From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: by sourceware.org (Postfix, from userid 48) id 1E7D83858C3A; Mon, 29 Apr 2024 11:49:37 +0000 (GMT) DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org 1E7D83858C3A DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gcc.gnu.org; s=default; t=1714391377; bh=cxWQ6aFh6Q6OY+HdLp5cKsJ0NjzbGx6zDu6+QRoT/to=; h=From:To:Subject:Date:In-Reply-To:References:From; b=n98AGrEzgmLPnZxq7nsOMy6ECiRQb8GSVdS13XGy0llaZEkIRhxHoIi+Bj9GffTg6 npw0QNOwdmJ67/TXm52FvvpLjYIiEkvLRWOFh/oe3Eck75fY4VDm2BvEvTGdJz1v/R IiJQtSn0fm2+OUWMD9VqEqF5E7v7o1ifVtexV4+E= From: "avieira at gcc dot gnu.org" To: gcc-bugs@gcc.gnu.org Subject: [Bug target/114801] [14/15 Regression] arm: ICE in find_cached_value, at rtx-vector-builder.cc:100 with MVE intrinsics Date: Mon, 29 Apr 2024 11:49:34 +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: ice-on-valid-code X-Bugzilla-Severity: normal X-Bugzilla-Who: avieira at gcc dot gnu.org X-Bugzilla-Status: ASSIGNED X-Bugzilla-Resolution: X-Bugzilla-Priority: P3 X-Bugzilla-Assigned-To: clyon at gcc dot gnu.org X-Bugzilla-Target-Milestone: 14.0 X-Bugzilla-Flags: X-Bugzilla-Changed-Fields: cc Message-ID: In-Reply-To: References: 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: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=3D114801 avieira at gcc dot gnu.org changed: What |Removed |Added ---------------------------------------------------------------------------- CC| |avieira at gcc dot gnu.org --- Comment #17 from avieira at gcc dot gnu.org --- Before anything, it might be worth to redefine the testcase to something wh= ere the predicate would have an effect in the result, for instance: #include uint32x4_t test_9() { return vdupq_m_n_u32(vdupq_n_u32(0xffffffff), 0, 0xcccc); } Next, it might be worth pointing out that the ISA does specify what happens when a predicate mask does not have all bits set for a specific element. Basically, the predicate mask operates on a per byte basis. Hence 16-bits in the mask, controlling all 16-bytes in a vector register. So for the above, the expected output would be {0xFFFF0000, 0xFFFF0000, 0xFFFF0000, 0xFFFF0000}. Having said that I can see how you'd interpret the ACLE specs as defining s= uch a mask to be 'UB', but I believe the intent was to make clear that all bits needed to be set if you wanted to true-predicate the full {32,16}-bit eleme= nt. This is the most common use, I can't imagine many users will be manipulating the mask in such ways. clang seems to follow this behavior generating an assembly sequence that le= ads to the expected output, though they use vpsel probably due to some canonicalization. And I'd prefer to be consistent with clang here.=