The functions were not "const" (they examined values pointed
by arguments passed to them, quoting gcc's doc: "Note that
a function that has pointer arguments and examines the data
pointed to must _not_ be declared 'const'.") but rather
"pure" and still not all of them.

Note also, that even some of the functions declared "pure"
are not pure, however, due to reasons stated in source code
the attribute has been kept.