[Bug tree-optimization/31343] New: ICE in data-refs dependence testing

[Bug tree-optimization/31343] New: ICE in data-refs dependence testing

[irar at il dot ibm dot com]

An attempt to divide by zero is made (causing ICE on the attached test
case) for evolution functions with zero step.

For the following evolution functions of pS[i_15].x and pS[i_15].y from the
attached test
  (chrec_a = {{0, +, 1}_1, +, 0}_2)
  (chrec_b = {{1, +, 1}_1, +, 0}_2)
the difference (-1) is calculated, and then the check whether the step
(0)divides the difference is performed in function
chrec_steps_divide_constant_p (tree-data-ref.c), causing ICE.


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           Summary: ICE in data-refs dependence testing
           Product: gcc
           Version: 4.3.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: tree-optimization
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: irar at il dot ibm dot com


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=31343

[Bug tree-optimization/31343] ICE in data-refs dependence testing

[irar at il dot ibm dot com]

------- Comment #1 from irar at il dot ibm dot com  2007-03-25 10:02 -------
Created an attachment (id=13281)
 --> (http://gcc.gnu.org/bugzilla/attachment.cgi?id=13281&action=view)
test case


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http://gcc.gnu.org/bugzilla/show_bug.cgi?id=31343

[Bug tree-optimization/31343] ICE in data-refs dependence testing

[pthaugen at us dot ibm dot com]

------- Comment #2 from pthaugen at us dot ibm dot com  2007-03-25 18:38 -------
I hit the same ICE building the 191.fma3d benchmark from cpu2000 when compiling
lsold.f90 with -O2 -ftree-loop-linear.


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pthaugen at us dot ibm dot com changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |pthaugen at us dot ibm dot
                   |                            |com


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=31343

[Bug tree-optimization/31343] ICE in data-refs dependence testing

[spop at gcc dot gnu dot org]

------- Comment #3 from spop at gcc dot gnu dot org  2007-04-11 01:09 -------
Subject: Bug 31343

Author: spop
Date: Wed Apr 11 01:09:35 2007
New Revision: 123708

URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=123708
Log:
        PR tree-optimization/31343
        * tree-chrec.h (chrec_zerop): Moved before build_polynomial_chrec.
        (build_polynomial_chrec): Return a scalar when the evolution is zero.
        * testsuite/gcc.dg/vect/pr31343.c: New.


Added:
    trunk/gcc/testsuite/gcc.dg/vect/pr31343.c
Modified:
    trunk/gcc/ChangeLog
    trunk/gcc/tree-chrec.h


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http://gcc.gnu.org/bugzilla/show_bug.cgi?id=31343

[Bug tree-optimization/31343] ICE in data-refs dependence testing

[spop at gcc dot gnu dot org]

------- Comment #4 from spop at gcc dot gnu dot org  2007-07-10 08:34 -------
Fixed.


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spop at gcc dot gnu dot org changed:

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


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=31343