Transfer table addres to function using inline ASM?-solved

[Mindaugasu]

Re: Transfer table addres to function using inline ASM?-solv

Ok I have concrete question to those who knows AVR-GCC.
My data is in flash memory:

const uint8_t sinewave[] PROGMEM= //256 values 
{ 
0x80,0x83,0x86,0x89,0x8c,0x8f,.....

I have a function which outputs data from this lookup table to PORTD.

void signalOUT1(const uint8_t *signal)
{
	uint8_t i=0;
   do{
   PORTD=pgm_read_byte(&signal[i++]);
   }while(1);
}

I looked in compiled listing and I have noticed that pointer address is given to r24 and r25 registers.

2738 05b6 80E0      		ldi r24,lo8(sinewave)
 2739 05b8 90E0      		ldi r25,hi8(sinewave)
 2740               	.L150:
 2741 05ba 99DD      		rcall signalOUT

And then within function signalOUT r24 and r25 are passed to r31 and r30 by command movw r30,r24.


Is there any way to show a compiler to pass pointer address directly to r30 and r31 (Z) that I could work with inline asm function:

void signalOUT(const uint8_t *signal, uint8_t ad2, uint8_t ad1, uint8_t ad0)
{
asm volatile("eor r28, r28    ;r28<-0"   "\n\t"
      "eor r29, r29    ;r29<-0"   "\n\t"
      "1:"               "\n\t"
      "add r28, %0   ;1 cycle"         "\n\t"
      "adc r29, %1   ;1 cycle"         "\n\t"   
      "adc %A3, %2   ;1 cycle"         "\n\t"
      "lpm __tmp_reg__, %a3+   ;3 cycles" "\n\t"
      "out %4, __tmp_reg__   ;1 cycle"   "\n\t"
      "rjmp 1b      ;2 cycles. Total 9 cycles"   "\n\t"
      :
      :"r" (ad0),"r" (ad1),"r" (ad2),"e" (signal),"I" (_SFR_IO_ADDR(PORTD))
      :"r28", "r29"
   );
}

because according to avrlibc ) directive "e" (signal) in inline asm assigns a Z pointer to value. Is there some kin of a bug or I am missing something.
Thank you

Added after 5 hours 29 minutes:

Added after 2 minutes:

Just in case someone is interested...

Using static inline function makes compiler optimize code this way, that when calling function table pointer is directly passed to r30:r31 register pair.




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