This is the mail archive of the
libc-alpha@sourceware.org
mailing list for the glibc project.
Re: Do not use const attribute for nan functions (bug 23277) [committed]
* Joseph Myers:
> On Tue, 12 Jun 2018, Florian Weimer wrote:
>
>> * Joseph Myers:
>>
>> > +static int
>> > +do_test (void)
>> > +{
>> > + char buf[2] = { '2', 0 };
>> > + float a = nanf (buf);
>> > + buf[0] = '3';
>> > + float b = nanf (buf);
>> > + return memcmp (&a, &b, sizeof (float)) == 0;
>> > +}
>>
>> By the way, there's TEST_COMPARE_BLOB now, which can simplify
>> debugging of test failures because the failure message includes the
>> blobs that differ.
>
> In this case, the requirement is actually that the blobs must differ, with
> a failure if they are the same (if the compiler optimized out the second
> nanf call and so produced the same NaN for both calls).
Oh, right. I was confused.