Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!samsung!noose.ecn.purdue.edu!iuvax!rutgers!mcnc!rti!mozart!sasrer From: sasrer@unx.sas.com (Rodney Radford) Newsgroups: comp.sys.m88k Subject: Re: Emulating other computers on 88K's and Benchmarks Message-ID: <1990Oct11.174838.7990@unx.sas.com> Date: 11 Oct 90 17:48:38 GMT References: <1990Oct3.095041.9295@canterbury.ac.nz> <41965@mips.mips.COM> Organization: SAS Institute Inc. Lines: 37 In article <41965@mips.mips.COM> mash@mips.COM (John Mashey) writes: >In article newton@smoggy.gg.caltech.edu (Mike Newton) writes: >>The m88k has a fundamental advantage over the other RISC's that I know >>regarding: >> Interpetation of code for other processors >> Compilers for certain very high level languages -- (especially: Prolog) >>and this is 31 truly general purpose registers. > >I'm afraid this posting needs a grain of salt. Most current commercial >RISCs have at least 32 integer registers available at once, plus at least >32 32-bit FP, or 16 64-bit FP. These include: MIPS, SPARC, AMD 29K, >Intel i860, IBM POWER, HP PA. Clipper indeed has less registers. >All of the rest have at least 2X the general purpose (integer + FP) >register state of the 88K... But there are cases when having the same register set for both the general purpose registers and the floating point registers can offer improvements in the code by allowing you to operate on the floating point values with the same integer instructions (for example: using some of the specialized bit manipulation instructions). Also, the chips listed above that have the 'extra' FP registers you mention are actually on external floating point coprocessor chips, so they should not be included in the register count when comparing specific RISC processors. The choice of whether to use an external floating point coprocessor is a system designers choice, not a specific RISC chip requirement (it is possible for an 88K to also be hooked to an external math coprocessor, although I have not heard of such an arrangement). >-- >-john mashey DISCLAIMER: >UUCP: mash@mips.com OR {ames,decwrl,prls,pyramid}!mips!mash >DDD: 408-524-7015, 524-8253 or (main number) 408-720-1700 >USPS: MIPS Computer Systems, 930 E. Arques, Sunnyvale, CA 94086 -- Rodney E. Radford SAS Institute, Inc. sasrer@unx.sas.com DG/UX AViiON developer Box 8000, Cary, NC 27512 (919) 677-8000 x7703