Ping*2 [PATCH][Middle-end][version 2]2nd patch of PR78809 and PR83026

[Qing Zhao]

Hi,

I’d like to ping the following patch the 2nd time:

https://gcc.gnu.org/ml/gcc-patches/2017-12/msg01454.html 

I already addressed all the issues raised for the first version of the patch, and retested on both X86 and Aarch64, without any issue.

I’d really like to make it into GCC 8. 

thanks a lot for the help.

Qing

For your reference, the first version of this patch is at:

https://gcc.gnu.org/ml/gcc-patches/2017-12/msg00962.html