assembly in future C standard HCF Gerry Wheeler


    Sponsored Links


  • 1. Review: 3D-Array
    Hi c.l.c, Is this a correct method of allocating a 3-dimensional array? /* assume all malloc's succeed */ #define MAT 2 #define ROW 2 #define COL 2 char ***ptr = malloc ( MAT * sizeof *ptr ); for ( i = 0; i < MAT; i++ ) ptr[i] = malloc ( ROW * sizeof **ptr ); for ( i = 0; i < MAT; i++ ) for ( j = 0; j < ROW; j++ ) ptr[i][j] = malloc ( COL * sizeof ***ptr ); Thanks.
  • 2. errno 13
    Hi, I have created a directory with access: S_IRWXU. In it I have created a file for appending called log. I would also like to create a file for writing. However, this is not successful and the errno value that I get as a result is 13 (EACCES). I don't know how to resolve this. Thank you for your help. Marcia Hon
  • 3. What's the best way to create an associative array in C?
    Hello I want to create a lookup table where I can store string keys: For example: -> Purple -> Blue -> Red The first field are IP addresses - but basically a text string. The colour - eg Purple, Blue or Red is the value associated with the IP address (sort of the key). Angus Comber XXXX@XXXXX.COM
  • 4. beginer C question
    Hi everybody here is my code to print all nonblank character on Input.. This program according to my knowledge should run till i press Ctrl+D but,,, this is parsing the input untill i press RETURN ( ENTER).. Why is it so.. thx in advance prem mallappa #include <stdio.h> int main(void) { int c; while ( ( c = getchar() ) != EOF) { if ( c == ' ' || c == '\t' || c == '\n') ; else putchar (c); } return 0; }

Re: assembly in future C standard HCF Gerry Wheeler

Postby Walter Banks » Sat, 04 Nov 2006 22:35:39 GMT

As this thread wanders off topic this industry was introduced to a new
mnemonic in Byte article about decoding the undocumented
Motorola 6800 instructions. The HCF (Halt Catch Fire) opcode $DD
or $D9. HFC locked up the processor and cycled the address bus
The author of that article was Gerry Wheeler.

Gerry Wheeler, 54, died October 15, 2006, advanced non-Hodgkins
lymphoma cancer. Gerry made significant contributions to the technology
of the embedded systems world and was a key part of the development
of many household name products.

Programmer, Ham KG4NBB, author, father, husband, active commuity
participant Gerry will be missed by all.


Similar Threads:

1.assembly in future C standard

Peter Nilsson < XXXX@XXXXX.COM > wrote:

(Crossposted to comp.std.c, with followups directed there, hopefully
 appropriately.  The original post discussed the possibility of whether
 __asm or something similar to it would be added to the C standard.)

> Contrary to Richard Heathfield's categorical statement, it is not an
> absolute given that there will never be an asm keyword in C. But it
> is unlikely because it's already clear that the asm keyword in C++ has
> not served to truly standardise the syntax of inline assembly.

One idea that was not mentioned in the original thread (I imagine for
good reason, because it's a half-baked and probably stupid idea that
occurred to me reading your post) would be to allow for some kind of
conditional assembly, just perhaps something like

#pragma assemble
#pragma X86 /* Inner pragma's implementation-defined */
  /* Inline assembly, which the implementation can ignore or not */
#pragma no-assemble
  /* Stock C code for implementations that can't or won't accept the
   * assemble pragma: */
  for( i=1; i < 10; i++ ) {
    /* ... */
#pragma end-assemble

The end result would be something like "If the implementation attempts
to inline the assembly code contained within a #pragma assemble
directive, the behavior is implementation-defined.  Otherwise the
assembly code shall be ignored and the C code contained within any
corresponding #pragma no-assemble directive shall be compiled as
though no directives were present."  It would require adding some
duties to the #pragma directive, but it would allow implementors to
take a reasonable shot at using targetted assembly instructions when
appropriate and available, and reverting to ordinary C otherwise.

I'm sure there are reasons why this is stupid and/or impossible, or it
would have been done already :-)

> At the end of the day, the committee could probably spend many man
> weeks deciding issues on an __asm keyword, but for what? Most
> implementations will keep their existing syntax, and most programmers
> who use inline assembly will no doubt continue to prefer the localised
> syntax because it's less cumbersome than any standard syntax.

Indeed, but it's an interesting thought experiment to consider how the
committee *might* add assembly to C if they chose to do so.  (Well,
interesting to me, at least.)

C. Benson Manica           | I *should* know what I'm talking about - if I
cbmanica(at)      | don't, I need to know.  Flames welcome.

Return to c


Who is online

Users browsing this forum: No registered users and 67 guest