isnan.h

util/include/rusefi/interpolation.h

@@ -2,6 +2,7 @@
 
 #include <cstdint>
 
+#include "isnan.h"
 #include "scaled_channel.h"
 
 namespace priv {

util/include/rusefi/isnan.h

@@ -0,0 +1,14 @@
+#pragma once
+
+#if defined(__cplusplus) && defined(__OPTIMIZE__)
+#include <type_traits>
+// "g++ -O2" version, adds more strict type check and yet no "strict-aliasing" warnings!
+#define cisnan(f) ({ \
+	static_assert(sizeof(f) == sizeof(int32_t)); \
+	union cisnanu_t { std::remove_reference_t<decltype(f)> __f; int32_t __i; } __cisnan_u = { f }; \
+	__cisnan_u.__i == 0x7FC00000; \
+})
+#else
+// "g++ -O0" or other C++/C compilers
+#define cisnan(f) (*(((int*) (&f))) == 0x7FC00000)
+#endif /* __cplusplus && __OPTIMIZE__ */