| /* Copyright (C) 2000-2014 Free Software Foundation, Inc. |
| 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 the last occurrence 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(strrchr) |
| #ifdef PROF |
| ldgp gp, 0(pv) |
| lda AT, _mcount |
| jsr AT, (AT), _mcount |
| .prologue 1 |
| #else |
| .prologue 0 |
| #endif |
| |
| and a1, 0xff, t2 # E : 00000000000000ch |
| insbl a1, 1, t4 # U : 000000000000ch00 |
| insbl a1, 2, t5 # U : 0000000000ch0000 |
| ldq_u t0, 0(a0) # L : load first quadword Latency=3 |
| |
| mov zero, t6 # E : t6 is last match aligned addr |
| or t2, t4, a1 # E : 000000000000chch |
| sll t5, 8, t3 # U : 00000000ch000000 |
| mov zero, t8 # E : t8 is last match byte compare mask |
| |
| andnot a0, 7, v0 # E : align source addr |
| or t5, t3, t3 # E : 00000000chch0000 |
| sll a1, 32, t2 # U : 0000chch00000000 |
| sll a1, 48, t4 # U : chch000000000000 |
| |
| or t4, a1, a1 # E : chch00000000chch |
| or t2, t3, t2 # E : 0000chchchch0000 |
| or a1, t2, a1 # E : chchchchchchchch |
| lda t5, -1 # E : build garbage mask |
| |
| cmpbge zero, t0, t1 # E : bits set iff byte == zero |
| mskqh t5, a0, t4 # E : Complete garbage mask |
| xor t0, a1, t2 # E : make bytes == c zero |
| cmpbge zero, t4, t4 # E : bits set iff byte is garbage |
| |
| cmpbge zero, t2, t3 # E : bits set iff byte == c |
| andnot t1, t4, t1 # E : clear garbage from null test |
| andnot t3, t4, t3 # E : clear garbage from char test |
| bne t1, $eos # U : did we already hit the terminator? |
| |
| /* Character search main loop */ |
| $loop: |
| ldq t0, 8(v0) # L : load next quadword |
| cmovne t3, v0, t6 # E : save previous comparisons match |
| nop # : Latency=2, extra map slot (keep nop with cmov) |
| nop |
| |
| cmovne t3, t3, t8 # E : Latency=2, extra map slot |
| nop # : keep with cmovne |
| addq v0, 8, v0 # E : |
| xor t0, a1, t2 # E : |
| |
| cmpbge zero, t0, t1 # E : bits set iff byte == zero |
| cmpbge zero, t2, t3 # E : bits set iff byte == c |
| beq t1, $loop # U : if we havnt seen a null, loop |
| nop |
| |
| /* Mask out character matches after terminator */ |
| $eos: |
| negq t1, t4 # E : isolate first null byte match |
| and t1, t4, t4 # E : |
| subq t4, 1, t5 # E : build a mask of the bytes upto... |
| or t4, t5, t4 # E : ... and including the null |
| |
| and t3, t4, t3 # E : mask out char matches after null |
| cmovne t3, t3, t8 # E : save it, if match found Latency=2, extra map slot |
| nop # : Keep with cmovne |
| nop |
| |
| cmovne t3, v0, t6 # E : |
| nop # : Keep with cmovne |
| /* Locate the address of the last matched character */ |
| ctlz t8, t2 # U0 : Latency=3 (0x40 for t8=0) |
| nop |
| |
| cmoveq t8, 0x3f, t2 # E : Compensate for case when no match is seen |
| nop # E : hide the cmov latency (2) behind ctlz latency |
| lda t5, 0x3f($31) # E : |
| subq t5, t2, t5 # E : Normalize leading zero count |
| |
| addq t6, t5, v0 # E : and add to quadword address |
| ret # L0 : Latency=3 |
| nop |
| nop |
| |
| END(strrchr) |
| |
| weak_alias (strrchr, rindex) |
| libc_hidden_builtin_def (strrchr) |
