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688903eb | 1 | /* Copyright (C) 1996-2018 Free Software Foundation, Inc. |
60c74cf0 | 2 | This file is part of the GNU C Library. |
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3 | Contributed by Richard Henderson (rth@tamu.edu) |
4 | ||
60c74cf0 | 5 | The GNU C Library is free software; you can redistribute it and/or |
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6 | modify it under the terms of the GNU Lesser General Public |
7 | License as published by the Free Software Foundation; either | |
8 | version 2.1 of the License, or (at your option) any later version. | |
cf182b58 | 9 | |
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10 | The GNU C Library is distributed in the hope that it will be useful, |
11 | but WITHOUT ANY WARRANTY; without even the implied warranty of | |
12 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
3214b89b | 13 | Lesser General Public License for more details. |
cf182b58 | 14 | |
3214b89b | 15 | You should have received a copy of the GNU Lesser General Public |
ab84e3ff PE |
16 | License along with the GNU C Library. If not, see |
17 | <http://www.gnu.org/licenses/>. */ | |
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18 | |
19 | /* Return the address of a given character within a null-terminated | |
60c74cf0 | 20 | string, or null if it is not found. |
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21 | |
22 | This is generally scheduled for the EV5 (got to look out for my own | |
23 | interests :-), but with EV4 needs in mind. There *should* be no more | |
24 | stalls for the EV4 than there are for the EV5. | |
25 | */ | |
26 | ||
27 | #include <sysdep.h> | |
28 | ||
29 | .set noreorder | |
30 | .set noat | |
31 | ||
32 | ENTRY(strchr) | |
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33 | #ifdef PROF |
34 | ldgp gp, 0(pv) | |
35 | lda AT, _mcount | |
36 | jsr AT, (AT), _mcount | |
37 | .prologue 1 | |
38 | #else | |
cf182b58 | 39 | .prologue 0 |
60c74cf0 | 40 | #endif |
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41 | |
42 | zapnot a1, 1, a1 # e0 : zero extend the search character | |
43 | ldq_u t0, 0(a0) # .. e1 : load first quadword | |
44 | sll a1, 8, t5 # e0 : replicate the search character | |
45 | andnot a0, 7, v0 # .. e1 : align our loop pointer | |
46 | or t5, a1, a1 # e0 : | |
47 | lda t4, -1 # .. e1 : build garbage mask | |
48 | sll a1, 16, t5 # e0 : | |
49 | cmpbge zero, t0, t2 # .. e1 : bits set iff byte == zero | |
50 | mskqh t4, a0, t4 # e0 : | |
51 | or t5, a1, a1 # .. e1 : | |
52 | sll a1, 32, t5 # e0 : | |
53 | cmpbge zero, t4, t4 # .. e1 : bits set iff byte is garbage | |
54 | or t5, a1, a1 # e0 : | |
55 | xor t0, a1, t1 # .. e1 : make bytes == c zero | |
56 | cmpbge zero, t1, t3 # e0 : bits set iff byte == c | |
57 | or t2, t3, t0 # e1 : bits set iff char match or zero match | |
58 | andnot t0, t4, t0 # e0 : clear garbage bits | |
59 | bne t0, $found # .. e1 (zdb) | |
60 | ||
61 | $loop: ldq t0, 8(v0) # e0 : | |
62 | addq v0, 8, v0 # .. e1 : | |
63 | nop # e0 : | |
64 | xor t0, a1, t1 # .. e1 (ev5 data stall) | |
65 | cmpbge zero, t0, t2 # e0 : bits set iff byte == 0 | |
66 | cmpbge zero, t1, t3 # .. e1 : bits set iff byte == c | |
67 | or t2, t3, t0 # e0 : | |
68 | beq t0, $loop # .. e1 (zdb) | |
69 | ||
70 | $found: negq t0, t1 # e0 : clear all but least set bit | |
71 | and t0, t1, t0 # e1 (stall) | |
72 | ||
73 | and t0, t3, t1 # e0 : bit set iff byte was the char | |
74 | beq t1, $retnull # .. e1 (zdb) | |
75 | ||
76 | and t0, 0xf0, t2 # e0 : binary search for that set bit | |
77 | and t0, 0xcc, t3 # .. e1 : | |
78 | and t0, 0xaa, t4 # e0 : | |
79 | cmovne t2, 4, t2 # .. e1 : | |
80 | cmovne t3, 2, t3 # e0 : | |
81 | cmovne t4, 1, t4 # .. e1 : | |
82 | addq t2, t3, t2 # e0 : | |
83 | addq v0, t4, v0 # .. e1 : | |
84 | addq v0, t2, v0 # e0 : | |
85 | ret # .. e1 : | |
86 | ||
87 | $retnull: | |
88 | mov zero, v0 # e0 : | |
89 | ret # .. e1 : | |
90 | ||
91 | END(strchr) | |
92 | ||
93 | weak_alias (strchr, index) | |
79b7c863 | 94 | libc_hidden_builtin_def (strchr) |