[Bug tree-optimization/78076] New: [7 Regression] Conditional jump or move depends on uninitialised value @ tree-vect-loop.c:2307

[trippels at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=78076

            Bug ID: 78076
           Summary: [7 Regression] Conditional jump or move depends on
                    uninitialised value @ tree-vect-loop.c:2307
           Product: gcc
           Version: 7.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: tree-optimization
          Assignee: unassigned at gcc dot gnu.org
          Reporter: trippels at gcc dot gnu.org
  Target Milestone: ---

Created attachment 39868
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=39868&action=edit
unreduced testcase

markus@x4 tmp % valgrind --track-origins=yes --trace-children=yes gcc -c -O3
ptio.i
==23766== Memcheck, a memory error detector
==23766== Copyright (C) 2002-2015, and GNU GPL'd, by Julian Seward et al.
==23766== Using Valgrind-3.11.0 and LibVEX; rerun with -h for copyright info
==23766== Command: /var/tmp/gcc_test/usr/local/bin/gcc -c -O3 ptio.i
==23766==
==23779== Memcheck, a memory error detector
==23779== Copyright (C) 2002-2015, and GNU GPL'd, by Julian Seward et al.
==23779== Using Valgrind-3.11.0 and LibVEX; rerun with -h for copyright info
==23779== Command:
/var/tmp/gcc_test/usr/local/bin/../libexec/gcc/x86_64-pc-linux-gnu/7.0.0/cc1
-fpreprocessed ptio.i -quiet -dumpbase ptio.i -mtune=generic -march=x86-64
-auxbase ptio -O3 -o /tmp/ccrgJkXg.s
==23779==
==23779== Conditional jump or move depends on uninitialised value(s)
==23779==    at 0xDD2F03: vect_analyze_loop(loop*) (tree-vect-loop.c:2307)
==23779==    by 0xDEB42D: vectorize_loops() (tree-vectorizer.c:549)
==23779==    by 0xA9BCB7: execute_one_pass(opt_pass*) (passes.c:2341)
==23779==    by 0xA9C370: execute_pass_list_1(opt_pass*) (passes.c:2430)
==23779==    by 0xA9C382: execute_pass_list_1(opt_pass*) (passes.c:2431)
==23779==    by 0xA9C382: execute_pass_list_1(opt_pass*) (passes.c:2431)
==23779==    by 0xA9C3CC: execute_pass_list(function*, opt_pass*)
(passes.c:2441)
==23779==    by 0x76F63D: cgraph_node::expand() (cgraphunit.c:2001)
==23779==    by 0x770DEB: expand_all_functions (cgraphunit.c:2137)
==23779==    by 0x770DEB: symbol_table::compile() [clone .part.47]
(cgraphunit.c:2494)
==23779==    by 0x7734C4: compile (cgraphunit.c:2587)
==23779==    by 0x7734C4: symbol_table::finalize_compilation_unit()
(cgraphunit.c:2584)
==23779==    by 0xB70A7A: compile_file() (toplev.c:493)
==23779==    by 0x5CDAA6: do_compile (toplev.c:2012)
==23779==    by 0x5CDAA6: toplev::main(int, char**) (toplev.c:2146)
==23779==  Uninitialised value was created by a stack allocation
==23779==    at 0xCDBF5C: record_estimate(loop*, tree_node*,
generic_wide_int<fixed_wide_int_storage<192> > const&, gimple*, bool, bool,
bool) (tree-ssa-loop-niter.c:2976)
==23779==