[Bug tree-optimization/34123] [4.3 Regression] verify_ssa failed with -ftree-loop-linear

[spop at gcc dot gnu dot org]

--- Comment #7 from spop at gcc dot gnu dot org  2007-12-18 19:40 ---
Subject: Bug 34123

Author: spop
Date: Tue Dec 18 19:40:35 2007
New Revision: 131040

URL: http://gcc.gnu.org/viewcvs?root=gccview=revrev=131040
Log:
2007-12-18  Sebastian Pop  [EMAIL PROTECTED]

PR tree-optimization/34123
* lambda-code.c (can_duplicate_iv): New.
(cannot_convert_modify_to_perfect_nest): New.
(cannot_convert_bb_to_perfect_nest): New.
(can_convert_to_perfect_nest): Split up.

* gcc.dg/tree-ssa/pr34123.c: New test.


Added:
trunk/gcc/testsuite/gcc.dg/tree-ssa/pr34123.c
Modified:
trunk/gcc/ChangeLog
trunk/gcc/lambda-code.c
trunk/gcc/testsuite/ChangeLog


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=34123

[Bug tree-optimization/34123] [4.3 Regression] verify_ssa failed with -ftree-loop-linear

[spop at gcc dot gnu dot org]

--- Comment #8 from spop at gcc dot gnu dot org  2007-12-18 19:42 ---
Fixed.


-- 

spop at gcc dot gnu dot org changed:

   What|Removed |Added

 Status|NEW |RESOLVED
 Resolution||FIXED


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=34123

[Bug tree-optimization/34123] [4.3 Regression] verify_ssa failed with -ftree-loop-linear

[spop at gcc dot gnu dot org]

--- Comment #6 from spop at gcc dot gnu dot org  2007-12-17 19:15 ---
Subject: Re:  [4.3 Regression] verify_ssa failed with -ftree-loop-linear

Patch is here:
http://gcc.gnu.org/ml/gcc-patches/2007-12/msg00735.html
test result on amd64-linux is here:
http://gcc.gnu.org/ml/gcc-patches/2007-12/msg00752.html
waiting for approval.

Sebastian


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=34123

[Bug tree-optimization/34123] [4.3 Regression] verify_ssa failed with -ftree-loop-linear

[spop at gcc dot gnu dot org]

--- Comment #5 from spop at gcc dot gnu dot org  2007-12-15 20:37 ---
Subject: Re:  [4.3 Regression] verify_ssa failed with -ftree-loop-linear

I have a fix for this one, cleaning up the complex logic in
can_convert_to_perfect_nest.

Sebastian


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=34123

[Bug tree-optimization/34123] [4.3 Regression] verify_ssa failed with -ftree-loop-linear

[mmitchel at gcc dot gnu dot org]

-- 

mmitchel at gcc dot gnu dot org changed:

   What|Removed |Added

   Priority|P3  |P1


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=34123

[Bug tree-optimization/34123] [4.3 Regression] verify_ssa failed with -ftree-loop-linear

[jakub at gcc dot gnu dot org]

--- Comment #4 from jakub at gcc dot gnu dot org  2007-11-20 10:59 ---
The testcase is wrong, static unsigned char sbox[] = {}; means zero sized
array.
But using sbox[256] makes the testcase valid and the problem is still there.
This looks like a bug in can_convert_to_perfect_nest, this loop (at least
unless
earlier passes don't realize that sbox[i] == 0 for any i) can't be converted
into a perfect nest.
The basic block which is after the inner loop is:

bb 5:
# t_30 = PHI t_16(4)
D.1558_19 = (unsigned char) i_39;
t_20 = t_30 + D.1558_19;
i_21 = i_39 + 1;
if (i_21 = 15)
  goto bb 6;
else
  goto bb 8;

bb 6:

bb 7:
# i_39 = PHI 0(2), i_21(6)
# SMT.4_10 = PHI SMT.4_26(D)(2), SMT.4_28(6)
# t_29 = PHI 0(2), t_20(6)
goto bb 4;

can_convert_to_perfect_nest walks the statements of these bbs and is satisfied
with all of them, the first two stmts in bb5 are satisfied by:

2234  tree step = evolution_part_in_loop_num (scev,
loop-num);
2235  if (step  step != chrec_dont_know 
2236   TREE_CODE (step) == INTEGER_CST)
2237continue;

- step is for both integer_one_node, the third stmt is of course correctly a
stmt_is_bumper_for_loop and the last one is exit_condition.  But nothing scans
the PHIs which are relevant here.  # t_30 = PHI t_16(4) in bb5 sets t_30 to
t_16, which is computed by inner loop.  And # t_29 = PHI 0(2), t_20(6)
in bb7 sets t_29 used in the inner loop to t_20 set in bb5 (i.e. in the bb
which prevents perfect nest).  Should the PHIs be walked similarly to how
stmts are walked?


-- 

jakub at gcc dot gnu dot org changed:

   What|Removed |Added

 CC||dberlin at gcc dot gnu dot
   ||org


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=34123

[Bug tree-optimization/34123] [4.3 Regression] verify_ssa failed with -ftree-loop-linear

[pinskia at gcc dot gnu dot org]

-- 

pinskia at gcc dot gnu dot org changed:

   What|Removed |Added

 CC||pinskia at gcc dot gnu dot
   ||org
Summary|[4.3 Regression] verify_ssa |[4.3 Regression] verify_ssa
   |failed (definition in block |failed with -ftree-loop-
   |11 does not dominate use in |linear
   |block 7)|
   Target Milestone|--- |4.3.0


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=34123