[Bug middle-end/57055] New: Incorrect CFG after transactional memory passes

[Bug middle-end/57055] New: Incorrect CFG after transactional memory passes

[enkovich.gnu at gmail dot com]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=57055

             Bug #: 57055
           Summary: Incorrect CFG after transactional memory passes
    Classification: Unclassified
           Product: gcc
           Version: 4.9.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: middle-end
        AssignedTo: unassigned@gcc.gnu.org
        ReportedBy: enkovich.gnu@gmail.com


Transactional passes do not set cfun->calls_setjmp to true and do not fix CFG
accordingly after adding __builtin__ITM_beginTransaction call having
ECF_RETURNS_TWICE flag set.

It leads to inconsistency which may be revealed with special calls flags
recomputation.

If I add DCE pass after transactional memory then flags are recomputed and CFG
check fails because of call statements in the middle of basic block. Thus DCE
pass after transactional memory causes ~250 new fails in 'make check'.


Tried on 'gcc version 4.9.0 20130422 (experimental) (GCC)'

[Bug middle-end/57055] Incorrect CFG after transactional memory passes

[jakub at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=57055

Jakub Jelinek <jakub at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |jakub at gcc dot gnu.org

--- Comment #1 from Jakub Jelinek <jakub at gcc dot gnu.org> 2013-04-24 13:15:46 UTC ---
I think the TM code was taking care of edges so far, so either this TM
shouldn't be handled as ECF_RETURNS_TWICE for the purposes of the ab edge
creation code added recently by Richard, or we should handle it like any other
returns_twice.

[Bug middle-end/57055] Incorrect CFG after transactional memory passes

[rguenth at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=57055

Richard Biener <rguenth at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |NEW
   Last reconfirmed|                            |2013-04-25
             Blocks|                            |56982
     Ever Confirmed|0                           |1

--- Comment #2 from Richard Biener <rguenth at gcc dot gnu.org> 2013-04-25 08:17:07 UTC ---
I think we should handle it like any other returns-twice, that is, TM should
split the block properly (and either call notice_special_calls or set
->calls_setjmp).  TM can still handle edge creation itself because it knows
where abnormal transfer can originate from.