https://gcc.gnu.org/bugzilla/show_bug.cgi?id=95488
--- Comment #3 from Hongtao.liu <crazylht at gmail dot com> --- (In reply to Richard Biener from comment #2) > (In reply to Hongtao.liu from comment #1) > > I think it's this TYPE_SIGN (TREE_TYPE (REG_EXPR (op1))). > > That's not reliable. Mutliplication shouldn't care about sign? We need to extend v16qi to v16hi first, extension does care about sign.
