1 files changed, 101 insertions, 0 deletions
diff --git a/src/VBox/Runtime/common/math/fmaf.cpp b/src/VBox/Runtime/common/math/fmaf.cpp
new file mode 100644
index 00000000..cc29f0d2
--- /dev/null
+++ b/src/VBox/Runtime/common/math/fmaf.cpp
@@ -0,0 +1,101 @@
+/* $Id: fmaf.cpp $ */
+/** @file
+ * IPRT - No-CRT - fmaf().
+ */
+
+/*
+ * Copyright (C) 2022 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(float) rtNoCrtMathFma3f(float r32Factor1, float r32Factor2, float r32Addend);
+DECLASM(float) rtNoCrtMathFma4f(float r32Factor1, float r32Factor2, float r32Addend);
+
+
+#undef fmaf
+float RT_NOCRT(fmaf)(float r32Factor1, float r32Factor2, float r32Addend)
+{
+    /*
+     * 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 rtNoCrtMathFma3f(r32Factor1, r32Factor2, r32Addend);
+    if (enmSup == kCpuWithFma4)
+        return rtNoCrtMathFma4f(r32Factor1, r32Factor2, r32Addend);
+#endif
+
+    /*
+     * Fall back on SoftFloat.
+     */
+    /** @todo couldn't we just use double as a fallback here? */
+    AssertCompile(sizeof(r32Factor1) == sizeof(RTFLOAT32U));
+    softfloat_state_t State = SOFTFLOAT_STATE_INIT_DEFAULTS(); /** @todo init from MXCSR/FCW */
+    union { RTFLOAT32U Iprt; float32_t SoftFloat; } uFactor1, uFactor2, uAddend, uResult;
+    uFactor1.Iprt.r = r32Factor1;
+    uFactor2.Iprt.r = r32Factor2;
+    uAddend.Iprt.r  = r32Addend;
+    uResult.SoftFloat = f32_mulAdd(uFactor1.SoftFloat, uFactor2.SoftFloat, uAddend.SoftFloat, &State);
+    return uResult.Iprt.r;
+}
+RT_ALIAS_AND_EXPORT_NOCRT_SYMBOL(fmaf);
+