| /* Optimized strcpy 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> |
| |
| /* strcpy |
| |
| Register Use |
| r3:destination and return address |
| r4:source address |
| r10:temp destination address |
| |
| Implementation description |
| Loop by checking 2 words at a time, with dlmzb. Check if there is a null |
| in the 2 words. If there is a null jump to end checking to determine |
| where in the last 8 bytes it is. Copy the appropriate bytes of the last |
| 8 according to the null position. */ |
| |
| EALIGN (strcpy, 5, 0) |
| neg r7,r4 |
| subi r4,r4,1 |
| clrlwi. r8,r7,29 |
| subi r10,r3,1 |
| beq L(pre_word8_loop) |
| mtctr r8 |
| |
| L(loop): |
| lbzu r5,0x01(r4) |
| cmpi cr5,r5,0x0 |
| stbu r5,0x01(r10) |
| beq cr5,L(end_strcpy) |
| bdnz L(loop) |
| |
| L(pre_word8_loop): |
| subi r4,r4,3 |
| subi r10,r10,3 |
| |
| L(word8_loop): |
| lwzu r5,0x04(r4) |
| lwzu r6,0x04(r4) |
| dlmzb. r11,r5,r6 |
| bne L(byte_copy) |
| stwu r5,0x04(r10) |
| stwu r6,0x04(r10) |
| lwzu r5,0x04(r4) |
| lwzu r6,0x04(r4) |
| dlmzb. r11,r5,r6 |
| bne L(byte_copy) |
| stwu r5,0x04(r10) |
| stwu r6,0x04(r10) |
| lwzu r5,0x04(r4) |
| lwzu r6,0x04(r4) |
| dlmzb. r11,r5,r6 |
| bne L(byte_copy) |
| stwu r5,0x04(r10) |
| stwu r6,0x04(r10) |
| lwzu r5,0x04(r4) |
| lwzu r6,0x04(r4) |
| dlmzb. r11,r5,r6 |
| bne L(byte_copy) |
| stwu r5,0x04(r10) |
| stwu r6,0x04(r10) |
| b L(word8_loop) |
| |
| L(last_bytes_copy): |
| stwu r5,0x04(r10) |
| subi r11,r11,4 |
| mtctr r11 |
| addi r10,r10,3 |
| subi r4,r4,1 |
| |
| L(last_bytes_copy_loop): |
| lbzu r5,0x01(r4) |
| stbu r5,0x01(r10) |
| bdnz L(last_bytes_copy_loop) |
| blr |
| |
| L(byte_copy): |
| blt L(last_bytes_copy) |
| mtctr r11 |
| addi r10,r10,3 |
| subi r4,r4,5 |
| |
| L(last_bytes_copy_loop2): |
| lbzu r5,0x01(r4) |
| stbu r5,0x01(r10) |
| bdnz L(last_bytes_copy_loop2) |
| |
| L(end_strcpy): |
| blr |
| END (strcpy) |
| libc_hidden_builtin_def (strcpy) |
