[Bug sanitizer/70342] g++ -fsanitize=undefined never finishes compiling (>24h) in qtxmlpatterns test suite

[mpolacek at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=70342

Marek Polacek <mpolacek at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |NEW
   Last reconfirmed|                            |2016-03-21
                 CC|                            |mpolacek at gcc dot gnu.org
     Ever confirmed|0                           |1

--- Comment #1 from Marek Polacek <mpolacek at gcc dot gnu.org> ---
Confirmed.  Seems we're stuck in sth like

#0  0x000000000080038f in mul_mod (shift=12, inv=<optimized out>, y=8191,
x=1452939512) at /home/marek/src/gcc/gcc/hash-table.h:316
#1  hash_table_mod1 (index=10, hash=1452939512) at
/home/marek/src/gcc/gcc/hash-table.h:328
#2  hash_table<hash_map<tree_node*, tree_node*,
simple_hashmap_traits<default_hash_traits<tree_node*>, tree_node*>
>::hash_entry, xcallocator>::find_with_hash (hash=1452939512,
comparable=<synthetic pointer>, this=0x2afeb20) at
/home/marek/src/gcc/gcc/hash-table.h:823
#3  hash_map<tree_node*, tree_node*,
simple_hashmap_traits<default_hash_traits<tree_node*>, tree_node*> >::get
(k=<synthetic pointer>, this=0x2afeb20) at
/home/marek/src/gcc/gcc/hash-map.h:150
#4  cache_map::get (key=0x7f3ab4d0c7c0, this=0x1ff59b0 <fold_cache>) at
/home/marek/src/gcc/gcc/cp/cp-tree.h:5545
#5  cp_fold (x=0x7f3ab4d0c7c0) at /home/marek/src/gcc/gcc/cp/cp-gimplify.c:1940
#6  0x00000000008019b1 in cp_fold_r (stmt_p=0x7f3ab4108970,
walk_subtrees=0x7ffd7710b17c, data=0x0) at
/home/marek/src/gcc/gcc/cp/cp-gimplify.c:944
#7  0x0000000000f9d053 in walk_tree_1 (tp=0x7f3ab4108970,
func=func@entry=0x801990 <cp_fold_r(tree*, int*, void*)>, data=data@entry=0x0,
pset=pset@entry=0x0, lh=lh@entry=0x7ac670 <cp_walk_subtrees(tree_node**, int*,
tree_node* (*)(tree_node**, int*, void*), void*, hash_set<tree_node*,
default_hash_traits<tree_node*> >*)>) at /home/marek/src/gcc/gcc/tree.c:11531
#8  0x0000000000f9d5c7 in walk_tree_1 (tp=0x7f3ab4cb9fa8,
func=func@entry=0x801990 <cp_fold_r(tree*, int*, void*)>, data=data@entry=0x0,
pset=pset@entry=0x0, lh=lh@entry=0x7ac670 <cp_walk_subtrees(tree_node**, int*,
tree_node* (*)(tree_node**, int*, void*), void*, hash_set<tree_node*,
default_hash_traits<tree_node*> >*)>) at /home/marek/src/gcc/gcc/tree.c:11848
#9  0x0000000000f9d3aa in walk_tree_1 (tp=0x7f3ab4108938,
func=func@entry=0x801990 <cp_fold_r(tree*, int*, void*)>, data=data@entry=0x0,
pset=pset@entry=0x0, lh=lh@entry=0x7ac670 <cp_walk_subtrees(tree_node**, int*,
tree_node* (*)(tree_node**, int*, void*), void*, hash_set<tree_node*,
default_hash_traits<tree_node*> >*)>) at /home/marek/src/gcc/gcc/tree.c:11758
#10 0x0000000000f9d3aa in walk_tree_1 (tp=0x7f3ab4d0c718,
func=func@entry=0x801990 <cp_fold_r(tree*, int*, void*)>, data=data@entry=0x0,
pset=pset@entry=0x0, lh=lh@entry=0x7ac670 <cp_walk_subtrees(tree_node**, int*,
tree_node* (*)(tree_node**, int*, void*), void*, hash_set<tree_node*,
default_hash_traits<tree_node*> >*)>) at /home/marek/src/gcc/gcc/tree.c:11758
#11 0x0000000000f9d5c7 in walk_tree_1 (tp=0x7f3ab526d4c8,
func=func@entry=0x801990 <cp_fold_r(tree*, int*, void*)>, data=data@entry=0x0,
pset=pset@entry=0x0, lh=lh@entry=0x7ac670 <cp_walk_subtrees(tree_node**, int*,
tree_node* (*)(tree_node**, int*, void*), void*, hash_set<tree_node*,
default_hash_traits<tree_node*> >*)>) at /home/marek/src/gcc/gcc/tree.c:11848
#12 0x0000000000f9d5c7 in walk_tree_1 (tp=0x7f3ab41175b8,
func=func@entry=0x801990 <cp_fold_r(tree*, int*, void*)>, data=data@entry=0x0,
pset=pset@entry=0x0, lh=lh@entry=0x7ac670 <cp_walk_subtrees(tree_node**, int*,
tree_node* (*)(tree_node**, int*, void*), void*, hash_set<tree_node*,
default_hash_traits<tree_node*> >*)>) at /home/marek/src/gcc/gcc/tree.c:11848