From mboxrd@z Thu Jan  1 00:00:00 1970
Return-Path: <gcc-bugs-return-467155-listarch-gcc-bugs=gcc.gnu.org@gcc.gnu.org>
Received: (qmail 19544 invoked by alias); 18 Nov 2014 11:13:58 -0000
Mailing-List: contact gcc-bugs-help@gcc.gnu.org; run by ezmlm
Precedence: bulk
List-Id: <gcc-bugs.gcc.gnu.org>
List-Archive: <http://gcc.gnu.org/ml/gcc-bugs/>
List-Post: <mailto:gcc-bugs@gcc.gnu.org>
List-Help: <mailto:gcc-bugs-help@gcc.gnu.org>
Sender: gcc-bugs-owner@gcc.gnu.org
Received: (qmail 19499 invoked by uid 48); 18 Nov 2014 11:13:53 -0000
From: "rguenth at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug tree-optimization/63844] [4.8/4.9/5 Regression] open mp parallelization prevents vectorization
Date: Tue, 18 Nov 2014 11:13:00 -0000
X-Bugzilla-Reason: CC
X-Bugzilla-Type: changed
X-Bugzilla-Watch-Reason: None
X-Bugzilla-Product: gcc
X-Bugzilla-Component: tree-optimization
X-Bugzilla-Version: 4.9.3
X-Bugzilla-Keywords: missed-optimization, openmp
X-Bugzilla-Severity: normal
X-Bugzilla-Who: rguenth at gcc dot gnu.org
X-Bugzilla-Status: ASSIGNED
X-Bugzilla-Priority: P3
X-Bugzilla-Assigned-To: rguenth at gcc dot gnu.org
X-Bugzilla-Target-Milestone: 4.8.4
X-Bugzilla-Flags:
X-Bugzilla-Changed-Fields:
Message-ID: <bug-63844-4-5jfeEyh6DW@http.gcc.gnu.org/bugzilla/>
In-Reply-To: <bug-63844-4@http.gcc.gnu.org/bugzilla/>
References: <bug-63844-4@http.gcc.gnu.org/bugzilla/>
Content-Type: text/plain; charset="UTF-8"
Content-Transfer-Encoding: 7bit
X-Bugzilla-URL: http://gcc.gnu.org/bugzilla/
Auto-Submitted: auto-generated
MIME-Version: 1.0
X-SW-Source: 2014-11/txt/msg01627.txt.bz2

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=63844

--- Comment #7 from Richard Biener <rguenth at gcc dot gnu.org> ---
Ok, I think Tom had a similar patch for this but passing the .omp_data_i by
effective "reference" (restrict qualified pointer and DECL_BY_REFERENCE)
fixes this.

Index: gcc/omp-low.c
===================================================================
--- gcc/omp-low.c       (revision 217692)
+++ gcc/omp-low.c       (working copy)
@@ -1517,7 +1517,8 @@ fixup_child_record_type (omp_context *ct
       layout_type (type);
     }

-  TREE_TYPE (ctx->receiver_decl) = build_pointer_type (type);
+  TREE_TYPE (ctx->receiver_decl)
+    = build_qualified_type (build_pointer_type (type), TYPE_QUAL_RESTRICT);
 }

 /* Instantiate decls as necessary in CTX to satisfy the data sharing
@@ -2006,6 +2007,7 @@ create_omp_child_function (omp_context *
   DECL_NAMELESS (t) = 1;
   DECL_ARG_TYPE (t) = ptr_type_node;
   DECL_CONTEXT (t) = current_function_decl;
+  DECL_BY_REFERENCE (t) = 1;
   TREE_USED (t) = 1;
   if (cilk_for_count)
     DECL_CHAIN (t) = DECL_ARGUMENTS (decl);

there are more similar objects built, so the above may not fully optimize
all cases.