Re: Use i386/crtfastmath.c on Solaris 2/x86

[Rainer Orth <ro@CeBiTec.Uni-Bielefeld.DE>]

Richard Henderson <rth@redhat.com> writes:

> On 06/01/2011 07:51 AM, Rainer Orth wrote:
>> +  /* Set PC to the instruction after the faulting one to skip over it,
>> +     otherwise we enter an infinite loop.  4 is the size of the stmxcsr
>> +     instruction.  */
> ...
>> +      /* We need a single SSE instruction here so the handler can safely skip
>> +	 over it.  */
>> +      __asm__ volatile ("movss %xmm2,%xmm1");
>
> The comment referencing stmxcsr doesn't match the movss code.
> It's still a 4 byte opcode, so the code still works.

Copy-and-paste error ;-(  We already have the same code in
libgfortran/config/fpu-387.h and (without the comment) in
gcc/testsuite/lib/target-supports.exp.  I still mean to fix
driver-i386.c to correcly handle -march=native on Solaris 8 and 9 which
cannot in general execute SSE insns.  I wonder if there's a better place
to share this code?

> I do wonder if using "movaps %xmm0,%xmm0" might be cleaner,
> to avoid clobbering a register, even if that register is
> surely dead anyway.  That's a 3 byte opcode though, so the
> handler would need updating.

I'll give it a try.

Thanks.
        Rainer

-- 
-----------------------------------------------------------------------------
Rainer Orth, Center for Biotechnology, Bielefeld University