[Bug tree-optimization/95653] New: [11 Regression] ICE: SIGSEGV in gimple_bb (gimple.h:1847) with -ftree-loop-vectorize -fno-tree-scev-cprop

[zsojka at seznam dot cz]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=95653

            Bug ID: 95653
           Summary: [11 Regression] ICE: SIGSEGV in gimple_bb
                    (gimple.h:1847) with -ftree-loop-vectorize
                    -fno-tree-scev-cprop
           Product: gcc
           Version: 11.0
            Status: UNCONFIRMED
          Keywords: ice-on-valid-code
          Severity: normal
          Priority: P3
         Component: tree-optimization
          Assignee: unassigned at gcc dot gnu.org
          Reporter: zsojka at seznam dot cz
  Target Milestone: ---
              Host: x86_64-pc-linux-gnu

Created attachment 48722
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=48722&action=edit
reduced testcase

Compiler output:
$ x86_64-pc-linux-gnu-gcc -O2 -ftree-loop-vectorize -fno-tree-scev-cprop
testcase.c -wrapper valgrind,-q
==6104== Invalid read of size 8
==6104==    at 0x1AD8111: gimple_bb (gimple.h:1847)
==6104==    by 0x1AD8111: loop_containing_stmt (tree-ssa-loop.h:76)
==6104==    by 0x1AD8111: chrec_contains_symbols_defined_in_loop(tree_node
const*, unsigned int, hash_set<tree_node const*, false,
default_hash_traits<tree_node const*> >&) (tree-chrec.c:1009)
==6104==    by 0x1AD81F9: chrec_contains_symbols_defined_in_loop(tree_node
const*, unsigned int, hash_set<tree_node const*, false,
default_hash_traits<tree_node const*> >&) (tree-chrec.c:1026)
==6104==    by 0x1AD81F9: chrec_contains_symbols_defined_in_loop(tree_node
const*, unsigned int, hash_set<tree_node const*, false,
default_hash_traits<tree_node const*> >&) (tree-chrec.c:1026)
==6104==    by 0x1AD81F9: chrec_contains_symbols_defined_in_loop(tree_node
const*, unsigned int, hash_set<tree_node const*, false,
default_hash_traits<tree_node const*> >&) (tree-chrec.c:1026)
==6104==    by 0x1AD82B5: chrec_contains_symbols_defined_in_loop(tree_node
const*, unsigned int) (tree-chrec.c:1039)
==6104==    by 0x10D09E7: compute_overall_effect_of_inner_loop
(tree-scalar-evolution.c:473)
==6104==    by 0x10D09E7: compute_overall_effect_of_inner_loop(loop*,
tree_node*) (tree-scalar-evolution.c:447)
==6104==    by 0x10D0F6E: follow_ssa_edge_inner_loop_phi
(tree-scalar-evolution.c:1114)
==6104==    by 0x10D0F6E: follow_ssa_edge_expr(loop*, gimple*, tree_node*,
gphi*, tree_node**, int) (tree-scalar-evolution.c:1183)
==6104==    by 0x10D108E: follow_ssa_edge_in_condition_phi_branch
(tree-scalar-evolution.c:1011)
==6104==    by 0x10D108E: follow_ssa_edge_in_condition_phi
(tree-scalar-evolution.c:1037)
==6104==    by 0x10D108E: follow_ssa_edge_expr(loop*, gimple*, tree_node*,
gphi*, tree_node**, int) (tree-scalar-evolution.c:1165)
==6104==    by 0x10D108E: follow_ssa_edge_in_condition_phi_branch
(tree-scalar-evolution.c:1011)
==6104==    by 0x10D108E: follow_ssa_edge_in_condition_phi
(tree-scalar-evolution.c:1037)
==6104==    by 0x10D108E: follow_ssa_edge_expr(loop*, gimple*, tree_node*,
gphi*, tree_node**, int) (tree-scalar-evolution.c:1165)
==6104==    by 0x10CEF49: analyze_evolution_in_loop
(tree-scalar-evolution.c:1396)
==6104==    by 0x10CEF49: interpret_loop_phi (tree-scalar-evolution.c:1560)
==6104==    by 0x10CEF49: analyze_scalar_evolution_1(loop*, tree_node*)
(tree-scalar-evolution.c:1974)
==6104==    by 0x10CF79A: analyze_scalar_evolution(loop*, tree_node*)
(tree-scalar-evolution.c:2038)
==6104==    by 0x1AE20E6: get_base_for_alignment_1 (tree-data-ref.c:5738)
==6104==    by 0x1AE20E6: get_base_for_alignment(tree_node*, unsigned int*)
(tree-data-ref.c:5792)
==6104==  Address 0x10 is not stack'd, malloc'd or (recently) free'd
==6104== 
during GIMPLE pass: vect
testcase.c: In function 'g':
testcase.c:6:1: internal compiler error: Segmentation fault
    6 | g (char *h)
      | ^
Please submit a full bug report,
with preprocessed source if appropriate.
See <https://gcc.gnu.org/bugs/> for instructions.


$ x86_64-pc-linux-gnu-gcc -v
Using built-in specs.
COLLECT_GCC=/repo/gcc-trunk/binary-latest/bin/x86_64-pc-linux-gnu-gcc
COLLECT_LTO_WRAPPER=/repo/gcc-trunk/binary-trunk-r11-1248-20200612093253-g47fe96341d2-checking-yes-rtl-df-extra-amd64/bin/../libexec/gcc/x86_64-pc-linux-gnu/11.0.0/lto-wrapper
Target: x86_64-pc-linux-gnu
Configured with: /repo/gcc-trunk//configure --enable-languages=c,c++
--enable-valgrind-annotations --disable-nls --enable-checking=yes,rtl,df,extra
--with-cloog --with-ppl --with-isl --build=x86_64-pc-linux-gnu
--host=x86_64-pc-linux-gnu --target=x86_64-pc-linux-gnu
--with-ld=/usr/bin/x86_64-pc-linux-gnu-ld
--with-as=/usr/bin/x86_64-pc-linux-gnu-as --disable-libstdcxx-pch
--prefix=/repo/gcc-trunk//binary-trunk-r11-1248-20200612093253-g47fe96341d2-checking-yes-rtl-df-extra-amd64
Thread model: posix
Supported LTO compression algorithms: zlib zstd
gcc version 11.0.0 20200612 (experimental) (GCC)