| /* Optimized memcmp implementation for PowerPC476. |
| Copyright (C) 2010-2014 Free Software Foundation, Inc. |
| 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/>. */ |
| |
| #include <sysdep.h> |
| |
| /* memcmp |
| |
| r3:source1 address, return equality |
| r4:source2 address |
| r5:byte count |
| |
| Check 2 words from src1 and src2. If unequal jump to end and |
| return src1 > src2 or src1 < src2. |
| If count = zero check bytes before zero counter and then jump to end and |
| return src1 > src2, src1 < src2 or src1 = src2. |
| If src1 = src2 and no null, repeat. */ |
| |
| EALIGN (memcmp, 5, 0) |
| srwi. r6,r5,5 |
| beq L(preword2_count_loop) |
| mtctr r6 |
| clrlwi r5,r5,27 |
| |
| L(word8_compare_loop): |
| lwz r10,0(r3) |
| lwz r6,4(r3) |
| lwz r8,0(r4) |
| lwz r9,4(r4) |
| cmplw cr5,r8,r10 |
| cmplw cr1,r9,r6 |
| bne cr5,L(st2) |
| bne cr1,L(st1) |
| lwz r10,8(r3) |
| lwz r6,12(r3) |
| lwz r8,8(r4) |
| lwz r9,12(r4) |
| cmplw cr5,r8,r10 |
| cmplw cr1,r9,r6 |
| bne cr5,L(st2) |
| bne cr1,L(st1) |
| lwz r10,16(r3) |
| lwz r6,20(r3) |
| lwz r8,16(r4) |
| lwz r9,20(r4) |
| cmplw cr5,r8,r10 |
| cmplw cr1,r9,r6 |
| bne cr5,L(st2) |
| bne cr1,L(st1) |
| lwz r10,24(r3) |
| lwz r6,28(r3) |
| addi r3,r3,0x20 |
| lwz r8,24(r4) |
| lwz r9,28(r4) |
| addi r4,r4,0x20 |
| cmplw cr5,r8,r10 |
| cmplw cr1,r9,r6 |
| bne cr5,L(st2) |
| bne cr1,L(st1) |
| bdnz L(word8_compare_loop) |
| |
| L(preword2_count_loop): |
| srwi. r6,r5,3 |
| beq L(prebyte_count_loop) |
| mtctr r6 |
| clrlwi r5,r5,29 |
| |
| L(word2_count_loop): |
| lwz r10,0(r3) |
| lwz r6,4(r3) |
| addi r3,r3,0x08 |
| lwz r8,0(r4) |
| lwz r9,4(r4) |
| addi r4,r4,0x08 |
| cmplw cr5,r8,r10 |
| cmplw cr1,r9,r6 |
| bne cr5,L(st2) |
| bne cr1,L(st1) |
| bdnz L(word2_count_loop) |
| |
| L(prebyte_count_loop): |
| addi r5,r5,1 |
| mtctr r5 |
| bdz L(end_memcmp) |
| |
| L(byte_count_loop): |
| lbz r6,0(r3) |
| addi r3,r3,0x01 |
| lbz r8,0(r4) |
| addi r4,r4,0x01 |
| cmplw cr5,r8,r6 |
| bne cr5,L(st2) |
| bdnz L(byte_count_loop) |
| |
| L(end_memcmp): |
| addi r3,r0,0 |
| blr |
| |
| L(l_r): |
| addi r3,r0,1 |
| blr |
| |
| L(st1): |
| blt cr1,L(l_r) |
| addi r3,r0,-1 |
| blr |
| |
| L(st2): |
| blt cr5,L(l_r) |
| addi r3,r0,-1 |
| blr |
| END (memcmp) |
| libc_hidden_builtin_def (memcmp) |
| weak_alias (memcmp,bcmp) |
