1  /* Copyright (C) 2004-2023 Free Software Foundation, Inc.
       2     Contributor: Joern Rennecke <joern.rennecke@embecosm.com>
       3  		on behalf of Synopsys Inc.
       4  
       5  This file is free software; you can redistribute it and/or modify it
       6  under the terms of the GNU General Public License as published by the
       7  Free Software Foundation; either version 3, or (at your option) any
       8  later version.
       9  
      10  In addition to the permissions in the GNU General Public License, the
      11  Free Software Foundation gives you unlimited permission to link the
      12  compiled version of this file into combinations with other programs,
      13  and to distribute those combinations without any restriction coming
      14  from the use of this file.  (The General Public License restrictions
      15  do apply in other respects; for example, they cover modification of
      16  the file, and distribution when not linked into a combine
      17  executable.)
      18  
      19  This file is distributed in the hope that it will be useful, but
      20  WITHOUT ANY WARRANTY; without even the implied warranty of
      21  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
      22  General Public License for more details.
      23  
      24  You should have received a copy of the GNU General Public License
      25  along with this program; see the file COPYING3.  If not see
      26  <http://www.gnu.org/licenses/>.  */
      27  
      28  /* Calculate division table for ARC700 integer division
      29     Contributed by Joern Rennecke
      30     joern.rennecke@arc.com  */
      31  
      32  #include <stdio.h>
      33  #include <math.h>
      34  
      35  int
      36  main ()
      37  {
      38    int i, j;
      39    unsigned x;
      40    double q, r, err, max_err = -1;
      41  
      42    puts("/* This table has been generated by divtab-arc700.c.  */");
      43    puts("\
      44  /* 1/512 .. 1/256, normalized.  There is a leading 1 in bit 31.\n\
      45     For powers of two, we list unnormalized numbers instead.  The values\n\
      46     for powers of 2 are loaded, but not used.  The value for 1 is actually\n\
      47     the first instruction after .Lmuldiv.  */\n\
      48  	.balign 4");
      49    puts (".Ldivtab:\n");
      50    for (i = 256; i >= 2; --i)
      51      {
      52        j = i < 0 ? -i : i;
      53        if (j & (j-1))
      54  	while (j < 128)
      55  	  j += j;
      56        else
      57  	/* Power of two. */
      58  	j *= 128;
      59        q = 4.*(1<<30)*128/j;
      60        r = ceil (q);
      61        printf ("\t.long\t0x%X\n", (unsigned) r);
      62        err = r - q;
      63        if (err > max_err)
      64  	max_err = err;
      65      }
      66  #if 0
      67    printf ("\t/* maximum error: %f */\n", max_err);
      68  #endif
      69    exit (0);
      70  }