http://gcc.gnu.org/bugzilla/show_bug.cgi?id=56294
Martin Jambor <jamborm at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
Status|ASSIGNED |NEW
AssignedTo|jamborm at gcc dot gnu.org |unassigned at gcc dot
| |gnu.org
--- Comment #11 from Martin Jambor <jamborm at gcc dot gnu.org> 2013-02-27
16:11:02 UTC ---
OK, patch http://gcc.gnu.org/ml/gcc-patches/2013-02/msg01233.html
fixes the testcase from comment #7 and patch
http://gcc.gnu.org/ml/gcc-patches/2013-02/msg01235.html should avoid
some further (although apparently not that crucial) differences in SRA
-g and -g0 output. Unfortunately, they do not fix the debug
comparison failure from comment #9.
The problematic difference is:
--- testcase.gkd 2013-02-27 16:25:54.036565436 +0100
+++ testcase.gk.gkd 2013-02-27 16:25:54.185565083 +0100
@@ -140,3 +140,3 @@
(insn:TI# 0 0 5 (set (reg/f:DI 6 bp [orig:62 D.xxxx ] [62])
- (mem/f:DI (const_int 0 [0]) [ *control_var_27(D)+0 S8 A64]))
testcase.ii:166# {*movdi_internal_rex64}
+ (mem/f:DI (const_int 0 [0]) [ *control_var_28(D)+0 S8 A64]))
testcase.ii:166# {*movdi_internal_rex64}
(nil))
and appears for the first time in release_ssa pass. It seems to me
that (right after early SRA), two SSA names simply have a different
order in -g0 and -g compilations:
-SSA_NAME 63: elim_cost$complexity_63
- DEF: elim_cost$complexity_63 = PHI <elim_cost$complexity_50(D)(3),
elim_cost$complexity_85(5), elim_cost$complexity_85(4)>
+SSA_NAME 63: cost$cost_63
+ DEF: cost$cost_63 = PHI <cost$cost_80(D)(17), cost$cost_79(18)>
-SSA_NAME 71: cost$cost_71
- DEF: cost$cost_71 = PHI <cost$cost_80(D)(17), cost$cost_79(18)>
+SSA_NAME 71: elim_cost$complexity_71
+ DEF: elim_cost$complexity_71 = PHI <elim_cost$complexity_50(D)(3),
elim_cost$complexity_85(5), elim_cost$complexity_85(4)>
Also, if I just do not produce DEBUG statements with
elim_cost$complexity on the RHS, the problem goes away. However, I do
not anything wrong with the statements. Later, just before
release_ssa, three SSA names have different order:
-SSA_NAME 67: .MEM_67
- DEF: comp ={v} {CLOBBER};
+SSA_NAME 63: cost$cost_63
+ DEF: cost$cost_63 = PHI <cost$cost_80(D)(12), elim_cost$cost_72(13)>
-SSA_NAME 70: control_var_70(D)
- DEF: GIMPLE_NOP
+SSA_NAME 67: .MEM_67
+ DEF: comp ={v} {CLOBBER};
-SSA_NAME 71: cost$cost_71
- DEF: cost$cost_71 = PHI <cost$cost_80(D)(12), elim_cost$cost_72(13)>
+SSA_NAME 70: control_var_70(D)
+ DEF: GIMPLE_NOP
...and control_var manages to leak to the final dump, causing the
failure.
I'll return to this bug in a few days, but now I need a break from it,
so I'm un-assigning myself.
