[petsc-dev] Ugly feature of __float128

[Jed Brown]

Barry Smith <bsmith at mcs.anl.gov> writes:

>   After wasting hours debugging I just realized that gcc __float128
>   REQUIRES that numerical constants be written with a q suffix or
>   first they are treated as double and then converted to __float. 

Unsuffixed numeric literals are double.  It's the semantic of the
language, not something they can change by adding a type.  Sorry.

>    I cannot understand why this is done this way. Who wants to convert a code to __float128 and have to then label all floating point numbers with a q which of course also means the code is not compilable with other compilers in double.

It's ugly, but you can put it in a macro:

#define NUM(a)   a ## q
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