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diff --git a/public/mathlib/math_pfns.h b/public/mathlib/math_pfns.h
new file mode 100644
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+++ b/public/mathlib/math_pfns.h
@@ -0,0 +1,80 @@
+//========= Copyright Valve Corporation, All rights reserved. ============//
+//
+// Purpose: 
+//
+//=====================================================================================//
+
+#ifndef _MATH_PFNS_H_
+#define _MATH_PFNS_H_
+
+#if defined( _X360 )
+#include <xboxmath.h>
+#endif
+
+#if !defined( _X360 )
+
+// These globals are initialized by mathlib and redirected based on available fpu features
+extern float (*pfSqrt)(float x);
+extern float (*pfRSqrt)(float x);
+extern float (*pfRSqrtFast)(float x);
+extern void  (*pfFastSinCos)(float x, float *s, float *c);
+extern float (*pfFastCos)(float x);
+
+// The following are not declared as macros because they are often used in limiting situations,
+// and sometimes the compiler simply refuses to inline them for some reason
+#define FastSqrt(x)			(*pfSqrt)(x)
+#define	FastRSqrt(x)		(*pfRSqrt)(x)
+#define FastRSqrtFast(x)    (*pfRSqrtFast)(x)
+#define FastSinCos(x,s,c)   (*pfFastSinCos)(x,s,c)
+#define FastCos(x)			(*pfFastCos)(x)
+
+#if defined(__i386__) || defined(_M_IX86)
+// On x86, the inline FPU or SSE sqrt instruction is faster than
+// the overhead of setting up a function call and saving/restoring
+// the FPU or SSE register state and can be scheduled better, too.
+#undef FastSqrt
+#define FastSqrt(x)			::sqrtf(x)
+#endif
+
+#endif // !_X360
+
+#if defined( _X360 )
+
+FORCEINLINE float _VMX_Sqrt( float x )
+{
+	return __fsqrts( x );
+}
+
+FORCEINLINE float _VMX_RSqrt( float x )
+{
+	float rroot = __frsqrte( x );
+
+	// Single iteration NewtonRaphson on reciprocal square root estimate
+	return (0.5f * rroot) * (3.0f - (x * rroot) * rroot);
+}
+
+FORCEINLINE float _VMX_RSqrtFast( float x )
+{
+	return __frsqrte( x );
+}
+
+FORCEINLINE void _VMX_SinCos( float a, float *pS, float *pC )
+{
+	XMScalarSinCos( pS, pC, a );
+}
+
+FORCEINLINE float _VMX_Cos( float a )
+{
+	return XMScalarCos( a );
+}
+
+// the 360 has fixed hw and calls directly
+#define FastSqrt(x)			_VMX_Sqrt(x)
+#define	FastRSqrt(x)		_VMX_RSqrt(x)
+#define FastRSqrtFast(x)	_VMX_RSqrtFast(x)
+#define FastSinCos(x,s,c)	_VMX_SinCos(x,s,c)
+#define FastCos(x)			_VMX_Cos(x)
+
+#endif // _X360
+
+#endif // _MATH_PFNS_H_