Re: [PATCH] testsuite: scev: expect fail on ilp32

[Richard Biener <rguenther@suse.de>]

On Sat, 2 Dec 2023, Hans-Peter Nilsson wrote:

> > Date: Fri, 1 Dec 2023 08:07:14 +0100 (CET)
> > From: Richard Biener <rguenther@suse.de>
> 
> > On Fri, 1 Dec 2023, Hans-Peter Nilsson wrote:
> > 
> > > > From: Hans-Peter Nilsson <hp@axis.com>
> > > > Date: Thu, 30 Nov 2023 18:09:10 +0100
> > > 
> > >     Richard B.:
> > > > > > In the end we might need to move/duplicate the test to some
> > > > > > gcc.target/* dir and restrict it to a specific tuning.
> > > > 
> > > > I intend to post two alternative patches to get this
> > > > resolved:
> > > > 1: Move the tests to gcc.target/i386/scev-[3-5].c
> > > 
> > > Subject: [PATCH 1/2] testsuite: Fix XPASS for gcc.dg/tree-ssa/scev-3.c, -4.c and -5.c [PR112786]
> > > 
> > > This is the first alternative, perhaps the more appropriate one.
> > > 
> > > Tested cris-elf, arm-eabi (default), x86_64-linux, ditto -m32,
> > > h8300-elf and shle-linux; xpassing, skipped and passing as
> > > applicable and intended.
> > > 
> > > Ok to commit?
> > 
> > Digging in history reveals the testcases were added by
> > Jiangning Liu <jiangning.liu@arm.com>, not for any
> > particular bugreport but "The problem is originally from a real benchmark,
> > and the test case only tries to detect the GIMPLE level changes."
> > 
> > I'm not sure we can infer the testcase should be moved to
> > gcc.target/arm/ because of that, but it does seem plausible.
> 
> It's been so long and so many changes since these tests were
> regression guards, that the original target has lost
> importance.  Heck, it was even xfail lp64 at one time!
> According to my git dig, it's been adjusted for pass
> changes, including reordering and dump output changes.  But
> you know that; you've been instrumental in many of those
> changes. :)
> 
> I'd say gcc.target/arm/ is the one target that's *not*
> plausible, as according to Alex result differs between
> subtargets.
> 
> > I read from your messages that the testcases pass on arm*-*-*?
> 
> Yes: they pass (currently XPASS) on arm-eabi and
> arm-unknown-linux-gnueabi, default configurations.  But,
> scev-3 and -5 fail with for example -mcpu=cortex-r5

I see.  As said, the testcases test for "cost" things, so that we
"regressed" might mean we really "regressed" here.  Even the x86 -m32
result is questionable.

Of course whether using a single IV makes sense for all archs is
unknown.

Btw, if we turn the testcases into ones that are (sub-)target
specific then we want to again use C code as input.

I think at this point we've lost track and I'm juggling between
removing the testcases or moving them to a place they succeed
(with some specific -mcpu=?)

Richard.