[Bug target/64113] New: Gcc on Alpha: Error: No lda !gpdisp!282 was found

["mcree at orcon dot net.nz" <gcc-bugzilla at gcc dot gnu dot org>]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=64113

            Bug ID: 64113
           Summary: Gcc on Alpha: Error: No lda !gpdisp!282 was found
           Product: gcc
           Version: 4.9.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: target
          Assignee: unassigned at gcc dot gnu.org
          Reporter: mcree at orcon dot net.nz
            Target: alpha-linux-gnu

gcc-4.9.x (and the trunk a couple of weeks ago) compiling certain software
packages (e.g. systemd) on an Alpha running Debian Alpha Linux results in
errors at the link stage such as:

{standard input}: Assembler messages:
{standard input}:5327: Error: No lda !gpdisp!282 was found
lto-wrapper: gcc returned 1 exit status
/usr/bin/ld: lto-wrapper failed
collect2: error: ld returned 1 exit status

These packages are successfully compiled with gcc-4.8.x.  

I have not been able to construct a minimal source exhibiting the problem.  But
because gcc-4.9.0 exhibits the failure and gcc-4.8.0 compiles the code
successfully I have been able to bisect to the first commit in gcc that
produces those errors, and that commit is:

commit c59258dcb37171743fdc6d393e767834aac9642b
Author: law <law@138bc75d-0d04-0410-961f-82ee72b054a4>
Date:   Tue Nov 12 16:41:51 2013 +0000

        * gimple-ssa-isolate-paths.c (check_loadstore): New function.
        (insert_trap_and_remove_trailing_statements): New argument OP which
        is the NULL pointer.  Emit the trap after the load/store through
        the NULL pointer.  Simplify the RHS of a store through a NULL pointer
        when trivial to do so.
        (isolate_path): Corresponding changes.
        (gimple_ssa_isolate_erroneous_path): Likewise.

        * gcc.dg/tree-ssa/isolate-1.c: Update expected output.
        * gcc.dg/tree-ssa/isolate-5.c: New test.

    git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@204708
138bc75d-0d04-0410-961f-82ee72b054a4