From patchwork Wed Jun 28 13:29:16 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: =?utf-8?q?Llu=C3=ADs_Vilanova?= X-Patchwork-Id: 781704 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Received: from lists.gnu.org (lists.gnu.org [IPv6:2001:4830:134:3::11]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (No client certificate requested) by ozlabs.org (Postfix) with ESMTPS id 3wyNvb1lLYz9s4q for ; Wed, 28 Jun 2017 23:30:19 +1000 (AEST) Received: from localhost ([::1]:33411 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1dQD2u-0007RD-Oo for incoming@patchwork.ozlabs.org; Wed, 28 Jun 2017 09:30:16 -0400 Received: from eggs.gnu.org ([2001:4830:134:3::10]:58481) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1dQD2R-0007Qg-Uk for qemu-devel@nongnu.org; Wed, 28 Jun 2017 09:29:49 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1dQD2M-00021L-Va for qemu-devel@nongnu.org; Wed, 28 Jun 2017 09:29:47 -0400 Received: from roura.ac.upc.es ([147.83.33.10]:42529) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1dQD2M-00020e-ES; Wed, 28 Jun 2017 09:29:42 -0400 Received: from correu-2.ac.upc.es (correu-2.ac.upc.es [147.83.30.92]) by roura.ac.upc.es (8.13.8/8.13.8) with ESMTP id v5SDTZ0w027561; Wed, 28 Jun 2017 15:29:35 +0200 Received: from localhost (unknown [132.68.50.243]) by correu-2.ac.upc.es (Postfix) with ESMTPSA id C7C751E3; Wed, 28 Jun 2017 15:29:17 +0200 (CEST) From: =?utf-8?b?TGx1w61z?= Vilanova To: qemu-devel@nongnu.org Date: Wed, 28 Jun 2017 16:29:16 +0300 Message-Id: <149865655643.17063.11835076868609448555.stgit@frigg.lan> X-Mailer: git-send-email 2.11.0 In-Reply-To: <149865219962.17063.10630533069463266646.stgit@frigg.lan> References: <149865219962.17063.10630533069463266646.stgit@frigg.lan> User-Agent: StGit/0.17.1-dirty MIME-Version: 1.0 X-MIME-Autoconverted: from 8bit to quoted-printable by roura.ac.upc.es id v5SDTZ0w027561 X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.6.x [fuzzy] X-Received-From: 147.83.33.10 Subject: [Qemu-devel] [PATCH v11 18/29] target/arm: [tcg] Port to tb_start 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: Peter Maydell , Peter Crosthwaite , "Emilio G. Cota" , "open list:ARM" , Paolo Bonzini , =?UTF-8?q?Alex=20Benn=C3=A9e?= , Richard Henderson Errors-To: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org Sender: "Qemu-devel" Incrementally paves the way towards using the generic instruction translation loop. Signed-off-by: Lluís Vilanova Reviewed-by: Richard Henderson --- target/arm/translate.c | 82 ++++++++++++++++++++++++++---------------------- 1 file changed, 44 insertions(+), 38 deletions(-) diff --git a/target/arm/translate.c b/target/arm/translate.c index fc28cd45f7..029c4d3550 100644 --- a/target/arm/translate.c +++ b/target/arm/translate.c @@ -11855,6 +11855,49 @@ static void arm_trblock_init_globals(DisasContextBase *dcbase, CPUState *cpu) cpu_M0 = tcg_temp_new_i64(); } +static void arm_trblock_tb_start(DisasContextBase *dcbase, CPUState *cpu) +{ + DisasContext *dc = container_of(dcbase, DisasContext, base); + + /* A note on handling of the condexec (IT) bits: + * + * We want to avoid the overhead of having to write the updated condexec + * bits back to the CPUARMState for every instruction in an IT block. So: + * (1) if the condexec bits are not already zero then we write + * zero back into the CPUARMState now. This avoids complications trying + * to do it at the end of the block. (For example if we don't do this + * it's hard to identify whether we can safely skip writing condexec + * at the end of the TB, which we definitely want to do for the case + * where a TB doesn't do anything with the IT state at all.) + * (2) if we are going to leave the TB then we call gen_set_condexec() + * which will write the correct value into CPUARMState if zero is wrong. + * This is done both for leaving the TB at the end, and for leaving + * it because of an exception we know will happen, which is done in + * gen_exception_insn(). The latter is necessary because we need to + * leave the TB with the PC/IT state just prior to execution of the + * instruction which caused the exception. + * (3) if we leave the TB unexpectedly (eg a data abort on a load) + * then the CPUARMState will be wrong and we need to reset it. + * This is handled in the same way as restoration of the + * PC in these situations; we save the value of the condexec bits + * for each PC via tcg_gen_insn_start(), and restore_state_to_opc() + * then uses this to restore them after an exception. + * + * Note that there are no instructions which can read the condexec + * bits, and none which can write non-static values to them, so + * we don't need to care about whether CPUARMState is correct in the + * middle of a TB. + */ + + /* Reset the conditional execution bits immediately. This avoids + complications trying to do it at the end of the block. */ + if (dc->condexec_mask || dc->condexec_cond) { + TCGv_i32 tmp = tcg_temp_new_i32(); + tcg_gen_movi_i32(tmp, 0); + store_cpu_field(tmp, condexec_bits); + } +} + /* generate intermediate code for basic block 'tb'. */ void gen_intermediate_code(CPUState *cpu, TranslationBlock *tb) { @@ -11896,45 +11939,8 @@ void gen_intermediate_code(CPUState *cpu, TranslationBlock *tb) gen_tb_start(tb); tcg_clear_temp_count(); + arm_trblock_tb_start(&dc->base, cpu); - /* A note on handling of the condexec (IT) bits: - * - * We want to avoid the overhead of having to write the updated condexec - * bits back to the CPUARMState for every instruction in an IT block. So: - * (1) if the condexec bits are not already zero then we write - * zero back into the CPUARMState now. This avoids complications trying - * to do it at the end of the block. (For example if we don't do this - * it's hard to identify whether we can safely skip writing condexec - * at the end of the TB, which we definitely want to do for the case - * where a TB doesn't do anything with the IT state at all.) - * (2) if we are going to leave the TB then we call gen_set_condexec() - * which will write the correct value into CPUARMState if zero is wrong. - * This is done both for leaving the TB at the end, and for leaving - * it because of an exception we know will happen, which is done in - * gen_exception_insn(). The latter is necessary because we need to - * leave the TB with the PC/IT state just prior to execution of the - * instruction which caused the exception. - * (3) if we leave the TB unexpectedly (eg a data abort on a load) - * then the CPUARMState will be wrong and we need to reset it. - * This is handled in the same way as restoration of the - * PC in these situations; we save the value of the condexec bits - * for each PC via tcg_gen_insn_start(), and restore_state_to_opc() - * then uses this to restore them after an exception. - * - * Note that there are no instructions which can read the condexec - * bits, and none which can write non-static values to them, so - * we don't need to care about whether CPUARMState is correct in the - * middle of a TB. - */ - - /* Reset the conditional execution bits immediately. This avoids - complications trying to do it at the end of the block. */ - if (dc->condexec_mask || dc->condexec_cond) - { - TCGv_i32 tmp = tcg_temp_new_i32(); - tcg_gen_movi_i32(tmp, 0); - store_cpu_field(tmp, condexec_bits); - } do { dc->base.num_insns++; dc->insn_start_idx = tcg_op_buf_count();