diff options
author | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 15:20:36 -0700 |
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committer | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 15:20:36 -0700 |
commit | 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch) | |
tree | 0bba044c4ce775e45a88a51686b5d9f90697ea9d /include/asm-generic/div64.h |
Linux-2.6.12-rc2v2.6.12-rc2
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.
Let it rip!
Diffstat (limited to 'include/asm-generic/div64.h')
-rw-r--r-- | include/asm-generic/div64.h | 58 |
1 files changed, 58 insertions, 0 deletions
diff --git a/include/asm-generic/div64.h b/include/asm-generic/div64.h new file mode 100644 index 000000000000..8f4e3193342e --- /dev/null +++ b/include/asm-generic/div64.h @@ -0,0 +1,58 @@ +#ifndef _ASM_GENERIC_DIV64_H +#define _ASM_GENERIC_DIV64_H +/* + * Copyright (C) 2003 Bernardo Innocenti <bernie@develer.com> + * Based on former asm-ppc/div64.h and asm-m68knommu/div64.h + * + * The semantics of do_div() are: + * + * uint32_t do_div(uint64_t *n, uint32_t base) + * { + * uint32_t remainder = *n % base; + * *n = *n / base; + * return remainder; + * } + * + * NOTE: macro parameter n is evaluated multiple times, + * beware of side effects! + */ + +#include <linux/types.h> +#include <linux/compiler.h> + +#if BITS_PER_LONG == 64 + +# define do_div(n,base) ({ \ + uint32_t __base = (base); \ + uint32_t __rem; \ + __rem = ((uint64_t)(n)) % __base; \ + (n) = ((uint64_t)(n)) / __base; \ + __rem; \ + }) + +#elif BITS_PER_LONG == 32 + +extern uint32_t __div64_32(uint64_t *dividend, uint32_t divisor); + +/* The unnecessary pointer compare is there + * to check for type safety (n must be 64bit) + */ +# define do_div(n,base) ({ \ + uint32_t __base = (base); \ + uint32_t __rem; \ + (void)(((typeof((n)) *)0) == ((uint64_t *)0)); \ + if (likely(((n) >> 32) == 0)) { \ + __rem = (uint32_t)(n) % __base; \ + (n) = (uint32_t)(n) / __base; \ + } else \ + __rem = __div64_32(&(n), __base); \ + __rem; \ + }) + +#else /* BITS_PER_LONG == ?? */ + +# error do_div() does not yet support the C64 + +#endif /* BITS_PER_LONG */ + +#endif /* _ASM_GENERIC_DIV64_H */ |