[prev] [thread] [next] [lurker] [Date index for 2007/01/29]
It was thus said that the Great David Cantrell once stated: > On Mon, Jan 29, 2007 at 02:54:21PM -0500, Sean Conner wrote: > > > VMS. Or rather, VMS on the VAX architecture > > Ahh, the pinnacle of CISC. I have learnt to never be surprised at Weird > Shit in the VAX instruction set. I expect to find a single-instruction > printf() in there at some point. No, don't see a printf(), but there is a CRC instruction, and the CASE instruction could, in theory, fill all available memory. Oddly enough, it's missing an AND and OR instruction. Hateful, that. But dispite that, the instruction set *is* very orthogonal. All the registers are general purpose (although R15 also doubles as PC) and as far as I can see, there are no restrictions on addressing modes for any instruction---so while the assembler *might* restrict something like: ADDL2 #45,#66 It *is* possible to do that (talk about self-modifying code) since that instruction is actually encoded as: ADDL2 (R15)+,(R15)+ which is also: ADDL2 (PC)+,(PC)+ -spc (And VMS at the command line is *very* hateful, except for the help facility, which makes Unix's man hateful)There's stuff above here
Generated at 23:01 on 06 Feb 2007 by mariachi 0.52