[UCRT:MATH] Implement _dclass, _fdclass

sdk/lib/ucrt/math/_dclass.c

@@ -0,0 +1,48 @@
+//
+// _dclass.c
+//
+//      Copyright (c) 2024 Timo Kreuzer
+//
+// Implementation of _dclass.
+//
+// SPDX-License-Identifier: MIT
+//
+
+#include <math.h>
+#include <stdint.h>
+
+#ifdef _MSC_VER
+#pragma function(_dclass)
+#endif
+
+//
+// Returns the floating-point classification of _X.
+//
+//     FP_NAN - A quiet, signaling, or indeterminate NaN
+//     FP_INFINITE - A positive or negative infinity
+//     FP_NORMAL - A positive or negative normalized non-zero value
+//     FP_SUBNORMAL - A positive or negative subnormal (denormalized) value
+//     FP_ZERO - A positive or negative zero value
+//
+_Check_return_
+short
+__cdecl
+_dclass(_In_ double _X)
+{
+    union { double f; uint64_t ui64; } u = { _X };
+    uint64_t e = u.ui64 & 0x7FF0000000000000ull;
+    uint64_t m = u.ui64 & 0x000FFFFFFFFFFFFFull;
+
+    if (e == 0x7FF0000000000000ull)
+    {
+        return m ? FP_NAN : FP_INFINITE;
+    }
+    else if (e == 0)
+    {
+        return m ? FP_SUBNORMAL : FP_ZERO;
+    }
+    else
+    {
+        return FP_NORMAL;
+    }
+}

sdk/lib/ucrt/math/_fdclass.c

@@ -0,0 +1,48 @@
+//
+// _fdclass.c
+//
+//      Copyright (c) 2024 Timo Kreuzer
+//
+// Implementation of _fdclass.
+//
+// SPDX-License-Identifier: MIT
+//
+
+#include <math.h>
+#include <stdint.h>
+
+#ifdef _MSC_VER
+#pragma function(_fdclass)
+#endif
+
+//
+// Returns the floating-point classification of _X.
+//
+//     FP_NAN - A quiet, signaling, or indeterminate NaN
+//     FP_INFINITE - A positive or negative infinity
+//     FP_NORMAL - A positive or negative normalized non-zero value
+//     FP_SUBNORMAL - A positive or negative subnormal (denormalized) value
+//     FP_ZERO - A positive or negative zero value
+//
+_Check_return_
+short
+__cdecl
+_fdclass(_In_ float _X)
+{
+    union { float f; uint32_t ui32; } u = { _X };
+    uint32_t e = u.ui32 & 0x7F800000u;
+    uint32_t m = u.ui32 & 0x007FFFFFu;
+
+    if (e == 0x7F800000u)
+    {
+        return m ? FP_NAN : FP_INFINITE;
+    }
+    else if (e == 0)
+    {
+        return m ? FP_SUBNORMAL : FP_ZERO;
+    }
+    else
+    {
+        return FP_NORMAL;
+    }
+}

sdk/lib/ucrt/math/math.cmake

@@ -1,4 +1,6 @@
 
 list(APPEND UCRT_MATH_SOURCES
+    math/_dclass.c
+    math/_fdclass.c
     math/matherr.cpp
 )