> 1. Can anyone see reason why is push r2, and pop SR. Is it for fun?
These are disassembly tricks. Compile your source with -S flag then see
_pure_ assembly.
> 2. has anyone found in early math lessons, that 144 = -112 !!!?
You already answered your question below.
> I fully understand, that 112+144 = 256. I also understand, that 2+2=4
This might be an answer.
> But these are not what states in C.
they are.
> Funny is that if constant is below 126 everything is OK.
> casting to int doesn't help
> I am used to write HW mul myself but after 1 year and many updates I
> thought somebody has fixed it up.
t= usart0_rx_buffer[usart0_rx_extract_idx]*144;
mov #642, r13 ;#0x0282
mov &0x026c,r15 ;src addr 0x026c
add r13, r15 ;
push r2 ;
dint
nop
mov.b @r15, &0x0130 ;
mov.b #0, &0x0131 ;subst r3 with As==00
mov #-112, &0x0138 ;#0xff90
mov.b #0, &0x0139 ;subst r3 with As==00
These two load second operand with int 144 (tricky, isn't it? :)
mov &0x013a,r10 ;src addr 0x013a
pop SR
this is the same as pop r2 (disassembly tricks only!)
> I have also suggestion to free(void* ptr) in malloc( which I am using
for
> ages. It helps me to free not only memory allocated via malloc, but
also
> pointers to memory in eeprom- which I directly use via pointer. I call
> free() without worring if deallocation is possible. I also must
mention,
> that first int after __noinit_end is used to store value of memory
size
> allocated with malloc.(*t)
> So if p is not withing malloc range no action is taken.
That's correct.
:
void myfree (void *p)
{
size_t *t = &__noinit_end;
if(((int)p < ((int)t +*t)) && ((int)p > (int)t)){
p--;
*t -= XSIZE(((size_t*)p));
MARK_FREE (((size_t*)p));
}
}
~d
--
Pozdrowienia
Robert Seczkowski
rs...@poczta.onet.pl
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