1/*        $NetBSD: bzero.S,v 1.4 2008/04/28 20:22:57 martin Exp $     */
2
3/*-
4 * Copyright (c) 2006 The NetBSD Foundation, Inc.
5 * All rights reserved.
6 *
7 * This code is derived from software contributed to The NetBSD Foundation
8 * by Ross Harvey.
9 *
10 * Redistribution and use in source and binary forms, with or without
11 * modification, are permitted provided that the following conditions
12 * are met:
13 * 1. Redistributions of source code must retain the above copyright
14 *    notice, this list of conditions and the following disclaimer.
15 * 2. Redistributions in binary form must reproduce the above copyright
16 *    notice, this list of conditions and the following disclaimer in the
17 *    documentation and/or other materials provided with the distribution.
18 *
19 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
20 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING,  BUT NOT LIMITED
21 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
22 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
23 * BE LIABLE FOR ANY DIRECT, INDIRECT,  INCIDENTAL,  SPECIAL,  EXEMPLARY,  OR
24 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,  PROCUREMENT OF
25 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA,  OR PROFITS; OR BUSINESS
26 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
27 * CONTRACT, STRICT LIABILITY,  OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
28 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
29 * POSSIBILITY OF SUCH DAMAGE.
30 */
31
32#include  <machine/asm.h>
33
34          .file     "bzero.c"
35ENTRY(bzero)
36          mr        5, 4                # translate to memcpy signature
37          li        4, 0                # add missing memcpy param
38ENTRY(memset)
39          cmpldi    7, 5, 7             # only optimize if len >= 8
40          mr        9, 3
41          ble       7, 2f
42          rldicl.   0, 3, 0, 61         # only optimize if aligned
43          beq       0, 4f
442:
45          cmpdi     7, 5, 0
46          beqlr     7
473:
48          mtctr     5
49          rldicl    0, 4, 0, 56
50          .p2align 4,, 15
512:
52          stb       0, 0(9)             # byte-at-a-time loop
53          addi      9, 9, 1
54          bdnz      2b
55          blr                           # done
564:
57          rldicl    4, 4, 0, 56         # construct parallel store
58          cmpldi    7, 5, 31
59          mr        10, 3
60          sldi      0, 4, 8
61          or        0, 0, 4
62          sldi      9, 0, 16
63          or        0, 0, 9
64          sldi      11, 0, 32
65          or        0, 0, 11
66          ble       7, 5f
67          addi      9, 5, -32
68          srdi      9, 9, 5
69          addi      9, 9, 1
70          mtctr     9
71          .p2align 4,, 15
722:
73          std       0, 0(10)  # 8-way + unrolled store loop
74          std       0, 8(10)
75          addi      5, 5, -32 # schedule count decrement
76          std       0, 16(10)
77          std       0, 24(10)
78          addi      10, 10, 32
79          bdnz      2b
80          cmpldi    7, 5, 7
81          ble       7, 8f
825:
83          addi      9, 5, -8
84          srdi      9, 9, 3
85          addi      9, 9, 1
86          mtctr     9
87          .p2align 4,, 15
8814:
89          std       0, 0(10)  # 8-way not-unrolled loop
90          addi      5, 5, -8
91          addi      10, 10, 8
92          bdnz      14b
938:
94          cmpdi     7, 5, 0
95          mr        9, 10
96          bne       7, 3b
97          blr
98          .long     0
99          .byte     0, 0, 0, 0, 0, 0, 0, 0
100          .size     .memset, .-.memset
101