| Greentime Hu | ace02e2 | 2017-10-25 14:27:22 +0800 | [diff] [blame] | 1 | // SPDX-License-Identifier: GPL-2.0 |
| 2 | // Copyright (C) 2005-2017 Andes Technology Corporation |
| 3 | |
| 4 | #include <linux/linkage.h> |
| 5 | |
| 6 | .text |
| 7 | ENTRY(memset) |
| 8 | move $r5, $r0 ! Return value |
| 9 | beqz $r2, end_memset ! Exit when len = 0 |
| 10 | srli $p1, $r2, 2 ! $p1 is how many words to copy |
| 11 | andi $r2, $r2, 3 ! How many bytes are less than a word |
| 12 | beqz $p1, byte_set ! When n is less than a word |
| 13 | |
| 14 | ! set $r1 from ??????ab to abababab |
| 15 | andi $r1, $r1, #0x00ff ! $r1 = 000000ab |
| 16 | slli $p0, $r1, #8 ! $p0 = 0000ab00 |
| 17 | or $r1, $r1, $p0 ! $r1 = 0000abab |
| 18 | slli $p0, $r1, #16 ! $p0 = abab0000 |
| 19 | or $r1, $r1, $p0 ! $r1 = abababab |
| 20 | word_set: |
| 21 | addi $p1, $p1, #-1 ! How many words left to copy |
| 22 | smw.bim $r1, [$r0], $r1 ! Copy the word to det |
| 23 | bnez $p1, word_set ! Still words to set, continue looping |
| 24 | beqz $r2, end_memset ! No left byte to set |
| 25 | byte_set: ! Less than 4 bytes left to set |
| 26 | addi $r2, $r2, #-1 ! Decrease len by 1 |
| 27 | sbi.bi $r1, [$r0], #1 ! Set data of the next byte to $r1 |
| 28 | bnez $r2, byte_set ! Still bytes left to set |
| 29 | end_memset: |
| 30 | move $r0, $r5 |
| 31 | ret |
| 32 | |
| 33 | ENDPROC(memset) |