From patchwork Wed Dec 1 16:38:06 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: 12650359 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 AF0EEC433EF for ; Wed, 1 Dec 2021 16:43:22 +0000 (UTC) Received: from localhost ([::1]:33184 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1msShV-0002ON-Ib for qemu-devel@archiver.kernel.org; Wed, 01 Dec 2021 11:43:21 -0500 Received: from eggs.gnu.org ([209.51.188.92]:40992) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1msSdl-0008RJ-HG; Wed, 01 Dec 2021 11:39:29 -0500 Received: from [201.28.113.2] (port=20732 helo=outlook.eldorado.org.br) by eggs.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1msSdj-0001L4-0M; Wed, 01 Dec 2021 11:39:29 -0500 Received: from power9a ([10.10.71.235]) by outlook.eldorado.org.br with Microsoft SMTPSVC(8.5.9600.16384); Wed, 1 Dec 2021 13:39:21 -0300 Received: from eldorado.org.br (unknown [10.10.71.29]) by power9a (Postfix) with ESMTP id 91C23800CFF; Wed, 1 Dec 2021 13:39:21 -0300 (-03) From: "Lucas Mateus Castro (alqotel)" To: qemu-devel@nongnu.org, qemu-ppc@nongnu.org Subject: [PATCH v4 1/3] target/ppc: Fixed call to deferred exception Date: Wed, 1 Dec 2021 13:38:06 -0300 Message-Id: <20211201163808.440385-2-lucas.araujo@eldorado.org.br> X-Mailer: git-send-email 2.31.1 In-Reply-To: <20211201163808.440385-1-lucas.araujo@eldorado.org.br> References: <20211201163808.440385-1-lucas.araujo@eldorado.org.br> MIME-Version: 1.0 X-OriginalArrivalTime: 01 Dec 2021 16:39:21.0749 (UTC) FILETIME=[FE2ACC50:01D7E6D1] 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: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: richard.henderson@linaro.org, danielhb413@gmail.com, mark.cave-ayland@ilande.co.uk, "Lucas Mateus Castro \(alqotel\)" , pc@us.ibm.com, david@gibson.dropbear.id.au, matheus.ferst@eldorado.org.br, clg@kaod.org Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" 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. Since fp_status isn't used, gen_reset_fpstatus() was removed. The hardware used to compare QEMU's behavior to was a Power9. Signed-off-by: Lucas Mateus Castro (alqotel) --- target/ppc/fpu_helper.c | 48 ++++++++++++++++++++++++++++++ target/ppc/helper.h | 1 + target/ppc/translate/fp-impl.c.inc | 9 ++---- 3 files changed, 52 insertions(+), 6 deletions(-) diff --git a/target/ppc/fpu_helper.c b/target/ppc/fpu_helper.c index c4896cecc8..bb72715827 100644 --- a/target/ppc/fpu_helper.c +++ b/target/ppc/fpu_helper.c @@ -414,6 +414,54 @@ 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_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_VE) { + if (fpscr & FP_VXSOFT) { + error = POWERPC_EXCP_FP_VXSOFT; + } else if (fpscr & FP_VXSNAN) { + error = POWERPC_EXCP_FP_VXSNAN; + } else if (fpscr & FP_VXISI) { + error = POWERPC_EXCP_FP_VXISI; + } else if (fpscr & FP_VXIDI) { + error = POWERPC_EXCP_FP_VXIDI; + } else if (fpscr & FP_VXZDZ) { + error = POWERPC_EXCP_FP_VXZDZ; + } else if (fpscr & FP_VXIMZ) { + error = POWERPC_EXCP_FP_VXIMZ; + } else if (fpscr & FP_VXVC) { + error = POWERPC_EXCP_FP_VXVC; + } else if (fpscr & FP_VXSQRT) { + error = POWERPC_EXCP_FP_VXSQRT; + } else if (fpscr & FP_VXCVI) { + error = POWERPC_EXCP_FP_VXCVI; + } else { + return; + } + } else { + return; + } + 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 627811cefc..632a81c676 100644 --- a/target/ppc/helper.h +++ b/target/ppc/helper.h @@ -63,6 +63,7 @@ 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 c9e05201d9..8afd6a087d 100644 --- a/target/ppc/translate/fp-impl.c.inc +++ b/target/ppc/translate/fp-impl.c.inc @@ -769,7 +769,6 @@ static void gen_mtfsb1(DisasContext *ctx) return; } crb = 31 - crbD(ctx->opcode); - gen_reset_fpstatus(); /* XXX: we pretend we can only do IEEE floating-point computations */ if (likely(crb != FPSCR_FEX && crb != FPSCR_VX && crb != FPSCR_NI)) { TCGv_i32 t0; @@ -782,7 +781,7 @@ 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 */ @@ -803,7 +802,6 @@ static void gen_mtfsf(DisasContext *ctx) gen_inval_exception(ctx, POWERPC_EXCP_INVAL_INVAL); return; } - gen_reset_fpstatus(); if (l) { t0 = tcg_const_i32((ctx->insns_flags2 & PPC2_ISA205) ? 0xffff : 0xff); } else { @@ -818,7 +816,7 @@ 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); } @@ -840,7 +838,6 @@ static void gen_mtfsfi(DisasContext *ctx) return; } sh = (8 * w) + 7 - bf; - gen_reset_fpstatus(); t0 = tcg_const_i64(((uint64_t)FPIMM(ctx->opcode)) << (4 * sh)); t1 = tcg_const_i32(1 << sh); gen_helper_store_fpscr(cpu_env, t0, t1); @@ -851,7 +848,7 @@ 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); } static void gen_qemu_ld32fs(DisasContext *ctx, TCGv_i64 dest, TCGv addr)