On Thu, 20 Jul 2006 18:29:48 +0000, john gilmore <[EMAIL PROTECTED]> wrote: > >Higher fetch width is "good", but it can have odd side effects. There were >System/360 models for which Load Halfword (LH) was slower than Load (L) not >just because of sign propagation but also because LH fetched four or eight >bytes from storage two or six of which then had to be discarded. > >Analogously, there are z/Architecture situations in which eight-byte >(64-bit) instructions are faster than their four-byte (32-bit) variants. > Are you sure?
Color me skeptical. Tom Marchant ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [EMAIL PROTECTED] with the message: GET IBM-MAIN INFO Search the archives at http://bama.ua.edu/archives/ibm-main.html
