newlib/libm/machine/amdgcn/v64df_rint.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/s_rint.c in Newlib.  */
  27
  28 #include "amdgcnmach.h"
  29
  30 static const double TWO52[2] = {
  31   4.50359962737049600000e+15, /* 0x43300000, 0x00000000 */
  32  -4.50359962737049600000e+15, /* 0xC3300000, 0x00000000 */
  33 };
  34
  35 DEF_VD_MATH_FUNC (v64df, rint, v64df x)
  36 {
  37   FUNCTION_INIT (v64df);
  38
  39   v64si i0, i1;
  40   EXTRACT_WORDS (i0, i1, x);
  41   v64si sx = (i0 >> 31) & 1;
  42   v64df two52 = VECTOR_MERGE (VECTOR_INIT (TWO52[1]), VECTOR_INIT (TWO52[0]), sx != 0);
  43   v64si j0 = ((i0 >> 20) & 0x7ff) - 0x3ff;
  44   v64si i;
  45   VECTOR_IF (j0 < 20, cond)
  46     VECTOR_IF2 (j0 < 0, cond2, cond)
  47       VECTOR_RETURN (x, cond2 & (((i0 & 0x7fffffff) | i1) == 0));
  48       VECTOR_COND_MOVE (i1, i1 | (i0 & 0x0fffff), cond2);
  49       VECTOR_COND_MOVE (i0, i0 & 0xfffe0000, cond2);
  50       VECTOR_COND_MOVE (i0, i0 | (((i1 | -i1) >> 12) & 0x80000), cond2);
  51       SET_HIGH_WORD (x, i0, cond2);
  52       v64df w = two52 + x;
  53       v64df t = w - two52;
  54       GET_HIGH_WORD (i0, t, cond2);
  55       SET_HIGH_WORD (t, (i0&0x7fffffff)|(sx<<31), cond2);
  56       VECTOR_RETURN (t, cond2);
  57     VECTOR_ELSE2 (cond2, cond)
  58       i = (0x000fffff) >> j0;
  59       VECTOR_RETURN (x, cond2 & (((i0 & i) | i1) == 0));      /* x is integral */
  60       i >>= 1;
  61       VECTOR_IF2 (((i0 & i) | i1) != 0, cond3, cond2)
  62         VECTOR_COND_MOVE (i1, CAST_VECTOR(v64si, VECTOR_INIT (0x80000000)), cond3 & (j0 == 19));
  63         VECTOR_COND_MOVE (i1, VECTOR_INIT (0), cond3 & (j0 != 19));
  64         VECTOR_COND_MOVE (i0, (i0 & (~i)) | ((0x40000) >> j0), cond3);
  65       VECTOR_ENDIF
  66     VECTOR_ENDIF
  67   VECTOR_ELSEIF (j0 > 51, cond)
  68     VECTOR_RETURN (x + x, cond & (j0 == 0x400));
  69     VECTOR_RETURN (x, cond);
  70   VECTOR_ELSE (cond)
  71     i = CAST_VECTOR (v64si, VECTOR_INIT (0xffffffff) >> (j0 - 20));
  72     VECTOR_RETURN (x, cond & ((i1 & i) == 0));
  73     i >>= 1;
  74     VECTOR_COND_MOVE (i1, (i1 & (~i)) | (0x40000000 >> (j0 - 20)), cond & ((i1 & i) != 0));
  75   VECTOR_ENDIF
  76   INSERT_WORDS (x, i0, i1, NO_COND);
  77   v64df w = two52 + x;
  78   VECTOR_RETURN (w - two52, NO_COND);
  79
  80   FUNCTION_RETURN;
  81 }
  82
  83 DEF_VARIANTS (rint, df, df)