From nobody Mon Nov 10 19:33:39 2025 Delivered-To: importer@patchew.org Received-SPF: pass (zoho.com: domain of gnu.org designates 209.51.188.17 as permitted sender) client-ip=209.51.188.17; envelope-from=qemu-devel-bounces+importer=patchew.org@nongnu.org; helo=lists.gnu.org; Authentication-Results: mx.zohomail.com; spf=pass (zoho.com: domain of gnu.org designates 209.51.188.17 as permitted sender) smtp.mailfrom=qemu-devel-bounces+importer=patchew.org@nongnu.org ARC-Seal: i=1; a=rsa-sha256; t=1558263518; cv=none; d=zoho.com; s=zohoarc; b=YbVNwFm0Ii+0kghdjaKLEjaJYRKsqwxq3x8nTd9k14m2C4tr/S+7y3zD+RNjURuDkzKepUEcxYfbrZsUffLvTkVKIOfZnIqU5OniJNO3RHgiPOZWD8qb+G0GqR6NFIuaEj2lBRaZpS+jgVNXVy51lyJKWgpgdsBc/KkU+t6R/ZA= ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=zoho.com; s=zohoarc; t=1558263518; h=Cc:Date:From:In-Reply-To:List-Subscribe:List-Post:List-Id:List-Archive:List-Help:List-Unsubscribe:Message-ID:References:Sender:Subject:To:ARC-Authentication-Results; bh=kovNixE2CBHwIo8Z294ismDIlDSf0Tf9XXayHY4tTKk=; b=GyGKeiIpKtAoI3Hb/OeSYaZYemVs4vjmuaciv0twb+BNreJvisc/6SOin+VSq2wRtvKl02EEXgjFzwLM0PXXtrZrkLf7x4DnwXCpuKhFRUKD7J7sbgv0pKF1ua3dDYdydhw7qdntIh7X80xfjupn7cXUjf8QADGZWRU9dUETkSE= ARC-Authentication-Results: i=1; mx.zoho.com; spf=pass (zoho.com: domain of gnu.org designates 209.51.188.17 as permitted sender) smtp.mailfrom=qemu-devel-bounces+importer=patchew.org@nongnu.org Return-Path: Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) by mx.zohomail.com with SMTPS id 1558263518011520.3377854164438; Sun, 19 May 2019 03:58:38 -0700 (PDT) Received: from localhost ([127.0.0.1]:46907 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1hSJWU-0006tY-Q4 for importer@patchew.org; Sun, 19 May 2019 06:58:34 -0400 Received: from eggs.gnu.org ([209.51.188.92]:56581) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1hSJRo-0003EQ-5i for qemu-devel@nongnu.org; Sun, 19 May 2019 06:53:45 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1hSJRl-0001oD-Uk for qemu-devel@nongnu.org; Sun, 19 May 2019 06:53:44 -0400 Received: from mx2.rt-rk.com ([89.216.37.149]:42712 helo=mail.rt-rk.com) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1hSJRl-00015m-N3 for qemu-devel@nongnu.org; Sun, 19 May 2019 06:53:41 -0400 Received: from localhost (localhost [127.0.0.1]) by mail.rt-rk.com (Postfix) with ESMTP id 813191A0F04; Sun, 19 May 2019 12:52:33 +0200 (CEST) Received: from rtrkw774-lin.domain.local (rtrkw774-lin.domain.local [10.10.13.43]) by mail.rt-rk.com (Postfix) with ESMTPSA id 65A591A1FBA; Sun, 19 May 2019 12:52:33 +0200 (CEST) X-Virus-Scanned: amavisd-new at rt-rk.com From: Aleksandar Markovic To: qemu-devel@nongnu.org Date: Sun, 19 May 2019 12:52:15 +0200 Message-Id: <1558263144-8776-2-git-send-email-aleksandar.markovic@rt-rk.com> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1558263144-8776-1-git-send-email-aleksandar.markovic@rt-rk.com> References: <1558263144-8776-1-git-send-email-aleksandar.markovic@rt-rk.com> X-detected-operating-system: by eggs.gnu.org: GNU/Linux 3.x X-Received-From: 89.216.37.149 Subject: [Qemu-devel] [PULL 01/10] target/mips: Make the results of DIV_. the same as on hardware 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@linaro.org, amarkovic@wavecomp.com Errors-To: qemu-devel-bounces+importer=patchew.org@nongnu.org Sender: "Qemu-devel" Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" From: Mateja Marjanovic MSA instructions DIV_. when dividing by zero, didn't return the same value when executed on a referent hardware (FPGA MIPS 64 r6, little endian) and when executed on QEMU, which is not a real bug, because the result when dividing by zero is UNPREDICTABLE [1] (page 141, 142). [1] MIPS Architecture for Programmers Volume IV-j: The MIPS64 SIMD Architecture Module, Revision 1.12 Signed-off-by: Mateja Marjanovic Signed-off-by: Aleksandar Markovic Reviewed-by: Aleksandar Markovic Message-Id: <1554207110-9113-2-git-send-email-mateja.marjanovic@rt-rk.com> --- target/mips/msa_helper.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/target/mips/msa_helper.c b/target/mips/msa_helper.c index c74e3cd..596190b 100644 --- a/target/mips/msa_helper.c +++ b/target/mips/msa_helper.c @@ -641,14 +641,15 @@ static inline int64_t msa_div_s_df(uint32_t df, int64= _t arg1, int64_t arg2) if (arg1 =3D=3D DF_MIN_INT(df) && arg2 =3D=3D -1) { return DF_MIN_INT(df); } - return arg2 ? arg1 / arg2 : 0; + return arg2 ? arg1 / arg2 + : arg1 >=3D 0 ? -1 : 1; } =20 static inline int64_t msa_div_u_df(uint32_t df, int64_t arg1, int64_t arg2) { uint64_t u_arg1 =3D UNSIGNED(arg1, df); uint64_t u_arg2 =3D UNSIGNED(arg2, df); - return u_arg2 ? u_arg1 / u_arg2 : 0; + return arg2 ? u_arg1 / u_arg2 : -1; } =20 static inline int64_t msa_mod_s_df(uint32_t df, int64_t arg1, int64_t arg2) --=20 2.7.4