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-rw-r--r--arch/csky/abiv2/memcmp.S152
1 files changed, 152 insertions, 0 deletions
diff --git a/arch/csky/abiv2/memcmp.S b/arch/csky/abiv2/memcmp.S
new file mode 100644
index 0000000000..bf0d809f09
--- /dev/null
+++ b/arch/csky/abiv2/memcmp.S
@@ -0,0 +1,152 @@
+/* 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)