From mboxrd@z Thu Jan  1 00:00:00 1970
Return-Path: <gcc-bugs-return-454847-listarch-gcc-bugs=gcc.gnu.org@gcc.gnu.org>
Received: (qmail 14295 invoked by alias); 25 Jun 2014 08:09:11 -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 14259 invoked by uid 48); 25 Jun 2014 08:09:07 -0000
From: "glisse at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug tree-optimization/57742] memset(malloc(n),0,n) -> calloc(n,1)
Date: Wed, 25 Jun 2014 08:09:00 -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: 4.9.0
X-Bugzilla-Keywords:
X-Bugzilla-Severity: enhancement
X-Bugzilla-Who: glisse at gcc dot gnu.org
X-Bugzilla-Status: REOPENED
X-Bugzilla-Priority: P3
X-Bugzilla-Assigned-To: unassigned at gcc dot gnu.org
X-Bugzilla-Target-Milestone: 4.10.0
X-Bugzilla-Flags:
X-Bugzilla-Changed-Fields:
Message-ID: <bug-57742-4-QmEduVp8JI@http.gcc.gnu.org/bugzilla/>
In-Reply-To: <bug-57742-4@http.gcc.gnu.org/bugzilla/>
References: <bug-57742-4@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: 2014-06/txt/msg01929.txt.bz2

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=57742

--- Comment #21 from Marc Glisse <glisse at gcc dot gnu.org> ---
I am testing the following:

--- tree-ssa-strlen.c    (revision 211967)
+++ tree-ssa-strlen.c    (working copy)
@@ -1646,20 +1646,22 @@ handle_builtin_memset (gimple_stmt_itera
   enum built_in_function code1 = DECL_FUNCTION_CODE (callee1);
   tree size = gimple_call_arg (stmt2, 2);
   if (code1 == BUILT_IN_CALLOC)
     /* Not touching stmt1 */ ;
   else if (code1 == BUILT_IN_MALLOC
        && operand_equal_p (gimple_call_arg (stmt1, 0), size, 0))
     {
       gimple_stmt_iterator gsi1 = gsi_for_stmt (stmt1);
       update_gimple_call (&gsi1, builtin_decl_implicit (BUILT_IN_CALLOC), 2,
               size, build_one_cst (size_type_node));
+      si1->length = build_int_cst (size_type_node, 0);
+      si1->stmt = gsi_stmt (gsi1);
     }
   else
     return true;
   tree lhs = gimple_call_lhs (stmt2);
   unlink_stmt_vdef (stmt2);
   if (lhs)
     {
       gimple assign = gimple_build_assign (lhs, ptr);
       gsi_replace (gsi, assign, false);
     }