https://gcc.gnu.org/bugzilla/show_bug.cgi?id=85447
Martin Jambor <jamborm at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
CC| |hubicka at gcc dot gnu.org
--- Comment #3 from Martin Jambor <jamborm at gcc dot gnu.org> ---
The problem here is that IPA-CP clones node cgraph_edge Notify/1680
which has a speculative self-recursive edge. Because it now needs to
make sure that eventually clones of such edges call the node clone and
not the original node (while the original edge is not redirected and
still leads to the original node), it takes such edges out of
redirect_callers and stores in a vector to deal with post-cloning.
Normally, after create_virtual_clone returns, it walks this vector,
finds clones of these self-recursive edges in array next_edge_clone
because that is where they are linked by ipcp_edge_duplication_hook,
and redirects the clone.
However, in this case, before create_virtual_clone returns
ipa_fn_summary_t::duplicate is invoked and it re-evaluates edge
predicates, during which it decides the edge is impossible, which
leads to speculation resolution removing the new edge, clone,
ipcp_edge_removal_hook being invoked which deletes it from the linked
list of edge clones and subsequently ipa-cp code not finding it there.
Breakpoint 6, ipcp_edge_removal_hook (cs=<cgraph_edge Notify.constprop/7327 ->
Notify/1680>)
at /home/mjambor/gcc/icln/src/gcc/ipa-cp.c:3435
3435 grow_edge_clone_vectors ();
(gdb) bt
#0 ipcp_edge_removal_hook (cs=<cgraph_edge Notify.constprop/7327 ->
Notify/1680>)
at /home/mjambor/gcc/icln/src/gcc/ipa-cp.c:3435
#1 0x0000000000be7669 in symbol_table::call_edge_removal_hooks
(this=0x7ffff67aa100,
e=<cgraph_edge Notify.constprop/7327 -> Notify/1680>) at
/home/mjambor/gcc/icln/src/gcc/cgraph.c:329
#2 0x0000000000be8e66 in cgraph_edge::remove (this=<cgraph_edge
Notify.constprop/7327 -> Notify/1680>)
at /home/mjambor/gcc/icln/src/gcc/cgraph.c:1028
#3 0x0000000000be94c0 in cgraph_edge::resolve_speculation (
this=<cgraph_edge Notify.constprop/7327 -> Notify/1680>,
callee_decl=<function_decl 0x7ffff68a2900 __builtin_unreachable>)
at /home/mjambor/gcc/icln/src/gcc/cgraph.c:1200
#4 0x0000000000eb8f97 in redirect_to_unreachable (e=<cgraph_edge
Notify.constprop/7327 -> Notify/1680>)
at /home/mjambor/gcc/icln/src/gcc/ipa-fnsummary.c:239
#5 0x0000000000eb90a0 in edge_set_predicate (e=<cgraph_edge
Notify.constprop/7327 -> Notify/1680>,
predicate=0x7fffffffd680) at
/home/mjambor/gcc/icln/src/gcc/ipa-fnsummary.c:267
#6 0x0000000000eba5ef in ipa_fn_summary_t::duplicate (this=0x7fffe7c702a0,
src=<symtab_function 0x7fffec0cb170 Notify/1680>,
dst=<symtab_function 0x7ffff519c5c0 Notify.constprop/7327>,
info=0x7fffe7c54e70)
at /home/mjambor/gcc/icln/src/gcc/ipa-fnsummary.c:714
#7 0x0000000000ec7339 in function_summary<ipa_fn_summary*>::symtab_duplication
(
node=<symtab_function 0x7fffec0cb170 Notify/1680>,
node2=<symtab_function 0x7ffff519c5c0 Notify.constprop/7327>,
data=0x7fffe7c702a0)
at /home/mjambor/gcc/icln/src/gcc/symbol-summary.h:189
#8 0x0000000000be7b2c in symbol_table::call_cgraph_duplication_hooks
(this=0x7ffff67aa100,
node=<symtab_function 0x7fffec0cb170 Notify/1680>,
node2=<symtab_function 0x7ffff519c5c0 Notify.constprop/7327>)
at /home/mjambor/gcc/icln/src/gcc/cgraph.c:495
#9 0x0000000000c04800 in cgraph_node::create_virtual_clone (
this=<symtab_function 0x7fffec0cb170 Notify/1680>, redirect_callers=...,
tree_map=0x7fffee721370,
args_to_skip=0x7fffef8570c0, suffix=0x24396e0 "constprop")
at /home/mjambor/gcc/icln/src/gcc/cgraphclones.c:618
#10 0x0000000001bf5341 in create_specialized_node (node=<symtab_function
0x7fffec0cb170 Notify/1680>,
known_csts=..., known_contexts=..., aggvals=0x0, callers=...)
at /home/mjambor/gcc/icln/src/gcc/ipa-cp.c:3863
