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 B9B41385840D; Tue, 14 Nov 2023 06:48:19 +0000 (GMT)
DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org B9B41385840D
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gcc.gnu.org;
	s=default; t=1699944499;
	bh=lu4P9mGFeeOU6ZhfCiUxUx4qu44Zo7HOTrBZAkD30SI=;
	h=From:To:Subject:Date:In-Reply-To:References:From;
	b=fxGyZ2FFYv/FNb+kb70Uo8kn/MUHQ2To2+chbcCCG1t4Juburjwh2tY/sV5cmk/JQ
	 /V/VbL/17e93NEHXB5rI2J4+tWu4Dltg32Xq725egT18Cky/3nPlfL/BDkOQD22d/u
	 x30dObnMNvcMrD7RjNlpy9bYHkxPpTom3zcEKyRk=
From: "guojiufu at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug rtl-optimization/112525] fail to eliminate unused store
Date: Tue, 14 Nov 2023 06:48:19 +0000
X-Bugzilla-Reason: CC
X-Bugzilla-Type: changed
X-Bugzilla-Watch-Reason: None
X-Bugzilla-Product: gcc
X-Bugzilla-Component: rtl-optimization
X-Bugzilla-Version: unknown
X-Bugzilla-Keywords: missed-optimization
X-Bugzilla-Severity: normal
X-Bugzilla-Who: guojiufu at gcc dot gnu.org
X-Bugzilla-Status: UNCONFIRMED
X-Bugzilla-Resolution: 
X-Bugzilla-Priority: P3
X-Bugzilla-Assigned-To: unassigned at gcc dot gnu.org
X-Bugzilla-Target-Milestone: ---
X-Bugzilla-Flags: 
X-Bugzilla-Changed-Fields: 
Message-ID: <bug-112525-4-lGOj2b6P8d@http.gcc.gnu.org/bugzilla/>
In-Reply-To: <bug-112525-4@http.gcc.gnu.org/bugzilla/>
References: <bug-112525-4@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=3D112525

--- Comment #1 from Jiu Fu Guo <guojiufu at gcc dot gnu.org> ---
(In reply to Jiu Fu Guo from comment #0)
> For below code:
> ```
> typedef struct teststruct
> {
>   double d;
>   int arr[15]; /* for ppc64le example foo1, 14: foo is just blr. 15: foo =
has
> 8 'std's */
> } teststruct;

Here, if the code is "int arr[14];", the struct is just passed via registers
(in foo function); and in the expander pass, they are stored to frame area.=
=20
If the code is "int arr[15];",  the struct is passed through registers
partially, and the other partial is through memory; and in the expander pas=
s,
they are stored to the area which is pointed via arg pointer.

In DSE pass, the 'dead' stores to 'frame' can be eliminated.=