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author | Michal Marek <mmarek@suse.cz> | 2010-10-12 15:09:06 +0200 |
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committer | Michal Marek <mmarek@suse.cz> | 2010-10-12 15:09:06 +0200 |
commit | 239060b93bb30a4ad55f1ecaa512464a035cc5ba (patch) | |
tree | 77f79810e57d4fc24356eca0cd6db463e8994128 /arch/tile/lib/memmove_32.c | |
parent | kconfig: Use PATH_MAX instead of 128 for path buffer sizes. (diff) | |
parent | kbuild: fix oldnoconfig to do the right thing (diff) | |
download | linux-239060b93bb30a4ad55f1ecaa512464a035cc5ba.tar.xz linux-239060b93bb30a4ad55f1ecaa512464a035cc5ba.zip |
Merge branch 'kbuild/rc-fixes' into kbuild/kconfig
We need to revert the temporary hack in 71ebc01, hence the merge.
Diffstat (limited to 'arch/tile/lib/memmove_32.c')
-rw-r--r-- | arch/tile/lib/memmove_32.c | 63 |
1 files changed, 63 insertions, 0 deletions
diff --git a/arch/tile/lib/memmove_32.c b/arch/tile/lib/memmove_32.c new file mode 100644 index 000000000000..fd615ae6ade7 --- /dev/null +++ b/arch/tile/lib/memmove_32.c @@ -0,0 +1,63 @@ +/* + * Copyright 2010 Tilera Corporation. All Rights Reserved. + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License + * as published by the Free Software Foundation, version 2. + * + * This program 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, GOOD TITLE or + * NON INFRINGEMENT. See the GNU General Public License for + * more details. + */ + +#include <linux/types.h> +#include <linux/string.h> +#include <linux/module.h> + +void *memmove(void *dest, const void *src, size_t n) +{ + if ((const char *)src >= (char *)dest + n + || (char *)dest >= (const char *)src + n) { + /* We found no overlap, so let memcpy do all the heavy + * lifting (prefetching, etc.) + */ + return memcpy(dest, src, n); + } + + if (n != 0) { + const uint8_t *in; + uint8_t x; + uint8_t *out; + int stride; + + if (src < dest) { + /* copy backwards */ + in = (const uint8_t *)src + n - 1; + out = (uint8_t *)dest + n - 1; + stride = -1; + } else { + /* copy forwards */ + in = (const uint8_t *)src; + out = (uint8_t *)dest; + stride = 1; + } + + /* Manually software-pipeline this loop. */ + x = *in; + in += stride; + + while (--n != 0) { + *out = x; + out += stride; + x = *in; + in += stride; + } + + *out = x; + } + + return dest; +} +EXPORT_SYMBOL(memmove); |