newlib/libm/machine/amdgcn/v64df_hypot.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/mathfp/e_hypot.c in Newlib.  */
  27
  28 #include "amdgcnmach.h"
  29
  30 v64df v64df_sqrt_aux (v64df, v64di);
  31
  32 DEF_VD_MATH_FUNC (v64df, hypot, v64df x, v64df y)
  33 {
  34   FUNCTION_INIT (v64df);
  35
  36   v64df a = x;
  37   v64df b = y;
  38
  39   v64si ha;
  40   GET_HIGH_WORD (ha, x, NO_COND);
  41   ha &= 0x7fffffffL;
  42   v64si hb;
  43   GET_HIGH_WORD (hb, y, NO_COND);
  44   hb &= 0x7fffffffL;
  45
  46   VECTOR_IF (hb > ha, cond)
  47     VECTOR_COND_MOVE (a, y, cond);
  48     VECTOR_COND_MOVE (b, x, cond);
  49     v64si j = ha;
  50     VECTOR_COND_MOVE (ha, hb, cond);
  51     VECTOR_COND_MOVE (hb, j, cond);
  52   VECTOR_ENDIF
  53   SET_HIGH_WORD (a, ha, NO_COND);       /* a <- |a| */
  54   SET_HIGH_WORD (b, hb, NO_COND);       /* b <- |b| */
  55   VECTOR_IF((ha - hb) > 0x3c00000L, cond)       // x/y > 2**60 */
  56     VECTOR_RETURN (a + b, cond);
  57   VECTOR_ENDIF
  58
  59   v64si k = VECTOR_INIT (0);
  60
  61   VECTOR_IF (ha > 0x5f300000L, cond)            /* a>2**500 */
  62     VECTOR_IF2 (ha >= 0x7ff00000L, cond2, cond) /* Inf or NaN */
  63       v64df w = a + b;                  // for sNaN */
  64       v64si low;
  65       GET_LOW_WORD (low, a, cond2);
  66       VECTOR_COND_MOVE (w, a, cond2 & (((ha & 0xfffff) | low) == 0));
  67       GET_LOW_WORD (low, b, cond2);
  68       VECTOR_COND_MOVE (w, b, cond2 & (((hb & 0xfffff) | low) == 0));
  69       VECTOR_RETURN (w, cond);
  70     VECTOR_ENDIF
  71     /* scale a and b by 2**-600 */
  72     VECTOR_COND_MOVE (ha, ha - 0x25800000, cond);
  73     VECTOR_COND_MOVE (hb, hb - 0x25800000, cond);
  74     VECTOR_COND_MOVE (k, k + 600, cond);
  75     SET_HIGH_WORD (a, ha, cond);
  76     SET_HIGH_WORD (b, hb, cond);
  77   VECTOR_ENDIF
  78   VECTOR_IF (hb < 0x20b00000, cond)             /* b < 2**-500 */
  79     VECTOR_IF2 (hb <= 0x000fffff, cond2, cond)  /* subnormal b or 0 */
  80       v64si low;
  81       GET_LOW_WORD (low, b, cond);
  82       VECTOR_RETURN (a, cond2 & ((hb | low) == 0));
  83       /* t1=2^1022 */
  84       v64df t1 = VECTOR_INIT (0.0);
  85       SET_HIGH_WORD (t1, VECTOR_INIT (0x7fd00000), cond2);
  86       VECTOR_COND_MOVE (b, b * t1, cond2);
  87       VECTOR_COND_MOVE (a, a * t1, cond2);
  88       VECTOR_COND_MOVE (k, k - 1022, cond2);
  89     VECTOR_ELSE2 (cond2, cond)          /* scale a and b by 2^600 */
  90       VECTOR_COND_MOVE (ha, ha + 0x25800000, cond2);    /* a *= 2^600 */
  91       VECTOR_COND_MOVE (hb, hb + 0x25800000, cond2);    /* b *= 2^600 */
  92       VECTOR_COND_MOVE (k, k - 600, cond2);
  93       SET_HIGH_WORD (a, ha, cond2);
  94       SET_HIGH_WORD (b, hb, cond2);
  95     VECTOR_ENDIF
  96   VECTOR_ENDIF
  97   /* medium size a and b */
  98   v64df w = a - b;
  99   VECTOR_IF (w > b, cond)
 100     v64df t1 = VECTOR_INIT (0.0);
 101     SET_HIGH_WORD (t1, ha, cond);
 102     v64df t2 = a - t1;
 103     VECTOR_COND_MOVE (w, v64df_sqrt_aux (t1*t1 - (b*(-b) - t2 * (a + t1)), __mask), cond);
 104   VECTOR_ELSE (cond)
 105     VECTOR_COND_MOVE (a, a+a, cond);
 106     v64df y1 = VECTOR_INIT (0.0);
 107     SET_HIGH_WORD (y1, hb, cond);
 108     v64df y2 = b - y1;
 109     v64df t1;
 110     SET_HIGH_WORD (t1, ha + 0x00100000, cond);
 111     v64df t2 = a - t1;
 112     VECTOR_COND_MOVE (w, v64df_sqrt_aux (t1*y1 - (w*(-w) - (t1*y2 + t2*b)), __mask), cond);
 113   VECTOR_ENDIF
 114   VECTOR_IF (k != 0, cond)
 115     v64si high;
 116     v64df t1 = VECTOR_INIT (1.0);
 117     GET_HIGH_WORD (high, t1, cond);
 118     SET_HIGH_WORD (t1, high + (k << 20), cond);
 119     VECTOR_RETURN (t1 * w, cond);
 120   VECTOR_ELSE (cond)
 121     VECTOR_RETURN (w, cond);
 122   VECTOR_ENDIF
 123
 124   FUNCTION_RETURN;
 125 }
 126
 127 DEF_VARIANTS2 (hypot, df, df)