https://gcc.gnu.org/bugzilla/show_bug.cgi?id=92611
--- Comment #2 from Hongtao.liu <crazylht at gmail dot com> --- (In reply to Richard Biener from comment #1) > I think Richard laid ground for this to work on x86 (it needs AVX512?), AVX512 is not needed. > not sure what is needed in the backend here to make V4QI -> V4SI conversions > vectorized? There're many expressions depends on type promotion. Such like void foo(int *__restrict dst, char *__restrict src1, char *__restrict src2) { for(int x = 0; x < 4; x++ ) dst[x] = src1[x] + src2[x]; } And I think it also affects pr92492.