From mboxrd@z Thu Jan 1 00:00:00 1970 From: bugzilla-daemon@freedesktop.org Subject: [Bug 35257] r300_fragprog_emit.c::emit_alu(): Too many ALU instructions Date: Mon, 14 Mar 2011 17:28:24 -0700 (PDT) Message-ID: <20110315002824.92AFE13004E@annarchy.freedesktop.org> References: Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Received: from annarchy.freedesktop.org (annarchy.freedesktop.org [131.252.210.176]) by gabe.freedesktop.org (Postfix) with ESMTP id AF35A9ECC6 for ; Mon, 14 Mar 2011 17:28:24 -0700 (PDT) In-Reply-To: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: dri-devel-bounces+sf-dri-devel=m.gmane.org@lists.freedesktop.org Errors-To: dri-devel-bounces+sf-dri-devel=m.gmane.org@lists.freedesktop.org To: dri-devel@lists.freedesktop.org List-Id: dri-devel@lists.freedesktop.org https://bugs.freedesktop.org/show_bug.cgi?id=35257 --- Comment #7 from Tom Stellard 2011-03-14 17:28:24 PDT --- (In reply to comment #5) > (In reply to comment #4) > > Like Marek said, this isn't a bug it is a hardware limitation. The only way > > this could work is with changes to Gnome Shell, so you should contact the Gnome > > Shell developers, although they might tell your hardware is unsupported. > > Since we know there's a lot of work still to be done in the compiler's higher > level optimization passes, I always feel like this is a bit of a cop out > answer. The TGSI input is 125 instructions, and it looks like a nightmare of > lowered if-statements. There are way more CMP/SEQ/MUL sequences than any > program should generate. Unsurprisingly, the driver chokes on it. I'm sure > the i915 driver, which has limitations similar to r300, would choke even worse. > > Comparing the GLSL to the generated TGSI might reveal some high-level > optimization opportunities that we're missing. It may also help us give some > suggestions to the gnome-shell folks to make the shader more friendly to older > hardware. There are, after all, a lot of i915s and r300s out there. > > Just for giggles, could we get the output of MESA_GLSL=dump too? Use the same > procedure as for RADEON_DEBUG=fp. We were able to give some suggestions to the gnome shell developers to get the shader to fit. The optimization that is missing is pre-computing of equivalent expressions (not sure what the technical term is). In this shader there was a four clause conditional that was being used in two different IF statements. I've attached the before and after versions of the shader if you're interested -- Configure bugmail: https://bugs.freedesktop.org/userprefs.cgi?tab=email ------- You are receiving this mail because: ------- You are the assignee for the bug.