optimization/4714: Haney's real matrix performance regression

[Paolo Carlini]

Daniel Berlin wrote:

>General induction variable.
>
>for (i = 0; i < 50; i ++)
>{
>	a = i * 5;
>}
>
>i is a biv (basic induction variable).
>a is a giv, since it's a linear function of a biv.
>
Thanks Daniel for the clear explanation and example.
Indeed, the recent improvements to C++ alias analysis (coauthored by 
yourself) is responsible for a much better behaviour of 3.2 on this 
testcase. I'm not sure if it's already optimal, however.

Ciao, Paolo.