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Re: PR 21438 : Warning about division by zero depends on lexical form


On 29/01/07, Dirk Mueller <dmueller@suse.de> wrote:
On Sunday, 14. January 2007 16:16, Manuel López-Ibáñez wrote:

> The C front-end does not warning about division by zero for floating
> point because it is a legitimate way of obtaining infinities and NaNs.

only if division by zero is a real constant, not if it is an integer constant.

> With this patch we don't emit the warning if the integer zero is
> promoted to real type.

.. which is not intended.

Really? Strange. Well, I can turn the patch around and fix the C++ front-end to follow the C front-end.

> The C++ front-end, on the contrary, warns always. Is this an inconsistency?

Yes, I submitted a patch about this a few months ago to fix this, but
unfortunately it was never approved (there was a discussion about it though
where I lerned the difference between 0.0/0.0 and 0.0/0).

>+ 1.0f/0, /* { dg-bogus "division by zero" } */

it *should* warn here.

Could you point me to the discussion or give some hint to find it?


Cheers,

Manuel.


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