Improve docs; pacify check-names
Signed-off-by: Dave Rodgman <dave.rodgman@arm.com>
diff --git a/library/sha3.c b/library/sha3.c
index 99a8acb..64a87a8 100644
--- a/library/sha3.c
+++ b/library/sha3.c
@@ -10,9 +10,20 @@
* https://nvlpubs.nist.gov/nistpubs/fips/nist.fips.202.pdf
*/
-#undef MBEDTLS_SHA3_THETA_UNROLL
-#define MBEDTLS_SHA3_RHO_UNROLL
-#define MBEDTLS_SHA3_PI_UNROLL
+/*
+ * These macros select manually unrolled implementations of parts of the main permutation function.
+ *
+ * Unrolling has a major impact on both performance and code size. gcc performance benefits a lot
+ * from manually unrolling at higher optimisation levels.
+ *
+ * Rolling up the theta loop saves a lot of code-size at small performance cost. The code-size
+ * saving then enables us to unroll the other loops for a net code-size saving with a net
+ * performance win.
+ */
+#undef MBEDTLS_SHA3_THETA_UNROLL //no-check-names
+#define MBEDTLS_SHA3_RHO_UNROLL //no-check-names
+#define MBEDTLS_SHA3_PI_UNROLL //no-check-names
+
#include "common.h"