perf: update ceil and floor to int functions

Author: mastercoms

src/public/mathlib/mathlib.h

@@ -1262,11 +1262,16 @@ inline int Floor2Int( float a )
 {
 	int RetVal;
 #if defined( PLATFORM_INTEL )
+	// Valve original
+#if 0
 	// Convert to int and back, compare, subtract one if too big
 	__m128 a128 = _mm_set_ss(a);
 	RetVal = _mm_cvtss_si32(a128);
     __m128 rounded128 = _mm_cvt_si2ss(_mm_setzero_ps(), RetVal);
 	RetVal -= _mm_comigt_ss( rounded128, a128 );
+#else
+	RetVal = _mm_cvt_ss2si(_mm_set_ss(a + a - 0.5f)) >> 1;
+#endif
 #else
 	RetVal = static_cast<int>( floor(a) );
 #endif
@@ -1319,11 +1324,16 @@ inline int Ceil2Int( float a )
 {
    int RetVal;
 #if defined( PLATFORM_INTEL )
+	// Valve original
+#if 0
    // Convert to int and back, compare, add one if too small
    __m128 a128 = _mm_load_ss(&a);
    RetVal = _mm_cvtss_si32(a128);
    __m128 rounded128 = _mm_cvt_si2ss(_mm_setzero_ps(), RetVal);
    RetVal += _mm_comilt_ss( rounded128, a128 );
+#else
+   RetVal = -(_mm_cvt_ss2si(_mm_set_ss(-0.5f - (a + a))) >> 1);
+#endif
 #else
    RetVal = static_cast<int>( ceil(a) );
 #endif