Path: utzoo!mnetor!uunet!husc6!think!ames!ucsd!sdcsvax!ucsdhub!hp-sdd!hplabs!hpda!hpcuhb!hpcllla!hpcllz2!walter
From: walter@hpcllz2.HP.COM (Walter Murray)
Newsgroups: comp.lang.c
Subject: Re: I forget what it was originally called.
Message-ID: <7330001@hpcllz2.HP.COM>
Date: 11 Mar 88 22:37:39 GMT
References: <3505@bloom-beacon.MIT.EDU>
Organization: HP ITG/ISO Computer Language Lab
Lines: 31

> Which brings me to another question:  How good are compilers these
> day?  Can they optimize just as well as a programmer (without
> resorting to assembly, that is) or not?  For example:
> 
> A)
>    temp = {expression}
>    a[temp] = 1;
>    b[temp] = 2;
>    c[temp] = 3;
> B)
>    a[temp={expression}]=1;
>    b[temp]=2;
>    c[temp]=3;
> C)
>    a[{expression}]=1;
>    b[{expression}]=2;
>    c[{expression}]=3;
> D)
>    {
>    register temp;
>    temp = {expression};
>    .
>    .
>    .
>    }

I tried these on the HP C compiler on an HP 9000 Series 800
and (with optimization turned on) got the same code for all 
four approaches.

Walter Murray