From mboxrd@z Thu Jan 1 00:00:00 1970 From: Luc Van Oostenryck Subject: Re: Possible linearizer issue Date: Tue, 21 Mar 2017 00:59:24 +0100 Message-ID: <20170320235923.w5sdofxvbi66d24o@macpro.local> References: Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Received: from mail-wr0-f180.google.com ([209.85.128.180]:36607 "EHLO mail-wr0-f180.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754873AbdCTX73 (ORCPT ); Mon, 20 Mar 2017 19:59:29 -0400 Received: by mail-wr0-f180.google.com with SMTP id u108so102292610wrb.3 for ; Mon, 20 Mar 2017 16:59:28 -0700 (PDT) Content-Disposition: inline In-Reply-To: Sender: linux-sparse-owner@vger.kernel.org List-Id: linux-sparse@vger.kernel.org To: Dibyendu Majumdar Cc: Linux-Sparse On Mon, Mar 20, 2017 at 11:43:33PM +0000, Dibyendu Majumdar wrote: > On 18 March 2017 at 11:41, Dibyendu Majumdar wrote: > > I am investigating a failure in one of the tests. The generated > > linearized code has instructions such as: > > > > .L363: > > br VOID, .L366, .L439 > > .L366: > > load.32 %r413 <- 44[%arg1] > > br %r413, .L368, .L369 > > .L368: > > load.64 %r415 <- 0[s7813er] > > call.32 %r416 <- printf, %r415, $2 > > br .L369 > > .L369: > > phisrc.32 %phi97(rc) <- $2 > > br .L439 > > .L439: > > phi.32 %r557 <- %phi95(rc), VOID, %phi97(rc), VOID, VOID, VOID > > > > The test program is here: > > > > https://github.com/dibyendumajumdar/dmr_c/blob/master/tests/set1/cq2.c > > It's quite old as there is several instance of very similar code that are quite OK and just this last one is wrong. I'll look at it tomorrow. > It seems that the issue is occurring in simplify_flow(). If I disable > the call to this, then the program compiles successfully and also > runs. None of my other tests fail with this step disabled. > > Any clues what might be going wrong? I suspect an issue with the tracking of pseudo usage. > Does disabling simplify_flow() have any other effect except for missed > optimizations? It should not. -- Luc