Re: [PATCH] testsuite: Generalize check_effective_target_lra

[Hans-Peter Nilsson <hp@axis.com>]

> From: Richard Sandiford <richard.sandiford@arm.com>
> Date: Wed, 8 Feb 2023 17:54:15 +0100

> Hans-Peter Nilsson via Gcc-patches <gcc-patches@gcc.gnu.org> writes:
> > Tested native x86_64-pc-linux-gnu and cris-elf (non-LRA and
> > also hacked to switch to LRA).
> 
> Since !LRA is hopefully not long for this world, I'd personally
> prefer to keep it simple & obvious (at least for most targets).
> There's a risk that we could lose testing on most targets through
> an innocuous-looking change to one of LRA's fprintfs.
> 
> If this is for -mlra-like options, I think it would be OK to guard the
> new code with a target check.  So the patch is OK with the existing
> "return 0" replaced by the new return, and with the istarget list
> extended if necessary, but with the outer structure the same.

If you, like me, are aiming for simple and obvious, why then
complicate what already works "for -mlra-like options" with
a target list?

> That might not do what you want though...

That assessment is correct.  I'd rather the test-suite
result be consistent for all targets.

brgds, H-P
PS. thanks for the review though

> 
> Thanks,
> Richard
> 
> >
> > Ok to commit?
> >
> > --- 8< ---
> > The LRA target list is incomplete.  Rather than syncing it with actual
> > LRA targets, better use existing infrastructure and look for a
> > LRA-specific pattern in the reload dump (which has the same name, but
> > completely different contents).
> >
> > 	* lib/target-supports.exp: Replace target list with looking for
> > 	a LRA-specific string in the reload dump.
> > ---
> >  gcc/testsuite/lib/target-supports.exp | 9 +++++----
> >  1 file changed, 5 insertions(+), 4 deletions(-)
> >
> > diff --git a/gcc/testsuite/lib/target-supports.exp b/gcc/testsuite/lib/target-supports.exp
> > index 227e3004077a..e62b7a2c869d 100644
> > --- a/gcc/testsuite/lib/target-supports.exp
> > +++ b/gcc/testsuite/lib/target-supports.exp
> > @@ -12192,10 +12192,11 @@ proc check_effective_target_o_flag_in_section { } {
> >  # return 1 if LRA is supported.
> >  
> >  proc check_effective_target_lra { } {
> > -    if { [istarget hppa*-*-*] } {
> > -	return 0
> > -    }
> > -    return 1
> > +    # Iterating over extended basic blocks is new with LRA.  Also need
> > +    # a context to avoid spuriously matching a register name.
> > +    return [check_no_messages_and_pattern lra "EBB 2 3" rtl-reload {
> > +	void foo (void) { }
> > +    }]
> >  }
> >  
> >  # Test whether optimizations are enabled ('__OPTIMIZE__') per the
>