From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:49254) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ZlkaA-0004lH-Vr for qemu-devel@nongnu.org; Mon, 12 Oct 2015 17:24:35 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1Zlka6-0001GJ-1r for qemu-devel@nongnu.org; Mon, 12 Oct 2015 17:24:35 -0400 Received: from mail-pa0-x233.google.com ([2607:f8b0:400e:c03::233]:32954) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Zlka5-0001GF-TZ for qemu-devel@nongnu.org; Mon, 12 Oct 2015 17:24:30 -0400 Received: by pabrc13 with SMTP id rc13so28595423pab.0 for ; Mon, 12 Oct 2015 14:24:29 -0700 (PDT) Received: from bigtime.com ([101.191.203.214]) by smtp.gmail.com with ESMTPSA id zc4sm20083274pbb.24.2015.10.12.14.24.26 for (version=TLSv1/SSLv3 cipher=OTHER); Mon, 12 Oct 2015 14:24:27 -0700 (PDT) Sender: Richard Henderson From: Richard Henderson Date: Tue, 13 Oct 2015 08:23:45 +1100 Message-Id: <1444685028-4950-1-git-send-email-rth@twiddle.net> Subject: [Qemu-devel] [PATCH 0/3] powerpc tcg backend improvements List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org I happened to notice the ppc backend had a dependency on the placement of the prologue, which has just changed. There is a 32 byte window at code_gen_buffer + 16MB where we might do the wrong thing. The second patch reduces the code size reserved for performing goto_tb from 7 insns to 4. We probably haven't emitted all 7 insns for quite some time, since the TCG_REG_RA patch went in. But in the process, allow for the atomic update of the insns, something that I could see being required eventually. The third patch is a guess. But it matches the preferences in gcc, giving out-of-order processors a tad more freedom by avoiding cr0 when possible. Anyway, I've been running an alpha guest on a ppc64le host with these patches for a week now. r~ Richard Henderson (3): tcg/ppc: Adjust exit_tb for change in prologue placement tcg/ppc: Revise goto_tb implementation tcg/ppc: Prefer mask over andi. tcg/ppc/tcg-target.c | 79 ++++++++++++++++++++++++++++++++++------------------ translate-all.c | 2 ++ 2 files changed, 54 insertions(+), 27 deletions(-) -- 2.4.3