From patchwork Wed May 29 10:54:39 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Thomas Huth X-Patchwork-Id: 13678692 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 2D169C25B75 for ; Wed, 29 May 2024 10:57:43 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1sCGxi-0004d1-6T; Wed, 29 May 2024 06:55:18 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1sCGxe-0004b0-E0 for qemu-devel@nongnu.org; Wed, 29 May 2024 06:55:14 -0400 Received: from us-smtp-delivery-124.mimecast.com ([170.10.133.124]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1sCGxc-000392-Hx for qemu-devel@nongnu.org; Wed, 29 May 2024 06:55:14 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1716980111; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=0hGgy6Hp9s9MqVRuTqz+IGZjvh9B+VjQjOFSX8Q6f4I=; b=NtJiE1GekRxyoYU/OL+0/poRqY96Put3ue/ny7m8NK0XobfPI9uGdk/g0vG4PR49Yi7qDp 34Dgx0IGFjhNNHgxl1OGXB7Zw+oMzxWOlbaNh1scyqp0yD/xS+DemU9VOz/iCx8ExKhFVX WACu1kr5dsqbiQHRWRgpmMNk8DMwF3U= Received: from mimecast-mx02.redhat.com (mimecast-mx02.redhat.com [66.187.233.88]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-408-NzkeJLNHNN-UBRBq_09Urg-1; Wed, 29 May 2024 06:55:09 -0400 X-MC-Unique: NzkeJLNHNN-UBRBq_09Urg-1 Received: from smtp.corp.redhat.com (int-mx03.intmail.prod.int.rdu2.redhat.com [10.11.54.3]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id 4FBA4857A81; Wed, 29 May 2024 10:55:09 +0000 (UTC) Received: from thuth-p1g4.redhat.com (unknown [10.39.192.109]) by smtp.corp.redhat.com (Postfix) with ESMTP id BC890105480A; Wed, 29 May 2024 10:55:07 +0000 (UTC) From: Thomas Huth To: qemu-devel@nongnu.org, Richard Henderson Cc: qemu-s390x@nongnu.org, Ilya Leoshkevich Subject: [PULL 07/22] target/s390x: Simplify help_branch Date: Wed, 29 May 2024 12:54:39 +0200 Message-ID: <20240529105454.1149225-8-thuth@redhat.com> In-Reply-To: <20240529105454.1149225-1-thuth@redhat.com> References: <20240529105454.1149225-1-thuth@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 3.4.1 on 10.11.54.3 Received-SPF: pass client-ip=170.10.133.124; envelope-from=thuth@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -20 X-Spam_score: -2.1 X-Spam_bar: -- X-Spam_report: (-2.1 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.036, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_NONE=-0.0001, RCVD_IN_MSPIKE_H4=0.001, RCVD_IN_MSPIKE_WL=0.001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001, T_SCC_BODY_TEXT_LINE=-0.01 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org From: Richard Henderson Always use a tcg branch, instead of movcond. The movcond was not a bad idea before PER was added, but since then we have either 2 or 3 actions to perform on each leg of the branch, and multiple movcond is inefficient. Reorder the taken branch to be fallthrough of the tcg branch. Reviewed-by: Ilya Leoshkevich Signed-off-by: Richard Henderson Message-ID: <20240502054417.234340-8-richard.henderson@linaro.org> Signed-off-by: Thomas Huth --- target/s390x/tcg/translate.c | 152 ++++++++++++----------------------- 1 file changed, 50 insertions(+), 102 deletions(-) diff --git a/target/s390x/tcg/translate.c b/target/s390x/tcg/translate.c index 7ae928c3b0..78066aaf84 100644 --- a/target/s390x/tcg/translate.c +++ b/target/s390x/tcg/translate.c @@ -353,25 +353,6 @@ static void per_branch(DisasContext *s, bool to_next) #endif } -static void per_branch_cond(DisasContext *s, TCGCond cond, - TCGv_i64 arg1, TCGv_i64 arg2) -{ -#ifndef CONFIG_USER_ONLY - if (s->base.tb->flags & FLAG_MASK_PER_BRANCH) { - TCGLabel *lab = gen_new_label(); - tcg_gen_brcond_i64(tcg_invert_cond(cond), arg1, arg2, lab); - - tcg_gen_movi_i64(gbea, s->base.pc_next); - gen_helper_per_branch(tcg_env, gbea, psw_addr); - - gen_set_label(lab); - } else { - TCGv_i64 pc = tcg_constant_i64(s->base.pc_next); - tcg_gen_movcond_i64(cond, gbea, arg1, arg2, gbea, pc); - } -#endif -} - static void per_breaking_event(DisasContext *s) { tcg_gen_movi_i64(gbea, s->base.pc_next); @@ -1128,14 +1109,12 @@ static DisasJumpType help_goto_indirect(DisasContext *s, TCGv_i64 dest) static DisasJumpType help_branch(DisasContext *s, DisasCompare *c, bool is_imm, int imm, TCGv_i64 cdest) { - DisasJumpType ret; uint64_t dest = s->base.pc_next + (int64_t)imm * 2; - TCGLabel *lab; + TCGLabel *lab, *over; /* Take care of the special cases first. */ if (c->cond == TCG_COND_NEVER) { - ret = DISAS_NEXT; - goto egress; + return DISAS_NEXT; } if (is_imm) { /* @@ -1145,104 +1124,73 @@ static DisasJumpType help_branch(DisasContext *s, DisasCompare *c, if (c->cond == TCG_COND_ALWAYS || (dest == s->pc_tmp && !(s->base.tb->flags & FLAG_MASK_PER_BRANCH))) { - ret = help_goto_direct(s, dest); - goto egress; + return help_goto_direct(s, dest); } } else { if (!cdest) { /* E.g. bcr %r0 -> no branch. */ - ret = DISAS_NEXT; - goto egress; + return DISAS_NEXT; } if (c->cond == TCG_COND_ALWAYS) { - ret = help_goto_indirect(s, cdest); - goto egress; + return help_goto_indirect(s, cdest); } } - if (use_goto_tb(s, s->pc_tmp)) { - if (is_imm && use_goto_tb(s, dest)) { - /* Both exits can use goto_tb. */ - update_cc_op(s); - - lab = gen_new_label(); - if (c->is_64) { - tcg_gen_brcond_i64(c->cond, c->u.s64.a, c->u.s64.b, lab); - } else { - tcg_gen_brcond_i32(c->cond, c->u.s32.a, c->u.s32.b, lab); - } - - /* Branch not taken. */ - tcg_gen_goto_tb(0); - tcg_gen_movi_i64(psw_addr, s->pc_tmp); - tcg_gen_exit_tb(s->base.tb, 0); - - /* Branch taken. */ - gen_set_label(lab); - per_breaking_event(s); - tcg_gen_goto_tb(1); - tcg_gen_movi_i64(psw_addr, dest); - tcg_gen_exit_tb(s->base.tb, 1); + update_cc_op(s); - ret = DISAS_NORETURN; - } else { - /* Fallthru can use goto_tb, but taken branch cannot. */ - /* Store taken branch destination before the brcond. This - avoids having to allocate a new local temp to hold it. - We'll overwrite this in the not taken case anyway. */ - if (!is_imm) { - tcg_gen_mov_i64(psw_addr, cdest); - } + /* + * Ensure the taken branch is fall-through of the tcg branch. + * This keeps @cdest usage within the extended basic block, + * which avoids an otherwise unnecessary spill to the stack. + */ + lab = gen_new_label(); + if (s->base.tb->flags & FLAG_MASK_PER_BRANCH) { + over = gen_new_label(); + } else { + over = NULL; + } - lab = gen_new_label(); - if (c->is_64) { - tcg_gen_brcond_i64(c->cond, c->u.s64.a, c->u.s64.b, lab); - } else { - tcg_gen_brcond_i32(c->cond, c->u.s32.a, c->u.s32.b, lab); - } + if (c->is_64) { + tcg_gen_brcond_i64(tcg_invert_cond(c->cond), + c->u.s64.a, c->u.s64.b, lab); + } else { + tcg_gen_brcond_i32(tcg_invert_cond(c->cond), + c->u.s32.a, c->u.s32.b, lab); + } - /* Branch not taken. */ - update_cc_op(s); - tcg_gen_goto_tb(0); - tcg_gen_movi_i64(psw_addr, s->pc_tmp); - tcg_gen_exit_tb(s->base.tb, 0); + /* Branch taken. */ + if (is_imm) { + tcg_gen_movi_i64(psw_addr, dest); + } else { + tcg_gen_mov_i64(psw_addr, cdest); + } + per_branch(s, false); - gen_set_label(lab); - if (is_imm) { - tcg_gen_movi_i64(psw_addr, dest); - } - per_breaking_event(s); - ret = DISAS_PC_UPDATED; - } + if (is_imm && use_goto_tb(s, dest)) { + tcg_gen_goto_tb(0); + tcg_gen_exit_tb(s->base.tb, 0); + } else if (over) { + tcg_gen_br(over); } else { - /* Fallthru cannot use goto_tb. This by itself is vanishingly rare. - Most commonly we're single-stepping or some other condition that - disables all use of goto_tb. Just update the PC and exit. */ + tcg_gen_lookup_and_goto_ptr(); + } - TCGv_i64 next = tcg_constant_i64(s->pc_tmp); - if (is_imm) { - cdest = tcg_constant_i64(dest); - } + gen_set_label(lab); - if (c->is_64) { - tcg_gen_movcond_i64(c->cond, psw_addr, c->u.s64.a, c->u.s64.b, - cdest, next); - per_branch_cond(s, c->cond, c->u.s64.a, c->u.s64.b); - } else { - TCGv_i32 t0 = tcg_temp_new_i32(); - TCGv_i64 t1 = tcg_temp_new_i64(); - TCGv_i64 z = tcg_constant_i64(0); - tcg_gen_setcond_i32(c->cond, t0, c->u.s32.a, c->u.s32.b); - tcg_gen_extu_i32_i64(t1, t0); - tcg_gen_movcond_i64(TCG_COND_NE, psw_addr, t1, z, cdest, next); - per_branch_cond(s, TCG_COND_NE, t1, z); - } + /* Branch not taken. */ + tcg_gen_movi_i64(psw_addr, s->pc_tmp); + if (use_goto_tb(s, s->pc_tmp)) { + tcg_gen_goto_tb(1); + tcg_gen_exit_tb(s->base.tb, 1); + } - ret = DISAS_PC_UPDATED; + if (over) { + gen_set_label(over); + return DISAS_PC_UPDATED; } - egress: - return ret; + tcg_gen_lookup_and_goto_ptr(); + return DISAS_NORETURN; } /* ====================================================================== */