https://gcc.gnu.org/bugzilla/show_bug.cgi?id=101163
--- Comment #6 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
Yes, the C++ FE has quadratic behavior here:
#define A(n) int f##n;
#define B(n) A(n##0) A(n##1) A(n##2) A(n##3) A(n##4) A(n##5) A(n##6) A(n##7)
A(n##8) A(n##9)
#define C(n) B(n##0) B(n##1) B(n##2) B(n##3) B(n##4) B(n##5) B(n##6) B(n##7)
B(n##8) B(n##9)
#define D(n) C(n##0) C(n##1) C(n##2) C(n##3) C(n##4) C(n##5) C(n##6) C(n##7)
C(n##8) C(n##9)
#define E(n) D(n##0) D(n##1) D(n##2) D(n##3) D(n##4) D(n##5) D(n##6) D(n##7)
D(n##8) D(n##9)
#define F(n) E(n##0) E(n##1) E(n##2) E(n##3) E(n##4) E(n##5) E(n##6) E(n##7)
E(n##8) E(n##9)
#define G(n) F(n##0) F(n##1) F(n##2) F(n##3) F(n##4) F(n##5) F(n##6) F(n##7)
F(n##8) F(n##9)
struct S {
E(0) E(1) E(2) E(3) E(4) E(5) E(6)
};
The C FE too, but only in checking builds (
3358 #ifdef ENABLE_TREE_CHECKING
3359 {
3360 tree t2;
3361 for (t2 = op2; t2; t2 = TREE_CHAIN (t2))
3362 gcc_assert (t2 != t1);
3363 }
3364 #endif
in chainon).
E(0) E(1) E(2) E(3) E(4) E(5)
time ~/src/gcc/obj88/gcc/cc1 -quiet pr101164.C
real 0m15.515s
user 0m15.430s
sys 0m0.037s
time ~/src/gcc/obj88/gcc/cc1plus -quiet pr101164.C
real 0m25.771s
user 0m25.654s
sys 0m0.036s
E(0) E(1) E(2) E(3) E(4) E(5) E(6)
time ~/src/gcc/obj88/gcc/cc1 -quiet pr101164.C
real 0m20.994s
user 0m20.875s
sys 0m0.050s
time ~/src/gcc/obj88/gcc/cc1plus -quiet pr101164.C
real 0m35.292s
user 0m35.138s
sys 0m0.035s
In the C++ case it is
#0 fields_linear_search (klass=<record_type 0x7fffea1a3f18 S>,
name=<identifier_node 0x7fffe9649840 f22623>, want_type=true) at
../../gcc/cp/name-lookup.c:1799
#1 0x0000000000c7b400 in get_class_binding_direct (klass=<record_type
0x7fffea1a3f18 S>, name=<identifier_node 0x7fffe9649840 f22623>,
want_type=true)
at ../../gcc/cp/name-lookup.c:1881
#2 0x0000000000c7b9be in get_class_binding (klass=<record_type 0x7fffea1a3f18
S>, name=<identifier_node 0x7fffe9649840 f22623>, want_type=true) at
../../gcc/cp/name-lookup.c:1950
#3 0x0000000000db109c in lookup_field_r (binfo=<tree_binfo 0x7fffea1a8420>,
data=0x7fffffffcb20) at ../../gcc/cp/search.c:1023
#4 0x0000000000db2324 in dfs_walk_all (binfo=<tree_binfo 0x7fffea1a8420>,
pre_fn=0xdb0f2c <lookup_field_r(tree, void*)>, post_fn=0x0,
data=0x7fffffffcb20)
at ../../gcc/cp/search.c:1453
#5 0x0000000000db1711 in lookup_member (xbasetype=<tree 0x0>,
name=<identifier_node 0x7fffe9649840 f22623>, protect=2, want_type=true,
complain=3, afi=0x0)
at ../../gcc/cp/search.c:1166
#6 0x0000000000c8a8be in get_class_binding (name=<identifier_node
0x7fffe9649840 f22623>, scope=0x7fffea04ce10) at
../../gcc/cp/name-lookup.c:5333
#7 0x0000000000c8b158 in push_class_level_binding_1 (name=<identifier_node
0x7fffe9649840 f22623>, x=<field_decl 0x7fffe79a2b48 f22623>) at
../../gcc/cp/name-lookup.c:5439
#8 0x0000000000c8b669 in push_class_level_binding (name=<identifier_node
0x7fffe9649840 f22623>, x=<field_decl 0x7fffe79a2b48 f22623>) at
../../gcc/cp/name-lookup.c:5545
#9 0x0000000000c8a49e in pushdecl_class_level (x=<field_decl 0x7fffe79a2b48
f22623>) at ../../gcc/cp/name-lookup.c:5280
#10 0x0000000000dc3866 in finish_member_declaration (decl=<field_decl
0x7fffe79a2b48 f22623>) at ../../gcc/cp/semantics.c:3521
#11 0x0000000000cd2d68 in cp_parser_member_declaration (parser=0x7fffea06e7b8)
at ../../gcc/cp/parser.c:26627
#12 0x0000000000cd17dc in cp_parser_member_specification_opt
(parser=0x7fffea06e7b8) at ../../gcc/cp/parser.c:25990
#13 0x0000000000ccf414 in cp_parser_class_specifier_1 (parser=0x7fffea06e7b8)
at ../../gcc/cp/parser.c:25061
#14 0x0000000000cd057a in cp_parser_class_specifier (parser=0x7fffea06e7b8) at
../../gcc/cp/parser.c:25377
#15 0x0000000000cc1a1a in cp_parser_type_specifier (parser=0x7fffea06e7b8,
flags=1, decl_specs=0x7fffffffd410, is_declaration=true,
declares_class_or_enum=0x7fffffffd37c,
is_cv_qualifier=0x7fffffffd37b) at ../../gcc/cp/parser.c:18609
#16 0x0000000000cbc00e in cp_parser_decl_specifier_seq (parser=0x7fffea06e7b8,
flags=1, decl_specs=0x7fffffffd410, declares_class_or_enum=0x7fffffffd40c)
at ../../gcc/cp/parser.c:15210
#17 0x0000000000cba6ff in cp_parser_simple_declaration (parser=0x7fffea06e7b8,
function_definition_allowed_p=true, maybe_range_for_decl=0x0) at
../../gcc/cp/parser.c:14466
#18 0x0000000000cba687 in cp_parser_block_declaration (parser=0x7fffea06e7b8,
statement_p=false) at ../../gcc/cp/parser.c:14413
#19 0x0000000000cba353 in cp_parser_declaration (parser=0x7fffea06e7b8,
prefix_attrs=<tree 0x0>) at ../../gcc/cp/parser.c:14284
#20 0x0000000000cba448 in cp_parser_toplevel_declaration
(parser=0x7fffea06e7b8) at ../../gcc/cp/parser.c:14313
#21 0x0000000000ca5568 in cp_parser_translation_unit (parser=0x7fffea06e7b8) at
../../gcc/cp/parser.c:4942
