1 /* SPDX-License-Identifier: GPL-2.0 */ 2 // Copyright (C) 2018 Hangzhou C-SKY Microsystems co.,ltd. 3 4 #include <linux/linkage.h> 5 #include "sysdep.h" 6 7 ENTRY(strlen) 8 /* Check if the start addr is aligned. */ 9 mov r3, r0 10 andi r1, r0, 3 11 movi r2, 4 12 movi r0, 0 13 bnez r1, .L_start_not_aligned 14 15 LABLE_ALIGN 16 .L_start_addr_aligned: 17 /* Check if all the bytes in the word are not zero. */ 18 ldw r1, (r3) 19 tstnbz r1 20 bf .L_string_tail 21 22 ldw r1, (r3, 4) 23 addi r0, 4 24 tstnbz r1 25 bf .L_string_tail 26 27 ldw r1, (r3, 8) 28 addi r0, 4 29 tstnbz r1 30 bf .L_string_tail 31 32 ldw r1, (r3, 12) 33 addi r0, 4 34 tstnbz r1 35 bf .L_string_tail 36 37 ldw r1, (r3, 16) 38 addi r0, 4 39 tstnbz r1 40 bf .L_string_tail 41 42 ldw r1, (r3, 20) 43 addi r0, 4 44 tstnbz r1 45 bf .L_string_tail 46 47 ldw r1, (r3, 24) 48 addi r0, 4 49 tstnbz r1 50 bf .L_string_tail 51 52 ldw r1, (r3, 28) 53 addi r0, 4 54 tstnbz r1 55 bf .L_string_tail 56 57 addi r0, 4 58 addi r3, 32 59 br .L_start_addr_aligned 60 61 .L_string_tail: 62 # ifdef __CSKYBE__ 63 xtrb0 r3, r1 64 bez r3, .L_return 65 addi r0, 1 66 xtrb1 r3, r1 67 bez r3, .L_return 68 addi r0, 1 69 xtrb2 r3, r1 70 bez r3, .L_return 71 addi r0, 1 72 # else 73 xtrb3 r3, r1 74 bez r3, .L_return 75 addi r0, 1 76 xtrb2 r3, r1 77 bez r3, .L_return 78 addi r0, 1 79 xtrb1 r3, r1 80 bez r3, .L_return 81 addi r0, 1 82 # endif /* !__CSKYBE__ */ 83 84 .L_return: 85 rts 86 87 .L_start_not_aligned: 88 sub r2, r2, r1 89 .L_start_not_aligned_loop: 90 ldb r1, (r3) 91 PRE_BNEZAD (r2) 92 addi r3, 1 93 bez r1, .L_return 94 addi r0, 1 95 BNEZAD (r2, .L_start_not_aligned_loop) 96 br .L_start_addr_aligned 97 ENDPROC(strlen) 98