[Bug middle-end/44133] New: [4.5/4.6 Regression] Uninit warning regression with new SRA

[Bug middle-end/44133] New: [4.5/4.6 Regression] Uninit warning regression with new SRA

[jakub at gcc dot gnu dot org]

struct S { int i, j; };

int foo (int l)
{
  struct S s;
  s.j = l - 22;
  return s.i + s.j;
}

with -O2 -W -Wall in 4.4 this used to warn:
v.c: In function 'foo':
v.c:6: warning: 's.i' is used uninitialized in this function
but with 4.5+ it warns:
v.c: In function 'foo':
v.c:6:11: warning: '({anonymous})' is used uninitialized in this function
[-Wuninitialized]

For:
struct S { int i, j; };

int foo (int l)
{
  struct S s;
  if (l > 126)
    {
      s.j = l - 22;
      return s.i + s.j;
    }
  s.i = 12;
  s.j = l + 40;
  return s.i + s.j;
}
the warning is ok in both 4.4 and 4.5+.

I'd say that SRA should add the D.XXXX = s$i; stmts, perhaps right before
D.XXXX uses.


-- 
           Summary: [4.5/4.6 Regression] Uninit warning regression with new
                    SRA
           Product: gcc
           Version: 4.5.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: middle-end
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: jakub at gcc dot gnu dot org


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=44133

[Bug middle-end/44133] [4.5/4.6 Regression] Uninit warning regression with new SRA

[jakub at gcc dot gnu dot org]

-- 

jakub at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Target Milestone|---                         |4.5.1


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=44133

[Bug middle-end/44133] [4.5/4.6 Regression] Uninit warning regression with new SRA

[jamborm at gcc dot gnu dot org]

------- Comment #1 from jamborm at gcc dot gnu dot org  2010-05-14 09:47 -------
Mine.


-- 

jamborm at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
         AssignedTo|unassigned at gcc dot gnu   |jamborm at gcc dot gnu dot
                   |dot org                     |org
             Status|UNCONFIRMED                 |ASSIGNED
     Ever Confirmed|0                           |1
   Last reconfirmed|0000-00-00 00:00:00         |2010-05-14 09:47:27
               date|                            |


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=44133

[Bug middle-end/44133] [4.5/4.6 Regression] Uninit warning regression with new SRA

[jamborm at gcc dot gnu dot org]

------- Comment #2 from jamborm at gcc dot gnu dot org  2010-05-16 21:09 -------
Patch posted to the mailing list:
http://gcc.gnu.org/ml/gcc-patches/2010-05/msg01209.html


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=44133

[Bug middle-end/44133] [4.5/4.6 Regression] Uninit warning regression with new SRA

[jamborm at gcc dot gnu dot org]

------- Comment #3 from jamborm at gcc dot gnu dot org  2010-05-17 12:48 -------
Subject: Bug 44133

Author: jamborm
Date: Mon May 17 12:48:34 2010
New Revision: 159482

URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=159482
Log:
2010-05-17  Martin Jambor  <mjambor@suse.cz>

        PR middle-end/44133
        * tree-sra.c (create_access_replacement): New parameter rename, mark
        the replaement for renaming only when it is true.
        (get_access_replacement): Pass true in the rename parameter of
        create_access_replacement.
        (get_unrenamed_access_replacement): New function.
        (replace_uses_with_default_def_ssa_name): New parameter racc, get the
        replacement declaration from it.

        * testsuite/gcc.dg/tree-ssa/pr44133.c: New test.
        * testsuite/gcc.dg/tree-ssa/sra-9.c: Make the scan regular
        expression more precise.


Added:
    trunk/gcc/testsuite/gcc.dg/tree-ssa/pr44133.c
Modified:
    trunk/gcc/ChangeLog
    trunk/gcc/testsuite/ChangeLog
    trunk/gcc/testsuite/gcc.dg/tree-ssa/sra-9.c
    trunk/gcc/tree-sra.c


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=44133

[Bug middle-end/44133] [4.5 Regression] Uninit warning regression with new SRA

[rguenth at gcc dot gnu dot org]

-- 

rguenth at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
           Keywords|                            |diagnostic
      Known to work|                            |4.6.0
           Priority|P3                          |P2
            Summary|[4.5/4.6 Regression] Uninit |[4.5 Regression] Uninit
                   |warning regression with new |warning regression with new
                   |SRA                         |SRA


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=44133

[Bug middle-end/44133] [4.5 Regression] Uninit warning regression with new SRA

[jamborm at gcc dot gnu dot org]

------- Comment #4 from jamborm at gcc dot gnu dot org  2010-05-21 17:36 -------
On the 4.5 branch we have a different problem, the warning is not
issued at all.  The patch does not apply because we treat scalar loads
differently.  The easiest way would be to backport this behavior to
4.5:

http://gcc.gnu.org/ml/gcc-patches/2010-04/msg00440.html

and then commit this change on top of it.  That would of course change
the code generated by SRA in general but it does not seem too risky
now.  What do you think?


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=44133

[Bug middle-end/44133] [4.5 Regression] Uninit warning regression with new SRA

[jamborm at gcc dot gnu dot org]

------- Comment #5 from jamborm at gcc dot gnu dot org  2010-06-17 13:14 -------
A request for approval to backport the two patches sent to the mailing list:
http://gcc.gnu.org/ml/gcc-patches/2010-06/msg01663.html


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=44133

[Bug middle-end/44133] [4.5 Regression] Uninit warning regression with new SRA

[jamborm at gcc dot gnu dot org]

------- Comment #6 from jamborm at gcc dot gnu dot org  2010-06-29 13:09 -------
Subject: Bug 44133

Author: jamborm
Date: Tue Jun 29 13:08:46 2010
New Revision: 161532

URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=161532
Log:
2010-06-29  Martin Jambor  <mjambor@suse.cz>

        Backport from mainline
        2010-05-17  Martin Jambor  <mjambor@suse.cz>

        PR middle-end/44133
        * tree-sra.c (create_access_replacement): New parameter rename, mark
        the replaement for renaming only when it is true.
        (get_access_replacement): Pass true in the rename parameter of
        create_access_replacement.
        (get_unrenamed_access_replacement): New function.
        (replace_uses_with_default_def_ssa_name): New parameter racc, get the
        replacement declaration from it.

        * testsuite/gcc.dg/tree-ssa/pr44133.c: New test.


Added:
    branches/gcc-4_5-branch/gcc/testsuite/gcc.dg/tree-ssa/pr44133.c
Modified:
    branches/gcc-4_5-branch/gcc/ChangeLog
    branches/gcc-4_5-branch/gcc/testsuite/ChangeLog
    branches/gcc-4_5-branch/gcc/tree-sra.c


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=44133

[Bug middle-end/44133] [4.5 Regression] Uninit warning regression with new SRA

[jamborm at gcc dot gnu dot org]

------- Comment #7 from jamborm at gcc dot gnu dot org  2010-06-29 13:10 -------
This is now fixed on both the trunk and the 4.5 branch.


-- 

jamborm at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|ASSIGNED                    |RESOLVED
         Resolution|                            |FIXED


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=44133