Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932377AbbKMArP (ORCPT ); Thu, 12 Nov 2015 19:47:15 -0500 Received: from mailapp01.imgtec.com ([195.59.15.196]:22797 "EHLO mailapp01.imgtec.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932142AbbKMArM (ORCPT ); Thu, 12 Nov 2015 19:47:12 -0500 Date: Fri, 13 Nov 2015 00:47:08 +0000 From: "Maciej W. Rozycki" To: Ralf Baechle CC: Andrew Morton , Matthew Fortune , , Subject: [PATCH 3/8] MIPS: math-emu: Add IEEE Std 754-2008 ABS.fmt and NEG.fmt emulation In-Reply-To: Message-ID: References: User-Agent: Alpine 2.00 (DEB 1167 2008-08-23) MIME-Version: 1.0 Content-Type: text/plain; charset="US-ASCII" X-Originating-IP: [10.100.200.62] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3525 Lines: 129 Implement IEEE Std 754-2008 non-arithmetic ABS.fmt and NEG.fmt emulation wired to the state of the FCSR.ABS2008 bit. In the non-arithmetic mode the sign bit is altered according to the operation requested regardless of the datum encoded in the input operand, no other bits are changed, the resulting bit pattern is written to the output operand and no exception is ever signalled. Signed-off-by: Maciej W. Rozycki --- linux-mips-emu-abs2008.diff Index: linux-sfr-test/arch/mips/math-emu/dp_simple.c =================================================================== --- linux-sfr-test.orig/arch/mips/math-emu/dp_simple.c 2015-11-10 17:45:25.145419000 +0000 +++ linux-sfr-test/arch/mips/math-emu/dp_simple.c 2015-11-11 02:19:59.120054000 +0000 @@ -23,27 +23,39 @@ union ieee754dp ieee754dp_neg(union ieee754dp x) { - unsigned int oldrm; union ieee754dp y; - oldrm = ieee754_csr.rm; - ieee754_csr.rm = FPU_CSR_RD; - y = ieee754dp_sub(ieee754dp_zero(0), x); - ieee754_csr.rm = oldrm; + if (ieee754_csr.abs2008) { + y = x; + DPSIGN(y) = !DPSIGN(x); + } else { + unsigned int oldrm; + + oldrm = ieee754_csr.rm; + ieee754_csr.rm = FPU_CSR_RD; + y = ieee754dp_sub(ieee754dp_zero(0), x); + ieee754_csr.rm = oldrm; + } return y; } union ieee754dp ieee754dp_abs(union ieee754dp x) { - unsigned int oldrm; union ieee754dp y; - oldrm = ieee754_csr.rm; - ieee754_csr.rm = FPU_CSR_RD; - if (DPSIGN(x)) - y = ieee754dp_sub(ieee754dp_zero(0), x); - else - y = ieee754dp_add(ieee754dp_zero(0), x); - ieee754_csr.rm = oldrm; + if (ieee754_csr.abs2008) { + y = x; + DPSIGN(y) = 0; + } else { + unsigned int oldrm; + + oldrm = ieee754_csr.rm; + ieee754_csr.rm = FPU_CSR_RD; + if (DPSIGN(x)) + y = ieee754dp_sub(ieee754dp_zero(0), x); + else + y = ieee754dp_add(ieee754dp_zero(0), x); + ieee754_csr.rm = oldrm; + } return y; } Index: linux-sfr-test/arch/mips/math-emu/sp_simple.c =================================================================== --- linux-sfr-test.orig/arch/mips/math-emu/sp_simple.c 2015-11-10 17:45:25.147428000 +0000 +++ linux-sfr-test/arch/mips/math-emu/sp_simple.c 2015-11-11 02:19:59.165062000 +0000 @@ -23,27 +23,39 @@ union ieee754sp ieee754sp_neg(union ieee754sp x) { - unsigned int oldrm; union ieee754sp y; - oldrm = ieee754_csr.rm; - ieee754_csr.rm = FPU_CSR_RD; - y = ieee754sp_sub(ieee754sp_zero(0), x); - ieee754_csr.rm = oldrm; + if (ieee754_csr.abs2008) { + y = x; + SPSIGN(y) = !SPSIGN(x); + } else { + unsigned int oldrm; + + oldrm = ieee754_csr.rm; + ieee754_csr.rm = FPU_CSR_RD; + y = ieee754sp_sub(ieee754sp_zero(0), x); + ieee754_csr.rm = oldrm; + } return y; } union ieee754sp ieee754sp_abs(union ieee754sp x) { - unsigned int oldrm; union ieee754sp y; - oldrm = ieee754_csr.rm; - ieee754_csr.rm = FPU_CSR_RD; - if (SPSIGN(x)) - y = ieee754sp_sub(ieee754sp_zero(0), x); - else - y = ieee754sp_add(ieee754sp_zero(0), x); - ieee754_csr.rm = oldrm; + if (ieee754_csr.abs2008) { + y = x; + SPSIGN(y) = 0; + } else { + unsigned int oldrm; + + oldrm = ieee754_csr.rm; + ieee754_csr.rm = FPU_CSR_RD; + if (SPSIGN(x)) + y = ieee754sp_sub(ieee754sp_zero(0), x); + else + y = ieee754sp_add(ieee754sp_zero(0), x); + ieee754_csr.rm = oldrm; + } return y; } -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/