[Bug middle-end/23299] New: GCSE? caused miscompilation

["jakub at redhat dot com" <gcc-bugzilla at gcc dot gnu dot org>]

The following testcase is miscompiled on ppc and ppc64 at -Os.
In E::~E() GCSE changes:
(insn 3 6 4 0 (set (reg/f:DI 121 [ this ])
        (reg:DI 3 3 [ this ])) 297 {*movdi_internal64} (nil)
    (nil))
...
(insn 22 46 23 1 (set (reg/f:DI 125)
        (plus:DI (reg/f:DI 121 [ this ])
            (const_int 16 [0x10]))) 208 {*adddi3_internal1} (nil)
    (nil))
...
(insn 30 29 31 2 (set (reg/f:DI 129)
        (plus:DI (reg/f:DI 121 [ this ])
            (const_int 16 [0x10]))) 208 {*adddi3_internal1} (nil)
    (nil))

(each insn in a different bb, the last in EH bb) into:
(insn 57 6 3 0 (set (reg/f:DI 130)
        (plus:DI (reg/f:DI 121 [ this ])
            (const_int 16 [0x10]))) 208 {*adddi3_internal1} (nil)
    (nil))

(insn 3 57 4 0 (set (reg/f:DI 121 [ this ])
        (reg:DI 3 3 [ this ])) 297 {*movdi_internal64} (nil)
    (nil))
and using pseudo 130 in place of 125 and 129.

-- 
           Summary: GCSE? caused miscompilation
           Product: gcc
           Version: 4.0.2
            Status: UNCONFIRMED
          Severity: critical
          Priority: P2
         Component: middle-end
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: jakub at redhat dot com
                CC: gcc-bugs at gcc dot gnu dot org
GCC target triplet: powerpc{,64}-linux


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=23299