From mboxrd@z Thu Jan  1 00:00:00 1970
Return-Path: <gcc-bugzilla@gcc.gnu.org>
Received: by sourceware.org (Postfix, from userid 48)
	id 577213858427; Fri,  8 Mar 2024 13:02:54 +0000 (GMT)
DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org 577213858427
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gcc.gnu.org;
	s=default; t=1709902974;
	bh=QDqM/4qEDXHncwhi+Tk49SzXkv1DVOflCtC5893zpnk=;
	h=From:To:Subject:Date:In-Reply-To:References:From;
	b=p6MA+TJZiMZiLioOVieR9NRcDYHaOx+rYf0ANV3QlSEe2WZTU9jZBIHf8VgTiVyQB
	 XMtVLRjkLQ4WZxIqz7P0JV57zgkOavIDOJNz4zKHcPlvWDsPPzcDqu/vUeayd5HuXn
	 nclpwQOh5DcSaxerrGKCN1QxTxMB5t5S0YlA9iy0=
From: "rguenth at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug target/111822] [12/13/14 Regression] during RTL pass:
 lr_shrinkage ICE: in operator[], at vec.h:910 with -O2 -m32
 -flive-range-shrinkage -fno-dce -fnon-call-exceptions since
 r12-5301-g045206450386bc
Date: Fri, 08 Mar 2024 13:02:53 +0000
X-Bugzilla-Reason: CC
X-Bugzilla-Type: changed
X-Bugzilla-Watch-Reason: None
X-Bugzilla-Product: gcc
X-Bugzilla-Component: target
X-Bugzilla-Version: 14.0
X-Bugzilla-Keywords: EH, ice-on-valid-code, wrong-code
X-Bugzilla-Severity: normal
X-Bugzilla-Who: rguenth at gcc dot gnu.org
X-Bugzilla-Status: NEW
X-Bugzilla-Resolution: 
X-Bugzilla-Priority: P2
X-Bugzilla-Assigned-To: unassigned at gcc dot gnu.org
X-Bugzilla-Target-Milestone: 12.4
X-Bugzilla-Flags: 
X-Bugzilla-Changed-Fields: 
Message-ID: <bug-111822-4-YzvxYmBejv@http.gcc.gnu.org/bugzilla/>
In-Reply-To: <bug-111822-4@http.gcc.gnu.org/bugzilla/>
References: <bug-111822-4@http.gcc.gnu.org/bugzilla/>
Content-Type: text/plain; charset="UTF-8"
Content-Transfer-Encoding: quoted-printable
X-Bugzilla-URL: http://gcc.gnu.org/bugzilla/
Auto-Submitted: auto-generated
MIME-Version: 1.0
List-Id: <gcc-bugs.sourceware.org>

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=3D111822

--- Comment #12 from Richard Biener <rguenth at gcc dot gnu.org> ---
(In reply to Uro=C5=A1 Bizjak from comment #11)
> (In reply to Richard Biener from comment #10)
> > The easiest fix would be to refuse applying STV to a insn that
> > can_throw_internal () (that's an insn that has associated EH info).  Up=
dating
> > in this case would require splitting the BB or at least moving the now
> > no longer throwing insn to the next block (along the fallthru edge).
>=20
> This would be simply:
>=20
> --cut here--
> diff --git a/gcc/config/i386/i386-features.cc
> b/gcc/config/i386/i386-features.cc
> index 1de2a07ed75..90acb33db49 100644
> --- a/gcc/config/i386/i386-features.cc
> +++ b/gcc/config/i386/i386-features.cc
> @@ -437,6 +437,10 @@ scalar_chain::add_insn (bitmap candidates, unsigned =
int
> insn_uid,
>        && !HARD_REGISTER_P (SET_DEST (def_set)))
>      bitmap_set_bit (defs, REGNO (SET_DEST (def_set)));
>=20=20
> +  if (cfun->can_throw_non_call_exceptions

that part shouldn't be necessary, can_throw_internal is cheap enough
(but yes, unless STV handles calls it's correct)

> +      && can_throw_internal (insn))
> +    return false;
> +
>    /* ???  The following is quadratic since analyze_register_chain
>       iterates over all refs to look for dual-mode regs.  Instead this
>       should be done separately for all regs mentioned in the chain once.=
  */
> --cut here--
>=20
> But I think, we could do better. Adding CC.

We sure could, but I doubt it's too important?  Maybe for Go/Ada.=