[Bug tree-optimization/52037] New: [4.7 regression] ICE in update_ssa, at tree-into-ssa.c:3362 while linking LTO libxul

["markus at trippelsdorf dot de" <gcc-bugzilla at gcc dot gnu dot org>]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=52037

             Bug #: 52037
           Summary: [4.7 regression] ICE in update_ssa, at
                    tree-into-ssa.c:3362 while linking LTO libxul
    Classification: Unclassified
           Product: gcc
           Version: 4.7.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: tree-optimization
        AssignedTo: unassigned@gcc.gnu.org
        ReportedBy: markus@trippelsdorf.de


ICE happens during final libxul link in a Firefox LTO build.

 % g++ @testcase -flto=4 -O3
In file included from :2560:0:
/var/tmp/mozilla-central/content/base/src/nsAttrValue.cpp: In member function
âEqualsâ:
/var/tmp/mozilla-central/content/base/src/nsAttrValue.cpp:689:1: internal
compiler error: in update_ssa, at tree-into-ssa.c:3362
Please submit a full bug report,
with preprocessed source if appropriate.
See <http://gcc.gnu.org/bugs.html> for instructions.

I managed to reduce it from 2770 input files to 17 (but no further) with delta.

 % cat testcase
/var/tmp/mozilla-central/moz-build-dir/toolkit/library/nsUnicharUtils.o
/var/tmp/mozilla-central/moz-build-dir/toolkit/library/../../netwerk/dns/nsIDNService.o
/var/tmp/mozilla-central/moz-build-dir/toolkit/library/../../netwerk/streamconv/converters/nsMultiMixedConv.o
/var/tmp/mozilla-central/moz-build-dir/toolkit/library/../../content/base/src/mozSanitizingSerializer.o
/var/tmp/mozilla-central/moz-build-dir/toolkit/library/../../content/base/src/nsAttrValue.o
/var/tmp/mozilla-central/moz-build-dir/toolkit/library/../../content/base/src/nsContentUtils.o
/var/tmp/mozilla-central/moz-build-dir/toolkit/library/../../content/base/src/nsDocument.o
/var/tmp/mozilla-central/moz-build-dir/toolkit/library/../../content/base/src/nsDocumentEncoder.o
/var/tmp/mozilla-central/moz-build-dir/toolkit/library/../../content/base/src/nsDocumentFragment.o
/var/tmp/mozilla-central/moz-build-dir/toolkit/library/../../content/base/src/nsGenConImageContent.o
/var/tmp/mozilla-central/moz-build-dir/toolkit/library/../../content/base/src/nsGenericElement.o
/var/tmp/mozilla-central/moz-build-dir/toolkit/library/../../content/base/src/nsHTMLContentSerializer.o
/var/tmp/mozilla-central/moz-build-dir/toolkit/library/../../content/base/src/nsImageLoadingContent.o
/var/tmp/mozilla-central/moz-build-dir/toolkit/library/../../xpcom/build/nsCOMPtr.o
/var/tmp/mozilla-central/moz-build-dir/toolkit/library/../../xpcom/string/src/nsReadableUtils.o
/var/tmp/mozilla-central/moz-build-dir/toolkit/library/../../xpcom/string/src/nsSubstring.o
/var/tmp/mozilla-central/moz-build-dir/toolkit/library/../../xpcom/string/src/nsStringComparator.o