summaryrefslogtreecommitdiffstats
path: root/src/VBox/Runtime/common/math/fma.cpp
diff options
context:
space:
mode:
Diffstat (limited to 'src/VBox/Runtime/common/math/fma.cpp')
-rw-r--r--src/VBox/Runtime/common/math/fma.cpp100
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);
+