Re: 24 bits (u)ints

Diogo Martins Silva writes:

> Hello all.
>
> The avr-gcc wiki (https://gcc.gnu.org/wiki/avr-gcc) lists 24 bits
> (u)ints as an extension since version 4.7. How do I use them?

Use __uint24 as the type. Like so

$ cat test.c
volatile __uint24 x;
int main() { 
  x++;
  x--;
}

$ avr-gcc -S test.c -Os

$ cat test.s
	.file	"test.c"
__SP_H__ = 0x3e
__SP_L__ = 0x3d
__SREG__ = 0x3f
__tmp_reg__ = 0
__zero_reg__ = 1
	.section	.text.startup,"ax",@progbits
.global	main
	.type	main, @function
main:
/* prologue: function */
/* frame size = 0 */
/* stack size = 0 */
.L__stack_usage = 0
	lds r24,x
	lds r25,x+1
	lds r26,x+2
	adiw r24,1
	adc r26,__zero_reg__
	sts x,r24
	sts x+1,r25
	sts x+2,r26
	lds r24,x
	lds r25,x+1
	lds r26,x+2
	sbiw r24,1
	sbc r26,__zero_reg__
	sts x,r24
	sts x+1,r25
	sts x+2,r26
	ret
	.size	main, .-main
	.comm	x,3,1
	.ident	"GCC: (AVR_8_bit_GNU_Toolchain_3.5.4_1709) 4.9.2"
.global __do_clear_bss

Regards
Senthil
>
> Thanks
>
> Diogo
>
>
> _______________________________________________
> AVR-GCC-list mailing list
> [email protected]
> https://lists.nongnu.org/mailman/listinfo/avr-gcc-list