[Bug c/65395] New: compiler crash, -ftree-pre leads to SSA corruption

[Bug c/65395] New: compiler crash, -ftree-pre leads to SSA corruption

[jens.gustedt at inria dot fr]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=65395

            Bug ID: 65395
           Summary: compiler crash, -ftree-pre leads to SSA corruption
           Product: gcc
           Version: 4.9.2
            Status: UNCONFIRMED
          Severity: blocker
          Priority: P3
         Component: c
          Assignee: unassigned at gcc dot gnu.org
          Reporter: jens.gustedt at inria dot fr

Created attachment 35015
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=35015&action=edit
code to reproduce compiler crash

The attached, very contrived code, has gcc crashing with

gcc -c -O3 orwl_proc_symbols-prepro.c

the code compiles fine with

gcc -c -O3 -fno-tree-pre orwl_proc_symbols-prepro.c

As indicated the code is very contrived and the result of reducing a
complicated macro expanded code to a minimal example. So the one I give here
seems to be minimal to reproduce the crash. It has

 - nested for loops of a depth 15 or so
 - uses setjmp (but no longjmp)
 - uses an inline function that does not much but calling a _Noreturn function
conditionally

without any of these components the bug goes away ...

BTW, I observed the bug already for earlier versions of gcc 4.9. gcc 4.8 works
fine. My system is a x86_64 with debian jessie, nothing fancy.

[Bug c/65395] [4.9 Regression] compiler crash, -ftree-pre leads to SSA corruption

[jakub at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=65395

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |jakub at gcc dot gnu.org
   Target Milestone|---                         |4.9.3
            Summary|compiler crash, -ftree-pre  |[4.9 Regression] compiler
                   |leads to SSA corruption     |crash, -ftree-pre leads to
                   |                            |SSA corruption

--- Comment #1 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
Started with r198681, got fixed again with r211625.

[Bug tree-optimization/65395] [4.9 Regression] compiler crash, -ftree-pre leads to SSA corruption

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=65395

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
           Priority|P3                          |P2
             Status|UNCONFIRMED                 |ASSIGNED
   Last reconfirmed|                            |2015-03-12
          Component|c                           |tree-optimization
      Known to work|                            |4.8.3, 5.0
           Assignee|unassigned at gcc dot gnu.org      |rguenth at gcc dot gnu.org
     Ever confirmed|0                           |1
      Known to fail|                            |4.9.2
           Severity|blocker                     |normal

--- Comment #2 from Richard Biener <rguenth at gcc dot gnu.org> ---
I will eventually have a look.

[Bug tree-optimization/65395] [4.9 Regression] compiler crash, -ftree-pre leads to SSA corruption

[jakub at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=65395

--- Comment #3 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
GCC 4.9.3 has been released.

[Bug tree-optimization/65395] [4.9 Regression] compiler crash, -ftree-pre leads to SSA corruption

[jakub at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=65395

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Target Milestone|4.9.3                       |4.9.4