From patchwork Fri Aug 5 14:15:22 2022 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: 12937335 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 89724C00140 for ; Fri, 5 Aug 2022 14:20:28 +0000 (UTC) Received: from localhost ([::1]:52400 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1oJyBf-0002RV-Kq for qemu-devel@archiver.kernel.org; Fri, 05 Aug 2022 10:20:27 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:45134) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1oJy7A-00081w-Jn; Fri, 05 Aug 2022 10:15:49 -0400 Received: from [200.168.210.66] (port=13350 helo=outlook.eldorado.org.br) by eggs.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1oJy78-0004vg-IQ; Fri, 05 Aug 2022 10:15:47 -0400 Received: from p9ibm ([10.10.71.235]) by outlook.eldorado.org.br over TLS secured channel with Microsoft SMTPSVC(8.5.9600.16384); Fri, 5 Aug 2022 11:15:23 -0300 Received: from eldorado.org.br (unknown [10.10.70.45]) by p9ibm (Postfix) with ESMTP id 78168800358; Fri, 5 Aug 2022 11:15:23 -0300 (-03) From: "Lucas Mateus Castro(alqotel)" To: qemu-ppc@nongnu.org, qemu-devel@nongnu.org Cc: richard.henderson@linaro.org, danielhb413@gmail.com, "Lucas Mateus Castro (alqotel)" , =?utf-8?q?C?= =?utf-8?q?=C3=A9dric_Le_Goater?= , David Gibson , Greg Kurz Subject: [PATCH 2/2] target/ppc: Bugfix FP when OE/UE are set Date: Fri, 5 Aug 2022 11:15:22 -0300 Message-Id: <20220805141522.412864-3-lucas.araujo@eldorado.org.br> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20220805141522.412864-1-lucas.araujo@eldorado.org.br> References: <20220805141522.412864-1-lucas.araujo@eldorado.org.br> MIME-Version: 1.0 X-OriginalArrivalTime: 05 Aug 2022 14:15:23.0704 (UTC) FILETIME=[CD85FB80:01D8A8D5] X-Host-Lookup-Failed: Reverse DNS lookup failed for 200.168.210.66 (failed) Received-SPF: pass client-ip=200.168.210.66; envelope-from=lucas.araujo@eldorado.org.br; helo=outlook.eldorado.org.br X-Spam_score_int: -4 X-Spam_score: -0.5 X-Spam_bar: / X-Spam_report: (-0.5 / 5.0 requ) BAYES_00=-1.9, PDS_HP_HELO_NORDNS=0.659, RDNS_NONE=0.793, SPF_HELO_NONE=0.001, SPF_PASS=-0.001, T_SCC_BODY_TEXT_LINE=-0.01 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: , Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" From: "Lucas Mateus Castro (alqotel)" When an overflow exception occurs and OE is set the intermediate result should be adjusted (by subtracting from the exponent) to avoid rounding to inf. The same applies to an underflow exceptionion and UE (but adding to the exponent). To do this set the fp_status.rebias_overflow when OE is set and fp_status.rebias_underflow when UE is set as the FPU will recalculate in case of a overflow/underflow if the according rebias* is set. Signed-off-by: Lucas Mateus Castro (alqotel) Reviewed-by: Richard Henderson --- target/ppc/cpu.c | 2 ++ target/ppc/fpu_helper.c | 2 -- 2 files changed, 2 insertions(+), 2 deletions(-) diff --git a/target/ppc/cpu.c b/target/ppc/cpu.c index 401b6f9e63..0ebac04bc4 100644 --- a/target/ppc/cpu.c +++ b/target/ppc/cpu.c @@ -120,6 +120,8 @@ void ppc_store_fpscr(CPUPPCState *env, target_ulong val) val |= FP_FEX; } env->fpscr = val; + env->fp_status.rebias_overflow = (FP_OE & env->fpscr) ? true : false; + env->fp_status.rebias_underflow = (FP_UE & env->fpscr) ? true : false; if (tcg_enabled()) { fpscr_set_rounding_mode(env); } diff --git a/target/ppc/fpu_helper.c b/target/ppc/fpu_helper.c index 134804628b..c17575de5d 100644 --- a/target/ppc/fpu_helper.c +++ b/target/ppc/fpu_helper.c @@ -344,7 +344,6 @@ static inline int float_overflow_excp(CPUPPCState *env) bool overflow_enabled = !!(env->fpscr & FP_OE); if (overflow_enabled) { - /* XXX: should adjust the result */ /* Update the floating-point enabled exception summary */ env->fpscr |= FP_FEX; /* We must update the target FPR before raising the exception */ @@ -363,7 +362,6 @@ static inline void float_underflow_excp(CPUPPCState *env) /* Update the floating-point exception summary */ env->fpscr |= FP_FX; if (env->fpscr & FP_UE) { - /* XXX: should adjust the result */ /* Update the floating-point enabled exception summary */ env->fpscr |= FP_FEX; /* We must update the target FPR before raising the exception */