libstdc++-v3: do not duplicate some math functions when using newlib

[Andre Vieira (lists)]

On 31/10/2024 08:23, Alexandre Oliva wrote:
> On Oct 25, 2024, "Andre Vieira (lists)" <andre.simoesdiasvieira@arm.com> wrote:
> 
>> I have to admit I am not super familiar with long doubles, either than
>> knowing they are 128-bit FP representations... but bisect has pointed
>> me to this patch when investigating a regression on
>> aarch64_be-none-elf for the libstdc++ testcase:
>> 26_numerics/complex/13450.cc
> 
>> Can you just confirm this is 'wrong' and that the problem is likely to
>> be with the big-endian implementation of sqrtl in I'm guessing newlib?
> 
> Yeah, this looks like a bug in newlib.  sqrtl is always defined there,
> it manipulates long doubles' internal representation, but unlike double
> and float, its ieeefp.h doesn't distinguish between big and little
> endian.  That should be easy to fix by defining another version of
> struct ieee_ext on big endian systems.
> 

Thanks, reported it in https://sourceware.org/bugzilla/show_bug.cgi?id=32326