[lno] [RFC] if-conversion and auto vectorizer

[Devang Patel]

On Mar 15, 2004, at 7:33 PM, Richard Henderson wrote:

> One thing that might should be checked before marking various
> variables for ssa-renaming, however, is that you get
>
> 	if (x_1 < y_1)
> 	  x_2 = a, y_2 = b;
> 	x_3 = PHI(x_1, x_2)
> 	y_3 = PHI(y_1, y_2)
>  ==>
> 	x_3 = (x_1 < y_1 ? a : x_1)
> 	y_3 = (x_1 < y_1 ? b : y_1)
>
> Note that x_1 outlives the creation of x_3, which is new to
> this transformed code.  This mere fact might argue for the
> creation of a boolean temporary for the comparison.

Yes. I also need to simplify boolean exp.

--
Devang