At 10:24 25/05/99 -0700, you wrote:
>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
>
>



<<<<<FLAME SUIT ON>>>>>>
Humm,
I see what you are doing, I have used the Hitech products for quite some
time now and niggly little things like this have poped up, but Hitech is
not alone!
I have had a look at the code that you're  after and have to ask a question:-


typedef struct {
        unsigned        b7:1;
        unsigned        b6:1;
        unsigned        b5:1;
        unsigned        b4:1;
        unsigned        b3:1;
        unsigned        b2:1;
        unsigned        b1:1;
        unsigned        b0:1;
} SFR_BITS;                     /*bit structure field to bit address some things
*/

/************
****begin***/

static SFR_BITS PORTA_BITS      @ 0x08; /*the address of the register etc*/

#define PA7     PORTA_BITS.b7
#define PA6     PORTA_BITS.b6
#define PA5     PORTA_BITS.b5
#define PA4     PORTA_BITS.b4
#define PA3     PORTA_BITS.b3
#define PA2     PORTA_BITS.b2
#define PA1     PORTA_BITS.b1
#define PA0     PORTA_BITS.b0


        What code does something like
        {
         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 other versions beome a little more conviluted

Yes I understand that the "@" is not used by many compilers and I here the
"Portability" stuff, but we are dealing with embedded code here. I must say
that I do cringe when I see in-line assembly


<<<<<<FLAME SUIT OFF>>>>>>

Badly burnt
Dennis