[Bug ipa/79787] ICE in remove_unreachable_nodes, at ipa.c:469

[marxin at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=79787

Martin Liška  changed:

   What|Removed |Added

 Status|NEW |RESOLVED
 CC||marxin at gcc dot gnu.org
 Resolution|--- |WONTFIX

--- Comment #4 from Martin Liška  ---
MPX is removed, won't fix then.

[Bug ipa/79787] ICE in remove_unreachable_nodes, at ipa.c:469

[ienkovich at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=79787

Ilya Enkovich  changed:

   What|Removed |Added

 CC||ienkovich at gcc dot gnu.org

--- Comment #3 from Ilya Enkovich  ---
This code in remove_unreachable_nodes is supposed to prevent removal of fn1.
Thusly we remove node which is not considered as unreachable by
remove_unreachable_nodes.

Did you try to find out how fn1 node is removed and prevent it?

[Bug ipa/79787] ICE in remove_unreachable_nodes, at ipa.c:469

[aivchenk at gmail dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=79787

Alexander Ivchenko  changed:

   What|Removed |Added

 CC||aivchenk at gmail dot com

--- Comment #2 from Alexander Ivchenko  ---
Reduced testcase:
inline __attribute__((__always_inline__)) __attribute__ ((target("bmi"))) int
fn1() {}

__attribute__((__always_inline__)) __attribute__ ((target("bmi"))) int fn2() {
fn1(); }

int fn3() { return fn1(); }


Initial call graph:
fn3 -(not inlinable because of attribute mismatch)-> fn1
fn2 -> fn1

Call graph before chkp_ecleanup
fn3 -> fn3.chkp -(not inlinable because of attribute mismatch)-> fn1.chkp 
fn2.chkp  -> fn1.chkp 
fn2 (fn1 is inlined here)


When compiler inlines fn1 to fn2 in expand_call_inline, it removes fn1 cnode,
as it is no longer needed.
There it execute this code (in cgraph_node::remove):

if (instrumented_version)
  {  
instrumented_version->instrumented_version = NULL;   
instrumented_version = NULL; 
  }
Hence, now fn1.chkp.instrumened_version==NULL and fn1 is removed.

And later on in chkp_cleanup in reachability analysis in
symbol_table::remove_unreachable_nodes 
we fail on this assert, where cnode==fn1.chkp


  /* For instrumentation clones we always need original 
 function node for proper LTO privatization.  */
  if (cnode->instrumentation_clone  
  && cnode->definition) 
{   
=>gcc_assert (cnode->instrumented_version || in_lto_p);

(since fn1 is removed, we don't consider it in chkp_produce_thunks
(early=false))