tests/mpq/t-get_d.c failure on m68k-linux

Niels Möller nisse at lysator.liu.se
Mon Feb 18 08:36:26 CET 2013

Aldy Hernandez <aldyh at redhat.com> writes:

> [Disclaimer: I am not a 68k guru.  Well, for that matter neither am I
> an FP guru...:)].

Neither am I...

> This means that EQ/NE comparisons with FP values on 68k are extremely
> problematic because the programmer has no way of knowing if the values
> are in memory or in the FP registers.  For example, the compiler may
> have spilled an FPR to memory and read it back, thus losing some
> precision, causing the equality to fail.
> I suggest running the testcase (and possibly all of GMP) with
> -ffloat-store on m68k.

I think I've seen other code which declares certain double variables as
volatile, to force the compiler to store them in memory. Maybe that
would be a more local and portable workaround?


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