https://gcc.gnu.org/bugzilla/show_bug.cgi?id=114590
jbeulich at suse dot com changed: What |Removed |Added ---------------------------------------------------------------------------- CC| |jbeulich at suse dot com --- Comment #3 from jbeulich at suse dot com --- Indeed. Just look at spec version 4.0. Omitting shift count operands has been consistently dropped - in line with the SDM. Wherever the legacy forms with omitted operands came from, that model simply cannot be continued anymore, for being confusing. SHLD/SHRD aren't directly affected by the confusing aspect, but need to follow suit to match the shifts/rotates.