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(memcmp) 8 /* Test if len less than 4 bytes. */ 9 mov r3, r0 10 movi r0, 0 11 mov r12, r4 12 cmplti r2, 4 13 bt .L_compare_by_byte 14 15 andi r13, r0, 3 16 movi r19, 4 17 18 /* Test if s1 is not 4 bytes aligned. */ 19 bnez r13, .L_s1_not_aligned 20 21 LABLE_ALIGN 22 .L_s1_aligned: 23 /* If dest is aligned, then copy. */ 24 zext r18, r2, 31, 4 25 /* Test if len less than 16 bytes. */ 26 bez r18, .L_compare_by_word 27 28 .L_compare_by_4word: 29 /* If aligned, load word each time. */ 30 ldw r20, (r3, 0) 31 ldw r21, (r1, 0) 32 /* If s1[i] != s2[i], goto .L_byte_check. */ 33 cmpne r20, r21 34 bt .L_byte_check 35 36 ldw r20, (r3, 4) 37 ldw r21, (r1, 4) 38 cmpne r20, r21 39 bt .L_byte_check 40 41 ldw r20, (r3, 8) 42 ldw r21, (r1, 8) 43 cmpne r20, r21 44 bt .L_byte_check 45 46 ldw r20, (r3, 12) 47 ldw r21, (r1, 12) 48 cmpne r20, r21 49 bt .L_byte_check 50 51 PRE_BNEZAD (r18) 52 addi a3, 16 53 addi a1, 16 54 55 BNEZAD (r18, .L_compare_by_4word) 56 57 .L_compare_by_word: 58 zext r18, r2, 3, 2 59 bez r18, .L_compare_by_byte 60 .L_compare_by_word_loop: 61 ldw r20, (r3, 0) 62 ldw r21, (r1, 0) 63 addi r3, 4 64 PRE_BNEZAD (r18) 65 cmpne r20, r21 66 addi r1, 4 67 bt .L_byte_check 68 BNEZAD (r18, .L_compare_by_word_loop) 69 70 .L_compare_by_byte: 71 zext r18, r2, 1, 0 72 bez r18, .L_return 73 .L_compare_by_byte_loop: 74 ldb r0, (r3, 0) 75 ldb r4, (r1, 0) 76 addi r3, 1 77 subu r0, r4 78 PRE_BNEZAD (r18) 79 addi r1, 1 80 bnez r0, .L_return 81 BNEZAD (r18, .L_compare_by_byte_loop) 82 83 .L_return: 84 mov r4, r12 85 rts 86 87 # ifdef __CSKYBE__ 88 /* d[i] != s[i] in word, so we check byte 0. */ 89 .L_byte_check: 90 xtrb0 r0, r20 91 xtrb0 r2, r21 92 subu r0, r2 93 bnez r0, .L_return 94 95 /* check byte 1 */ 96 xtrb1 r0, r20 97 xtrb1 r2, r21 98 subu r0, r2 99 bnez r0, .L_return 100 101 /* check byte 2 */ 102 xtrb2 r0, r20 103 xtrb2 r2, r21 104 subu r0, r2 105 bnez r0, .L_return 106 107 /* check byte 3 */ 108 xtrb3 r0, r20 109 xtrb3 r2, r21 110 subu r0, r2 111 # else 112 /* s1[i] != s2[i] in word, so we check byte 3. */ 113 .L_byte_check: 114 xtrb3 r0, r20 115 xtrb3 r2, r21 116 subu r0, r2 117 bnez r0, .L_return 118 119 /* check byte 2 */ 120 xtrb2 r0, r20 121 xtrb2 r2, r21 122 subu r0, r2 123 bnez r0, .L_return 124 125 /* check byte 1 */ 126 xtrb1 r0, r20 127 xtrb1 r2, r21 128 subu r0, r2 129 bnez r0, .L_return 130 131 /* check byte 0 */ 132 xtrb0 r0, r20 133 xtrb0 r2, r21 134 subu r0, r2 135 br .L_return 136 # endif /* !__CSKYBE__ */ 137 138 /* Compare when s1 is not aligned. */ 139 .L_s1_not_aligned: 140 sub r13, r19, r13 141 sub r2, r13 142 .L_s1_not_aligned_loop: 143 ldb r0, (r3, 0) 144 ldb r4, (r1, 0) 145 addi r3, 1 146 subu r0, r4 147 PRE_BNEZAD (r13) 148 addi r1, 1 149 bnez r0, .L_return 150 BNEZAD (r13, .L_s1_not_aligned_loop) 151 br .L_s1_aligned 152 ENDPROC(memcmp) 153