On Mon, Jul 03, 2000 at 07:30:42PM +0200, Andreas Jaeger wrote:
> Porting glibc to MIPS I noticed that the initial contents of the fpu
> control word doesn't seem to be right (at least on the machines I've
> tried - one with a normal MIPS 2.2.13 and one with 2.2.15 and the
> MIPS/Algorithmics patches (including FPU emulator).
> The appended small test program should return a 0 (that's the desired
> value by glibc for full ISO C99 support) - but it seems to be set to
> 0x600.
>
> Could the kernel folks fix this, please? I grepped through the sources
> and didn't find a place where the FPU gets initialised.:-(
Surprise - the kernel initializes this to zero and the libc should do
the same afair. Did this change?
I tried your program on a Indy running 2.4.0-test2 + glibc 2.2 and it was
printing ``0 0''.
Could you check the source of your kernel for the value it's writing to
fcr31? That's the constant FPU_DEFAULT defined in arch/mips/kernel/
r4k_switch.S. Some quite old kernel were using a different value but I
was actually assuming those versions have already died out.
Ralf
|