28.2.52 __builtin_popcount

Description

Count the number of 1’s (set bits) in an integer.

Prototype

int16_t __builtin_popcount(uint16_t num);

Argument

num – integer number

Return Value

Returns the number of 1’s found.

Example Instruction sequence

        clr     w0
        mov     w1,w3
 .LL1:
        ff1r    w3,w2
        bra     c,.LL2
        inc     w0,w0
        lsr     w3,w2,w3
        bra     .LL1
 .LL2: