public inbox for gcc-patches@gcc.gnu.org
 help / color / mirror / Atom feed
From: "Marc Poulhiès" <poulhies@adacore.com>
To: gcc-patches@gcc.gnu.org
Cc: Eric Botcazou <ebotcazou@adacore.com>
Subject: [COMMITTED] ada: Lift restriction on optimization of aliased objects
Date: Mon, 16 Jan 2023 15:48:41 +0100	[thread overview]
Message-ID: <20230116144841.3171334-1-poulhies@adacore.com> (raw)

From: Eric Botcazou <ebotcazou@adacore.com>

It turns out that the only blocking case is an aliased object whose nominal
subtype is an unconstrained array because the bounds must be allocated.

gcc/ada/

	* exp_ch3.adb (Expand_N_Object_Declaration): Also optimize aliased
	objects if their nominal subtype is not an unconstrained array.

Tested on x86_64-pc-linux-gnu, committed on master.

---
 gcc/ada/exp_ch3.adb | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/gcc/ada/exp_ch3.adb b/gcc/ada/exp_ch3.adb
index 536ae0c36e4..c866a9c40f5 100644
--- a/gcc/ada/exp_ch3.adb
+++ b/gcc/ada/exp_ch3.adb
@@ -7965,10 +7965,10 @@ package body Exp_Ch3 is
 
               Is_Entity_Name (Original_Node (Obj_Def))
 
-                --  The aliased case has to be excluded because the expression
-                --  will not be aliased in the general case.
+                --  Nor if it is effectively an unconstrained declaration
 
-                and then not Aliased_Present (N)
+                and then not (Is_Array_Type (Typ)
+                               and then Is_Constr_Subt_For_UN_Aliased (Typ))
 
                 --  We may use a renaming if the initializing expression is a
                 --  captured function call that meets a few conditions.
-- 
2.34.1


                 reply	other threads:[~2023-01-16 14:48 UTC|newest]

Thread overview: [no followups] expand[flat|nested]  mbox.gz  Atom feed

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20230116144841.3171334-1-poulhies@adacore.com \
    --to=poulhies@adacore.com \
    --cc=ebotcazou@adacore.com \
    --cc=gcc-patches@gcc.gnu.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for read-only IMAP folder(s) and NNTP newsgroup(s).