http://gcc.gnu.org/bugzilla/show_bug.cgi?id=47205
--- Comment #1 from Jan Hubicka <hubicka at ucw dot cz> 2011-01-07 12:47:23 UTC
---
> extern int foo(void);
>
> int main(void)
> {
> return foo() * 0;
> }
This is because gimple part of optimizers for some reason leads to the
following in the optimized dump:
main ()
{
<bb 2>:
foo ();
return 0;
}
and only RTL optimizers do the trick.
This is weird since pure/const detect function as pure (seen in pure-const
dump)
Read info for foo/2 const nothrow
pure const state: const
previously known state: const
but tree-ssa-dce apparently fails to remove the statement. I guess it is
confused by lack of return value. I will take a look. But this is
tree-optimization bug.
Honza
