[Bug tree-optimization/113361] New: wrong code with __builtin_mul_overflow_p() and _BitInt() at -O0

[Bug tree-optimization/113361] New: wrong code with __builtin_mul_overflow_p() and _BitInt() at -O0

[zsojka at seznam dot cz]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=113361

            Bug ID: 113361
           Summary: wrong code with __builtin_mul_overflow_p() and
                    _BitInt() at -O0
           Product: gcc
           Version: 14.0
            Status: UNCONFIRMED
          Keywords: ice-on-valid-code, wrong-code
          Severity: normal
          Priority: P3
         Component: tree-optimization
          Assignee: unassigned at gcc dot gnu.org
          Reporter: zsojka at seznam dot cz
                CC: jakub at gcc dot gnu.org
  Target Milestone: ---
              Host: x86_64-pc-linux-gnu
            Target: x86_64-pc-linux-gnu

Created attachment 57059
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=57059&action=edit
reduced testcase

Output:
$ x86_64-pc-linux-gnu-gcc testcase.c
$ ./a.out 
Aborted

It fails at different -On levels, depending on the value of 'x'.
If the type of 'x' is changed to _BitInt(63), it ICEs instead:
$ x86_64-pc-linux-gnu-gcc testcase.c
during GIMPLE pass: bitintlower0
testcase.c: In function 'foo':
testcase.c:2:1: internal compiler error: in build_bitint_type, at tree.cc:7178
    2 | foo(_BitInt(63) x)
      | ^~~
0x89c77a build_bitint_type(unsigned long, int)
        /repo/gcc-trunk/gcc/tree.cc:7178
0x2706118 handle_operand_addr
        /repo/gcc-trunk/gcc/gimple-lower-bitint.cc:2244
0x270fc92 lower_mul_overflow
        /repo/gcc-trunk/gcc/gimple-lower-bitint.cc:4291
0x270fc92 lower_call
        /repo/gcc-trunk/gcc/gimple-lower-bitint.cc:5101
0x271a4b9 gimple_lower_bitint
        /repo/gcc-trunk/gcc/gimple-lower-bitint.cc:6524
Please submit a full bug report, with preprocessed source (by using
-freport-bug).
Please include the complete backtrace with any bug report.
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-amd64/bin/x86_64-pc-linux-gnu-gcc
COLLECT_LTO_WRAPPER=/repo/gcc-trunk/binary-trunk-r14-7215-20240112190107-g8b447fa89d5-checking-yes-rtl-df-extra-nobootstrap-amd64/bin/../libexec/gcc/x86_64-pc-linux-gnu/14.0.1/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
--disable-bootstrap --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-r14-7215-20240112190107-g8b447fa89d5-checking-yes-rtl-df-extra-nobootstrap-amd64
Thread model: posix
Supported LTO compression algorithms: zlib zstd
gcc version 14.0.1 20240112 (experimental) (GCC)

[Bug tree-optimization/113361] wrong code with __builtin_mul_overflow_p() and _BitInt() at -O0

[cvs-commit at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=113361

--- Comment #1 from GCC Commits <cvs-commit at gcc dot gnu.org> ---
The master branch has been updated by Jakub Jelinek <jakub@gcc.gnu.org>:

https://gcc.gnu.org/g:f77a87982db60baa047b489ee4fea58b190503fb

commit r14-7224-gf77a87982db60baa047b489ee4fea58b190503fb
Author: Jakub Jelinek <jakub@redhat.com>
Date:   Sat Jan 13 11:29:15 2024 +0100

    lower-bitint: Fix up handle_operand_addr INTEGER_CST handling [PR113361]

    As the testcase shows, the INTEGER_CST handling in handle_operand_addr
    (i.e. what is used when passing address of an integer to a bitint library
    routine) wasn't correct.  If the minimum precision to represent an
    INTEGER_CST is smaller or equal to limb_prec, the code correctly uses
    m_limb_type; if the minimum precision of a _BitInt INTEGER_CST is large
    enough such that the bitint is middle, large or huge, everything is fine
    too.  But the code wasn't handling correctly e.g. __int128 constants which
    need more than limb_prec bits or _BitInt constants which on the
architecture
    are considered small (say have DImode limb_mode, TImode abi_limb_mode and
    for [65, 128] bits use TImode scalar like the proposed aarch64 patch).
    Best would be to use an array of 2/3/4 limbs in that case, but we'd need to
    convert the INTEGER_CST to a CONSTRUCTOR in the right endianity etc.,
    so the code was using mid_min_prec to enforce a middle _BitInt precision.
    Except that mid_min_prec can be 0 and not computed yet, or it doesn't have
    to be the smallest middle _BitInt precision, just the smallest so far
    encountered.  So, on the testcase one possibility was that it used
precision
    65 from mid_min_prec, even when the INTEGER_CST actually needed larger
    minimum precision (96 bits at least), or crashed when mid_min_prec was 0.

    The patch fixes it in 2 hunks, the first makes sure we actually try to
    create a BITINT_TYPE for the > limb_prec cases like __int128, and the
second
    instead of using mid_min_prec attempts to increase mp precision until it
    isn't small anymore.

    2024-01-13  Jakub Jelinek  <jakub@redhat.com>

            PR tree-optimization/113361
            * gimple-lower-bitint.cc (bitint_large_huge::handle_operand_addr):
            Fix up determination of the type for > limb_prec constants.

            * gcc.dg/torture/bitint-47.c: New test.

[Bug tree-optimization/113361] wrong code with __builtin_mul_overflow_p() and _BitInt() at -O0

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=113361

Richard Biener <rguenth at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
         Resolution|---                         |FIXED
             Status|UNCONFIRMED                 |RESOLVED

--- Comment #2 from Richard Biener <rguenth at gcc dot gnu.org> ---
Fixed I assume.

[Bug tree-optimization/113361] wrong code with __builtin_mul_overflow_p() and _BitInt() at -O0

[jakub at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=113361

--- Comment #3 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
Yes, sorry for not closing it.

[Bug tree-optimization/113361] wrong code with __builtin_mul_overflow_p() and _BitInt() at -O0

[pinskia at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=113361

Andrew Pinski <pinskia at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Target Milestone|---                         |14.0