diff options
Diffstat (limited to 'arch/sh/lib64/memcpy.c')
-rw-r--r-- | arch/sh/lib64/memcpy.c | 81 |
1 files changed, 81 insertions, 0 deletions
diff --git a/arch/sh/lib64/memcpy.c b/arch/sh/lib64/memcpy.c new file mode 100644 index 00000000000..fba436a92bf --- /dev/null +++ b/arch/sh/lib64/memcpy.c @@ -0,0 +1,81 @@ +/* + * Copyright (C) 2002 Mark Debbage (Mark.Debbage@superh.com) + * + * May be copied or modified under the terms of the GNU General Public + * License. See linux/COPYING for more information. + * + */ + +#include <linux/types.h> +#include <asm/string.h> + +// This is a simplistic optimization of memcpy to increase the +// granularity of access beyond one byte using aligned +// loads and stores. This is not an optimal implementation +// for SH-5 (especially with regard to prefetching and the cache), +// and a better version should be provided later ... + +void *memcpy(void *dest, const void *src, size_t count) +{ + char *d = (char *) dest, *s = (char *) src; + + if (count >= 32) { + int i = 8 - (((unsigned long) d) & 0x7); + + if (i != 8) + while (i-- && count--) { + *d++ = *s++; + } + + if (((((unsigned long) d) & 0x7) == 0) && + ((((unsigned long) s) & 0x7) == 0)) { + while (count >= 32) { + unsigned long long t1, t2, t3, t4; + t1 = *(unsigned long long *) (s); + t2 = *(unsigned long long *) (s + 8); + t3 = *(unsigned long long *) (s + 16); + t4 = *(unsigned long long *) (s + 24); + *(unsigned long long *) (d) = t1; + *(unsigned long long *) (d + 8) = t2; + *(unsigned long long *) (d + 16) = t3; + *(unsigned long long *) (d + 24) = t4; + d += 32; + s += 32; + count -= 32; + } + while (count >= 8) { + *(unsigned long long *) d = + *(unsigned long long *) s; + d += 8; + s += 8; + count -= 8; + } + } + + if (((((unsigned long) d) & 0x3) == 0) && + ((((unsigned long) s) & 0x3) == 0)) { + while (count >= 4) { + *(unsigned long *) d = *(unsigned long *) s; + d += 4; + s += 4; + count -= 4; + } + } + + if (((((unsigned long) d) & 0x1) == 0) && + ((((unsigned long) s) & 0x1) == 0)) { + while (count >= 2) { + *(unsigned short *) d = *(unsigned short *) s; + d += 2; + s += 2; + count -= 2; + } + } + } + + while (count--) { + *d++ = *s++; + } + + return d; +} |