[Bug middle-end/42510] New: Invalid memory access in graphite

["hjl dot tools at gmail dot com" <gcc-bugzilla at gcc dot gnu dot org>]

gcc.dg/graphite/block-4.c fails at random. On Linux/x86-64, valgrind
reports:

==11194== Invalid read of size 8
==11194==    at 0xC714EE: lst_interchange_select_inner
(graphite-interchange.c:708)
==11194==    by 0xC72725: lst_interchange_select_outer
(graphite-interchange.c:732)
==11194==    by 0xC7278D: lst_interchange_select_outer
(graphite-interchange.c:743)
==11194==    by 0xC7278D: lst_interchange_select_outer
(graphite-interchange.c:743)
==11194==    by 0xC727CB: scop_do_interchange (graphite-interchange.c:754)
==11194==    by 0xC681A1: scop_do_block (graphite-blocking.c:293)
==11194==    by 0xBE5A57: apply_poly_transforms (graphite-poly.c:253)
==11194==    by 0xBDF68F: graphite_transform_loops (graphite.c:276)
==11194==    by 0x883286: graphite_transforms (tree-ssa-loop.c:300)
==11194==    by 0x70F54A: execute_one_pass (passes.c:1561)
==11194==    by 0x70F7D4: execute_pass_list (passes.c:1616)
==11194==    by 0x70F7E6: execute_pass_list (passes.c:1617)
==11194==  Address 0xb6aeb70 is 16 bytes inside a block of size 24 free'd
==11194==    at 0x4A04D72: free (vg_replace_malloc.c:325)
==11194==    by 0xC725B7: lst_interchange_select_inner (graphite-poly.h:704)
==11194==    by 0xC72725: lst_interchange_select_outer
(graphite-interchange.c:732)
==11194==    by 0xC7278D: lst_interchange_select_outer
(graphite-interchange.c:743)
==11194==    by 0xC7278D: lst_interchange_select_outer
(graphite-interchange.c:743)
==11194==    by 0xC727CB: scop_do_interchange (graphite-interchange.c:754)
==11194==    by 0xC681A1: scop_do_block (graphite-blocking.c:293)
==11194==    by 0xBE5A57: apply_poly_transforms (graphite-poly.c:253)
==11194==    by 0xBDF68F: graphite_transform_loops (graphite.c:276)
==11194==    by 0x883286: graphite_transforms (tree-ssa-loop.c:300)
==11194==    by 0x70F54A: execute_one_pass (passes.c:1561)
==11194==    by 0x70F7D4: execute_pass_list (passes.c:1616)
==11194==


-- 
           Summary: Invalid memory access in graphite
           Product: gcc
           Version: 4.5.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: middle-end
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: hjl dot tools at gmail dot com


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=42510