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Re: 128-bit integer - nonsensical documentation?
- From: Jeffrey Walton <noloader at gmail dot com>
- To: Jonathan Wakely <jwakely dot gcc at gmail dot com>
- Cc: gcc-help <gcc-help at gcc dot gnu dot org>
- Date: Wed, 26 Aug 2015 08:48:45 -0400
- Subject: Re: 128-bit integer - nonsensical documentation?
- Authentication-results: sourceware.org; auth=none
- References: <1B1111BE-E274-4C80-8189-22B78D77647A at gmail dot com> <CAH6eHdTumersYZtRi62uGVhjW+nxmCkXRC__bN1En2Q6shRa3w at mail dot gmail dot com>
- Reply-to: noloader at gmail dot com
On Wed, Aug 26, 2015 at 8:22 AM, Jonathan Wakely <jwakely.gcc@gmail.com> wrote:
> On 26 August 2015 at 12:04, Kostas Savvidis wrote:
>> The online documentation contains the attached passage as part of the "C-Extensionsâ chapter. There are no actual machines which have an " integer mode wide enough to hold 128 bitsâ as the document puts it.
>
> It's not talking about machine integers, it's talking about GCC
> integer modes. Several targets support that.
>
>> This would be a harmless confusion if it didnât go on to say ââ long long integer less than 128 bits wideâ (???!!!) Whereas in reality "long long intâ is 64 bits everywhere i have seen.
>
>
> Read it more carefully, it says you can't express an integer constant
> of type __int128 on such platforms.
Is there a way to detect the presence or availability of __int128 via
preprocessor macros?
Jeff