| // SPDX-License-Identifier: GPL-2.0 |
| // Copyright (C) 2005-2017 Andes Technology Corporation |
| |
| #include <linux/linkage.h> |
| |
| .text |
| ENTRY(memset) |
| move $r5, $r0 ! Return value |
| beqz $r2, end_memset ! Exit when len = 0 |
| srli $p1, $r2, 2 ! $p1 is how many words to copy |
| andi $r2, $r2, 3 ! How many bytes are less than a word |
| beqz $p1, byte_set ! When n is less than a word |
| |
| ! set $r1 from ??????ab to abababab |
| andi $r1, $r1, #0x00ff ! $r1 = 000000ab |
| slli $p0, $r1, #8 ! $p0 = 0000ab00 |
| or $r1, $r1, $p0 ! $r1 = 0000abab |
| slli $p0, $r1, #16 ! $p0 = abab0000 |
| or $r1, $r1, $p0 ! $r1 = abababab |
| word_set: |
| addi $p1, $p1, #-1 ! How many words left to copy |
| smw.bim $r1, [$r0], $r1 ! Copy the word to det |
| bnez $p1, word_set ! Still words to set, continue looping |
| beqz $r2, end_memset ! No left byte to set |
| byte_set: ! Less than 4 bytes left to set |
| addi $r2, $r2, #-1 ! Decrease len by 1 |
| sbi.bi $r1, [$r0], #1 ! Set data of the next byte to $r1 |
| bnez $r2, byte_set ! Still bytes left to set |
| end_memset: |
| move $r0, $r5 |
| ret |
| |
| ENDPROC(memset) |