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| /* SPDX-License-Identifier: GPL-2.0 */
| // Copyright (C) 2018 Hangzhou C-SKY Microsystems co.,ltd.
|
| #include <linux/linkage.h>
| #include "sysdep.h"
|
| ENTRY(memcmp)
| /* Test if len less than 4 bytes. */
| mov r3, r0
| movi r0, 0
| mov r12, r4
| cmplti r2, 4
| bt .L_compare_by_byte
|
| andi r13, r0, 3
| movi r19, 4
|
| /* Test if s1 is not 4 bytes aligned. */
| bnez r13, .L_s1_not_aligned
|
| LABLE_ALIGN
| .L_s1_aligned:
| /* If dest is aligned, then copy. */
| zext r18, r2, 31, 4
| /* Test if len less than 16 bytes. */
| bez r18, .L_compare_by_word
|
| .L_compare_by_4word:
| /* If aligned, load word each time. */
| ldw r20, (r3, 0)
| ldw r21, (r1, 0)
| /* If s1[i] != s2[i], goto .L_byte_check. */
| cmpne r20, r21
| bt .L_byte_check
|
| ldw r20, (r3, 4)
| ldw r21, (r1, 4)
| cmpne r20, r21
| bt .L_byte_check
|
| ldw r20, (r3, 8)
| ldw r21, (r1, 8)
| cmpne r20, r21
| bt .L_byte_check
|
| ldw r20, (r3, 12)
| ldw r21, (r1, 12)
| cmpne r20, r21
| bt .L_byte_check
|
| PRE_BNEZAD (r18)
| addi a3, 16
| addi a1, 16
|
| BNEZAD (r18, .L_compare_by_4word)
|
| .L_compare_by_word:
| zext r18, r2, 3, 2
| bez r18, .L_compare_by_byte
| .L_compare_by_word_loop:
| ldw r20, (r3, 0)
| ldw r21, (r1, 0)
| addi r3, 4
| PRE_BNEZAD (r18)
| cmpne r20, r21
| addi r1, 4
| bt .L_byte_check
| BNEZAD (r18, .L_compare_by_word_loop)
|
| .L_compare_by_byte:
| zext r18, r2, 1, 0
| bez r18, .L_return
| .L_compare_by_byte_loop:
| ldb r0, (r3, 0)
| ldb r4, (r1, 0)
| addi r3, 1
| subu r0, r4
| PRE_BNEZAD (r18)
| addi r1, 1
| bnez r0, .L_return
| BNEZAD (r18, .L_compare_by_byte_loop)
|
| .L_return:
| mov r4, r12
| rts
|
| # ifdef __CSKYBE__
| /* d[i] != s[i] in word, so we check byte 0. */
| .L_byte_check:
| xtrb0 r0, r20
| xtrb0 r2, r21
| subu r0, r2
| bnez r0, .L_return
|
| /* check byte 1 */
| xtrb1 r0, r20
| xtrb1 r2, r21
| subu r0, r2
| bnez r0, .L_return
|
| /* check byte 2 */
| xtrb2 r0, r20
| xtrb2 r2, r21
| subu r0, r2
| bnez r0, .L_return
|
| /* check byte 3 */
| xtrb3 r0, r20
| xtrb3 r2, r21
| subu r0, r2
| # else
| /* s1[i] != s2[i] in word, so we check byte 3. */
| .L_byte_check:
| xtrb3 r0, r20
| xtrb3 r2, r21
| subu r0, r2
| bnez r0, .L_return
|
| /* check byte 2 */
| xtrb2 r0, r20
| xtrb2 r2, r21
| subu r0, r2
| bnez r0, .L_return
|
| /* check byte 1 */
| xtrb1 r0, r20
| xtrb1 r2, r21
| subu r0, r2
| bnez r0, .L_return
|
| /* check byte 0 */
| xtrb0 r0, r20
| xtrb0 r2, r21
| subu r0, r2
| br .L_return
| # endif /* !__CSKYBE__ */
|
| /* Compare when s1 is not aligned. */
| .L_s1_not_aligned:
| sub r13, r19, r13
| sub r2, r13
| .L_s1_not_aligned_loop:
| ldb r0, (r3, 0)
| ldb r4, (r1, 0)
| addi r3, 1
| subu r0, r4
| PRE_BNEZAD (r13)
| addi r1, 1
| bnez r0, .L_return
| BNEZAD (r13, .L_s1_not_aligned_loop)
| br .L_s1_aligned
| ENDPROC(memcmp)
|
|
