+/**
+ * Compute a CRC-32 checksum of a buffer using a hardware-accelerated
+ * implementation.
+ *
+ * @note This function is exposed to support special cases where the
+ * calling code is absolutely certain it ought to invoke a hardware-
+ * accelerated CRC-32 implementation - unit tests, for example. For
+ * all other scenarios, please call crc32() and let it pick an
+ * implementation based on the capabilities of the underlying CPU.
+ */
+uint32_t
+crc32_hw(const uint8_t* data, size_t nbytes, uint32_t startingChecksum = ~0U);
+
+#if FOLLY_SSE_PREREQ(4, 2)
+uint32_t
+crc32_hw_aligned(uint32_t remainder, const __m128i* p, size_t vec_count);
+#endif
+
+/**
+ * Check whether a hardware-accelerated CRC-32 implementation is
+ * supported on the current CPU.
+ */
+bool crc32_hw_supported();