From mboxrd@z Thu Jan 1 00:00:00 1970 From: David Mosberger Date: Mon, 10 May 2004 20:16:33 +0000 Subject: Re: [PATCH] new ".serialize" gas directive Message-Id: <16543.58145.776571.385405@napali.hpl.hp.com> List-Id: References: <16537.51724.854691.934006@napali.hpl.hp.com> In-Reply-To: <16537.51724.854691.934006@napali.hpl.hp.com> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: linux-ia64@vger.kernel.org >>>>> On 07 May 2004 00:48:46 -0700, Jim Wilson said: Jim> I don't have a lot of time for IA-64 gcc work at the moment. It might Jim> be useful to have a gcc bug report for this so we don't lose track of Jim> it. I was going to submit a bug-report, but it's difficult to provide a reliable test-case, because other changes in the compiler can easily make one particular warning go away, just to show up in some other place. For example, with the CVS gcc (pre-3.5), the warning from mm/vmscan.c is gone but instead we get several other warnings such as this one from net/drivers/bonding/bond_main.c: $ as -x drivers/net/bonding/bond_main.s drivers/net/bonding/bond_main.s: Assembler messages: drivers/net/bonding/bond_main.s:3409: Warning: Use of 'addl' may violate WAW dependency 'GR%, % in 1 - 127' (impliedf), specific resource number is 42 drivers/net/bonding/bond_main.s:3408: Warning: This is the location of the conflicting usage The code in question looks like this: cmp4.eq p12, p13 = 6, r14 addl r28 = @ltoffx(.LC26), r1 mov r40 = r32 ;; (p13) cmp.eq p16, p17 = 0, r34 ld8.mov r41 = [r28], .LC26 (p12) br.cond.dpnt .L1108 ;; (p16) addl r42 = @ltoffx(.LC28), r1 (p17) addl r42 = @ltoffx(.LC27), r1 So, I think the best the bug report could say is "try building the Linux kernel and look for spurious dependency-violation warnings". Is this worth putting in a bug-report? --david