diff --git a/src/Functions/greatCircleDistance.cpp b/src/Functions/greatCircleDistance.cpp
index 94f44ba37ba..8b9df91e117 100644
--- a/src/Functions/greatCircleDistance.cpp
+++ b/src/Functions/greatCircleDistance.cpp
@@ -99,6 +99,12 @@ void geodistInit()
     }
 }
 
+inline NO_SANITIZE_UNDEFINED size_t floatToIndex(float x)
+{
+    /// Implementation specific behaviour on overflow or infinite value.
+    return static_cast<size_t>(x);
+}
+
 inline float geodistDegDiff(float f)
 {
     f = fabsf(f);
@@ -110,7 +116,7 @@ inline float geodistDegDiff(float f)
 inline float geodistFastCos(float x)
 {
     float y = fabsf(x) * (COS_LUT_SIZE / PI / 2);
-    size_t i = static_cast<size_t>(y);
+    size_t i = floatToIndex(y);
     y -= i;
     i &= (COS_LUT_SIZE - 1);
     return cos_lut[i] + (cos_lut[i + 1] - cos_lut[i]) * y;
@@ -119,7 +125,7 @@ inline float geodistFastCos(float x)
 inline float geodistFastSin(float x)
 {
     float y = fabsf(x) * (COS_LUT_SIZE / PI / 2);
-    size_t i = static_cast<size_t>(y);
+    size_t i = floatToIndex(y);
     y -= i;
     i = (i - COS_LUT_SIZE / 4) & (COS_LUT_SIZE - 1); // cos(x - pi / 2) = sin(x), costable / 4 = pi / 2
     return cos_lut[i] + (cos_lut[i + 1] - cos_lut[i]) * y;
@@ -139,7 +145,7 @@ inline float geodistFastAsinSqrt(float x)
     {
         // distance under 17083 km, 512-entry LUT error under 0.00072%
         x *= ASIN_SQRT_LUT_SIZE;
-        size_t i = static_cast<size_t>(x);
+        size_t i = floatToIndex(x);
         return asin_sqrt_lut[i] + (asin_sqrt_lut[i + 1] - asin_sqrt_lut[i]) * (x - i);
     }
     return asinf(sqrtf(x)); // distance over 17083 km, just compute exact
@@ -160,12 +166,6 @@ DECLARE_MULTITARGET_CODE(
 namespace
 {
 
-inline NO_SANITIZE_UNDEFINED size_t metricLUTIndex(float latitude_midpoint)
-{
-    /// Implementation specific behaviour on overflow or infinite value.
-    return static_cast<size_t>(latitude_midpoint) & (METRIC_LUT_SIZE - 1);
-}
-
 template <Method method>
 float distance(float lon1deg, float lat1deg, float lon2deg, float lat2deg)
 {
@@ -183,7 +183,7 @@ float distance(float lon1deg, float lat1deg, float lon2deg, float lat2deg)
         /// But if longitude is close but latitude is different enough, there is no difference between meridian and great circle line.
 
         float latitude_midpoint = (lat1deg + lat2deg + 180) * METRIC_LUT_SIZE / 360; // [-90, 90] degrees -> [0, KTABLE] indexes
-        size_t latitude_midpoint_index = metricLUTIndex(latitude_midpoint);
+        size_t latitude_midpoint_index = floatToIndex(latitude_midpoint) & (METRIC_LUT_SIZE - 1);
 
         /// This is linear interpolation between two table items at index "latitude_midpoint_index" and "latitude_midpoint_index + 1".