https://gcc.gnu.org/bugzilla/show_bug.cgi?id=81614
--- Comment #7 from Jan Hubicka <hubicka at gcc dot gnu.org> --- As a historical note, X86_TUNE_PARTIAL_REG_STALL was moved to historical relics at the time both current designs (Penium 4 and Athlon) were using PARTIAL_REG_DEPENDENCY. I believed that main reason for this design was good perofrmance for 16bit code which is no longer a priority. It should have been pulled back when this concept was re-introduced for Pentium M and Cores (which i did not notice :)
