newlib/libm/machine/amdgcn/v64sf_ilogb.c

   1 /*
   2  * Copyright 2023 Siemens
   3  *
   4  * The authors hereby grant permission to use, copy, modify, distribute,
   5  * and license this software and its documentation for any purpose, provided
   6  * that existing copyright notices are retained in all copies and that this
   7  * notice is included verbatim in any distributions.  No written agreement,
   8  * license, or royalty fee is required for any of the authorized uses.
   9  * Modifications to this software may be copyrighted by their authors
  10  * and need not follow the licensing terms described here, provided that
  11  * the new terms are clearly indicated on the first page of each file where
  12  * they apply.
  13  */
  14
  15 /*
  16  * ====================================================
  17  * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.
  18  *
  19  * Developed at SunPro, a Sun Microsystems, Inc. business.
  20  * Permission to use, copy, modify, and distribute this
  21  * software is freely granted, provided that this notice
  22  * is preserved.
  23  * ====================================================
  24  */
  25
  26 /* Based on newlib/libm/common/sf_ilogb.c in Newlib.  */
  27
  28 #include "amdgcnmach.h"
  29
  30 DEF_VS_MATH_FUNC (v64si, ilogbf, v64sf x)
  31 {
  32   FUNCTION_INIT(v64si);
  33
  34   v64si hx, ix;
  35   GET_FLOAT_WORD (hx, x, NO_COND);
  36   hx &= 0x7fffffff;
  37   VECTOR_IF (FLT_UWORD_IS_ZERO (hx), cond)
  38     VECTOR_RETURN (VECTOR_INIT (-__INT_MAX__), cond);  // FP_ILOGB0
  39   VECTOR_ENDIF
  40   VECTOR_IF (FLT_UWORD_IS_SUBNORMAL (hx), cond)
  41     ix = VECTOR_INIT (-126);
  42     for (v64si i = (hx << 8);
  43        !ALL_ZEROES_P (cond & (i > 0));
  44        i <<= 1)
  45       VECTOR_COND_MOVE (ix, ix - 1, cond & (i > 0));
  46     VECTOR_RETURN (ix, cond);
  47   VECTOR_ELSEIF (~FLT_UWORD_IS_FINITE (hx), cond)
  48     VECTOR_RETURN (VECTOR_INIT (__INT_MAX__), cond);
  49   VECTOR_ENDIF
  50
  51   VECTOR_RETURN ((hx >> 23) - 127, NO_COND);
  52
  53   FUNCTION_RETURN;
  54 }
  55
  56 DEF_VARIANTS (ilogbf, si, sf)