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93 lines
2.4 KiB
C
93 lines
2.4 KiB
C
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/*
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* arch/v850/lib/memcpy.c -- Memory copying
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*
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* Copyright (C) 2001,02 NEC Corporation
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* Copyright (C) 2001,02 Miles Bader <miles@gnu.org>
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*
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* This file is subject to the terms and conditions of the GNU General
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* Public License. See the file COPYING in the main directory of this
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* archive for more details.
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*
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* Written by Miles Bader <miles@gnu.org>
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*/
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#include <linux/types.h>
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#include <asm/string.h>
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#define CHUNK_SIZE 32 /* bytes */
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#define CHUNK_ALIGNED(addr) (((unsigned long)addr & 0x3) == 0)
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/* Note that this macro uses 8 call-clobbered registers (not including
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R1), which are few enough so that the following functions don't need
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to spill anything to memory. It also uses R1, which is nominally
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reserved for the assembler, but here it should be OK. */
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#define COPY_CHUNK(src, dst) \
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asm ("mov %0, ep;" \
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"sld.w 0[ep], r1; sld.w 4[ep], r12;" \
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"sld.w 8[ep], r13; sld.w 12[ep], r14;" \
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"sld.w 16[ep], r15; sld.w 20[ep], r17;" \
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"sld.w 24[ep], r18; sld.w 28[ep], r19;" \
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"mov %1, ep;" \
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"sst.w r1, 0[ep]; sst.w r12, 4[ep];" \
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"sst.w r13, 8[ep]; sst.w r14, 12[ep];" \
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"sst.w r15, 16[ep]; sst.w r17, 20[ep];" \
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"sst.w r18, 24[ep]; sst.w r19, 28[ep]" \
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:: "r" (src), "r" (dst) \
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: "r1", "r12", "r13", "r14", "r15", \
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"r17", "r18", "r19", "ep", "memory");
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void *memcpy (void *dst, const void *src, __kernel_size_t size)
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{
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char *_dst = dst;
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const char *_src = src;
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if (size >= CHUNK_SIZE && CHUNK_ALIGNED(_src) && CHUNK_ALIGNED(_dst)) {
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/* Copy large blocks efficiently. */
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unsigned count;
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for (count = size / CHUNK_SIZE; count; count--) {
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COPY_CHUNK (_src, _dst);
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_src += CHUNK_SIZE;
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_dst += CHUNK_SIZE;
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}
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size %= CHUNK_SIZE;
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}
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if (size > 0)
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do
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*_dst++ = *_src++;
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while (--size);
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return dst;
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}
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void *memmove (void *dst, const void *src, __kernel_size_t size)
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{
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if ((unsigned long)dst < (unsigned long)src
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|| (unsigned long)src + size < (unsigned long)dst)
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return memcpy (dst, src, size);
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else {
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char *_dst = dst + size;
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const char *_src = src + size;
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if (size >= CHUNK_SIZE
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&& CHUNK_ALIGNED (_src) && CHUNK_ALIGNED (_dst))
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{
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/* Copy large blocks efficiently. */
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unsigned count;
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for (count = size / CHUNK_SIZE; count; count--) {
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_src -= CHUNK_SIZE;
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_dst -= CHUNK_SIZE;
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COPY_CHUNK (_src, _dst);
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}
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size %= CHUNK_SIZE;
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}
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if (size > 0)
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do
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*--_dst = *--_src;
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while (--size);
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return _dst;
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}
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}
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