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Re: [PATCH] Define CLOCKS_PER_SEC type to the type clock_t
- From: "H.J. Lu" <hjl dot tools at gmail dot com>
- To: Paul Eggert <eggert at cs dot ucla dot edu>
- Cc: GNU C Library <libc-alpha at sourceware dot org>
- Date: Mon, 5 Jan 2015 14:45:58 -0800
- Subject: Re: [PATCH] Define CLOCKS_PER_SEC type to the type clock_t
- Authentication-results: sourceware.org; auth=none
- References: <20150105204653 dot GA31001 at intel dot com> <54AB1115 dot 80608 at cs dot ucla dot edu>
On Mon, Jan 5, 2015 at 2:32 PM, Paul Eggert <eggert@cs.ucla.edu> wrote:
> On 01/05/2015 12:46 PM, H.J. Lu wrote:
>>
>> C99 specifies that CLOCKS_PER_SEC is a constant expression
>
>
> A minor point (mostly for comments): CLOCKS_PER_SEC needn't be a constant
> expression. Even POSIX doesn't require that: on the contrary, it explicitly
> warns you that it might not be a constant expression, even though it must
> evaluate to 1000000.
>
>> + * bits/time2.h: New file.
>> + * sysdeps/unix/sysv/linux/x86/bits/time2.h: Likewise.
>
>
> Wouldn't it be simpler and clearer to replace "# define CLOCKS_PER_SEC
> 1000000l" with "# define CLOCKS_PER_SEC ((clock_t) 1000000)"? That way, one
> wouldn't need all these other little files running around.
My copy of C99 has
---
CLOCKS_PER_SEC
which expands to a constant expression with type clock_t (described below)
that is the number per second of the value returned by the clock function.
---
Has it been changed?
--
H.J.