[Bug tree-optimization/18832] missed jump threading with ||

law at redhat dot com gcc-bugzilla@gcc.gnu.org
Sat Apr 23 01:08:00 GMT 2005


------- Additional Comments From law at redhat dot com  2005-04-23 01:08 -------
The threading issues in f0 have been addressed.  Some simple code hoisting would
make f0 slightly better from a code size standpoint, but probably wouldn't
help runtime.

The lameness in f1 isn't really a jump threading problem.  We have a merge
point  before the second pair of tests which is going to make it damn near
impossible to track the values well enough to optimize this code.  This
isn't a jump threading problem.

f2 and f3 look good.

Basically there's no jump threading issues left here.



(In reply to comment #1)
> Oh and this one too:
> int f3(int c,int a, int b)
> {
>   if (a== 0||b==0) c+=2;
>   return c;
> }



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http://gcc.gnu.org/bugzilla/show_bug.cgi?id=18832



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