hg: jdk9/hs-comp/hotspot: 8148754: C2 loop unrolling fails due to unexpected graph shape

[zoltan.majo at oracle.com]

Changeset: bcf5a0a5731b
Author:    zmajo
Date:      2016-03-21 09:51 +0100
URL:       http://hg.openjdk.java.net/jdk9/hs-comp/hotspot/rev/bcf5a0a5731b

8148754: C2 loop unrolling fails due to unexpected graph shape
Summary: Check if graph shape is appropriate for optimization, bail out optimization if not.
Reviewed-by: kvn, twisti, shade, dnsimon

! src/share/vm/opto/loopTransform.cpp
! src/share/vm/opto/loopnode.cpp
! src/share/vm/opto/loopnode.hpp
! src/share/vm/opto/superword.cpp