>Hi Friends,
>Has anyone come up with a decent workaround for using inline
>assembly in HiTech C when the optimizer screws it up? Compiling the
>assembler part to a separate module without optimizing is not really a
>good option(that's the recommended thing to do, and it's stupid).
>
>For instance, if I want to count loops until pin 4 of PORTC drops and have
>it drop through on overflow, I'd do this:
>
>aa1     decfsz  _count
>        btfss   7,4     ;that's portc pin 4
>        goto    aa2
>        goto    aa1
>aa2     more stuff here...
>
>then the optimizer gets it's hands on it and does:
>aa1     decfsz  _count
>        btfsc   7,4     ;note btfss is now btfsc
>        goto    aa1
>        more stuff here...
>
>Needless to say it no longer has the timeout working. There is no "keep
>hands off" directive.
>
>What I've been doing is adding a nop to make space and then loading the
>hex code into MPLAB and patching the code back to my original. Hack!
>
>Anyone?
>
>Thanks,
>Bob
>
>

>        {
>         unsigned char uc_count = 0;
>
>                while (count--)
>                {
>                        if (PA4)
>                                break;
>                }
>                more stuff here...
>        }
>        produce?
>
>
>        you could also look at
>
>        {
>                while (PA4)
>                {
>                        unsigend char uc_count = 0;
>                        if (!--count)
>                                break;
>                }
>                more stuff here...
>        }
>
>        or
>
>        {
>                for (;;)
>                {
>                unsigned char uc_count = 0;
>
>                        if (!PA4 || !--count)
>                                break;
>                }
>                more stuff here...
>        }

> The code these produce is not bad, just takes one more cycle and two more
> words than the assembler example did. They do about the same sort of thing
> as my original:
>
> while((--count) && RC4);
>
> which worked fine, I just wanted as tight a loop as possible for accuracy.
> The extra cycle was what I chopped off with assembly, it used decfsz
> whereas the C version generated a decf followed by a btfsX.
>
> What has continually bothered me is the frustration I have each time I try
> to use inline assembly and it hoses my code. Then I end up having to
> settle
> for what the C equivalent generates or patching the hex code in MPLAB.
>
> I was hoping someone here had figured out a better workaround. If I have
> to
> put the assembler in a separate module with no optimization, I can do
> that,
> but unless it's in a function, I have no idea how to do it in a way that
> plants it in the middle of the program the way the inline assembly would
> (and should) be.
>