From patchwork Sat Apr 28 08:29:08 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Laurent Vivier X-Patchwork-Id: 906072 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Authentication-Results: ozlabs.org; spf=pass (mailfrom) smtp.mailfrom=nongnu.org (client-ip=208.118.235.17; helo=lists.gnu.org; envelope-from=qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org; receiver=) Authentication-Results: ozlabs.org; dmarc=fail (p=none dis=none) header.from=redhat.com Received: from lists.gnu.org (lists.gnu.org [208.118.235.17]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (No client certificate requested) by ozlabs.org (Postfix) with ESMTPS id 40Y3rV5p4wz9s08 for ; Sat, 28 Apr 2018 18:29:44 +1000 (AEST) Received: from localhost ([::1]:51315 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1fCLEi-00007K-Sf for incoming@patchwork.ozlabs.org; Sat, 28 Apr 2018 04:29:40 -0400 Received: from eggs.gnu.org ([2001:4830:134:3::10]:52435) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1fCLEO-000072-89 for qemu-devel@nongnu.org; Sat, 28 Apr 2018 04:29:21 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1fCLEL-0006bc-21 for qemu-devel@nongnu.org; Sat, 28 Apr 2018 04:29:20 -0400 Received: from mx3-rdu2.redhat.com ([66.187.233.73]:53302 helo=mx1.redhat.com) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1fCLEK-0006ar-TK for qemu-devel@nongnu.org; Sat, 28 Apr 2018 04:29:16 -0400 Received: from smtp.corp.redhat.com (int-mx04.intmail.prod.int.rdu2.redhat.com [10.11.54.4]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 34159406C75C; Sat, 28 Apr 2018 08:29:13 +0000 (UTC) Received: from thinkpad.redhat.com (ovpn-116-184.ams2.redhat.com [10.36.116.184]) by smtp.corp.redhat.com (Postfix) with ESMTP id 54E7C2026980; Sat, 28 Apr 2018 08:29:09 +0000 (UTC) From: Laurent Vivier To: qemu-devel@nongnu.org Date: Sat, 28 Apr 2018 10:29:08 +0200 Message-Id: <20180428082908.32351-1-lvivier@redhat.com> X-Scanned-By: MIMEDefang 2.78 on 10.11.54.4 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.11.55.5]); Sat, 28 Apr 2018 08:29:13 +0000 (UTC) X-Greylist: inspected by milter-greylist-4.5.16 (mx1.redhat.com [10.11.55.5]); Sat, 28 Apr 2018 08:29:13 +0000 (UTC) for IP:'10.11.54.4' DOMAIN:'int-mx04.intmail.prod.int.rdu2.redhat.com' HELO:'smtp.corp.redhat.com' FROM:'lvivier@redhat.com' RCPT:'' X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] [fuzzy] X-Received-From: 66.187.233.73 Subject: [Qemu-devel] [RFC v2] tcg: workaround branch instruction overflow in tcg_out_qemu_ld/st X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Laurent Vivier , Richard Henderson Errors-To: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org Sender: "Qemu-devel" ppc64 uses a BC instruction to call the tcg_out_qemu_ld/st slow path. BC instruction uses a relative address encoded on 14 bits. The slow path functions are added at the end of the generated instructions buffer, in the reverse order of the callers. So more we have slow path functions more the distance between the caller (BC) and the function increases. This patch changes the behavior to generate the functions in the same order of the callers. Fixes: 15fa08f845 ("tcg: Dynamically allocate TCGOps") Signed-off-by: Laurent Vivier --- Notes: v2: - add a pointer to the tail of the list to add new element at the end and keep the original ordering - remove the recursive call tcg/tcg-ldst.inc.c | 11 ++++++++--- tcg/tcg.c | 3 ++- tcg/tcg.h | 3 ++- 3 files changed, 12 insertions(+), 5 deletions(-) diff --git a/tcg/tcg-ldst.inc.c b/tcg/tcg-ldst.inc.c index 0e14cf4357..735ebf8da6 100644 --- a/tcg/tcg-ldst.inc.c +++ b/tcg/tcg-ldst.inc.c @@ -46,7 +46,7 @@ static bool tcg_out_ldst_finalize(TCGContext *s) TCGLabelQemuLdst *lb; /* qemu_ld/st slow paths */ - for (lb = s->ldst_labels; lb != NULL; lb = lb->next) { + for (lb = s->ldst_head; lb != NULL; lb = lb->next) { if (lb->is_ld) { tcg_out_qemu_ld_slow_path(s, lb); } else { @@ -72,7 +72,12 @@ static inline TCGLabelQemuLdst *new_ldst_label(TCGContext *s) { TCGLabelQemuLdst *l = tcg_malloc(sizeof(*l)); - l->next = s->ldst_labels; - s->ldst_labels = l; + l->next = NULL; + if (s->ldst_tail) { + s->ldst_tail->next = l; + } else { + s->ldst_head = l; + } + s->ldst_tail = l; return l; } diff --git a/tcg/tcg.c b/tcg/tcg.c index bb24526c93..3ab195a23f 100644 --- a/tcg/tcg.c +++ b/tcg/tcg.c @@ -3324,7 +3324,8 @@ int tcg_gen_code(TCGContext *s, TranslationBlock *tb) s->code_ptr = tb->tc.ptr; #ifdef TCG_TARGET_NEED_LDST_LABELS - s->ldst_labels = NULL; + s->ldst_head = NULL; + s->ldst_tail = NULL; #endif #ifdef TCG_TARGET_NEED_POOL_LABELS s->pool_labels = NULL; diff --git a/tcg/tcg.h b/tcg/tcg.h index 30896ca304..22cb7cbffc 100644 --- a/tcg/tcg.h +++ b/tcg/tcg.h @@ -699,7 +699,8 @@ struct TCGContext { /* These structures are private to tcg-target.inc.c. */ #ifdef TCG_TARGET_NEED_LDST_LABELS - struct TCGLabelQemuLdst *ldst_labels; + struct TCGLabelQemuLdst *ldst_head; + struct TCGLabelQemuLdst *ldst_tail; #endif #ifdef TCG_TARGET_NEED_POOL_LABELS struct TCGLabelPoolData *pool_labels;