https://gcc.gnu.org/bugzilla/show_bug.cgi?id=82101
Manuel López-Ibáñez <manu at gcc dot gnu.org> changed:
What |Removed |Added
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CC| |manu at gcc dot gnu.org
--- Comment #2 from Manuel López-Ibáñez <manu at gcc dot gnu.org> ---
(In reply to Richard Biener from comment #1)
> Dup of some existing bug for sure. t looks like initialized to GCC on the
> backedge:
Not any that I know.
> but that gets later optimistically propagated away (the variable is dead
> anyway)
> and thus the late pass warning about maybe-uninitialized doesn't get here.
Does the late pass ever warn for self-initialization?
void foo(int);
int main(){
for(int i = 0 ; i < 10 ; i ++){
int t=t;
foo(t);
}
return 0;
}
> Now what is special here is that the uninit value is on the loop entry edge
> so the early pass _could_ warn.
This seems the bug indeed.
void foo(void);
int main(){
for(int i = 0 ; i < 10 ; i ++){
int t=t;
foo();
}
return 0;
}
> It also looks like we could improve on scoping here when re-writing into SSA.
> t doesn't need a PHI node as the value is not live over the backedge.
missed-opt then?
