or download this
perl -e'use re 'debug';qr/x{100}.*y{100}/'
Compiling REx "x{100}.*y{100}"
...
11: END (0)
anchored "xxxxxxxxxxxxxxxxxxxxxxxxxxxxxx"... at 0 floating "yyyyyyyyyy
+yyyyyyyyyyyyyyyyyyyy"... at 100..2147483647 (checking floating) minle
+n 200
Freeing REx: "x{100}.*y{100}"