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Diffstat (limited to 'newlib/libc/machine/nds32/memcpy.S')
| -rw-r--r-- | newlib/libc/machine/nds32/memcpy.S | 77 |
1 files changed, 77 insertions, 0 deletions
diff --git a/newlib/libc/machine/nds32/memcpy.S b/newlib/libc/machine/nds32/memcpy.S new file mode 100644 index 000000000..f27858c09 --- /dev/null +++ b/newlib/libc/machine/nds32/memcpy.S @@ -0,0 +1,77 @@ +/* +Copyright (c) 2013 Andes Technology Corporation. +All rights reserved. + +Redistribution and use in source and binary forms, with or without +modification, are permitted provided that the following conditions are met: + + Redistributions of source code must retain the above copyright + notice, this list of conditions and the following disclaimer. + + Redistributions in binary form must reproduce the above copyright + notice, this list of conditions and the following disclaimer in the + documentation and/or other materials provided with the distribution. + + The name of the company may not be used to endorse or promote + products derived from this software without specific prior written + permission. + +THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" +AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE +IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE +DISCLAIMED. IN NO EVENT SHALL RED HAT INCORPORATED BE LIABLE FOR ANY +DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES +(INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; +LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND +ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT +(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS +SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. + + + Function: + memcpy - copy memory regions + Syntax: + void *memcpy(void *s1, const void *s2, size_t n); + Description: + The memcpy function copies n characters from the object pointed to + by s2 into the object pointed to by s1. If copying takes place + between objects that overlap, the behavior is undeļ¬ned. + Return value: + The memcpy function returns the value of s1. +*/ + .text + .align 2 + .globl memcpy + .type memcpy, @function +memcpy: + /* Corner cases. If *s1 equals *s2 + or size_t is zero, just go return. */ + beq $r0, $r1, .Lend_memcpy + beqz $r2, .Lend_memcpy + + /* Keep *s1 as return value. + Set $r3 as how many words to copy. + Set $r2 as how many bytes are less than a word. */ + move $r5, $r0 + srli $r3, $r2, 2 + andi $r2, $r2, 3 + beqz $r3, .Lbyte_copy + +.Lword_copy: + /* Do the word copy $r3 times. Then, do the byte copy $r2 times. */ + lmw.bim $r4, [$r1], $r4, 0 + addi $r3, $r3, -1 + smw.bim $r4, [$r5], $r4, 0 + bnez $r3, .Lword_copy /* Loop again ? */ + beqz $r2, .Lend_memcpy /* Fall THRU or go return ? */ + +.Lbyte_copy: + /* Do the byte copy $r2 times. */ + lbi.bi $r4, [$r1], 1 + addi $r2, $r2, -1 + sbi.bi $r4, [$r5], 1 + bnez $r2, .Lbyte_copy /* Loop again ? */ + +.Lend_memcpy: + ret + .size memcpy, .-memcpy |