[Bug tree-optimization/24117] New: [4.1 Regression] DCE kills call-clobbered part of structure

[Bug tree-optimization/24117] New: [4.1 Regression] DCE kills call-clobbered part of structure

[rguenth at gcc dot gnu dot org]

For

typedef struct  {
  int x;
  int z;
} Foo_t;

char *xm;
void bar(void);

void foo(void)
{
  Foo_t x;
  x.x = 1;
  x.z = 2;
  xm = (char *)&x;
  bar();
}

where we decompose the struct for aliasing, the store to x.z is killed,
which is wrong.

Testcase is reduced from fortranio_2.f90 test.  The fortran frontend
does such things for IO.  The fortranio_2.f90 failure get's triggered
by the array-aliasing patches as it's sturcture contains an array and
only with the patches we start decomposing the structure at all.

-- 
           Summary: [4.1 Regression] DCE kills call-clobbered part of
                    structure
           Product: gcc
           Version: 4.1.0
            Status: UNCONFIRMED
          Keywords: wrong-code, alias
          Severity: normal
          Priority: P2
         Component: tree-optimization
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: rguenth at gcc dot gnu dot org
                CC: gcc-bugs at gcc dot gnu dot org


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=24117

[Bug tree-optimization/24117] [4.1 Regression] DCE kills call-clobbered part of structure

[pinskia at gcc dot gnu dot org]

------- Additional Comments From pinskia at gcc dot gnu dot org  2005-09-29 13:29 -------
Confirmed.

-- 
           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |dberlin at gcc dot gnu dot
                   |                            |org, pinskia at gcc dot gnu
                   |                            |dot org
             Status|UNCONFIRMED                 |NEW
     Ever Confirmed|                            |1
   Last reconfirmed|0000-00-00 00:00:00         |2005-09-29 13:29:05
               date|                            |
   Target Milestone|---                         |4.1.0


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=24117

[Bug tree-optimization/24117] [4.1 Regression] struct is not marked fully as call clobbered

[cvs-commit at gcc dot gnu dot org]

------- Additional Comments From cvs-commit at gcc dot gnu dot org  2005-09-29 19:38 -------
Subject: Bug 24117

CVSROOT:	/cvs/gcc
Module name:	gcc
Changes by:	dberlin@gcc.gnu.org	2005-09-29 19:38:01

Modified files:
	gcc            : ChangeLog tree-ssa-structalias.c 
Added files:
	gcc/testsuite/gcc.dg/tree-ssa: pr24117.c 

Log message:
	2005-09-29  Daniel Berlin  <dberlin@dberlin.org>
	
	Fix PR tree-optimization/24117
	* tree-ssa-structalias.c (find_func_aliases): Strip nops
	before considering whether to use anyoffset.

Patches:
http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/gcc/ChangeLog.diff?cvsroot=gcc&r1=2.10049&r2=2.10050
http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/gcc/tree-ssa-structalias.c.diff?cvsroot=gcc&r1=2.29&r2=2.30
http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/gcc/testsuite/gcc.dg/tree-ssa/pr24117.c.diff?cvsroot=gcc&r1=NONE&r2=1.1



-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=24117

[Bug tree-optimization/24117] [4.1 Regression] struct is not marked fully as call clobbered

[dberlin at gcc dot gnu dot org]

------- Additional Comments From dberlin at gcc dot gnu dot org  2005-09-29 19:39 -------
Fixed

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


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=24117