| /* Copyright (C) 2000-2018 Free Software Foundation, Inc. |
| Contributed by Richard Henderson <rth@tamu.edu>, 1996. |
| EV67 optimized by Rick Gorton <rick.gorton@alpha-processor.com>. |
| This file is part of the GNU C Library. |
| |
| The GNU C Library is free software; you can redistribute it and/or |
| modify it under the terms of the GNU Lesser General Public |
| License as published by the Free Software Foundation; either |
| version 2.1 of the License, or (at your option) any later version. |
| |
| The GNU C Library is distributed in the hope that it will be useful, |
| but WITHOUT ANY WARRANTY; without even the implied warranty of |
| MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
| Lesser General Public License for more details. |
| |
| You should have received a copy of the GNU Lesser General Public |
| License along with the GNU C Library. If not, see |
| <http://www.gnu.org/licenses/>. */ |
| |
| /* Return the address of a given character within a null-terminated |
| string, or null if it is not found. */ |
| |
| #include <sysdep.h> |
| |
| .arch ev6 |
| .set noreorder |
| .set noat |
| |
| ENTRY(strchr) |
| #ifdef PROF |
| ldgp gp, 0(pv) |
| lda AT, _mcount |
| jsr AT, (AT), _mcount |
| .prologue 1 |
| #else |
| .prologue 0 |
| #endif |
| |
| ldq_u t0, 0(a0) # L : load first quadword Latency=3 |
| and a1, 0xff, t3 # E : 00000000000000ch |
| insbl a1, 1, t5 # U : 000000000000ch00 |
| insbl a1, 7, a2 # U : ch00000000000000 |
| |
| insbl t3, 6, a3 # U : 00ch000000000000 |
| or t5, t3, a1 # E : 000000000000chch |
| andnot a0, 7, v0 # E : align our loop pointer |
| lda t4, -1 # E : build garbage mask |
| |
| mskqh t4, a0, t4 # U : only want relevant part of first quad |
| or a2, a3, a2 # E : chch000000000000 |
| inswl a1, 2, t5 # E : 00000000chch0000 |
| inswl a1, 4, a3 # E : 0000chch00000000 |
| |
| or a1, a2, a1 # E : chch00000000chch |
| or a3, t5, t5 # E : 0000chchchch0000 |
| cmpbge zero, t0, t2 # E : bits set iff byte == zero |
| cmpbge zero, t4, t4 # E : bits set iff byte is garbage |
| |
| /* This quad is _very_ serialized. Lots of stalling happens */ |
| or t5, a1, a1 # E : chchchchchchchch |
| xor t0, a1, t1 # E : make bytes == c zero |
| cmpbge zero, t1, t3 # E : bits set iff byte == c |
| or t2, t3, t0 # E : bits set iff char match or zero match |
| |
| andnot t0, t4, t0 # E : clear garbage bits |
| cttz t0, a2 # U0 : speculative (in case we get a match) |
| nop # E : |
| bne t0, $found # U : |
| |
| /* |
| * Yuk. This loop is going to stall like crazy waiting for the |
| * data to be loaded. Not much can be done about it unless it's |
| * unrolled multiple times, which is generally unsafe. |
| */ |
| $loop: |
| ldq t0, 8(v0) # L : Latency=3 |
| addq v0, 8, v0 # E : |
| xor t0, a1, t1 # E : |
| cmpbge zero, t0, t2 # E : bits set iff byte == 0 |
| |
| cmpbge zero, t1, t3 # E : bits set iff byte == c |
| or t2, t3, t0 # E : |
| cttz t3, a2 # U0 : speculative (in case we get a match) |
| beq t0, $loop # U : |
| |
| $found: |
| negq t0, t1 # E : clear all but least set bit |
| and t0, t1, t0 # E : |
| and t0, t3, t1 # E : bit set iff byte was the char |
| addq v0, a2, v0 # E : Add in the bit number from above |
| |
| cmoveq t1, $31, v0 # E : Two mapping slots, latency = 2 |
| nop |
| nop |
| ret # L0 : |
| |
| END(strchr) |
| |
| weak_alias (strchr, index) |
| libc_hidden_builtin_def (strchr) |
