[Bug bootstrap/71071] [7 regression] ICE --enable-checking=fold : fold check: original tree changed by fold

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

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=71071

Thomas Schwinge <tschwinge at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |tschwinge at gcc dot gnu.org

--- Comment #11 from Thomas Schwinge <tschwinge at gcc dot gnu.org> ---
Created attachment 38481
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=38481&action=edit
pre-rpcessed newlib/libc/stdlib/dtoa.c for nvptx-none

I also bisected a nvptx-none "fold check" ICE to be caused/triggered by the
recent r236117:

    build-gcc-offload-nvptx-none/gcc/cc1 -fpreprocessed dtoa.i -g -O2
-fno-builtin
     quorem _dtoa_r
    [...]/source-gcc/newlib/libc/stdlib/dtoa.c: In function '_dtoa_r':
    [...]/source-gcc/newlib/libc/stdlib/dtoa.c:269:2: internal compiler error:
fold check: original tree changed by fold
      "NaN";
      ^~~~~

    #1  0x000000000050fe29 in fold_check_failed (ret=<optimized out>,
expr=0x7ffff6a4b640) at [...]/source-gcc/gcc/fold-const.c:12099
    #2  0x00000000007f4f48 in fold_build2_stat_loc (loc=loc@entry=2147483836,
code=code@entry=TRUTH_ANDIF_EXPR, type=0x7ffff68d2690,
op0=op0@entry=0x7ffff6a4b640, op1=0x7ffff6a4b668) at
[...]/source-gcc/gcc/fold-const.c:12358
    #3  0x00000000005d7090 in c_fully_fold_internal
(expr=expr@entry=0x7ffff6a4b618, in_init=in_init@entry=false,
maybe_const_operands=maybe_const_operands@entry=0x7fffffffbf0a,
maybe_const_itself=maybe_const_itself@entry=0x7fffffffbf0d,
for_int_const=for_int_const@entry=false) at [...]/source-gcc/gcc/c/c-fold.c:457
    #4  0x00000000005d521a in c_fully_fold_internal
(expr=expr@entry=0x7ffff6a4a4b0, in_init=in_init@entry=false,
maybe_const_operands=maybe_const_operands@entry=0x7fffffffbf5e,
maybe_const_itself=maybe_const_itself@entry=0x7fffffffbf5f,
for_int_const=for_int_const@entry=false) at [...]/source-gcc/gcc/c/c-fold.c:482
    #5  0x00000000005d840b in c_fully_fold (expr=expr@entry=0x7ffff6a4a4b0,
in_init=in_init@entry=false, maybe_const=0x7fffffffbf5e, maybe_const@entry=0x0)
at [...]/source-gcc/gcc/c/c-fold.c:90
    #6  0x0000000000595803 in build_modify_expr
(location=location@entry=45810496, lhs=lhs@entry=0x7ffff6a49240,
lhs_origtype=lhs_origtype@entry=0x7ffff68e4a80,
modifycode=modifycode@entry=NOP_EXPR, rhs_loc=rhs_loc@entry=45818464,
rhs=<optimized out>, rhs@entry=0x7ffff6a4a4b0,
rhs_origtype=rhs_origtype@entry=0x7ffff68e4a80) at
[...]/source-gcc/gcc/c/c-typeck.c:5697
    #7  0x00000000005a674d in c_parser_expr_no_commas
(parser=parser@entry=0x7ffff6995000, after=after@entry=0x0,
omp_atomic_lhs=omp_atomic_lhs@entry=0x0) at
[...]/source-gcc/gcc/c/c-parser.c:6313
    #8  0x00000000005a6da5 in c_parser_expression
(parser=parser@entry=0x7ffff6995000) at [...]/source-gcc/gcc/c/c-parser.c:8450
    #9  0x00000000005a78aa in c_parser_expression_conv
(parser=parser@entry=0x7ffff6995000) at [...]/source-gcc/gcc/c/c-parser.c:8483
    #10 0x00000000005be3da in c_parser_statement_after_labels
(parser=parser@entry=0x7ffff6995000, if_p=if_p@entry=0x0,
chain=chain@entry=0x0) at [...]/source-gcc/gcc/c/c-parser.c:5285
    #11 0x00000000005c034c in c_parser_compound_statement_nostart
(parser=0x7ffff6995000) at [...]/source-gcc/gcc/c/c-parser.c:4859
    #12 0x00000000005c0c3f in c_parser_compound_statement
(parser=parser@entry=0x7ffff6995000) at [...]/source-gcc/gcc/c/c-parser.c:4694
    #13 0x00000000005bfcfd in c_parser_if_body (if_tinfo=...,
if_p=0x7fffffffc3ff, parser=0x7ffff6995000) at
[...]/source-gcc/gcc/c/c-parser.c:5384
    #14 c_parser_if_statement (chain=0x0, if_p=0x0, parser=0x7ffff6995000) at
[...]/source-gcc/gcc/c/c-parser.c:5502
    #15 c_parser_statement_after_labels (parser=parser@entry=0x7ffff6995000,
if_p=if_p@entry=0x0, chain=chain@entry=0x0) at
[...]/source-gcc/gcc/c/c-parser.c:5139
    #16 0x00000000005c034c in c_parser_compound_statement_nostart
(parser=0x7ffff6995000) at [...]/source-gcc/gcc/c/c-parser.c:4859
    #17 0x00000000005c0c3f in c_parser_compound_statement
(parser=parser@entry=0x7ffff6995000) at [...]/source-gcc/gcc/c/c-parser.c:4694
    #18 0x00000000005c2111 in c_parser_declaration_or_fndef
(parser=parser@entry=0x7ffff6995000, fndef_ok=fndef_ok@entry=true,
static_assert_ok=static_assert_ok@entry=true, empty_ok=empty_ok@entry=true,
nested=nested@entry=false, start_attr_ok=start_attr_ok@entry=true,
objc_foreach_object_declaration=objc_foreach_object_declaration@entry=0x0,
omp_declare_simd_clauses=..., omp_declare_simd_clauses@entry=...,
oacc_routine_clauses=oacc_routine_clauses@entry=0x0) at
[...]/source-gcc/gcc/c/c-parser.c:2106
    #19 0x00000000005cb797 in c_parser_external_declaration
(parser=0x7ffff6995000) at [...]/source-gcc/gcc/c/c-parser.c:1550
    #20 0x00000000005cc2aa in c_parser_translation_unit (parser=0x7ffff6995000)
at [...]/source-gcc/gcc/c/c-parser.c:1431
    #21 c_parse_file () at [...]/source-gcc/gcc/c/c-parser.c:17916
    #22 0x0000000000630b43 in c_common_parse_file () at
[...]/source-gcc/gcc/c-family/c-opts.c:1064
    #23 0x0000000000ae4e9f in compile_file () at
[...]/source-gcc/gcc/toplev.c:463
    #24 0x000000000054069a in do_compile () at
[...]/source-gcc/gcc/toplev.c:1987
    #25 toplev::main (this=this@entry=0x7fffffffc770, argc=argc@entry=51,
argv=argv@entry=0x7fffffffc878) at [...]/source-gcc/gcc/toplev.c:2095
    #26 0x00000000005422f7 in main (argc=51, argv=0x7fffffffc878) at
[...]/source-gcc/gcc/main.c:39