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[Bug c++/48481] New: C++ overloading memory hog
- From: "jakub at gcc dot gnu.org" <gcc-bugzilla at gcc dot gnu dot org>
- To: gcc-bugs at gcc dot gnu dot org
- Date: Wed, 6 Apr 2011 15:32:10 +0000
- Subject: [Bug c++/48481] New: C++ overloading memory hog
- Auto-submitted: auto-generated
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=48481
Summary: C++ overloading memory hog
Product: gcc
Version: 4.6.0
Status: UNCONFIRMED
Keywords: memory-hog
Severity: normal
Priority: P3
Component: c++
AssignedTo: unassigned@gcc.gnu.org
ReportedBy: jakub@gcc.gnu.org
CC: jason@gcc.gnu.org
#define A(n) \
struct S##n { int i; }; \
S##n v##n;\
extern int foo (S##n, S##n);\
extern void bar (S##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)
#ifndef N
#define N 10000
#endif
#if N == 1000
#define E(n) D(n##0)
#elif N == 2000
#define E(n) D(n##0) D(n##1)
#elif N == 3000
#define E(n) D(n##0) D(n##1) D(n##2)
#else
#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)
#endif
E(0)
void
foo ()
{
#undef A
#define A(n) if (foo (v##n, v##n)) bar (v##n);
E(0)
}
testcase eats huge amounts of memory. With -DN=1000 -O0 it compiles quickly,
using 432768 kB of memory (852MB in top), with -DN=2000 -O0 it already uses
1672544 kB (3.5GB in top). With -DN=3000 it took around 8GB in top.
In --enable-gather-detailed-mem-stats -fmem-report, for N=1000 I see:
cp/tree.c:1447 (ovl_cons) 64032000:15.1% 0:
0.0% 256032: 1.8% 0: 0.0% 2009001
c-family/c-common.c:9556 (make_tree_vector) 159840120:37.8% 0:
0.0% 0: 0.0% 0: 0.0% 3996003
cp/search.c:1135 (build_baselink) 191952000:45.4% 0:
0.0% 0: 0.0% 0: 0.0% 3999000
Total 422660566 8986384
14294815 2724053 10281399
source location Garbage Freed
Leak Overhead Times
and for N=2000:
cp/tree.c:1447 (ovl_cons) 256064000:15.3% 0:
0.0% 512032: 1.9% 0: 0.0% 8018001
c-family/c-common.c:9556 (make_tree_vector) 639680120:38.1% 0:
0.0% 0: 0.0% 0: 0.0% 15992003
cp/search.c:1135 (build_baselink) 767904000:45.8% 0:
0.0% 0: 0.0% 0: 0.0% 15998000
Total 1677099246 12464328
27061439 3876781 40545425
source location Garbage Freed
Leak Overhead Times