unnormal Intel 80-bit long doubles and isnanl

[Andreas Schwab]

On Nov 24 2020, Szabolcs Nagy via Gcc wrote:

>> glibc evaluates the bit pattern of the 80-bit long double and in the
>> process, ignores the integer bit, i.e. bit 63.  As a result, it considers
>> the unnormal number as a valid long double and isnanl returns 0.
>
> i think m68k and x86 are different here.

The mc68881 doesn't trap on unnormal numbers, it implicitly converts
such input representations to normal, denormal or zero, as appropriate.

Andreas.

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Andreas Schwab, schwab@linux-m68k.org
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