https://gcc.gnu.org/bugzilla/show_bug.cgi?id=99754
--- Comment #8 from CVS Commits <cvs-commit at gcc dot gnu.org> --- The releases/gcc-11 branch has been updated by hongtao Liu <liuho...@gcc.gnu.org>: https://gcc.gnu.org/g:85568e505c3b06708ec0fb21d1ab4f78e0c66896 commit r11-9699-g85568e505c3b06708ec0fb21d1ab4f78e0c66896 Author: Jakub Jelinek <ja...@redhat.com> Date: Mon Mar 14 10:44:38 2022 +0100 i386: Fix up _mm_loadu_si{16,32} [PR99754] These intrinsics are supposed to do an unaligned may_alias load of a 16-bit or 32-bit value and store it as the first element of a 128-bit integer vector, with all other elements cleared. The current _mm_storeu_* implementation implements that correctly, uses __*_u types to do the store and extracts the first element of a vector into it. But _mm_loadu_si{16,32} gets it all wrong. It performs an aligned non-may_alias load and because _mm_set_epi{16,32} has the args reversed, it also inserts it into the last vector element instead of first. The following patch fixes that. Note, while the Intrinsics guide for _mm_loadu_si32 says SSE2, for _mm_loadu_si16 it says strangely SSE. But the intrinsics returns __m128i, which is only defined in emmintrin.h, and _mm_set_epi16 is also only SSE2 and later in emmintrin.h. Even clang defines it in emmintrin.h and ends up with inlining failure when calling _mm_loadu_si16 from sse,no-sse2 function. So, isn't that a bug in the intrinsic guide instead? 2022-03-14 Jakub Jelinek <ja...@redhat.com> PR target/99754 * config/i386/emmintrin.h (_mm_loadu_si32): Put loaded value into first rather than last element of the vector, use __m32_u to do a really unaligned load, use just 0 instead of (int)0. (_mm_loadu_si16): Put loaded value into first rather than last element of the vector, use __m16_u to do a really unaligned load, use just 0 instead of (short)0. * gcc.target/i386/pr99754-1.c: New test. * gcc.target/i386/pr99754-2.c: New test.
