From patchwork Wed Oct 20 12:57:23 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Lucas Mateus Martins Araujo e Castro X-Patchwork-Id: 12572421 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 mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 2A694C433F5 for ; Wed, 20 Oct 2021 13:53:21 +0000 (UTC) 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 mail.kernel.org (Postfix) with ESMTPS id A92EE61260 for ; Wed, 20 Oct 2021 13:53:20 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.1 mail.kernel.org A92EE61260 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=eldorado.org.br Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=nongnu.org Received: from localhost ([::1]:58846 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1mdC1v-0003az-R0 for qemu-devel@archiver.kernel.org; Wed, 20 Oct 2021 09:53:19 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:38202) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1mdBtf-000127-Dl; Wed, 20 Oct 2021 09:44:47 -0400 Received: from [201.28.113.2] (port=17190 helo=outlook.eldorado.org.br) by eggs.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1mdBtd-0004Hp-FY; Wed, 20 Oct 2021 09:44:47 -0400 Received: from power9a ([10.10.71.235]) by outlook.eldorado.org.br with Microsoft SMTPSVC(8.5.9600.16384); Wed, 20 Oct 2021 09:57:32 -0300 Received: from eldorado.org.br (unknown [10.10.71.235]) by power9a (Postfix) with ESMTP id 164F980045D; Wed, 20 Oct 2021 09:57:32 -0300 (-03) From: "Lucas Mateus Castro (alqotel)" To: qemu-devel@nongnu.org, qemu-ppc@nongnu.org Subject: [PATCH 1/2] target/ppc: Fixed call to deferred exception Date: Wed, 20 Oct 2021 09:57:23 -0300 Message-Id: <20211020125724.78028-2-lucas.araujo@eldorado.org.br> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20211020125724.78028-1-lucas.araujo@eldorado.org.br> References: <20211020125724.78028-1-lucas.araujo@eldorado.org.br> X-OriginalArrivalTime: 20 Oct 2021 12:57:32.0321 (UTC) FILETIME=[0BC7C110:01D7C5B2] X-Host-Lookup-Failed: Reverse DNS lookup failed for 201.28.113.2 (failed) Received-SPF: pass client-ip=201.28.113.2; envelope-from=lucas.araujo@eldorado.org.br; helo=outlook.eldorado.org.br X-Spam_score_int: -10 X-Spam_score: -1.1 X-Spam_bar: - X-Spam_report: (-1.1 / 5.0 requ) BAYES_00=-1.9, PDS_HP_HELO_NORDNS=0.001, RDNS_NONE=0.793, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=no autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: "Lucas Mateus Castro \(alqotel\)" , richard.henderson@linaro.org, david@gibson.dropbear.id.au Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" From: "Lucas Mateus Castro (alqotel)" mtfsf, mtfsfi and mtfsb1 instructions call helper_float_check_status after updating the value of FPSCR, but helper_float_check_status checks fp_status and fp_status isn't updated based on FPSCR and since the value of fp_status is reset earlier in the instruction, it's always 0. Because of this helper_float_check_status would change the FI bit to 0 as this bit checks if the last operation was inexact and float_flag_inexact is always 0. These instructions also don't throw exceptions correctly since helper_float_check_status throw exceptions based on fp_status. This commit created a new helper, helper_fpscr_check_status that checks FPSCR value instead of fp_status and checks for a larger variety of exceptions than do_float_check_status. The hardware used to compare QEMU's behavior to, was a Power9. Resolves: https://gitlab.com/qemu-project/qemu/-/issues/266 Signed-off-by: Lucas Mateus Castro (alqotel) --- target/ppc/fpu_helper.c | 41 ++++++++++++++++++++++++++++++ target/ppc/helper.h | 1 + target/ppc/translate/fp-impl.c.inc | 6 ++--- 3 files changed, 45 insertions(+), 3 deletions(-) diff --git a/target/ppc/fpu_helper.c b/target/ppc/fpu_helper.c index c4896cecc8..f086cb503f 100644 --- a/target/ppc/fpu_helper.c +++ b/target/ppc/fpu_helper.c @@ -414,6 +414,47 @@ void helper_store_fpscr(CPUPPCState *env, uint64_t val, uint32_t nibbles) ppc_store_fpscr(env, val); } +void helper_fpscr_check_status(CPUPPCState *env) +{ + CPUState *cs = env_cpu(env); + target_ulong fpscr = env->fpscr; + int error = 0; + + if ((fpscr & FP_VXSOFT) && (fpscr_ve != 0)) { + error = POWERPC_EXCP_FP_VXSOFT; + } else if ((fpscr & FP_OX) && (fpscr & FP_OE)) { + error = POWERPC_EXCP_FP_OX; + } else if ((fpscr & FP_UX) && (fpscr & FP_UE)) { + error = POWERPC_EXCP_FP_UX; + } else if ((fpscr & FP_XX) && (fpscr & FP_XE)) { + error = POWERPC_EXCP_FP_XX; + } else if ((fpscr & FP_ZX) && (fpscr & FP_ZE)) { + error = POWERPC_EXCP_FP_ZX; + } else if ((fpscr & FP_VXSNAN) && (fpscr_ve != 0)) { + error = POWERPC_EXCP_FP_VXSNAN; + } else if ((fpscr & FP_VXISI) && (fpscr_ve != 0)) { + error = POWERPC_EXCP_FP_VXISI; + } else if ((fpscr & FP_VXIDI) && (fpscr_ve != 0)) { + error = POWERPC_EXCP_FP_VXIDI; + } else if ((fpscr & FP_VXZDZ) && (fpscr_ve != 0)) { + error = POWERPC_EXCP_FP_VXZDZ; + } else if ((fpscr & FP_VXIMZ) && (fpscr_ve != 0)) { + error = POWERPC_EXCP_FP_VXIMZ; + } else if ((fpscr & FP_VXVC) && (fpscr_ve != 0)) { + error = POWERPC_EXCP_FP_VXVC; + } + + if (error) { + cs->exception_index = POWERPC_EXCP_PROGRAM; + env->error_code = error | POWERPC_EXCP_FP; + /* Deferred floating-point exception after target FPSCR update */ + if (fp_exceptions_enabled(env)) { + raise_exception_err_ra(env, cs->exception_index, + env->error_code, GETPC()); + } + } +} + static void do_float_check_status(CPUPPCState *env, uintptr_t raddr) { CPUState *cs = env_cpu(env); diff --git a/target/ppc/helper.h b/target/ppc/helper.h index 4076aa281e..baa3715e73 100644 --- a/target/ppc/helper.h +++ b/target/ppc/helper.h @@ -61,6 +61,7 @@ DEF_HELPER_FLAGS_1(cntlzw32, TCG_CALL_NO_RWG_SE, i32, i32) DEF_HELPER_FLAGS_2(brinc, TCG_CALL_NO_RWG_SE, tl, tl, tl) DEF_HELPER_1(float_check_status, void, env) +DEF_HELPER_1(fpscr_check_status, void, env) DEF_HELPER_1(reset_fpstatus, void, env) DEF_HELPER_2(compute_fprf_float64, void, env, i64) DEF_HELPER_3(store_fpscr, void, env, i64, i32) diff --git a/target/ppc/translate/fp-impl.c.inc b/target/ppc/translate/fp-impl.c.inc index 9f7868ee28..0a9b1ecc60 100644 --- a/target/ppc/translate/fp-impl.c.inc +++ b/target/ppc/translate/fp-impl.c.inc @@ -782,7 +782,7 @@ static void gen_mtfsb1(DisasContext *ctx) tcg_gen_shri_i32(cpu_crf[1], cpu_crf[1], FPSCR_OX); } /* We can raise a deferred exception */ - gen_helper_float_check_status(cpu_env); + gen_helper_fpscr_check_status(cpu_env); } /* mtfsf */ @@ -818,7 +818,7 @@ static void gen_mtfsf(DisasContext *ctx) tcg_gen_shri_i32(cpu_crf[1], cpu_crf[1], FPSCR_OX); } /* We can raise a deferred exception */ - gen_helper_float_check_status(cpu_env); + gen_helper_fpscr_check_status(cpu_env); tcg_temp_free_i64(t1); } @@ -851,7 +851,7 @@ static void gen_mtfsfi(DisasContext *ctx) tcg_gen_shri_i32(cpu_crf[1], cpu_crf[1], FPSCR_OX); } /* We can raise a deferred exception */ - gen_helper_float_check_status(cpu_env); + gen_helper_fpscr_check_status(cpu_env); } /*** Floating-point load ***/