NetNews Offline 2/NetNews Offline Volume 2.iso/news/comp/sys/amiga/programmer/531

Internet Message Format | 1996-08-05 | 2.8 KB

Path: newsserver.rrzn.uni-hannover.de!tubsibr!duening
From: [e-mail] (Lars Duening)
Newsgroups: comp.sys.amiga.programmer
Subject: Re: PPC compilers
Date: 8 Jan 1996 23:12:14 GMT
Organization: TU Braunschweig, Informatik (Bueltenweg), Germany
Distribution: world
Message-ID: <4cs8ce$[e-mail]>
References: <[e-mail]> <4b77tq$[e-mail]> <MQAQx*[e-mail]> <4bqhnf$[e-mail]> <[e-mail]> <4c9i2l$[e-mail]> <4cf0ep$233@ra.i <4ck37m$[e-mail]>
Reply-To: [e-mail] (Lars Duening)
NNTP-Posting-Host: kastor.ibr.cs.tu-bs.de

In article <4ck37m$[e-mail]> [e-mail] (Stephan Schaem) writes:
>Organization: Teleport - Portland's Public Access [phone]
>Distribution: world
>
>Jim Cooper ([e-mail]) wrote:
>: In article <4cgo3i$[e-mail]> [e-mail] (Juergen "Rally" Fischer) writes:
>: > Lars Duening ([e-mail]) wrote:
>: > : That doesn't count because in C you don't need to know if this statement
>: > : compiles to a .w, to a .l or even to a .q .
>: >
>: > but when the .l meets a real-world color-register, you will notice
>: > your claim is not always true.
>
>: Why do you insist on making this seem harder than it needs to be?
>
>: The answer is quite simple and straightforward:
>
>: In ASM, *you*, the programmer, must remember to add the '.w' by hand every
>: time you reference the "real-world color-register," otherwise, possible
>: fireworks.
>
>: In C, the structure is defined *once*, in a system header file, in fact, and
>: the programmer never needs to know if the compiler will generate '.w', '.l',
>: or anything else.
>
> Just a reminder... in C or ASM you need to know what a color register
> is if you want to operate on it, unless you call high level function
> to do the job for you (Even them you need to look in the .h or doc
> what type is needed as parameter).

I need to know if it's a scalar type (further subdivided into integer
and floating types), an array, a structure, a pointer or else, but I
do not need to know it's exakt size in byte when using it.

Sometimes I don't even need to know the exact type 'cause the compiler
will create conversion code plus overflow checking (I'm not talking
just C here).

In optimum cases, the values of the chipregs have been assigned own
types, so I can just write 'blt0con_t *b;' or less specific 'int32
*b;'. Again I don't need to know the size of the type, just which of
the scalar integer types it is.

> Otherwise you need to know that color0 is a word holding 12bit
> of valid data grouped in 4bit nibles,

typedef struct {
  int r : 4;
  int g : 4;
  int b : 4;
} color0_t;

color0_t color0;
--
Lars Duening; [e-mail]