[Bug c/37684] New: [graphite] basic block containing VDEF of a scalar does not dominate basic block containing VUSE of the same scalar

[Bug c/37684] New: [graphite] basic block containing VDEF of a scalar does not dominate basic block containing VUSE of the same scalar

[hjagasia at gcc dot gnu dot org]

When translate_clast is called for a scop, scalar definitions are optimized out
and hence any subsequent uses of those scalars, outside the scop, represents a
problem. Also as code is generated for a scop, basic blocks in the scop are
moved around such that the block which contains the definition of a scalar no
longer dominates the basic block outside the scop which contains a use of that
scalar.

Attached reduced testcase block-3.c (derived from cpu2006-401.bzip2-bzlib.c)
fails in gloog->verify_ssa->verify_use at below:
>>>
  else if (bb != def_bb
           && !dominated_by_p (CDI_DOMINATORS, bb, def_bb))
    {
      error ("definition in block %i does not dominate use in block %i",
             def_bb->index, bb->index);
      err = true;
    }
>>>
Before translate_clast is called, here is an excerpt from the function:
<bb 3>:
  # SMT.48_24 = PHI <SMT.48_20(4), SMT.48_18(2)>
  # i_28 = PHI <i_10(4), 0(2)>
  # SMT.49_29 = PHI <SMT.49_21(4), SMT.49_19(2)>
  # SMT.48_20 = VDEF <SMT.48_24>
  # SMT.49_21 = VDEF <SMT.49_29>
  s_5->inUse[i_28] = 0;
  i_10 = i_28 + 1;
  if (i_10 <= 255)
    goto <bb 4>;
  else
    goto <bb 5>;

<bb 4>:
  goto <bb 3>;

<bb 5>:

<bb 6>:
  # VUSE <SMT.48_20, SMT.49_21>
  D.1656_11 = s_5->blockNo;
  D.1657_12 = D.1656_11 + 1;
  # SMT.48_22 = VDEF <SMT.48_20>
  # SMT.49_23 = VDEF <SMT.49_21>
  s_5->blockNo = D.1657_12;
  return;

At this point bb 3 which contains the VDEF for SMT.48_20 and SMT.49_21
dominates bb 6 which contains the VUSE for the same. The VDEF is associated
with s_5->blockNo and the VUSE with s_5->inUse[i_28].

After translate_clast is called, here is an excerpt from the function:
BZ2_bzCompressInit (struct bz_stream * strm, int blockSize100k, int verbosity,
int workFactor)
{
  struct EState * D.1728;
  int D.1725;
  int D.1726;
  int D.1727;
  int graphiteIV.63;
  int graphiteIV.62;
  Int32 pretmp.52;
  int D.1656;
  int D.1657;
  Int32 i;
  struct EState * s;
  void * D.1643;
  void * D.1642;
  void * (*<T494>) (void *, int, int) D.1641;

<bb 2>:
  # VUSE <SMT.47_14(D), SMT.49_15(D)>
  D.1641_2 = strm_1(D)->bzalloc;
  # VUSE <SMT.47_14(D), SMT.49_15(D)>
  D.1642_3 = strm_1(D)->opaque;
  # SMT.47_17 = VDEF <SMT.47_14(D)>
  # SMT.48_18 = VDEF <SMT.48_16(D)>
  # SMT.49_19 = VDEF <SMT.49_15(D)>
  D.1643_4 = D.1641_2 (D.1642_3, 304, 1);
  s_5 = (struct EState *) D.1643_4;

<bb 7>:
  # graphiteIV.62_13 = PHI <0(2), graphiteIV.62_6(8)>
  graphiteIV.62_6 = graphiteIV.62_13 + 1;
  if (graphiteIV.62_6 <= 3)
    goto <bb 11>;
  else
    goto <bb 5>;

<bb 11>:
  graphiteIV.63_9 = graphiteIV.62_13 * 64;

<bb 9>:
  # graphiteIV.63_27 = PHI <graphiteIV.63_9(11), graphiteIV.63_25(10)>
  # SMT.48_24 = PHI <>
  # SMT.49_29 = PHI <>
  graphiteIV.63_25 = graphiteIV.63_27 + 1;
  D.1725_26 = graphiteIV.62_13 * 64;
  D.1726_30 = D.1725_26 + 63;
  D.1727_31 = MIN_EXPR <D.1726_30, 255>;
  if (graphiteIV.63_25 <= D.1727_31)
    goto <bb 3>;
  else
    goto <bb 8>;

<bb 10>:
  goto <bb 9>;

<bb 8>:
  goto <bb 7>;

<bb 3>:
Invalid sum of outgoing probabilities 0.0%
Invalid sum of incoming frequencies 25, should be 9900
  D.1728_32 = (struct EState *) D.1643_4;
  D.1728_32->inUse[graphiteIV.63_27] = 0;
  goto <bb 10>;

<bb 4>:
Invalid sum of incoming frequencies 0, should be 9800

<bb 5>:

<bb 6>:
  # VUSE <SMT.48_20, SMT.49_21>
  D.1656_11 = s_5->blockNo;
  D.1657_12 = D.1656_11 + 1;
  # SMT.48_22 = VDEF <SMT.48_20>
  # SMT.49_23 = VDEF <SMT.49_21>
  s_5->blockNo = D.1657_12;
  return;

}

During translate_clast the scop is transformed and the scalar VDEFS for
SMT.48_20, SMT.49_21 are removed by graphite. Also bb 3 no longer
dominates bb 6.


-- 
           Summary: [graphite] basic block containing VDEF of a scalar does
                    not dominate basic block containing VUSE of the same
                    scalar
           Product: gcc
           Version: 4.4.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c
        AssignedTo: hjagasia at gcc dot gnu dot org
        ReportedBy: hjagasia at gcc dot gnu dot org
 GCC build triplet: x86_64-unknown-linux-gnu
  GCC host triplet: x86_64-unknown-linux-gnu
GCC target triplet: x86_64-unknown-linux-gnu


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=37684

[Bug c/37684] [graphite] basic block containing VDEF of a scalar does not dominate basic block containing VUSE of the same scalar

[hjagasia at gcc dot gnu dot org]

------- Comment #1 from hjagasia at gcc dot gnu dot org  2008-09-30 16:34 -------
Created an attachment (id=16434)
 --> (http://gcc.gnu.org/bugzilla/attachment.cgi?id=16434&action=view)
Reduced test case derived from CPU2006 401.bzip2 benchmark


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=37684

[Bug tree-optimization/37684] [graphite] basic block containing VDEF of a scalar does not dominate basic block containing VUSE of the same scalar

[hjagasia at gcc dot gnu dot org]

------- Comment #2 from hjagasia at gcc dot gnu dot org  2008-09-30 16:40 -------
Created an attachment (id=16435)
 --> (http://gcc.gnu.org/bugzilla/attachment.cgi?id=16435&action=view)
This patch fixes the reduced test case block-3.c

Until graphite can handle scalars and also update dominance properly (planned
for gcc 4.5), this patch will work by limiting the scop that contains bb 3,
which in turn contains the VDEFs for SMT.48_20, SMT.49_21, such that no code is
generated for it.

This patch depends on the patch submitted for 37485.


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=37684

[Bug tree-optimization/37684] [graphite] basic block containing VDEF of a scalar does not dominate basic block containing VUSE of the same scalar

[spop at gcc dot gnu dot org]

------- Comment #4 from spop at gcc dot gnu dot org  2008-10-03 21:11 -------
Bug is fixed in graphite branch.  Waiting review for trunk.

Sebastian


-- 

spop at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
         AssignedTo|hjagasia at gcc dot gnu dot |spop at gcc dot gnu dot org
                   |org                         |
             Status|UNCONFIRMED                 |ASSIGNED
     Ever Confirmed|0                           |1
   Last reconfirmed|0000-00-00 00:00:00         |2008-10-03 21:11:19
               date|                            |


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=37684

[Bug tree-optimization/37684] [graphite] basic block containing VDEF of a scalar does not dominate basic block containing VUSE of the same scalar

[spop at gcc dot gnu dot org]

------- Comment #3 from spop at gcc dot gnu dot org  2008-10-03 21:10 -------
Subject: Bug 37684

Author: spop
Date: Fri Oct  3 21:09:37 2008
New Revision: 140861

URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=140861
Log:
2008-10-03  Harsha Jagasia  <harsha.jagasia@amd.com>

        PR tree-optimization/37684
        * gcc.dg/graphite/pr37684.c: New.
        * graphite.c (exclude_component_ref): New.
        (is_simple_operand): Call exclude_component_ref.


Added:
    branches/graphite/gcc/testsuite/gcc.dg/graphite/pr37684.c
Modified:
    branches/graphite/gcc/ChangeLog.graphite
    branches/graphite/gcc/graphite.c


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=37684

[Bug tree-optimization/37684] [graphite] basic block containing VDEF of a scalar does not dominate basic block containing VUSE of the same scalar

[spop at gcc dot gnu dot org]

------- Comment #5 from spop at gcc dot gnu dot org  2008-11-03 16:44 -------
Fixed.


-- 

spop at gcc dot gnu dot org changed:

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


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=37684

[Bug tree-optimization/37684] [graphite] basic block containing VDEF of a scalar does not dominate basic block containing VUSE of the same scalar

[spop at gcc dot gnu dot org]

------- Comment #6 from spop at gcc dot gnu dot org  2008-11-03 16:44 -------
Subject: Bug 37684

Author: spop
Date: Mon Nov  3 16:43:02 2008
New Revision: 141551

URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=141551
Log:
2008-11-03  Harsha Jagasia  <harsha.jagasia@amd.com>

        PR tree-optimization/37684
        * gcc.dg/graphite/pr37684.c: New.
        * graphite.c (exclude_component_ref): New.
        (is_simple_operand): Call exclude_component_ref.


Added:
    trunk/gcc/testsuite/gcc.dg/graphite/pr37684.c
Modified:
    trunk/gcc/ChangeLog
    trunk/gcc/graphite.c


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=37684

[Bug tree-optimization/37684] [graphite] basic block containing VDEF of a scalar does not dominate basic block containing VUSE of the same scalar

[spop at gcc dot gnu dot org]

------- Comment #7 from spop at gcc dot gnu dot org  2008-12-03 20:50 -------
*** Bug 37851 has been marked as a duplicate of this bug. ***


-- 

spop at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |dwarak dot rajagopal at amd
                   |                            |dot com


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=37684