newlib-cygwin/newlib/libm/machine/amdgcn/v64df_scalbn.c

73 lines
2.6 KiB
C

/*
* Copyright 2023 Siemens
*
* The authors hereby grant permission to use, copy, modify, distribute,
* and license this software and its documentation for any purpose, provided
* that existing copyright notices are retained in all copies and that this
* notice is included verbatim in any distributions. No written agreement,
* license, or royalty fee is required for any of the authorized uses.
* Modifications to this software may be copyrighted by their authors
* and need not follow the licensing terms described here, provided that
* the new terms are clearly indicated on the first page of each file where
* they apply.
*/
/*
* ====================================================
* 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.
* ====================================================
*/
/* Based on newlib/libm/common/s_scalbn.c in Newlib. */
#include "amdgcnmach.h"
#include <limits.h>
#include <float.h>
static const double
two54 = 1.80143985094819840000e+16, /* 0x43500000, 0x00000000 */
twom54 = 5.55111512312578270212e-17, /* 0x3C900000, 0x00000000 */
huge = 1.0e+300,
tiny = 1.0e-300;
v64df v64df_copysign_aux (v64df, v64df, v64di);
DEF_VD_MATH_FUNC (v64df, scalbn, v64df x, v64si n)
{
FUNCTION_INIT (v64df);
const v64df huge_v = VECTOR_INIT ((double) huge);
const v64df tiny_v = VECTOR_INIT ((double) tiny);
v64si hx, lx;
EXTRACT_WORDS (hx, lx, x);
v64si k =(hx&0x7ff00000)>>20; /* extract exponent */
VECTOR_IF (k == 0, cond) /* 0 or subnormal x */
VECTOR_RETURN (x, cond & ((lx|(hx&0x7fffffff))==0)); /* +- 0 */
VECTOR_COND_MOVE (x, x * two54, cond);
GET_HIGH_WORD (hx, x, cond);
VECTOR_COND_MOVE (k, ((hx&0x7ff00000)>>20) - 54, cond);
VECTOR_RETURN (tiny*x, cond & (n < -50000)); /*underflow*/
VECTOR_ENDIF
VECTOR_RETURN (x+x, k == 0x7ff); /* NaN or Inf */
/* in case integer overflow in n+k */
VECTOR_RETURN (huge_v * v64df_copysign_aux (huge_v, x, __mask), n > 50000);
k = k + n;
VECTOR_RETURN (huge_v * v64df_copysign_aux (huge_v, x, __mask), k > 0x7fe);
VECTOR_IF (k > 0, cond) /* normal result */
SET_HIGH_WORD (x, (hx&0x800fffff)|(k<<20), cond);
VECTOR_RETURN (x, cond);
VECTOR_ENDIF
VECTOR_RETURN (tiny_v * v64df_copysign_aux (tiny_v, x, __mask), k <= -54); /*underflow*/
k += 54; /* subnormal result */
SET_HIGH_WORD (x, (hx&0x800fffff)|(k<<20), NO_COND);
VECTOR_RETURN (x * twom54, NO_COND);
FUNCTION_RETURN;
}