[Bug c/69347] New: excessive compile time with -O2

[dcb314 at hotmail dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=69347

            Bug ID: 69347
           Summary: excessive compile time with -O2
           Product: gcc
           Version: 6.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c
          Assignee: unassigned at gcc dot gnu.org
          Reporter: dcb314 at hotmail dot com
  Target Milestone: ---

Created attachment 37386
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=37386&action=edit
gzipped C source code

The attached code, when compiled by gcc 5.3.1 and flag -O2, takes 32 seconds.

With gcc trunk dated 20160117 and flag -O2, it takes 19 minutes.

Some 36 times longer is somewhat surprising.