[Bug tree-optimization/42889] New: "-fcompare-debug failure (length)" with "-O1 -fgcse"

["zsojka at seznam dot cz" <gcc-bugzilla at gcc dot gnu dot org>]

Command line:
gcc -O1 -fgcse -fcompare-debug -c testcase.c

Tested revisions:
r156293 - crash
r155833 - crash
r155363 - OK
r154886 - OK
r153685 - OK

Output:
$ /mnt/svn/gcc-trunk/binary-155833-lto/bin/gcc -O1 -fgcse -fcompare-debug -c
testcase.c
gcc: testcase.c: -fcompare-debug failure (length)

I noticed this because gentoo's weekly gcc-4.5.0_alpha builds started failing
with 20100107, last working 20091231, at both x86 and x86_64.
I reproduced bootstrap failure when configure with --disable-checking, fails at
builtins.o (there is actually different code being emited).


-- 
           Summary: "-fcompare-debug failure (length)" with "-O1 -fgcse"
           Product: gcc
           Version: 4.5.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: tree-optimization
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: zsojka at seznam dot cz
  GCC host triplet: x86_64-pc-linux-gnu
GCC target triplet: x86_64-pc-linux-gnu


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=42889