Array indexing vs. pointers...
mcdonald at uxe.cso.uiuc.edu
mcdonald at uxe.cso.uiuc.edu
Mon Oct 24 02:19:00 AEST 1988
>Besides, most efficiency losses are from poor
>choice of data structures or algorithms, not from fatty source code.
Agreed.... But.....
>Compilers are much better now. Age has encouraged a modesty which
>allows that the compiler may well know how to do things better than I
>do. That is certainly the case when I take my code off to some
>unfamiliar computer.
>I have concluded, and I think this is what Doug<Gwyn - not me> is saying,
>that one
>should not code in a way that will confuse either the reader of the
>code or the compiler.
>If your compiler doesn't do a good job of optimization then your money
>probably is spent better on a better compiler than it is on the time
>of coders diddling with the code.
Yes.... But.....
Sometimes the better compiler doesn't yet exist. An example is for
the 80386. So far no one is selling a 386 compiler that produces
code for MS-DOS (NOT, I should say, for 386 native mode, but one that
allows using 32 bit instructions in REAL mode - yes, you really can
do that!). By having my C compiler emit .asm output and replacing
5 lines of C with real 32 bit instructions I was able to speed up
a program by an astounding 40%! That is worth doing.
Microsoft - where is that /G3 compiler switch - it is long overdue!
Doug McDonald
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