Messages in this thread | | | Date | Sat, 21 Apr 2007 03:08:25 -0700 | From | Andrew Morton <> | Subject | Re: [PATCH] utilities: add helper functions for safe 64-bit integer operations as 32-bit halves |
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On Fri, 20 Apr 2007 20:55:49 -0400 (EDT) "John Anthony Kazos Jr." <jakj@j-a-k-j.com> wrote:
> +#define upper_32_bits(n) (sizeof(n) == 8 ? (u64)(n) >> 32 : 0)
It's very unclear what type this returns, in terms of both size and signedness. Perhaps it always returns a u64, dunno. If it does, that will cause the arithmetic which uses this macro to go 64-bit too. Casting the whole return value to u32 would fix all those doubts up.
> +#define lower_32_bits(n) (sizeof(n) == 8 ? (u32)(n) : (n))
n&0xffffffff would be simpler.
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