Re: C++ vs C compiler on size

yeh@netcom.com (Zhenghao Yeh) writes:
>> How much overhead we have to pay if we need:
>> 1. inheritance?
>> 2. virtual functions?
>> 3. template?


Bill Leonard <Bill.Leonard@hawk.hcsc.com> wrote:
>I don't think anyone can answer that definitively -- it depends too
>much on the compiler, the machine architecture, and exactly how those
>features are being used.


True. It happens that I hacked together a test to compare the
speed of virtual functions vs C equivalent. On the platform/compiler
combinations that I tried, virtual functions came in average 10%
slower.


>If you are comparing C++ to C, then you should compare two equivalent
>things. For instance, compare a virtual function call to the
>*equivalent* C code that would implement the same functionality.


In my case, I tried to compare apples to apples and the simplest
virtual function usage is slower than the most general ptr-to-function
usage.


--
Stanley Chow; schow@bnr.ca, stanley.chow-ott@nt.com; (613) 763-2831
Bell Northern Research Ltd., PO Box 3511 Station C, Ottawa, Ontario
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