diff options
Diffstat (limited to 'src/VBox/Runtime/common/math/fma.cpp')
-rw-r--r-- | src/VBox/Runtime/common/math/fma.cpp | 100 |
1 files changed, 100 insertions, 0 deletions
diff --git a/src/VBox/Runtime/common/math/fma.cpp b/src/VBox/Runtime/common/math/fma.cpp new file mode 100644 index 00000000..14d98f9a --- /dev/null +++ b/src/VBox/Runtime/common/math/fma.cpp @@ -0,0 +1,100 @@ +/* $Id: fma.cpp $ */ +/** @file + * IPRT - No-CRT - fma(). + */ + +/* + * Copyright (C) 2022-2023 Oracle and/or its affiliates. + * + * This file is part of VirtualBox base platform packages, as + * available from https://www.virtualbox.org. + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License + * as published by the Free Software Foundation, in version 3 of the + * License. + * + * This program is distributed in the hope that it will be useful, but + * WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, see <https://www.gnu.org/licenses>. + * + * The contents of this file may alternatively be used under the terms + * of the Common Development and Distribution License Version 1.0 + * (CDDL), a copy of it is provided in the "COPYING.CDDL" file included + * in the VirtualBox distribution, in which case the provisions of the + * CDDL are applicable instead of those of the GPL. + * + * You may elect to license modified versions of this file under the + * terms and conditions of either the GPL or the CDDL or both. + * + * SPDX-License-Identifier: GPL-3.0-only OR CDDL-1.0 + */ + + +/********************************************************************************************************************************* +* Header Files * +*********************************************************************************************************************************/ +#define IPRT_NO_CRT_FOR_3RD_PARTY +#include "internal/nocrt.h" +#include <iprt/nocrt/math.h> +#include <iprt/assertcompile.h> +#if defined(RT_ARCH_AMD64) || defined(RT_ARCH_X86) +# include <iprt/asm-amd64-x86.h> +# include <iprt/x86.h> +#endif +#include <softfloat.h> + + +/********************************************************************************************************************************* +* External Symbols * +*********************************************************************************************************************************/ +DECLASM(double) rtNoCrtMathFma3(double rdFactor1, double rdFactor2, double rdAddend); +DECLASM(double) rtNoCrtMathFma4(double rdFactor1, double rdFactor2, double rdAddend); + + +#undef fma +double RT_NOCRT(fma)(double rdFactor1, double rdFactor2, double rdAddend) +{ + /* + * We prefer using native FMA instructions when available. + */ +#if defined(RT_ARCH_AMD64) || defined(RT_ARCH_X86) + typedef enum { kCpuDetect = 0, kCpuWithFma3, kCpuWithFma4, kCpuWithoutFma } CPUFMASUPPORT; + static CPUFMASUPPORT volatile s_enmSup = kCpuDetect; + CPUFMASUPPORT enmSup = s_enmSup; + if (enmSup != kCpuDetect) + { } + else + { + if (ASMCpuId_ECX(1) & X86_CPUID_FEATURE_ECX_FMA) + enmSup = kCpuWithFma3; + else if (ASMCpuId_ECX(UINT32_C(0x80000001)) & X86_CPUID_AMD_FEATURE_ECX_FMA4) + enmSup = kCpuWithFma4; + else + enmSup = kCpuWithoutFma; + s_enmSup = enmSup; + } + if (enmSup == kCpuWithFma3) + return rtNoCrtMathFma3(rdFactor1, rdFactor2, rdAddend); + if (enmSup == kCpuWithFma4) + return rtNoCrtMathFma4(rdFactor1, rdFactor2, rdAddend); +#endif + + /* + * Fall back on SoftFloat. + */ + AssertCompile(sizeof(rdFactor1) == sizeof(RTFLOAT64U)); + softfloat_state_t State = SOFTFLOAT_STATE_INIT_DEFAULTS(); /** @todo init from MXCSR/FCW */ + union { RTFLOAT64U Iprt; float64_t SoftFloat; } uFactor1, uFactor2, uAddend, uResult; + uFactor1.Iprt.rd = rdFactor1; + uFactor2.Iprt.rd = rdFactor2; + uAddend.Iprt.rd = rdAddend; + uResult.SoftFloat = f64_mulAdd(uFactor1.SoftFloat, uFactor2.SoftFloat, uAddend.SoftFloat, &State); + return uResult.Iprt.rd; +} +RT_ALIAS_AND_EXPORT_NOCRT_SYMBOL(fma); + |