ARCv2: optimised string/mem lib routines
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
diff --git a/arch/arc/lib/strcmp-archs.S b/arch/arc/lib/strcmp-archs.S
new file mode 100644
index 0000000..4f338ee
--- /dev/null
+++ b/arch/arc/lib/strcmp-archs.S
@@ -0,0 +1,78 @@
+/*
+ * Copyright (C) 2014-15 Synopsys, Inc. (www.synopsys.com)
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include <linux/linkage.h>
+
+ENTRY(strcmp)
+ or r2, r0, r1
+ bmsk_s r2, r2, 1
+ brne r2, 0, @.Lcharloop
+
+;;; s1 and s2 are word aligned
+ ld.ab r2, [r0, 4]
+
+ mov_s r12, 0x01010101
+ ror r11, r12
+ .align 4
+.LwordLoop:
+ ld.ab r3, [r1, 4]
+ ;; Detect NULL char in str1
+ sub r4, r2, r12
+ ld.ab r5, [r0, 4]
+ bic r4, r4, r2
+ and r4, r4, r11
+ brne.d.nt r4, 0, .LfoundNULL
+ ;; Check if the read locations are the same
+ cmp r2, r3
+ beq.d .LwordLoop
+ mov.eq r2, r5
+
+ ;; A match is found, spot it out
+#ifdef __LITTLE_ENDIAN__
+ swape r3, r3
+ mov_s r0, 1
+ swape r2, r2
+#else
+ mov_s r0, 1
+#endif
+ cmp_s r2, r3
+ j_s.d [blink]
+ bset.lo r0, r0, 31
+
+ .align 4
+.LfoundNULL:
+#ifdef __BIG_ENDIAN__
+ swape r4, r4
+ swape r2, r2
+ swape r3, r3
+#endif
+ ;; Find null byte
+ ffs r0, r4
+ bmsk r2, r2, r0
+ bmsk r3, r3, r0
+ swape r2, r2
+ swape r3, r3
+ ;; make the return value
+ sub.f r0, r2, r3
+ mov.hi r0, 1
+ j_s.d [blink]
+ bset.lo r0, r0, 31
+
+ .align 4
+.Lcharloop:
+ ldb.ab r2, [r0, 1]
+ ldb.ab r3, [r1, 1]
+ nop
+ breq r2, 0, .Lcmpend
+ breq r2, r3, .Lcharloop
+
+ .align 4
+.Lcmpend:
+ j_s.d [blink]
+ sub r0, r2, r3
+END(strcmp)