1 files changed, 66 insertions, 0 deletions
diff --git a/libc/string/nds32/memset.S b/libc/string/nds32/memset.S
new file mode 100644
index 000000000..edd15a410
--- /dev/null
+++ b/libc/string/nds32/memset.S
@@ -0,0 +1,66 @@
+/*
+ * Copyright (C) 2016 Andes Technology, Inc.
+ * Licensed under the LGPL v2.1, see the file COPYING.LIB in this tarball.
+ */
+
+/*  Copyright (C) 1998, 2003 Free Software Foundation, Inc.
+ *  Contributed by Philip Blundell <philb@gnu.org>
+ *
+ *  The GNU C Library is free software; you can redistribute it and/or
+ *  modify it under the terms of the GNU Lesser General Public
+ *  License as published by the Free Software Foundation; either
+ *  version 2.1 of the License, or (at your option) any later version.
+ *
+ *  The GNU C Library is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ *  Lesser General Public License for more details.
+ *
+ *  You should have received a copy of the GNU Lesser General Public
+ *  License along with the GNU C Library; if not, write to the Free
+ *  Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
+ *  02111-1307 USA.
+ */
+
+#include <features.h>
+#include <sysdep.h>
+!==========================================================
+!  void *memset(void *dst, int val, int len);
+!
+!        dst: $r0
+!        val: $r1
+!        len: $r2
+!        ret: $r0 - pointer to the memory area dst.
+!==========================================================
+.weak memset
+ENTRY(memset)
+	move	$r5, $r0	        ! Return value
+	beqz    $r2, .Lend_memset   ! Exit when len = 0
+	srli	$r3, $r2, 2	        ! r3 is how many words to copy
+	andi	$r2, $r2, 3	        ! How many bytes are less than a word
+	beqz	$r3, .Lbyte_set	    ! When n is less than a word
+
+    ! set r1 from to abababab
+	andi    $r1, $r1, 0x00ff        ! r1 = 000000ab
+	slli    $r4, $r1, 8             ! r4 = 0000ab00
+	or      $r1, $r1, $r4           ! r1 = 0000abab
+	slli    $r4, $r1, 16            ! r4 = abab0000
+	or      $r1, $r1, $r4           ! r1 = abababab
+
+.Lword_set:
+	addi	$r3, $r3, -1	        ! How many words left to copy
+	smw.bim $r1, [$r5], $r1	    	! Copy the word to det
+	bnez    $r3, .Lword_set			! Still words to set, continue looping
+	beqz	$r2, .Lend_memset		! No left byte to set
+
+.Lbyte_set:
+	! Less than 4 bytes left to set
+	addi	$r2, $r2, -1		! Decrease len by 1
+	sbi.p	$r1, [$r5], 1		! Set data of the next byte to r1
+	bnez	$r2, .Lbyte_set		! Still bytes left to set
+
+.Lend_memset:
+	ret
+
+END(memset)
+libc_hidden_def(memset)