[Bug rtl-optimization/20466] New: Missed invalidation of known memory contents in flow2...

[Bug rtl-optimization/20466] New: Missed invalidation of known memory contents in flow2...

[hp at gcc dot gnu dot org]

... causes invalid removal of memory write.  The following test-case will be
committed as gcc.c-torture/execute/prXXXXXX-1.c; it is miscompiled at -O2.
The first assignment to **ipp is removed in .flow2.  This bug has been there
since at least 3.2.1.

void f (int **, int *, int *, int **, int **) __attribute__ ((__noinline__));
void
f (int **ipp, int *i1p, int *i2p, int **i3, int **i4)
{
  **ipp = *i1p;
  *ipp = i2p;
  *i3 = *i4;
  **ipp = 99;
}

extern void exit (int);
extern void abort (void);

int main (void)
{
  int i = 42, i1 = 66, i2 = 1, i3 = -1, i4 = 55;
  int *ip = &i;
  int *i3p = &i3;
  int *i4p = &i4;
  
  f (&ip, &i1, &i2, &i3p, &i4p);
  if (i != 66 || ip != &i2 || i2 != 99 || i3 != -1 || i3p != i4p || i4 != 55)
    abort ();
  exit (0);
}

-- 
           Summary: Missed invalidation of known memory contents in flow2...
           Product: gcc
           Version: 4.1.0
            Status: UNCONFIRMED
          Keywords: wrong-code
          Severity: normal
          Priority: P2
         Component: rtl-optimization
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: hp at gcc dot gnu dot org
                CC: gcc-bugs at gcc dot gnu dot org
GCC target triplet: cris-*


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=20466

[Bug rtl-optimization/20466] Missed invalidation of known memory contents in flow2...

[hp at gcc dot gnu dot org]

-- 
           What    |Removed                     |Added
----------------------------------------------------------------------------
         AssignedTo|unassigned at gcc dot gnu   |hp at gcc dot gnu dot org
                   |dot org                     |
             Status|UNCONFIRMED                 |ASSIGNED
     Ever Confirmed|                            |1
   Last reconfirmed|0000-00-00 00:00:00         |2005-03-14 03:23:17
               date|                            |


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=20466

[Bug rtl-optimization/20466] Missed invalidation of known memory contents in flow2...

[pinskia at gcc dot gnu dot org]

------- Additional Comments From pinskia at gcc dot gnu dot org  2005-03-14 03:25 -------
Is this a regression?

-- 
           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |pinskia at gcc dot gnu dot
                   |                            |org


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=20466

[Bug rtl-optimization/20466] Missed invalidation of known memory contents in flow2...

[hp at gcc dot gnu dot org]

------- Additional Comments From hp at gcc dot gnu dot org  2005-03-14 04:28 -------
In response to comment #1, I have no answer besides what I wrote in the original
description: "This bug has been there since at least 3.2.1".

-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=20466

[Bug rtl-optimization/20466] Missed invalidation of known memory contents in flow2...

[hp at gcc dot gnu dot org]

------- Additional Comments From hp at gcc dot gnu dot org  2005-03-16 01:43 -------
Patch at <URL:http://gcc.gnu.org/ml/gcc-patches/2005-03/msg01385.html>.

-- 
           What    |Removed                     |Added
----------------------------------------------------------------------------
           Keywords|                            |patch


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=20466

[Bug rtl-optimization/20466] Missed invalidation of known memory contents in flow2...

[cvs-commit at gcc dot gnu dot org]

------- Additional Comments From cvs-commit at gcc dot gnu dot org  2005-04-08 23:18 -------
Subject: Bug 20466

CVSROOT:	/cvs/gcc
Module name:	gcc
Changes by:	hp@gcc.gnu.org	2005-04-08 23:18:32

Modified files:
	gcc/testsuite  : ChangeLog 
Added files:
	gcc/testsuite/gcc.c-torture/execute: pr20466-1.c 

Log message:
	PR rtl-optimization/20466
	* gcc.c-torture/execute/pr20466-1.c: New test.

Patches:
http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/gcc/testsuite/ChangeLog.diff?cvsroot=gcc&r1=1.5306&r2=1.5307
http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/gcc/testsuite/gcc.c-torture/execute/pr20466-1.c.diff?cvsroot=gcc&r1=NONE&r2=1.1



-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=20466

[Bug rtl-optimization/20466] Missed invalidation of known memory contents in flow2...

[cvs-commit at gcc dot gnu dot org]

------- Additional Comments From cvs-commit at gcc dot gnu dot org  2005-04-08 23:21 -------
Subject: Bug 20466

CVSROOT:	/cvs/gcc
Module name:	gcc
Changes by:	hp@gcc.gnu.org	2005-04-08 23:21:12

Modified files:
	gcc            : ChangeLog flow.c 

Log message:
	PR rtl-optimization/20466
	* flow.c (invalidate_mems_from_set): Handle a MEM by checking it
	for overlap of the address of each list member.
	(mark_set_1): Call invalidate_mems_from_set for MEMs too.

Patches:
http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/gcc/ChangeLog.diff?cvsroot=gcc&r1=2.8200&r2=2.8201
http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/gcc/flow.c.diff?cvsroot=gcc&r1=1.623&r2=1.624



-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=20466

[Bug rtl-optimization/20466] Missed invalidation of known memory contents in flow2...

[hp at gcc dot gnu dot org]

------- Additional Comments From hp at gcc dot gnu dot org  2005-04-08 23:24 -------
Correction committed.

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


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=20466

[Bug rtl-optimization/20466] Missed invalidation of known memory contents in flow2...

[pinskia at gcc dot gnu dot org]

-- 
           What    |Removed                     |Added
----------------------------------------------------------------------------
   Target Milestone|---                         |4.1.0


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=20466