1/* Copyright (C) 2000-2022 Free Software Foundation, Inc.
2 This file is part of the GNU C Library.
3
4 The GNU C Library is free software; you can redistribute it and/or
5 modify it under the terms of the GNU Lesser General Public
6 License as published by the Free Software Foundation; either
7 version 2.1 of the License, or (at your option) any later version.
8
9 The GNU C Library is distributed in the hope that it will be useful,
10 but WITHOUT ANY WARRANTY; without even the implied warranty of
11 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
12 Lesser General Public License for more details.
13
14 You should have received a copy of the GNU Lesser General Public
15 License along with the GNU C Library. If not, see
16 <https://www.gnu.org/licenses/>. */
17
18/* Return pointer to first occurrence of CH in STR. */
19
20#include <sysdep.h>
21
22 .set noreorder
23 .set noat
24
25ENTRY(__rawmemchr)
26#ifdef PROF
27 ldgp gp, 0(pv)
28 lda AT, _mcount
29 jsr AT, (AT), _mcount
30 .prologue 1
31#else
32 .prologue 0
33#endif
34
35 zapnot a1, 1, a1 # e0 : zero extend the search character
36 ldq_u t0, 0(a0) # .. e1 : load first quadword
37 sll a1, 8, t5 # e0 : replicate the search character
38 andnot a0, 7, v0 # .. e1 : align our loop pointer
39
40 or t5, a1, a1 # e0 :
41 lda t4, -1 # .. e1 : build garbage mask
42 sll a1, 16, t5 # e0 :
43 unop # :
44
45 mskqh t4, a0, t4 # e0 :
46 or t5, a1, a1 # .. e1 :
47 sll a1, 32, t5 # e0 :
48 cmpbge zero, t4, t4 # .. e1 : bits set iff byte is garbage
49
50 or t5, a1, a1 # e0 :
51 xor t0, a1, t1 # .. e1 : make bytes == c zero
52 cmpbge zero, t1, t3 # e0 : bits set iff byte == c
53 unop # :
54
55 andnot t3, t4, t0 # e0 : clear garbage bits
56 fnop # .. fa :
57 unop # :
58 bne t0, $found # .. e1 (zdb)
59
60 .align 4
61$loop:
62 ldq t0, 8(v0) # e0 :
63 addq v0, 8, v0 # .. e1 :
64 nop # e0 :
65 xor t0, a1, t1 # .. e1 (ev5 data stall)
66
67 cmpbge zero, t1, t0 # e0 : bits set iff byte == c
68 beq t0, $loop # .. e1 (zdb)
69
70$found:
71 negq t0, t1 # e0 : clear all but least set bit
72 and t0, t1, t0 # e1 (stall)
73 and t0, 0xf0, t2 # e0 : binary search for that set bit
74 and t0, 0xcc, t3 # .. e1 :
75
76 and t0, 0xaa, t4 # e0 :
77 cmovne t2, 4, t2 # .. e1 :
78 cmovne t3, 2, t3 # e0 :
79 cmovne t4, 1, t4 # .. e1 :
80
81 addq t2, t3, t2 # e0 :
82 addq v0, t4, v0 # .. e1 :
83 addq v0, t2, v0 # e0 :
84 ret # .. e1 :
85
86 END(__rawmemchr)
87
88libc_hidden_def (__rawmemchr)
89weak_alias (__rawmemchr, rawmemchr)
90

source code of glibc/sysdeps/alpha/rawmemchr.S