From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 30710 invoked by alias); 19 Oct 2004 20:16:56 -0000 Mailing-List: contact gcc-bugs-help@gcc.gnu.org; run by ezmlm Precedence: bulk List-Archive: List-Post: List-Help: Sender: gcc-bugs-owner@gcc.gnu.org Received: (qmail 30697 invoked by alias); 19 Oct 2004 20:16:55 -0000 Date: Tue, 19 Oct 2004 20:16:00 -0000 Message-ID: <20041019201655.30696.qmail@sourceware.org> From: "law at redhat dot com" To: gcc-bugs@gcc.gnu.org In-Reply-To: <20041018121604.18046.steven@gcc.gnu.org> References: <20041018121604.18046.steven@gcc.gnu.org> Reply-To: gcc-bugzilla@gcc.gnu.org Subject: [Bug tree-optimization/18046] Missed jump threading optimization X-Bugzilla-Reason: CC X-SW-Source: 2004-10/txt/msg02548.txt.bz2 List-Id: ------- Additional Comments From law at redhat dot com 2004-10-19 20:16 ------- Subject: Re: Missed jump threading optimization On Mon, 2004-10-18 at 16:50, stevenb at suse dot de wrote: > ------- Additional Comments From stevenb at suse dot de 2004-10-18 22:50 ------- > Subject: Re: Missed jump threading optimization > > Hmm, threading the default case sounds interesting, but the real > reason why the RTL threader catches this and the tree threader does > not is because on RTL the test case basically looks like this: > > extern void foo (void); > extern int i; > void > bar (void) > { > if (i == 0) > foo (); > > if (i == 0) > foo (); > } > > Hey, I can thread that! :-) > > So perhaps we should consider lowering SWITCH_EXPRs with only two > targets to COND_EXPRs after all...? That would be quite easy to > do. Jan and maybe others have talked about lowering SWITCH_EXPRs earlier. I don't recall if it ever got implemented. jeff -- http://gcc.gnu.org/bugzilla/show_bug.cgi?id=18046