Hi,
PR 49796 is basically a bug in the verifier. If IPA-CP creates a
clone of a node (__base_ctor) which also has an alias (__comp_ctor),
normally the verifier is able to trace both to the original node and
be happy but if the node ends up in a different partition, the alias
information is lost and verifier wrongly aborts the compilation.
I discussed this with Honza yesterday and he pre-approved a patch
dumbing down the verifier if the node from the statement decl comes
from a different partition. That is what the patch below does.
I have used the opportunity to clean up
verify_edge_corresponds_to_fndecl a bit, mostly so that it calls
cgraph_get_node just once. I acknowledge there is still an
inconsistency with regard to e->calle, at one point we do use
cgraph_function_or_thunk_node on it and twice we don't which was added
by Honza when introducing alias an thunk nodes. I think it should
never be necessary unless we ourselves create thunks/aliases for
artificial clones. So I kept it as it was.
Bootstrapped and tested on x86_64-linux, I also verified it fixed
xalancbmk. Since it was basically pre-approved, I will commit it
later today if there are no objections.
Thanks,
Martin
2011-07-21 Martin Jambor <mjam...@suse.cz>
PR lto/49796
* cgraphunit.c (verify_edge_corresponds_to_fndecl): Return false
if decl node is in another partition, call cgraph_get_node only
once.
Index: src/gcc/cgraphunit.c
===================================================================
*** src.orig/gcc/cgraphunit.c
--- src/gcc/cgraphunit.c
*************** cgraph_debug_gimple_stmt (struct functio
*** 456,472 ****
static bool
verify_edge_corresponds_to_fndecl (struct cgraph_edge *e, tree decl)
{
! if (!e->callee->global.inlined_to
! && decl
! && cgraph_get_node (decl)
! && (e->callee->former_clone_of
! != cgraph_function_or_thunk_node (cgraph_get_node (decl), NULL)->decl)
/* IPA-CP sometimes redirect edge to clone and then back to the former
function. This ping-pong has to go, eventaully. */
! && (cgraph_function_or_thunk_node (cgraph_get_node (decl), NULL)
! != cgraph_function_or_thunk_node (e->callee, NULL))
! && !clone_of_p (cgraph_get_node (decl),
! e->callee))
return true;
else
return false;
--- 456,478 ----
static bool
verify_edge_corresponds_to_fndecl (struct cgraph_edge *e, tree decl)
{
! struct cgraph_node *node;
!
! if (!decl || e->callee->global.inlined_to)
! return false;
! node = cgraph_get_node (decl);
!
! /* We do not know if a node from a different partition is an alias or what
it
! aliases and therefore cannot do the former_clone_of check reliably. */
! if (!node || node->in_other_partition)
! return false;
! node = cgraph_function_or_thunk_node (node, NULL);
!
! if ((e->callee->former_clone_of != node->decl)
/* IPA-CP sometimes redirect edge to clone and then back to the former
function. This ping-pong has to go, eventaully. */
! && (node != cgraph_function_or_thunk_node (e->callee, NULL))
! && !clone_of_p (node, e->callee))
return true;
else
return false;
