On Thu, Dec 22, 2005 at 03:31:31AM +0100, Maxime Bizon wrote:
> > FYI, GCC 3.4.4 produces the following code which is clearly wrong:
> > Please file a bug report at: "http://gcc.gnu.org/bugzilla/".
> Same with 3.3 and 3.2...
> I'm really not familiar with inline assembly so I would appreciate that
> any gcc guru here confirm instruction_hazard() code is correct before I
> (or he) submit the bug report.
> As the bug seems to be in all gcc versions, I guess we should find a
> workaround... I changed the code to use an asm label instead of the C
> label and the bug disappeared. But I'm not sure my changes are correct
> for any platform other than mine...
We ran into similar problems in the past. It only seems to be a matter
of the code nearby and the exact options to trigger it.
The alternative is manually loading the address using la / dla which
defeats gcc's splitting of address loading. And having to use different
code for 32-bit and 64-bit sucks.
> Could anyone with the right skills help me to write a valid workaround
> please ?
> Here is what I have:
> __asm__ __volatile__(
> "lui $2,1f\n"
> "addiu $2,1f\n"
> "jr.hb $2\n1:":: );
Wrong, breaks 64-bit and uses $2 without telling gcc about it.