Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!purdue!ames!sun-barr!male!pitstop!sundc!seismo!uunet!sco!seanf
From: seanf@sco.COM (Sean Fagan)
Newsgroups: comp.arch
Subject: Re: RISC and emulated languages
Message-ID: <2624@scolex.sco.COM>
Date: 30 Apr 89 21:19:49 GMT
References: <158@bms-at.UUCP>
Reply-To: seanf@scolex.UUCP (Sean Fagan)
Organization: The Santa Cruz Operation, Inc.
Lines: 26

In article <158@bms-at.UUCP> stuart@bms-at.UUCP (Stuart Gathman) writes:
>There is one interesting feature of RISC architecture that I haven't seen
>mentioned much: the fact that an emulated/interpreted program will often
>run faster than a compiled one.
>I first noticed this in benchmark results for the ARM where BASIC ran the
>benchmarks faster than C!

*sigh*  This is the result of a nice BASIC interpreter, written in
highly-optimized, hand-coded assembly language, versus a poor C compiler.

You can get the same results on an Apple ][, but that's more because most C
compilers for it are not all that great.

Also, there's a good chance that the "benchmark" you saw had many string
operations; BASIC is good at that, while C isn't (BASIC can also do floating
point operations in single-precision, while C generally doesn't).  And,
since (if I remember correctly) the ARM doesn't have a floating-point unit,
being able to not have to convert from single-precision to double-precision
(using only software!) can be a *big* win.

In other words, it's not a feature of RISC architecture.

-- 
Sean Eric Fagan  | "An acid is like a woman:  a good one will eat
seanf@sco.UUCP   |  through your pants." -- Mel Gibson, Saturday Night Live
(408) 458-1422   | Any opinions expressed are my own, not my employers'.