; ***************** prog.c ******************************************
;                 Dsp program sample demonstrates call of assembler
;                 function from C code according to calling
;                 convinience
;
; (c)OJSC R&D "ELVEES"
;
; *******************************************************************

/*
    Function: func
    float func (int p1, int p2, float p3, float p4)

    Parameters:
        - p1, p2, p3, p4 - parameters

    Results:
        - (float)p1*p3 + (float)p2*p4
*/

        .text
        .globl        _func
        .align        4
        .type        _func,@function
_func:
        ; this move instructions are for demonstrating in sample
        ; it is not necessarily copy r0.l, r2.l, r4.l regs to another regs

        move r0.l,   r11.l      ; get param1
        move r2.l,   r12.l      ; get param2
        move r4.l,   r13.l      ; get param3
        move (a7.l), r14.l      ; get param4

        cvif r11.l, r11.l
        cvif r12.l, r12.l

        fmpy r11.l, r13.l, r13.l
        fmpy r12.l, r14.l, r14.l

        fadd r13.l, r14.l, r10.l

        ; this move instructions is also for demonstrating in sample
        ; you may do 'fadd r12.l, r14.l, r0.l' in real application
        move r10.l, r0.l         ; set return parameter
        rts