+# Precompile all flag regexps. any_flags_used(), all_flags_used() get a lot
+# faster with this.
+@def_cflags = compile_flag_regexp(\%flag_renames, @def_cflags);
+@def_cflags_format = compile_flag_regexp(\%flag_renames, @def_cflags_format);
+@def_cflags_fortify = compile_flag_regexp(\%flag_renames, @def_cflags_fortify);
+@def_cflags_stack = compile_flag_regexp(\%flag_renames, @def_cflags_stack);
+@def_cflags_pie = compile_flag_regexp(\%flag_renames, @def_cflags_pie);
+@def_cxxflags = compile_flag_regexp(\%flag_renames, @def_cxxflags);
+@def_cppflags = compile_flag_regexp(\%flag_renames, @def_cppflags);
+@def_cppflags_fortify = compile_flag_regexp(\%flag_renames, @def_cppflags_fortify);
+@def_ldflags = compile_flag_regexp(\%flag_renames, @def_ldflags);
+@def_ldflags_relro = compile_flag_regexp(\%flag_renames, @def_ldflags_relro);
+@def_ldflags_bindnow = compile_flag_regexp(\%flag_renames, @def_ldflags_bindnow);
+@def_ldflags_pie = compile_flag_regexp(\%flag_renames, @def_ldflags_pie);
+@def_ldflags_pic = compile_flag_regexp(\%flag_renames, @def_ldflags_pic);
+