[PATCH] rtl cse: Fix PR94740, ICE on testsuite/gcc.dg/sso/t5.c with -mcpu=future -mpcrel -O1

[Jeff Law]

On Thu, 2020-04-30 at 08:54 +0100, Richard Sandiford wrote:
> Peter Bergner <bergner@linux.ibm.com> writes:
> > On 4/29/20 4:15 PM, Peter Bergner wrote:
> > > On 4/29/20 3:28 PM, Richard Sandiford wrote:
> > > > (Sorry for going ahead and writing an alternative patch, since if we do
> > > > go for this, I guess the earlier misdirections will have wasted two days
> > > > of your time.  But it seemed like I was just never going to think about
> > > > this PR properly unless I actually tried to write something. :-()
> > > 
> > > No worries from me!  I'm just glad to see this fixed before the release.
> > > I'll kill off a bootstrap and regtest on powerpc64le-linux too, in addition
> > > to your tests (arm & x86_64?).  Thanks for your help with this!
> > 
> > My bootstrap and regtesting of your patch on powerpc64le-linux was clean.
> 
> Thanks.  aarch64-linux-gnu and x86_64-linux-gnu bootstrap & regtests
> also came back clean.  I'll kick off an arm-linux-gnueabihf one too
> just to be safe.
> 
> I guess at this point it needs a review from someone else though.
> Jeff, WDYT?  Attached again below, this time without the shonky mime type.
It looks reasonable reasonable to me.  Re-using simplify_replace_fn_rtx seems
like a major simplification, which is definitely good.  Presumably one of the
major goals here is to get the CONST wrapping from simplify_plus_minus?

Jeff

ps.  Both forms looked the same in my inbox.  Not sure how they showed up in the
archives.