[Bug target/120450] GCN offloading: ICE 'during RTL pass: expand', 'in assign_temp, at function.cc:990' for C++ 'std::flat_map', 'std::flat_multimap'

[cvs-commit at gcc dot gnu.org via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=120450

--- Comment #3 from GCC Commits <cvs-commit at gcc dot gnu.org> ---
The trunk branch has been updated by Thomas Schwinge <tschwi...@gcc.gnu.org>:

https://gcc.gnu.org/g:651df6b43e817a8e4b87eed9f338ea227da7bccb

commit r16-4520-g651df6b43e817a8e4b87eed9f338ea227da7bccb
Author: Thomas Schwinge <tschwi...@baylibre.com>
Date:   Mon Oct 20 17:36:49 2025 +0200

    c++, gimplify: Implement C++26 P2795R5 - Erroneous behavior for
uninitialized reads: Adjust
'libgomp.c++/{target-flex-101.C,target-std__flat_map-concurrent.C,target-std__flat_multimap-concurrent.C}'
[PR114457, PR122268, PR120450]

    With commit r16-4212-gf256a13f8aed833fe964a2ba541b7b30ad9b4a76
    "c++, gimplify: Implement C++26 P2795R5 - Erroneous behavior for
uninitialized reads [PR114457]",
    we acquired:

        {+FAIL: libgomp.c++/target-flex-101.C (internal compiler error: in
assign_temp, at function.cc:990)+}
        [-PASS:-]{+FAIL:+} libgomp.c++/target-flex-101.C (test for excess
errors)
        [-PASS:-]{+UNRESOLVED:+} libgomp.c++/target-flex-101.C [-execution
test-]{+compilation failed to produce executable+}

    ... for GCN, nvptx offloading compilation, and on the other hand:

        [-XFAIL:-]{+XPASS:+} libgomp.c++/target-std__flat_map-concurrent.C
(internal compiler error[-: in assign_temp, at function.cc:990)-]
        [-XFAIL:-]{+XPASS:+} libgomp.c++/target-std__flat_map-concurrent.C
(test for excess errors)
        [-UNRESOLVED:-]{+PASS:+} libgomp.c++/target-std__flat_map-concurrent.C
[-compilation failed to produce executable-]{+execution test+}

        [-XFAIL:-]{+XPASS:+} libgomp.c++/target-std__flat_multimap-concurrent.C
(internal compiler error[-: in assign_temp, at function.cc:990)-]
        [-XFAIL:-]{+XPASS:+} libgomp.c++/target-std__flat_multimap-concurrent.C
(test for excess errors)
        [-UNRESOLVED:-]{+PASS:+}
libgomp.c++/target-std__flat_multimap-concurrent.C [-compilation failed to
produce executable-]{+execution test+}

    ... for GCN offloading compilation (already PASSed for nvptx).

    Note that these test cases explicitly use '-std=c++23', so don't undergo
the
    new C++26 P2795R5 functionality.  Yet, comparing before vs. after that
commit,
    in the 'gimple' dumps (that is, early host compilation), there are a lot of
    changes where 'gimple_assign <constructor, [...], {CLOBBER(bob)}, NULL,
NULL>'s
    and relatedly 'gimple_bind's newly appear/no longer appear elsewhere.  This
    leads to correspondingly different code at the beginning of offloading
    compilation.  Why/how that now ('libgomp.c++/target-flex-101.C') vs. before
   
('libgomp.c++/{target-std__flat_map-concurrent.C,target-std__flat_multimap-concurrent.C}')
    translates into 'expand' ICEs, I can't tell.

            PR c++/114457
            PR c++/122268
            PR c++/120450
            libgomp/
            * testsuite/libgomp.c++/target-flex-101.C: XFAIL GCN, nvptx
            offloading compilation.
            * testsuite/libgomp.c++/target-std__flat_map-concurrent.C:
            Un-XFAIL GCN offloading compilation.
            * testsuite/libgomp.c++/target-std__flat_multimap-concurrent.C:
            Likewise.