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-rw-r--r--arch/csky/abiv2/strlen.S97
1 files changed, 97 insertions, 0 deletions
diff --git a/arch/csky/abiv2/strlen.S b/arch/csky/abiv2/strlen.S
new file mode 100644
index 000000000..bcdd70764
--- /dev/null
+++ b/arch/csky/abiv2/strlen.S
@@ -0,0 +1,97 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+// Copyright (C) 2018 Hangzhou C-SKY Microsystems co.,ltd.
+
+#include <linux/linkage.h>
+#include "sysdep.h"
+
+ENTRY(strlen)
+ /* Check if the start addr is aligned. */
+ mov r3, r0
+ andi r1, r0, 3
+ movi r2, 4
+ movi r0, 0
+ bnez r1, .L_start_not_aligned
+
+ LABLE_ALIGN
+.L_start_addr_aligned:
+ /* Check if all the bytes in the word are not zero. */
+ ldw r1, (r3)
+ tstnbz r1
+ bf .L_string_tail
+
+ ldw r1, (r3, 4)
+ addi r0, 4
+ tstnbz r1
+ bf .L_string_tail
+
+ ldw r1, (r3, 8)
+ addi r0, 4
+ tstnbz r1
+ bf .L_string_tail
+
+ ldw r1, (r3, 12)
+ addi r0, 4
+ tstnbz r1
+ bf .L_string_tail
+
+ ldw r1, (r3, 16)
+ addi r0, 4
+ tstnbz r1
+ bf .L_string_tail
+
+ ldw r1, (r3, 20)
+ addi r0, 4
+ tstnbz r1
+ bf .L_string_tail
+
+ ldw r1, (r3, 24)
+ addi r0, 4
+ tstnbz r1
+ bf .L_string_tail
+
+ ldw r1, (r3, 28)
+ addi r0, 4
+ tstnbz r1
+ bf .L_string_tail
+
+ addi r0, 4
+ addi r3, 32
+ br .L_start_addr_aligned
+
+.L_string_tail:
+# ifdef __CSKYBE__
+ xtrb0 r3, r1
+ bez r3, .L_return
+ addi r0, 1
+ xtrb1 r3, r1
+ bez r3, .L_return
+ addi r0, 1
+ xtrb2 r3, r1
+ bez r3, .L_return
+ addi r0, 1
+# else
+ xtrb3 r3, r1
+ bez r3, .L_return
+ addi r0, 1
+ xtrb2 r3, r1
+ bez r3, .L_return
+ addi r0, 1
+ xtrb1 r3, r1
+ bez r3, .L_return
+ addi r0, 1
+# endif /* !__CSKYBE__ */
+
+.L_return:
+ rts
+
+.L_start_not_aligned:
+ sub r2, r2, r1
+.L_start_not_aligned_loop:
+ ldb r1, (r3)
+ PRE_BNEZAD (r2)
+ addi r3, 1
+ bez r1, .L_return
+ addi r0, 1
+ BNEZAD (r2, .L_start_not_aligned_loop)
+ br .L_start_addr_aligned
+ENDPROC(strlen)