[Bug rtl-optimization/82388] [8 Regression] wrong code at -O1 and above on x86_64-linux-gnu in 32-bit mode

["marxin at gcc dot gnu.org" <gcc-bugzilla at gcc dot gnu dot org>]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=82388

Martin Liška <marxin at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
           Keywords|                            |wrong-code
             Status|UNCONFIRMED                 |NEW
   Last reconfirmed|                            |2017-10-02
                 CC|                            |law at gcc dot gnu.org,
                   |                            |marxin at gcc dot gnu.org
   Target Milestone|---                         |8.0
            Summary|wrong code at -O1 and above |[8 Regression] wrong code
                   |on x86_64-linux-gnu in      |at -O1 and above on
                   |32-bit mode                 |x86_64-linux-gnu in 32-bit
                   |                            |mode
     Ever confirmed|0                           |1

--- Comment #2 from Martin Liška <marxin at gcc dot gnu.org> ---
It's related to PR82387, as:

==12691== Invalid read of size 8
==12691==    at 0x1B70E40: bitmap_bit_in_range_p(simple_bitmap_def const*,
unsigned int, unsigned int) (sbitmap.c:348)
==12691==    by 0x10FBD44: live_bytes_read(ao_ref, ao_ref*, simple_bitmap_def*)
(tree-ssa-dse.c:496)
==12691==    by 0x10FC09D: dse_classify_store(ao_ref*, gimple*, gimple**, bool,
simple_bitmap_def*) (tree-ssa-dse.c:594)
==12691==    by 0x10FC7AC:
dse_dom_walker::dse_optimize_stmt(gimple_stmt_iterator*) (tree-ssa-dse.c:820)
==12691==    by 0x10FC8B2:
dse_dom_walker::before_dom_children(basic_block_def*) (tree-ssa-dse.c:852)
==12691==    by 0x19D8C93: dom_walker::walk(basic_block_def*) (domwalk.c:308)
==12691==    by 0x10FC9FD: (anonymous namespace)::pass_dse::execute(function*)
(tree-ssa-dse.c:906)
==12691==    by 0xE33C6C: execute_one_pass(opt_pass*) (passes.c:2495)
==12691==    by 0xE33FBD: execute_pass_list_1(opt_pass*) (passes.c:2584)
==12691==    by 0xE33FEE: execute_pass_list_1(opt_pass*) (passes.c:2585)
==12691==    by 0xE34046: execute_pass_list(function*, opt_pass*)
(passes.c:2595)
==12691==    by 0xE32136: do_per_function_toporder(void (*)(function*, void*),
void*) (passes.c:1737)
==12691==  Address 0x65794e0 is 8 bytes after a block of size 40 alloc'd
==12691==    at 0x4C2E08F: malloc (in
/usr/lib64/valgrind/vgpreload_memcheck-amd64-linux.so)
==12691==    by 0x1BECD44: xmalloc (xmalloc.c:147)
==12691==    by 0x1B705EC: sbitmap_alloc(unsigned int) (sbitmap.c:50)
==12691==    by 0x990C5A: auto_sbitmap::auto_sbitmap(unsigned int)
(sbitmap.h:270)
==12691==    by 0x10FCC97: dse_dom_walker::dse_dom_walker(cdi_direction)
(tree-ssa-dse.c:661)
==12691==    by 0x10FC9E2: (anonymous namespace)::pass_dse::execute(function*)
(tree-ssa-dse.c:906)
==12691==    by 0xE33C6C: execute_one_pass(opt_pass*) (passes.c:2495)
==12691==    by 0xE33FBD: execute_pass_list_1(opt_pass*) (passes.c:2584)
==12691==    by 0xE33FEE: execute_pass_list_1(opt_pass*) (passes.c:2585)
==12691==    by 0xE34046: execute_pass_list(function*, opt_pass*)
(passes.c:2595)
==12691==    by 0xE32136: do_per_function_toporder(void (*)(function*, void*),
void*) (passes.c:1737)
==12691==    by 0xE34C2F: execute_ipa_pass_list(opt_pass*) (passes.c:2935)