perl -e'use re 'debug';qr/x{100}.*y{100}/'
Compiling REx "x{100}.*y{100}"
Final program:
   1: CURLY {100,100} (5)
   3:   EXACT <x> (0)
   5: STAR (7)
   6:   REG_ANY (0)
   7: CURLY {100,100} (11)
   9:   EXACT <y> (0)
  11: END (0)
anchored "xxxxxxxxxxxxxxxxxxxxxxxxxxxxxx"... at 0 floating "yyyyyyyyyyyyyyyyyyyyyyyyyyyyyy"... at 100..2147483647 (checking floating) minlen 200 
Freeing REx: "x{100}.*y{100}"