[Bug tree-optimization/25211] New: verify_ssa ICE for mesa with -Os -ftree-loop-linear

[Bug tree-optimization/25211] New: verify_ssa ICE for mesa with -Os -ftree-loop-linear

[janis at gcc dot gnu dot org]

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Current trunk and 4.1 branch ICE on powerpc-linux compiling mesa
from SPEC CPU2000:

elm3b11% /opt/gcc-nightly/4.1/bin/gcc -c -Os -ftree-loop-linear mesa1201.c
mesa1201.c: In function ‘foo’:
mesa1201.c:7: error: definition in block 9 does not dominate use in block 3
for SSA_NAME: q_25 in statement:
q_1 = PHI <q_15(0), q_25(3)>;
PHI argument
q_25
for PHI node
q_1 = PHI <q_15(0), q_25(3)>;
mesa1201.c:7: internal compiler error: verify_ssa failed

The testcase passes with GCC 4.0.2 and with the 4.0 branch.
A regression hunt identified the following very large patch:

  http://gcc.gnu.org/viewcvs?view=rev&rev=102356
  r102356 | irar | 2005-07-25 12:05:07 +0000 (Mon, 25 Jul 2005)

I'll attach a minimized testcase.


-- 
           Summary: verify_ssa ICE for mesa with -Os -ftree-loop-linear
           Product: gcc
           Version: 4.1.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: tree-optimization
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: janis at gcc dot gnu dot org
GCC target triplet: powerpc-linux


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=25211

[Bug tree-optimization/25211] verify_ssa ICE for mesa with -Os -ftree-loop-linear

[janis at gcc dot gnu dot org]

------- Comment #1 from janis at gcc dot gnu dot org  2005-12-01 22:10 -------
Created an attachment (id=10386)
 --> (http://gcc.gnu.org/bugzilla/attachment.cgi?id=10386&action=view)
minimized testcase


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http://gcc.gnu.org/bugzilla/show_bug.cgi?id=25211

[Bug tree-optimization/25211] [4.1/4.2 Regression] verify_ssa ICE for mesa with -Os -ftree-loop-linear

[pinskia at gcc dot gnu dot org]

-- 

pinskia at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
           Keywords|                            |ice-on-valid-code
            Summary|verify_ssa ICE for mesa with|[4.1/4.2 Regression]
                   |-Os -ftree-loop-linear      |verify_ssa ICE for mesa with
                   |                            |-Os -ftree-loop-linear
   Target Milestone|---                         |4.1.0


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=25211

[Bug tree-optimization/25211] [4.1/4.2 Regression] verify_ssa ICE for mesa with -Os -ftree-loop-linear

[pinskia at gcc dot gnu dot org]

------- Comment #2 from pinskia at gcc dot gnu dot org  2005-12-02 15:56 -------
Looks related to PR 20256.


-- 

pinskia at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
  BugsThisDependsOn|                            |20256


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=25211

[Bug tree-optimization/25211] [4.1/4.2 Regression] verify_ssa ICE for mesa with -Os -ftree-loop-linear

[pinskia at gcc dot gnu dot org]

------- Comment #3 from pinskia at gcc dot gnu dot org  2005-12-02 15:58 -------
Confirmed also on i686-pc-linux-gnu.


-- 

pinskia at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |NEW
     Ever Confirmed|0                           |1
 GCC target triplet|powerpc-linux               |32bit targets
      Known to fail|                            |4.1.0 4.2.0
      Known to work|                            |4.0.3
   Last reconfirmed|0000-00-00 00:00:00         |2005-12-02 15:58:25
               date|                            |


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=25211

[Bug tree-optimization/25211] [4.1/4.2 Regression] verify_ssa ICE for mesa with -Os -ftree-loop-linear

[irar at il dot ibm dot com]

------- Comment #4 from irar at il dot ibm dot com  2005-12-14 13:11 -------
I think the reason why this ICE occurs with my patch
(http://gcc.gnu.org/viewcvs?view=rev&rev=102356) is that my patch enables
data-refs analysis for INDIRECT_REFs. Similar ICE in PR 20256 happens also
before my patch since the data-refs there are ARRAY_REFs, and ARRAY_REFs were
already supported before.


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=25211

[Bug tree-optimization/25211] [4.1/4.2 Regression] verify_ssa ICE for mesa with -Os -ftree-loop-linear

[mmitchel at gcc dot gnu dot org]

------- Comment #5 from mmitchel at gcc dot gnu dot org  2005-12-19 19:07 -------
I don't quite understand how likely we are to see this ICE; -Os
-ftree-loop-linear seems like an obscure combination of flags.  I'll call it P2
for now.


-- 

mmitchel at gcc dot gnu dot org changed:

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


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=25211

[Bug tree-optimization/25211] [4.1/4.2 Regression] verify_ssa ICE for mesa with -Os -ftree-loop-linear

[mmitchel at gcc dot gnu dot org]

------- Comment #6 from mmitchel at gcc dot gnu dot org  2006-02-24 00:26 -------
This issue will not be resolved in GCC 4.1.0; retargeted at GCC 4.1.1.


-- 

mmitchel at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Target Milestone|4.1.0                       |4.1.1


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=25211

[Bug tree-optimization/25211] [4.1 Regression] verify_ssa ICE with -Os -ftree-loop-linear

[pinskia at gcc dot gnu dot org]

------- Comment #7 from pinskia at gcc dot gnu dot org  2006-05-18 05:50 -------
Fixed on the mainline by:

2006-05-17  Sebastian Pop  <pop@cri.ensmp.fr>

        PR middle-end/20256
        PR middle-end/26435
        * tree-loop-linear.c (linear_transform_loops): Don't test
perfect_nest_p.
        Call rewrite_into_loop_closed_ssa only when something changed.
        * lambda.h (gcc_loopnest_to_lambda_loopnest): Update declaration.
        * lambda-code.c (can_convert_to_perfect_nest): Declared.
        (gcc_loopnest_to_lambda_loopnest): Removed need_perfect_nest parameter.
        Test for perfect_nest_p here.  Fix formating.
        (replace_uses_equiv_to_x_with_y): Fix formating.
        (stmt_uses_op): Removed.
        (can_convert_to_perfect_nest): Removed loopivs parameter.
        Complete the test by checking the scalar dependences.
        (perfect_nestify): Remove the test for can_convert_to_perfect_nest.
        Fix formating.


-- 

pinskia at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
      Known to fail|4.1.0 4.2.0                 |4.1.0
      Known to work|4.0.3                       |4.0.3 4.2.0
            Summary|[4.1/4.2 Regression]        |[4.1 Regression] verify_ssa
                   |verify_ssa ICE with -Os -   |ICE with -Os -ftree-loop-
                   |ftree-loop-linear           |linear


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=25211

[Bug tree-optimization/25211] [4.1 Regression] verify_ssa ICE with -Os -ftree-loop-linear

[mmitchel at gcc dot gnu dot org]

------- Comment #8 from mmitchel at gcc dot gnu dot org  2006-05-25 02:33 -------
Will not be fixed in 4.1.1; adjust target milestone to 4.1.2.


-- 

mmitchel at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Target Milestone|4.1.1                       |4.1.2


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=25211

[Bug tree-optimization/25211] [4.1 Regression] verify_ssa ICE with -Os -ftree-loop-linear

[spop at gcc dot gnu dot org]

------- Comment #9 from spop at gcc dot gnu dot org  2006-08-17 13:14 -------
Subject: Bug 25211

Author: spop
Date: Thu Aug 17 13:14:26 2006
New Revision: 116223

URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=116223
Log:
        PR middle-end/25211
        PR middle-end/20256
        PR middle-end/26435
        * tree-loop-linear.c (linear_transform_loops): Don't test
perfect_nest_p.
        Call rewrite_into_loop_closed_ssa only when something changed.
        * lambda.h (gcc_loopnest_to_lambda_loopnest): Update declaration.
        * lambda-code.c (can_convert_to_perfect_nest): Declared.
        (gcc_loopnest_to_lambda_loopnest): Removed need_perfect_nest parameter.
        Test for perfect_nest_p here.  Fix formating.
        (replace_uses_equiv_to_x_with_y): Fix formating.
        (stmt_uses_op): Removed.
        (can_convert_to_perfect_nest): Removed loopivs parameter.
        Complete the test by checking the scalar dependences.
        (perfect_nestify): Remove the test for can_convert_to_perfect_nest.
        Fix formating.  Don't copy statements in the inner loop: move them to
        the inner loop header.


Added:
    branches/gcc-4_1-branch/gcc/testsuite/gcc.dg/tree-ssa/pr20256.c
    branches/gcc-4_1-branch/gcc/testsuite/gcc.dg/tree-ssa/pr26435.c
    branches/gcc-4_1-branch/gcc/testsuite/gfortran.dg/pr27745.f90
Modified:
    branches/gcc-4_1-branch/gcc/ChangeLog
    branches/gcc-4_1-branch/gcc/lambda-code.c
    branches/gcc-4_1-branch/gcc/lambda.h
    branches/gcc-4_1-branch/gcc/testsuite/gcc.dg/tree-ssa/ltrans-1.c
    branches/gcc-4_1-branch/gcc/tree-loop-linear.c


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http://gcc.gnu.org/bugzilla/show_bug.cgi?id=25211

[Bug tree-optimization/25211] [4.1 Regression] verify_ssa ICE with -Os -ftree-loop-linear

[pinskia at gcc dot gnu dot org]

------- Comment #10 from pinskia at gcc dot gnu dot org  2006-09-17 19:31 -------
Fixed.


-- 

pinskia at gcc dot gnu dot org changed:

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


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=25211