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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-05-06 01:02:30 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-05-06 01:02:30 +0000
commit76cb841cb886eef6b3bee341a2266c76578724ad (patch)
treef5892e5ba6cc11949952a6ce4ecbe6d516d6ce58 /arch/nds32/lib/memset.S
parentInitial commit. (diff)
downloadlinux-upstream/4.19.249.tar.xz
linux-upstream/4.19.249.zip
Adding upstream version 4.19.249.upstream/4.19.249upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'arch/nds32/lib/memset.S')
-rw-r--r--arch/nds32/lib/memset.S33
1 files changed, 33 insertions, 0 deletions
diff --git a/arch/nds32/lib/memset.S b/arch/nds32/lib/memset.S
new file mode 100644
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+++ b/arch/nds32/lib/memset.S
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+// SPDX-License-Identifier: GPL-2.0
+// Copyright (C) 2005-2017 Andes Technology Corporation
+
+#include <linux/linkage.h>
+
+ .text
+ENTRY(memset)
+ move $r5, $r0 ! Return value
+ beqz $r2, end_memset ! Exit when len = 0
+ srli $p1, $r2, 2 ! $p1 is how many words to copy
+ andi $r2, $r2, 3 ! How many bytes are less than a word
+ beqz $p1, byte_set ! When n is less than a word
+
+ ! set $r1 from ??????ab to abababab
+ andi $r1, $r1, #0x00ff ! $r1 = 000000ab
+ slli $p0, $r1, #8 ! $p0 = 0000ab00
+ or $r1, $r1, $p0 ! $r1 = 0000abab
+ slli $p0, $r1, #16 ! $p0 = abab0000
+ or $r1, $r1, $p0 ! $r1 = abababab
+word_set:
+ addi $p1, $p1, #-1 ! How many words left to copy
+ smw.bim $r1, [$r0], $r1 ! Copy the word to det
+ bnez $p1, word_set ! Still words to set, continue looping
+ beqz $r2, end_memset ! No left byte to set
+byte_set: ! Less than 4 bytes left to set
+ addi $r2, $r2, #-1 ! Decrease len by 1
+ sbi.bi $r1, [$r0], #1 ! Set data of the next byte to $r1
+ bnez $r2, byte_set ! Still bytes left to set
+end_memset:
+ move $r0, $r5
+ ret
+
+ENDPROC(memset)