https://gcc.gnu.org/bugzilla/show_bug.cgi?id=82976
--- Comment #4 from Martin Liška <marxin at gcc dot gnu.org> --- So for following GIMPLE stmt: $ (gdb) p debug_gimple_stmt(stmt) _54 = 0; RHS (kind == 1) is created here: (gdb) bt #0 make_int_cst (len=1, ext_len=1) at ../../gcc/tree.c:2286 #1 0x000000000139516a in build_new_int_cst (type=0x7ffff6827b28, cst=...) at ../../gcc/tree.c:1280 #2 0x0000000001395ef3 in wide_int_to_tree (type=0x7ffff6827b28, pcst=...) at ../../gcc/tree.c:1529 #3 0x0000000001010b84 in set_min_and_max_values_for_integral_type (type=0x7ffff6827b28, precision=8, sgn=UNSIGNED) at ../../gcc/stor-layout.c:2680 #4 0x0000000001010cfa in fixup_unsigned_type (type=0x7ffff6827b28) at ../../gcc/stor-layout.c:2711 #5 0x0000000001010016 in make_unsigned_type (precision=8) at ../../gcc/stor-layout.c:2538 #6 0x00000000013b4983 in build_common_tree_nodes (signed_char=false) at ../../gcc/tree.c:9562 #7 0x000000000091167e in gfc_init_decl_processing () at ../../gcc/fortran/f95-lang.c:506 #8 0x0000000000910f2a in gfc_init () at ../../gcc/fortran/f95-lang.c:242 #9 0x0000000001020600 in lang_dependent_init (name=0x7fffffffe202 "/home/marxin/Programming/gcc/gcc/testsuite/gfortran.dg/realloc_on_assign_16.f90") at ../../gcc/toplev.c:1819 #10 0x0000000001020b37 in do_compile () at ../../gcc/toplev.c:2045 #11 0x0000000001020e84 in toplev::main (this=0x7fffffffdc6e, argc=16, argv=0x7fffffffdd68) at ../../gcc/toplev.c:2194 #12 0x0000000001c3e1d2 in main (argc=16, argv=0x7fffffffdd68) at ../../gcc/main.c:39 LHS here: (gdb) bt #0 make_ssa_name_fn (fn=0x7ffff69c10b0, var=0x7ffff6833348, stmt=0x7ffff662aa00, version=0) at ../../gcc/tree-ssanames.c:313 #1 0x00000000012ee868 in copy_ssa_name_fn (fn=0x7ffff69c10b0, name=0x7ffff661a750, stmt=0x7ffff662aa00) at ../../gcc/tree-ssanames.c:691 #2 0x00000000012eeccf in duplicate_ssa_name_fn (fn=0x7ffff69c10b0, name=0x7ffff661a750, stmt=0x7ffff662aa00) at ../../gcc/tree-ssanames.c:752 #3 0x00000000010dc1a0 in duplicate_ssa_name (var=0x7ffff661a750, stmt=0x7ffff662aa00) at ../../gcc/tree-ssanames.h:134 #4 0x00000000010e3605 in create_new_def_for (old_name=0x7ffff661a750, stmt=0x7ffff662aa00, def=0x7ffff662aa40) at ../../gcc/tree-into-ssa.c:2949 #5 0x0000000001079665 in gimple_duplicate_bb (bb=0x7ffff661bea0) at ../../gcc/tree-cfg.c:6186 #6 0x0000000000a76d6c in duplicate_block (bb=0x7ffff661bea0, e=0x0, after=0x0) at ../../gcc/cfghooks.c:1077 #7 0x00000000012cc659 in create_block_for_threading (bb=0x7ffff661bea0, rd=0x2a8c950, count=0, duplicate_blocks=0x7fffffffd6e0) at ../../gcc/tree-ssa-threadupdate.c:336 #8 0x00000000012cde44 in ssa_create_duplicates (slot=0x2c3be30, local_info=0x7fffffffd6d0) at ../../gcc/tree-ssa-threadupdate.c:1124 #9 0x00000000012d182d in hash_table<redirection_data, xcallocator>::traverse_noresize<ssa_local_info_t*, &(ssa_create_duplicates(redirection_data**, ssa_local_info_t*))> (this=0x2c3bdf0, argument=0x7fffffffd6d0) at ../../gcc/hash-table.h:969 #10 0x00000000012d0d0f in hash_table<redirection_data, xcallocator>::traverse<ssa_local_info_t*, &(ssa_create_duplicates(redirection_data**, ssa_local_info_t*))> (this=0x2c3bdf0, argument=0x7fffffffd6d0) at ../../gcc/hash-table.h:990 #11 0x00000000012ce4e0 in thread_block_1 (bb=0x7ffff661bea0, noloop_only=true, joiners=false) at ../../gcc/tree-ssa-threadupdate.c:1387 #12 0x00000000012ce5b6 in thread_block (bb=0x7ffff661bea0, noloop_only=true) at ../../gcc/tree-ssa-threadupdate.c:1431 #13 0x00000000012d03a4 in thread_through_all_blocks (may_peel_loop_headers=false) at ../../gcc/tree-ssa-threadupdate.c:2298 #14 0x00000000011afcb9 in (anonymous namespace)::pass_dominator::execute (this=0x2aa0470, fun=0x7ffff69c10b0) at ../../gcc/tree-ssa-dom.c:749 #15 0x0000000000ef7b1f in execute_one_pass (pass=0x2aa0470) at ../../gcc/passes.c:2497 #16 0x0000000000ef7e70 in execute_pass_list_1 (pass=0x2aa0470) at ../../gcc/passes.c:2586 #17 0x0000000000ef7ea1 in execute_pass_list_1 (pass=0x2a9e270) at ../../gcc/passes.c:2587 #18 0x0000000000ef7ef9 in execute_pass_list (fn=0x7ffff69c10b0, pass=0x2a9e090) at ../../gcc/passes.c:2597 #19 0x0000000000ab8076 in cgraph_node::expand (this=0x7ffff69d3170) at ../../gcc/cgraphunit.c:2139 #20 0x0000000000ab86b2 in expand_all_functions () at ../../gcc/cgraphunit.c:2275 #21 0x0000000000ab9206 in symbol_table::compile (this=0x7ffff6817100) at ../../gcc/cgraphunit.c:2623 #22 0x0000000000ab947b in symbol_table::finalize_compilation_unit (this=0x7ffff6817100) at ../../gcc/cgraphunit.c:2716 #23 0x000000000101e4c8 in compile_file () at ../../gcc/toplev.c:480 #24 0x0000000001020b97 in do_compile () at ../../gcc/toplev.c:2059 #25 0x0000000001020e84 in toplev::main (this=0x7fffffffdc6e, argc=16, argv=0x7fffffffdd68) at ../../gcc/toplev.c:2194 #26 0x0000000001c3e1d2 in main (argc=16, argv=0x7fffffffdd68) at ../../gcc/main.c:39 Is it helpful information, or should I investigate more? Which is the problematic type?