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From: "akrl at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug target/97141] [10/11 Regression] aarch64, SVE: ICE in decompose, at rtl.h (during expand) since r10-4676-g9c437a108a
Date: Tue, 08 Dec 2020 14:39:09 +0000	[thread overview]
Message-ID: <bug-97141-4-jSqT3g1gES@http.gcc.gnu.org/bugzilla/> (raw)
In-Reply-To: <bug-97141-4@http.gcc.gnu.org/bugzilla/>

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=97141

--- Comment #1 from akrl at gcc dot gnu.org ---
Hi all,

this is so far my understanding of what is going on here:

While in expand the vector builder is trying to build to determine elt number 3
of a vector of POLY_INT_CST.

To do that the step has to be computed, therefore rtx_vector_builder::step is
calling wi::sub to compute the difference between elt1 and elt2.

wi::sub (in wide-int.h:2508) is making use of WIDE_INT_REF_FOR so we end up in
decompose where we have no handling for poly_int.

I'm a little puzzled because I'm not sure where in this stack would be correct
to add the poly_int handling.

decompose is returning a wi::storage_ref that AFAIU has no poly support.

It might be easier to handle the poly subtraction in rtx_vector_builder::step
before entering into wide-int specific code?

  Andrea

  parent reply	other threads:[~2020-12-08 14:39 UTC|newest]

Thread overview: 14+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-09-21 10:48 [Bug target/97141] New: " acoplan at gcc dot gnu.org
2020-09-21 11:29 ` [Bug target/97141] " rguenth at gcc dot gnu.org
2020-12-08 14:39 ` akrl at gcc dot gnu.org [this message]
2020-12-16 14:10 ` acoplan at gcc dot gnu.org
2021-01-14  9:21 ` rguenth at gcc dot gnu.org
2021-01-14  9:21 ` rguenth at gcc dot gnu.org
2021-03-30 11:05 ` rsandifo at gcc dot gnu.org
2021-03-31 18:34 ` cvs-commit at gcc dot gnu.org
2021-03-31 20:37 ` [Bug target/97141] [10 " rsandifo at gcc dot gnu.org
2021-03-31 20:38 ` rsandifo at gcc dot gnu.org
2021-04-08 12:02 ` rguenth at gcc dot gnu.org
2021-04-23  9:10 ` cvs-commit at gcc dot gnu.org
2021-04-23  9:14 ` rsandifo at gcc dot gnu.org
2021-12-12 13:18 ` pinskia at gcc dot gnu.org

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