Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752476AbdF1P6c (ORCPT ); Wed, 28 Jun 2017 11:58:32 -0400 Received: from mx2.rt-rk.com ([89.216.37.149]:50578 "EHLO mail.rt-rk.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751745AbdF1P5K (ORCPT ); Wed, 28 Jun 2017 11:57:10 -0400 From: Aleksandar Markovic To: linux-mips@linux-mips.org Cc: Aleksandar Markovic , Miodrag Dinic , Goran Ferenc , Douglas Leung , James Hogan , linux-kernel@vger.kernel.org, Paul Burton , Petar Jovanovic , Raghu Gandham , Ralf Baechle Subject: [PATCH v2 4/7] MIPS: math-emu: Handle zero accumulator case in MADDF and MSUBF separately Date: Wed, 28 Jun 2017 17:56:28 +0200 Message-Id: <1498665399-29007-5-git-send-email-aleksandar.markovic@rt-rk.com> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1498665399-29007-1-git-send-email-aleksandar.markovic@rt-rk.com> References: <1498665399-29007-1-git-send-email-aleksandar.markovic@rt-rk.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2037 Lines: 62 From: Aleksandar Markovic If accumulator value is zero, just return the value of previously calculated product. This brings logic in MADDf/MSUBF implementation closer to the logic in ADD/SUB case. Signed-off-by: Miodrag Dinic Signed-off-by: Goran Ferenc Signed-off-by: Aleksandar Markovic --- arch/mips/math-emu/dp_maddf.c | 5 ++++- arch/mips/math-emu/sp_maddf.c | 5 ++++- 2 files changed, 8 insertions(+), 2 deletions(-) diff --git a/arch/mips/math-emu/dp_maddf.c b/arch/mips/math-emu/dp_maddf.c index 4a2d03c..caa62f2 100644 --- a/arch/mips/math-emu/dp_maddf.c +++ b/arch/mips/math-emu/dp_maddf.c @@ -54,7 +54,7 @@ static union ieee754dp _dp_maddf(union ieee754dp z, union ieee754dp x, return ieee754dp_nanxcpt(z); case IEEE754_CLASS_DNORM: DPDNORMZ; - /* QNAN is handled separately below */ + /* QNAN and ZERO cases are handled separately below */ } switch (CLPAIR(xc, yc)) { @@ -210,6 +210,9 @@ static union ieee754dp _dp_maddf(union ieee754dp z, union ieee754dp x, } assert(rm & (DP_HIDDEN_BIT << 3)); + if (zc == IEEE754_CLASS_ZERO) + return ieee754dp_format(rs, re, rm); + /* And now the addition */ assert(zm & DP_HIDDEN_BIT); diff --git a/arch/mips/math-emu/sp_maddf.c b/arch/mips/math-emu/sp_maddf.c index a8cd8b4..c91d5e5 100644 --- a/arch/mips/math-emu/sp_maddf.c +++ b/arch/mips/math-emu/sp_maddf.c @@ -54,7 +54,7 @@ static union ieee754sp _sp_maddf(union ieee754sp z, union ieee754sp x, return ieee754sp_nanxcpt(z); case IEEE754_CLASS_DNORM: SPDNORMZ; - /* QNAN is handled separately below */ + /* QNAN and ZERO cases are handled separately below */ } switch (CLPAIR(xc, yc)) { @@ -203,6 +203,9 @@ static union ieee754sp _sp_maddf(union ieee754sp z, union ieee754sp x, } assert(rm & (SP_HIDDEN_BIT << 3)); + if (zc == IEEE754_CLASS_ZERO) + return ieee754sp_format(rs, re, rm); + /* And now the addition */ assert(zm & SP_HIDDEN_BIT); -- 2.7.4