[Bug target/70359] [6 Regression] Code size increase for ARM compared to gcc-5.3.0

[law at redhat dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=70359

--- Comment #13 from Jeffrey A. Law <law at redhat dot com> ---
The change to the assignment of p_22 is made by forwprop1.

It does create a situation where p_2 is live outside the loop and hides the CSE
opportunity, which may be the cause of the more significant differences at
expansion time.