[Bug tree-optimization/56294] BOOT_CFLAGS='-O2 -g -fno-ipa-sra' leads to bootstrap comparison failure

jamborm at gcc dot gnu.org gcc-bugzilla@gcc.gnu.org
Tue Mar 5 16:49:00 GMT 2013


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=56294

--- Comment #18 from Martin Jambor <jamborm at gcc dot gnu.org> 2013-03-05 16:49:29 UTC ---
(In reply to comment #17)
> Which is the testcase that still fails?  The attached and more reduced ones
> pass for me ...

The testcase from comment #10 (called "Another unrelated issue") still
fails for me with g++ -O2 -fno-ipa-sra -fcompare-debug.  (I use trunk
from yesterday).

(In reply to comment #16)
> can you check if rewrite_update_enter_block visits basic-blocks
> in different order -g vs. -g0?

No, from the dumps it does not seem so (see below).  The dump also
shows that in the -g1 case, the renamer sees elim_cost$complexity much
earlier with debug statements.  However, even seeing them only a
little bit earlier (BB 17 as opposed to 18) is enough to trigger the
problem.  Perhaps because there is a to-be SSA name definition at the
beginning of BB 18?

-g0:

Updating SSA:
Registering new PHI nodes in block #0
Registering new PHI nodes in block #2
Registering new PHI nodes in block #3
Registering new PHI nodes in block #4
Updating SSA information for statement elim_cost$cost = SR.30;
Updating SSA information for statement elim_cost$complexity = SR.31;
Updating SSA information for statement _22 = elim_cost$cost;
Registering new PHI nodes in block #5
Updating SSA information for statement elim_cost$cost = _24;
Registering new PHI nodes in block #6
Updating SSA information for statement cost$cost = elim_cost$cost;
Updating SSA information for statement _74 = cost$cost;
Registering new PHI nodes in block #7
Registering new PHI nodes in block #8
Registering new PHI nodes in block #9
Registering new PHI nodes in block #10
Registering new PHI nodes in block #11
Registering new PHI nodes in block #12
Registering new PHI nodes in block #13
Registering new PHI nodes in block #14
Registering new PHI nodes in block #15
Registering new PHI nodes in block #16
Updating SSA information for statement _50 = elim_cost$cost;
Updating SSA information for statement elim_cost$cost = _51;
Registering new PHI nodes in block #17
Registering new PHI nodes in block #18
Updating SSA information for statement cost$cost = elim_cost$cost;
Updating SSA information for statement cost$complexity = elim_cost$complexity;
Registering new PHI nodes in block #19
Updating SSA information for statement cost$cost = cost$cost;
Updating SSA information for statement _78 = cost$cost;
Registering new PHI nodes in block #20

Symbols to be put in SSA form
{ D.2850 D.2851 D.2854 D.2855 D.2856 D.2857 D.2858 D.2859 }
Incremental SSA update started at block: 0
Number of blocks in CFG: 21
Number of blocks to update: 20 ( 95%)
Affected blocks: 0 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20

-g1:

Updating SSA:
Registering new PHI nodes in block #0
Registering new PHI nodes in block #2
Registering new PHI nodes in block #3
Registering new PHI nodes in block #4
Updating SSA information for statement elim_cost$cost = SR.30;
Updating SSA information for statement elim_cost$complexity = SR.31;
Updating SSA information for statement _22 = elim_cost$cost;
Registering new PHI nodes in block #5
Updating SSA information for statement elim_cost$cost = _24;
Registering new PHI nodes in block #6
Updating SSA information for statement cost$cost = elim_cost$cost;
Updating SSA information for statement # DEBUG cost$complexity =>
elim_cost$complexity
Updating SSA information for statement _74 = cost$cost;
Registering new PHI nodes in block #7
Registering new PHI nodes in block #8
Registering new PHI nodes in block #9
Registering new PHI nodes in block #10
Registering new PHI nodes in block #11
Registering new PHI nodes in block #12
Registering new PHI nodes in block #13
Registering new PHI nodes in block #14
Registering new PHI nodes in block #15
Registering new PHI nodes in block #16
Updating SSA information for statement _50 = elim_cost$cost;
Updating SSA information for statement elim_cost$cost = _51;
Registering new PHI nodes in block #17
Updating SSA information for statement # DEBUG cost1$cost => elim_cost$cost
Updating SSA information for statement # DEBUG cost1$complexity =>
elim_cost$complexity
Registering new PHI nodes in block #18
Updating SSA information for statement cost$cost = elim_cost$cost;
Updating SSA information for statement cost$complexity = elim_cost$complexity;
Registering new PHI nodes in block #19
Updating SSA information for statement cost$cost = cost$cost;
Updating SSA information for statement # DEBUG cost$complexity =>
cost$complexity
Updating SSA information for statement _78 = cost$cost;
Registering new PHI nodes in block #20

Symbols to be put in SSA form
{ D.2850 D.2851 D.2854 D.2855 D.2856 D.2857 D.2858 D.2864 }
Incremental SSA update started at block: 0
Number of blocks in CFG: 21
Number of blocks to update: 20 ( 95%)
Affected blocks: 0 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20



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