should be it

external/duckdb/extension/parquet/parquet_float16.cpp

@@ -0,0 +1,44 @@
+#include "parquet_float16.hpp"
+
+#include "duckdb.hpp"
+
+namespace duckdb {
+
+float Float16ToFloat32(const uint16_t &float16_value) {
+	uint32_t sign = float16_value >> 15;
+	uint32_t exponent = (float16_value >> 10) & 0x1F;
+	uint32_t fraction = (float16_value & 0x3FF);
+	// Avoid strict aliasing issues and compiler warnings
+	uint32_t float32_value = 0;
+
+	if (exponent == 0) {
+		if (fraction == 0) {
+			// zero
+			float32_value = (sign << 31);
+		} else {
+			// can be represented as ordinary value in float32
+			// 2 ** -14 * 0.0101
+			// => 2 ** -16 * 1.0100
+			// int int_exponent = -14;
+			exponent = 127 - 14;
+			while ((fraction & (1 << 10)) == 0) {
+				// int_exponent--;
+				exponent--;
+				fraction <<= 1;
+			}
+			fraction &= 0x3FF;
+			// int_exponent += 127;
+			float32_value = (sign << 31) | (exponent << 23) | (fraction << 13);
+		}
+	} else if (exponent == 0x1F) {
+		/* Inf or NaN */
+		float32_value = (sign << 31) | (0xFF << 23) | (fraction << 13);
+	} else {
+		/* ordinary number */
+		float32_value = (sign << 31) | ((exponent + (127 - 15)) << 23) | (fraction << 13);
+	}
+
+	return Load<float>(const_data_ptr_cast(&float32_value));
+}
+
+} // namespace duckdb