diff options
author | Wolfgang Denk <wd@pollux.denx.de> | 2006-10-24 14:21:16 +0200 |
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committer | Wolfgang Denk <wd@pollux.denx.de> | 2006-10-24 14:21:16 +0200 |
commit | 7b64fef33c66be648826c0ff9758298ef13d0604 (patch) | |
tree | ea8a3685319987b5d135c2f48e9bc1eee4720640 /lib_avr32/div64.c | |
parent | 2da2d9a4766063b9848f3a35ad6025499cf87265 (diff) |
Add AVR32 architecture support
Patch by Haavard Skinnemoen, 6 Sep 2006 16:23:02 +0200
This patch adds common infrastructure code for the Atmel AVR32
architecture. See doc/README.AVR32 for details.
Signed-off-by: Haavard Skinnemoen <hskinnemoen@atmel.com>
Diffstat (limited to 'lib_avr32/div64.c')
-rw-r--r-- | lib_avr32/div64.c | 54 |
1 files changed, 54 insertions, 0 deletions
diff --git a/lib_avr32/div64.c b/lib_avr32/div64.c new file mode 100644 index 0000000000..99726e325d --- /dev/null +++ b/lib_avr32/div64.c @@ -0,0 +1,54 @@ +/* + * Copyright (C) 2003 Bernardo Innocenti <bernie@develer.com> + * + * Based on former do_div() implementation from asm-parisc/div64.h: + * Copyright (C) 1999 Hewlett-Packard Co + * Copyright (C) 1999 David Mosberger-Tang <davidm@hpl.hp.com> + * + * + * Generic C version of 64bit/32bit division and modulo, with + * 64bit result and 32bit remainder. + * + * The fast case for (n>>32 == 0) is handled inline by do_div(). + * + * Code generated for this function might be very inefficient + * for some CPUs. __div64_32() can be overridden by linking arch-specific + * assembly versions such as arch/ppc/lib/div64.S and arch/sh/lib/div64.S. + */ + +#include <linux/types.h> + +#include <asm/div64.h> + +uint32_t __div64_32(uint64_t *n, uint32_t base) +{ + uint64_t rem = *n; + uint64_t b = base; + uint64_t res, d = 1; + uint32_t high = rem >> 32; + + /* Reduce the thing a bit first */ + res = 0; + if (high >= base) { + high /= base; + res = (uint64_t) high << 32; + rem -= (uint64_t) (high*base) << 32; + } + + while ((int64_t)b > 0 && b < rem) { + b = b+b; + d = d+d; + } + + do { + if (rem >= b) { + rem -= b; + res += d; + } + b >>= 1; + d >>= 1; + } while (d); + + *n = res; + return rem; +} |