------- Comment #16 from rguenth at gcc dot gnu dot org 2007-05-01 13:35
-------
Created an attachment (id=13468)
--> (http://gcc.gnu.org/bugzilla/attachment.cgi?id=13468&action=view)
slightly simplified testcase
I don't see anything wrong with the testcase. I changed it to not take the
address of dummy, but pass zero instead. This reduces the diff of initial
aliasing to
- # _A_b1_61 = V_MAY_DEF <_A_b1_54>;
- # SFT.70_62 = V_MAY_DEF <SFT.70_55>;
- # SFT.71_63 = V_MAY_DEF <SFT.71_56>;
- # SFT.72_64 = V_MAY_DEF <SFT.72_57>;
- # SFT.73_65 = V_MAY_DEF <SFT.73_58>;
- # NONLOCAL.79_66 = V_MAY_DEF <NONLOCAL.79_60>;
+ # SFT.79_61 = V_MAY_DEF <SFT.79_57>;
this_41->rep_ = rep_42;
but before DCE (which makes a mess out of this testcase) we have practically
indentical dumps for A::bar() - Note that A::bar() is the offending function
that gets mis-optimized. We DCE the initialization of the function pointer so
we segfault at the indirect call to it.
@@ -78,21 +78,21 @@
sigc::slot0 A::bar() (this)
{
...
@@ -129,7 +129,7 @@
_A_func_2 = foo;
this_3 = (struct functor_base *) &D.2378;
this_4 = this_3;
- # SFT.73_6 = V_MUST_DEF <SFT.73_5>;
+ # SFT.80_6 = V_MUST_DEF <SFT.80_5>;
D.2378.func_ptr_ = foo;
_A_functor_7 = &D.2378;
# _A_b1_9 = V_MUST_DEF <_A_b1_8>;
@@ -151,33 +151,33 @@
this_24 = (struct functor_base *) this_23;
this_25 = this_24;
# D.2951_27 = V_MUST_DEF <D.2951_26>;
- # VUSE <SFT.73_6>;
+ # VUSE <SFT.80_6>;
D.2951 = D.2378;
- # SFT.70_50 = V_MAY_DEF <SFT.70_49>;
+ # SFT.77_50 = V_MAY_DEF <SFT.77_49>;
# VUSE <D.2951_27>;
this_20->functor_ = D.2951;
this_28 = &D.2514.bound1_;
this_29 = &D.2514.bound1_;
_A_argument_30 = &_A_b1;
D.2953_31 = 0B;
- # SFT.70_68 = V_MUST_DEF <SFT.70_50>;
+ # SFT.77_63 = V_MUST_DEF <SFT.77_50>;
D.2514.bound1_.visited_ = D.2953_31;
functor_32 = &D.2514;
# _A_b1_54 = V_MAY_DEF <_A_b1_9>;
- # SFT.70_55 = V_MAY_DEF <SFT.70_68>;
- # SFT.71_56 = V_MAY_DEF <SFT.71_52>;
- # SFT.72_57 = V_MAY_DEF <SFT.72_45>;
- # SFT.73_58 = V_MAY_DEF <SFT.73_6>;
- # NONLOCAL.79_59 = V_MAY_DEF <NONLOCAL.79_53>;
- D.3052_33 = operator new (20);
- this_34 = (struct typed_slot_rep<sigc::bind_functor<-0x000000001,
sigc::pointer_functor1<void*, void*>, void*> > *) D.3052_33;
+ # SFT.77_55 = V_MAY_DEF <SFT.77_63>;
+ # SFT.78_56 = V_MAY_DEF <SFT.78_52>;
+ # SFT.79_57 = V_MAY_DEF <SFT.79_45>;
+ # SFT.80_58 = V_MAY_DEF <SFT.80_6>;
+ # NONLOCAL.86_59 = V_MAY_DEF <NONLOCAL.86_53>;
+ D.3059_33 = operator new (20);
+ this_34 = (struct typed_slot_rep<sigc::bind_functor<-0x000000001,
sigc::pointer_functor1<void*, void*>, void*> > *) D.3059_33;
this_35 = this_34;
functor_36 = &D.2514;
this_37 = &this_35->D.2649;
this_38 = this_37;
- # NONLOCAL.79_60 = V_MAY_DEF <NONLOCAL.79_59>;
- # VUSE <SFT.70_55>;
- # VUSE <SFT.71_56>;
+ # NONLOCAL.86_60 = V_MAY_DEF <NONLOCAL.86_59>;
+ # VUSE <SFT.77_55>;
+ # VUSE <SFT.78_56>;
this_35->functor_ = D.2514;
rep_39 = (struct slot_rep *) this_34;
this_40 = &<retval>.D.2330;
@@ -185,14 +185,14 @@
rep_42 = rep_39;
this_43 = (struct functor_base *) &<retval>.D.2330;
this_44 = this_43;
- # SFT.72_69 = V_MUST_DEF <SFT.72_57>;
+ # SFT.79_64 = V_MUST_DEF <SFT.79_57>;
<retval>.D.2330.rep_ = rep_42;
- D.3058_46 = rep_39;
- D.3060_47 = call_it;
- D.3060_48 = call_it;
- # NONLOCAL.79_67 = V_MAY_DEF <NONLOCAL.79_60>;
- D.3058_46->call_ = call_it;
- # VUSE <SFT.72_69>;
+ D.3065_46 = rep_39;
+ D.3067_47 = call_it;
+ D.3067_48 = call_it;
+ # NONLOCAL.86_62 = V_MAY_DEF <NONLOCAL.86_60>;
+ D.3065_46->call_ = call_it;
+ # VUSE <SFT.79_64>;
return <retval>;
}
Still the DCE diff contains
<bb 2>:
- # SFT.73_6 = V_MUST_DEF <SFT.73_5>;
+ # SFT.80_6 = V_MUST_DEF <SFT.80_5>;
D.2378.func_ptr_ = foo;
# _A_b1_9 = V_MUST_DEF <_A_b1_8>;
_A_b1 = 0B;
- this_19 = &D.2514.D.2511.functor_;
- this_20 = this_19;
- # D.2951_27 = V_MUST_DEF <D.2951_26>;
- # VUSE <SFT.73_6>;
- D.2951 = D.2378;
- # SFT.70_50 = V_MAY_DEF <SFT.70_49>;
- # VUSE <D.2951_27>;
- this_20->functor_ = D.2951;
D.2953_31 = 0B;
- # SFT.70_68 = V_MUST_DEF <SFT.70_50>;
+ # SFT.77_63 = V_MUST_DEF <SFT.77_49>;
D.2514.bound1_.visited_ = D.2953_31;
where we removed the assignment
D.2951 = D.2378;
--
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=30252
