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From: kempf@hplabsc.UUCP (Jim Kempf)
Newsgroups: net.lang.c++
Subject: Re: C++ vs. Objective-C
Message-ID: <179@hplabsc.UUCP>
Date: Tue, 8-Apr-86 10:26:09 EST
Article-I.D.: hplabsc.179
Posted: Tue Apr  8 10:26:09 1986
Date-Received: Wed, 9-Apr-86 11:46:48 EST
References: <780@well.UUCP> <700@tymix.UUCP> <5896@fortune.UUCP> <562@watcgl.UUCP>
Organization: Hewlett Packard Labs, Palo Alto CA
Lines: 14

> Some of PPI's early literature indicated Obj-C was 2.5 times slower
> that the equivalent standard C code during execution.  Is the current
> version of Obj-C faster?

Messaging is about 2.5 times slower than a function call, since it
is done indirectly, by looking up the function pointer in a cache
(if there is a cache hit) or in the inheritance hierarchy (in
which case it is probably even slower) if there is a miss. There
is probably little they can do to improve this, as they are already
reusing the stack frame from the messaging function. It does give
Smalltalk-like messaging, however. They also encourage replacement
of messaging with a function call during profiling, and have
a couple of profiling tools to measure messaging and memory allocation.
		Jim Kempf		hplabs!kempf