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Annotation of qemu/roms/qemu-palcode/memset.c, revision 1.1.1.1

1.1       root        1: /* The standard memset function.
                      2: 
                      3:    Copyright (C) 2011 Richard Henderson
                      4: 
                      5:    This file is part of QEMU PALcode.
                      6: 
                      7:    This program is free software; you can redistribute it and/or modify
                      8:    it under the terms of the GNU General Public License as published by
                      9:    the Free Software Foundation; either version 2 of the License or
                     10:    (at your option) any later version.
                     11: 
                     12:    This program is distributed in the hope that it will be useful,
                     13:    but WITHOUT ANY WARRANTY; without even the implied warranty of
                     14:    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the text
                     15:    of the GNU General Public License for more details.
                     16: 
                     17:    You should have received a copy of the GNU General Public License
                     18:    along with this program; see the file COPYING.  If not see
                     19:    <http://www.gnu.org/licenses/>.  */
                     20: 
                     21: 
                     22: #include <string.h>
                     23: 
                     24: void *memset(void *optr, int ival, unsigned long size)
                     25: {
                     26:   unsigned long val = ival;
                     27:   void *ptr = optr;
                     28: 
                     29:   if (__builtin_expect (size == 0, 0))
                     30:     return optr;
                     31: 
                     32:   if (__builtin_expect (val != 0, 0))
                     33:     {
                     34:       val = val & 0xff;
                     35:       val |= val << 8;
                     36:       val |= val << 16;
                     37:       val |= val << 32;
                     38:     }
                     39: 
                     40:   if (__builtin_expect ((unsigned long)ptr & 1, 0))
                     41:     {
                     42:       *(char *)ptr = val;
                     43:       ptr += 1;
                     44:       size -= 1;
                     45:     }
                     46: 
                     47:   if (__builtin_expect ((unsigned long)ptr & 2, 0))
                     48:     {
                     49:       if (size < 2)
                     50:        goto tail_1;
                     51:       *(short *)ptr = val;
                     52:       ptr += 2;
                     53:       size -= 2;
                     54:     }
                     55: 
                     56:   if (__builtin_expect ((unsigned long)ptr & 4, 0))
                     57:     {
                     58:       if (size < 4)
                     59:        goto tail_3;
                     60:       *(int *)ptr = val;
                     61:       ptr += 4;
                     62:       size -= 4;
                     63:     }
                     64:   
                     65:   while (size >= 8)
                     66:     {
                     67:       *(long *)ptr = val;
                     68:       ptr += 8;
                     69:       size -= 8;
                     70:     }
                     71: 
                     72:   if (size >= 4)
                     73:     {
                     74:       *(int *)ptr = val;
                     75:       ptr += 4;
                     76:       size -= 4;
                     77:     }
                     78: 
                     79:  tail_3:
                     80:   if (size >= 2)
                     81:     {
                     82:       *(short *)ptr = val;
                     83:       ptr += 2;
                     84:       size -= 2;
                     85:     }
                     86: 
                     87:  tail_1:
                     88:   if (size > 0)
                     89:     {
                     90:       *(char *)ptr = val;
                     91:       ptr += 1;
                     92:       size -= 1;
                     93:     }
                     94: 
                     95:   return optr;
                     96: }

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