[Bug middle-end/23997] New: DCE removes a loop when it shouldn't

[Bug middle-end/23997] New: DCE removes a loop when it shouldn't

[dorit at il dot ibm dot com]

DCE (.t44.dce3) eliminates the third loop in the testcase below, although the 
print loop should be enough to keep it alive:

======================
subroutine foo(a,b)
real a,b
type bzz
   real d(100)
end type bzz
type (bzz) e

dimension a(100), b(100)
read *,x,y
a=log(x)    <--- loop 1
b=log(y)    <--- loop 2
e%d = a+b   <--- loop 3. eliminated
print *,e%d
end
======================

See related thread here: http://gcc.gnu.org/ml/gcc/2005-09/msg00645.html

-- 
           Summary: DCE removes a loop when it shouldn't
           Product: gcc
           Version: 4.1.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P2
         Component: middle-end
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: dorit at il dot ibm dot com
                CC: gcc-bugs at gcc dot gnu dot org
 GCC build triplet: ppc64-yellowdog-linux
  GCC host triplet: ppc64-yellowdog-linux
GCC target triplet: ppc64-yellowdog-linux


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=23997

[Bug middle-end/23997] DCE removes a loop when it shouldn't

[dorit at il dot ibm dot com]

------- Additional Comments From dorit at il dot ibm dot com  2005-09-21 13:46 -------
I don't know how this happened - I didn't mean to open this PR again. This 
should be closed.

-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=23997

Re: [Bug middle-end/23997] DCE removes a loop when it shouldn't

[Andrew Pinski]

On Sep 21, 2005, at 9:46 AM, dorit at il dot ibm dot com wrote:

>
> ------- Additional Comments From dorit at il dot ibm dot com  
> 2005-09-21 13:46 -------
> I don't know how this happened - I didn't mean to open this PR again. 
> This
> should be closed.

Daniel opened because there is a latent bug still.
I had meant not really to close this but I did.

-- Pinski

[Bug middle-end/23997] DCE removes a loop when it shouldn't

[pinskia at physics dot uc dot edu]

------- Additional Comments From pinskia at physics dot uc dot edu  2005-09-21 13:51 -------
Subject: Re:  DCE removes a loop when it shouldn't


On Sep 21, 2005, at 9:46 AM, dorit at il dot ibm dot com wrote:

>
> ------- Additional Comments From dorit at il dot ibm dot com  
> 2005-09-21 13:46 -------
> I don't know how this happened - I didn't mean to open this PR again. 
> This
> should be closed.

Daniel opened because there is a latent bug still.
I had meant not really to close this but I did.

-- Pinski



-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=23997

[Bug middle-end/23997] DCE removes a loop when it shouldn't

[pinskia at gcc dot gnu dot org]

------- Additional Comments From pinskia at gcc dot gnu dot org  2005-09-21 14:23 -------
Oh, this is a dup.  I missed the bug number change.

*** This bug has been marked as a duplicate of 23989 ***

-- 
           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |RESOLVED
         Resolution|                            |DUPLICATE


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=23997