[Bug tree-optimization/64058] New: Performance degradation after r216304

[izamyatin at gmail dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=64058

            Bug ID: 64058
           Summary: Performance degradation after r216304
           Product: gcc
           Version: 5.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: tree-optimization
          Assignee: unassigned at gcc dot gnu.org
          Reporter: izamyatin at gmail dot com
            Target: x86

Created attachment 34101
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=34101&action=edit
reproducer

Got a performance regression for the codes similar to attached test (well,
rather specific, my simple attempts to reduce it more failed). Regression root
cause is not obviuos at the first glance but noticed that after r216304 we have
l1=u1 placed differently after expand pass. 
Seems for r216303 this assignment was sinked lower and this potentially affects
live ranges and thus performance.

GCC options: -Ofast -flto -m32