On 6/14/26 05:10, Jonathan Yong wrote:
On 6/13/26 22:22, Oleg Tolmatcev wrote:
GCC could return __int128 values in SSE (%xmm0) on Windows x64 instead
of following the MS x64 ABI. Root cause: return classification allowed
128-bit integer-like scalars to be treated as direct register returns.
This patch updates the Windows x64 return-classification and codegen to
treat int128 as an indirect return (caller-provided slot passed as first
argument, pointer returned in RAX).
PR target/78799
* config/i386/i386.cc (function_value_ms_64): Do not treat
integral 16-byte values as SSE returns.
(ix86_return_in_memory): Likewise avoid treating integral 16-byte
values as XMM returns.
* gcc/testsuite/gcc.target/i386/pr78799.c: New test.
Signed-off-by: Oleg Tolmatcev <[email protected]>
Please use the change log format below next time, it should be pointed
to the changelog file and the files modified relative to it.
gcc:
PR target/78799
* config/i386/i386.cc (function_value_ms_64): Do not treat
integral 16-byte values as SSE returns.
(ix86_return_in_memory): Likewise avoid treating integral 16-byte
values as XMM returns.
gcc/testsuite:
* gcc.target/i386/pr78799.c: New test.
I have tested the change on x86_64 Linux, no new testsuite failures. Now
for other reviewers to comment on it.
Ping reviewers?
