.  */

#define SET_LOW_WORD(d,v)           \
do {                                \
    ieee_double_shape_type sl_u;    \
    sl_u.value = (d);               \
    sl_u.parts.lsw = (v);           \
    (d) = sl_u.value;               \
} while (0)

#define GET_FLOAT_WORD(i,d) do \
{ \
    ieee_float_shape_type gf_u; \
    gf_u.value = (d); \
    (i) = gf_u.word; \
} while(0)

#define SET_FLOAT_WORD(d,i) do \
{ \
    ieee_float_shape_type gf_u; \
    gf_u.word = (i); \
    (d) = gf_u.value; \
} while(0)


#ifdef FLT_EVAL_METHOD
/*
 * Attempt to get strict C99 semantics for assignment with non-C99 compilers.
 */
#if FLT_EVAL_METHOD == 0 || __GNUC__ == 0
#define	STRICT_ASSIGN(type, lval, rval)	((lval) = (rval))
#else
#define	STRICT_ASSIGN(type, lval, rval) do {	\
	volatile type __lval;			\
						\
	if (sizeof(type) >= sizeof(long double))	\
		(lval) = (rval);		\
	else {					\
		__lval = (rval);		\
		(lval) = __lval;		\
	}					\
} while (0)
#endif
#endif /* FLT_EVAL_METHOD */

/*
 * Mix 0, 1 or 2 NaNs.  First add 0 to each arg.  This normally just turns
 * signaling NaNs into quiet NaNs by setting a quiet bit.  We do this
 * because we want to never return a signaling NaN, and also because we
 * don't want the quiet bit to affect the result.  Then mix the converted
 * args using the specified operation.
 *
 * When one arg is NaN, the result is typically that arg quieted.  When both
 * args are NaNs, the result is typically the quietening of the arg whose
 * mantissa is largest after quietening.  When neither arg is NaN, the
 * result may be NaN because it is indeterminate, or finite for subsequent
 * construction of a NaN as the indeterminate 0.0L/0.0L.
 *
 * Technical complications: the result in bits after rounding to the final
 * precision might depend on the runtime precision and/or on compiler
 * optimizations, especially when different register sets are used for
 * different precisions.  Try to make the result not depend on at least the
 * runtime precision by always doing the main mixing step in long double
 * precision.  Try to reduce dependencies on optimizations by adding the
 * the 0's in different precisions (unless everything is in long double
 * precision).
 */
#define nan_mix(x, y)		(nan_mix_op((x), (y), +))
#define nan_mix_op(x, y, op)	(((x) + 0.0L) op ((y) + 0))