Question

The C function funsum below takes three arguments -- an integer val and two function pointers to functions f and g, respectively. f and g both take an integer argument and return an integer result. The function funsum applies f to val, applies g to val, and returns the sum of the two results. Translate to RISC-V following RISC-V register conventions. Note that you do not know, nor do you need to know, what f and g do, nor do you know what registers f and g use.

long long int funsum(long long int val, long long int (*f) (long long int), long long int (*g) (long long int))

{

return(f(val) + g(val));

}

Answer 1

Given below is the translation to RISC-V

funsum:

        addi    sp,sp,-64

        sd      ra,56(sp)

        sd      s0,48(sp)

        sd      s1,40(sp)

        addi    s0,sp,64

        sd      a0,-40(s0)

        sd      a1,-48(s0)

        sd      a2,-56(s0)

        ld      a5,-48(s0)

        ld      a0,-40(s0)

        jalr    a5

        mv      s1,a0

        ld      a5,-56(s0)

        ld      a0,-40(s0)

        jalr    a5

        mv      a5,a0

        add     a5,s1,a5

        mv      a0,a5

        ld      ra,56(sp)

        ld      s0,48(sp)

        ld      s1,40(sp)

        addi    sp,sp,64

        jr      ra

Thank You.