Re: "insn does not satisfy its constraints" compiling perl

Hi Kalvis,

On Tue, 2026-03-03 at 20:24 +1100, Kalvis Duckmanton wrote:
> On 3/3/26 18:05, John Paul Adrian Glaubitz wrote:
> > Hi Kalvis,
> > 
> > On Tue, 2026-03-03 at 16:20 +1100, Kalvis Duckmanton wrote:
> > > I'm not sure that I understand why the 'earlyclobber' constraint is
> > > applied to the output operand of '*extzv_aligned_2'.  If I remove the
> > > 'earlyclobber' constraint, GCC 12.5.0 compiles both the reduced test
> > > case and the original 'toke.i' without incident. (Also the NetBSD
> > > distribution, but it did that before.)
> > I'm not sure whether it makes much sense to debug the problem in detail,
> > as interesting as it sounds, when you confirm the issue is not present in
> > GCC 14.
> 
> I couldn't reproduce the problem with the same input.  I do suspect that 
> it is still there in GCC 14, but I'm not sure how to expose it (other 
> than by compiling GCC or Perl or something of that sort and seeing what 
> happens).

There were many improvements in the vax backend which is why I think that
chances are the issue was actually fixed.

Did you check the GCC commit history whether there is a related change?

Adrian

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