[Bug target/16589] New: segmentation fault on identical array accesses in the ?: operators' body

[Bug target/16589] New: segmentation fault on identical array accesses in the ?: operators' body

[loki at inf dot u-szeged dot hu]

There is something wrong around the array access on m68k.
If in body of the ?: operator the array "t" is accessed more
than once in same way the compiler'll drop some errors.

I made several crosscompiler, and I only found that m68k-*-elf 
doesn't handle the following c code:
 
float *t, a;
void good()
{
  a = (t[0] < 0 ? 0 : (a > 1 ? 1 : t[1]));
}
void bad() 
{
  a = (t[0] < 0 ? 0 : (a > 1 ? 1 : t[0]));
}

Command line:
m68k-elf-gcc -O1 -o pr.o pr.c

And I got:

pr.c: In function `bad':
pr.c:11: internal compiler error: in output_325, at insn-output.c:3475
Please submit a full bug report,
with preprocessed source if appropriate.
See <URL:http://gcc.gnu.org/bugs.html> for instructions.

-- 
           Summary: segmentation fault on identical array accesses in the ?:
                    operators' body
           Product: gcc
           Version: 3.5.0
            Status: UNCONFIRMED
          Severity: critical
          Priority: P2
         Component: target
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: loki at inf dot u-szeged dot hu
                CC: gcc-bugs at gcc dot gnu dot org
GCC target triplet: m68k-unknown-elf


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=16589

[Bug target/16589] [3.5.0 regression] [m68k] segmentation fault on identical array accesses in the ?: operators' body

[schwab at suse dot de]

------- Additional Comments From schwab at suse dot de  2004-07-16 13:59 -------
Confirmed. 

-- 
           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |schwab at suse dot de
             Status|UNCONFIRMED                 |NEW
     Ever Confirmed|                            |1
      Known to fail|                            |3.5.0
      Known to work|                            |3.4.2
   Last reconfirmed|0000-00-00 00:00:00         |2004-07-16 13:59:03
               date|                            |
            Summary|segmentation fault on       |[3.5.0 regression] [m68k]
                   |identical array accesses in |segmentation fault on
                   |the ?: operators' body      |identical array accesses in
                   |                            |the ?: operators' body
   Target Milestone|---                         |tree-ssa


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=16589

[Bug target/16589] [3.5.0 regression] [m68k] segmentation fault on identical array accesses in the ?: operators' body

[schwab at suse dot de]

------- Additional Comments From schwab at suse dot de  2004-07-16 14:54 -------
The problem is that gcc is now using the IEEE aware conditions which only work 
with CC in the FPU, but notice_update_cc still sets cc_status for the SET even 
if the destination is a DATA_REG in SFmode. 

-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=16589

[Bug target/16589] [3.5.0 regression] [m68k] segmentation fault on identical array accesses in the ?: operators' body

[pinskia at gcc dot gnu dot org]

-- 
           What    |Removed                     |Added
----------------------------------------------------------------------------
           Severity|critical                    |normal
           Keywords|                            |ice-on-valid-code
   Target Milestone|tree-ssa                    |3.5.0


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=16589

[Bug target/16589] [3.5.0 regression] [m68k] segmentation fault on identical array accesses in the ?: operators' body

[loki at inf dot u-szeged dot hu]

------- Additional Comments From loki at inf dot u-szeged dot hu  2004-08-31 09:21 -------
I have another testcase. Is it a similar problem?

Source:
int bar(float *e)
{
  if (!(e[0] > 0 && e[1] > 0))
    return 1;
  return 0;
}

Command line (version:2004-08-30 12:00:00 UTC):
m68k-elf-gcc -c -O2 pr.i

Output:
pr.i: In function `bar':
pr.i:6: internal compiler error: in output_348, at insn-output.c:3487


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=16589

[Bug target/16589] [3.5.0 regression] [m68k] segmentation fault on identical array accesses in the ?: operators' body

[wilson at specifixinc dot com]

------- Additional Comments From wilson at specifixinc dot com  2004-09-02 03:39 -------
Subject: Re:  [3.5.0 regression] [m68k] segmentation fault
 on identical array accesses in the ?: operators' body

loki at inf dot u-szeged dot hu wrote:
> ------- Additional Comments From loki at inf dot u-szeged dot hu  2004-08-31 09:21 -------
> I have another testcase. Is it a similar problem?
> pr.i:6: internal compiler error: in output_348, at insn-output.c:3487

Yes, it is the same problem.

By the way, this problem goes away with my flag_trapping_math bug fix 
(it should be on by default but is not).  However, the underlying 
problem remains, and can still be triggered if you use the 
-fno-trapping-math option.

The underlying problem seems to be that we have two condition codes, one 
integer one and one FP one, and cc_status can only track one of them at 
a time.  If we clobber cc_status when CC_IN_68881 is set, then this 
problem will be fixed, but we won't be able to optimize away FP compares 
anymore, and hence there will be some performance loss.  However, the 
current code looks like it will handle negative-zero incorrectly, and 
probably also signalling NaNs, and maybe some other stuff too, so this 
may be a good idea anyways in order to fix some IEEE math correctness 
problems.


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=16589

[Bug target/16589] [4.0 regression] [m68k] segmentation fault on identical array accesses in the ?: operators' body

[loki at inf dot u-szeged dot hu]

------- Additional Comments From loki at inf dot u-szeged dot hu  2004-10-22 11:44 -------
The bug has been fixed at Sep 3.


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


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=16589

[Bug target/16589] [4.0 regression] [m68k] segmentation fault on identical array accesses in the ?: operators' body

[schwab at suse dot de]

------- Additional Comments From schwab at suse dot de  2004-10-22 13:44 -------
See comment #4, this is still not fixed with -fno-trapping-math. 

-- 
           What    |Removed                     |Added
----------------------------------------------------------------------------
   Last reconfirmed|2004-07-16 13:59:03         |2004-10-22 13:44:51
               date|                            |


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=16589

[Bug target/16589] [4.0 regression] [m68k] segmentation fault on identical array accesses in the ?: operators' body

[schwab at suse dot de]

------- Additional Comments From schwab at suse dot de  2004-10-22 13:45 -------
See last comment. 

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


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=16589

[Bug target/16589] [4.0 regression] [m68k] segmentation fault on identical array accesses in the ?: operators' body

[pinskia at gcc dot gnu dot org]

-- 
           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|REOPENED                    |NEW


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=16589

[Bug target/16589] [4.0 regression] [m68k] segmentation fault on identical array accesses in the ?: operators' body

[pinskia at gcc dot gnu dot org]

-- 
           What    |Removed                     |Added
----------------------------------------------------------------------------
           Priority|P2                          |P3


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=16589

[Bug target/16589] [4.0 regression] [m68k] segmentation fault on identical array accesses in the ?: operators' body

[steven at gcc dot gnu dot org]

------- Additional Comments From steven at gcc dot gnu dot org  2004-12-03 12:25 -------
Is the remaining bug a regression? In fact, is this a regression at all
or merely a bug that was latent and somehow got exposed now?  Andreas,
are you going to post your patch from comment #5?



-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=16589

[Bug target/16589] [4.0 regression] [m68k] segmentation fault on identical array accesses in the ?: operators' body

[mmitchel at gcc dot gnu dot org]

------- Additional Comments From mmitchel at gcc dot gnu dot org  2005-01-21 17:31 -------
m68k is not a primary or secondary target; removing target milestone.

-- 
           What    |Removed                     |Added
----------------------------------------------------------------------------
   Target Milestone|4.0.0                       |---


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=16589

[Bug target/16589] [4.0/4.1 regression] [m68k] segmentation fault on identical array accesses in the ?: operators' body

[pinskia at gcc dot gnu dot org]

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


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=16589