| xf.li | bdd93d5 | 2023-05-12 07:10:14 -0700 | [diff] [blame] | 1 | /* Copyright (C) 1996-2016 Free Software Foundation, Inc. |
| 2 | This file is part of the GNU C Library. |
| 3 | Contributed by Richard Henderson (rth@tamu.edu) |
| 4 | |
| 5 | The GNU C Library is free software; you can redistribute it and/or |
| 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. |
| 9 | |
| 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 |
| 13 | Lesser General Public License for more details. |
| 14 | |
| 15 | You should have received a copy of the GNU Lesser General Public |
| 16 | License along with the GNU C Library. If not, see |
| 17 | <http://www.gnu.org/licenses/>. */ |
| 18 | |
| 19 | /* Return the address of a given character within a null-terminated |
| 20 | string, or null if it is not found. |
| 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) |
| 33 | #ifdef PROF |
| 34 | ldgp gp, 0(pv) |
| 35 | lda AT, _mcount |
| 36 | jsr AT, (AT), _mcount |
| 37 | .prologue 1 |
| 38 | #else |
| 39 | .prologue 0 |
| 40 | #endif |
| 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) |
| 94 | libc_hidden_builtin_def (strchr) |