[Bug target/128625] x86-64 ABI: struct with one __int128 vector_size(16) member is passed in 8 bytes; high half lost

Wed, 11 Nov 2026 12:48:04 -0800 

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=128625

--- Comment #2 from GCC Commits <cvs-commit at gcc dot gnu.org> ---
The master branch has been updated by Uros Bizjak <[email protected]>:

https://gcc.gnu.org/g:f3ddd8a6e2414b76a0ffda6961907ee32507d845

commit r17-6147-gf3ddd8a6e2414b76a0ffda6961907ee32507d845
Author: Uros Bizjak <[email protected]>
Date:   Wed Nov 11 13:44:28 2026 +0100

    i386: Pass V1TImode aggregates in a full SSE register [PR128625]

    classify_argument classified V1TImode as a single SSE eightbyte, so
    aggregates containing a V1TImode member were passed and returned with
    only the low 8 bytes.  Classify it as SSE + SSEUP like the other
    16-byte vector modes.

            PR target/128625

    gcc/ChangeLog:

            * config/i386/i386.cc (classify_argument): Classify E_V1TImode
            as X86_64_SSE_CLASS followed by X86_64_SSEUP_CLASS.

    gcc/testsuite/ChangeLog:

            * gcc.target/i386/pr128625.c: New test.

Reply via email to