Question

Language Assembly ( required)

Write and test a function, drawshape. The function has 2 parameters, the shape's character and the length of the shape's longest line.

draw shape(1, x) looks displays

x

x

draw shape(2, y) displays

yy

y

yy

draw shape(3, z) displays

zzz

zz

z

zz

zzz

and so on.

Answer 1

Below is the assembly language code for asked draw shape function.

draw_shape(int, char):

        push    rbp

        mov     rbp, rsp

        sub     rsp, 32

        mov     DWORD PTR [rbp-20], edi

        mov     eax, esi

        mov     BYTE PTR [rbp-24], al

        cmp     DWORD PTR [rbp-20], 1

        jne     .L2

        movsx   eax, BYTE PTR [rbp-24]

        mov     esi, eax

        mov     edi, OFFSET FLAT:_ZSt4cout

        call    std::basic_ostream<char, std::char_traits<char> >& std::operator<< <std::char_traits<char> > (std::basic_ostream<char, std::char_traits<char> >&, char)

        mov     esi, OFFSET FLAT:_ZSt4endlIcSt11char_traitsIcEERSt13basic_ostreamIT_T0_ES6_

        mov     rdi, rax

        call    std::basic_ostream<char, std::char_traits<char> >::operator<<(std::basic_ostream<char, std::char_t raits<char> >& (*)(std::basic_ostream<char, std::char_traits<char> >&))

        mov     rdx, rax

        movsx   eax, BYTE PTR [rbp-24]

        mov     esi, eax

        mov     rdi, rdx

        call    std::basic_ostream<char, std::char_traits<char> >& std::operator<< <std::char_traits<char> > (std::basic_ostream<char, std::char_traits<char> >&, char)

        jmp     .L11

.L2:

        mov     eax, DWORD PTR [rbp-20]

        mov     DWORD PTR [rbp-4], eax

.L7:

        cmp     DWORD PTR [rbp-4], 0

        jle     .L4

        mov     DWORD PTR [rbp-8], 1

.L6:

        mov     eax, DWORD PTR [rbp-8]

        cmp     eax, DWORD PTR [rbp-4]

        jg      .L5

        movsx   eax, BYTE PTR [rbp-24]

        mov     esi, eax

        mov     edi, OFFSET FLAT:_ZSt4cout

        call    std::basic_ostream<char, std::char_traits<char> >& std::operator<< <std::char_traits<char> > (std::basic_ostream<char, std::char_traits<char> >&, char)

        mov     esi, OFFSET FLAT:.LC0

        mov     rdi, rax

        call    std::basic_ostream<char, std::char_traits<char> >& std::operator<< <std::char_traits<char> > (std::basic_ostream<char, std::char_traits<char> >&, char const*)

        add     DWORD PTR [rbp-8], 1

        jmp     .L6

.L5:

        mov     esi, OFFSET FLAT:_ZSt4endlIcSt11char_traitsIcEERSt13basic_ostreamIT_T0_ES6_

        mov     edi, OFFSET FLAT:_ZSt4cout

        call    std::basic_ostream<char, std::char_traits<char> >::operator<<(std::basic_ostream<char, std::char_t raits<char> >& (*)(std::basic_ostream<char, std::char_traits<char> >&))

        sub     DWORD PTR [rbp-4], 1

        jmp     .L7

.L4:

        add     DWORD PTR [rbp-4], 2

.L10:

        mov     eax, DWORD PTR [rbp-4]

        cmp     eax, DWORD PTR [rbp-20]

        jg      .L11

        mov     DWORD PTR [rbp-8], 1

.L9:

        mov     eax, DWORD PTR [rbp-8]

        cmp     eax, DWORD PTR [rbp-4]

        jg      .L8

        movsx   eax, BYTE PTR [rbp-24]

        mov     esi, eax

        mov     edi, OFFSET FLAT:_ZSt4cout

        call    std::basic_ostream<char, std::char_traits<char> >& std::operator<< <std::char_traits<char> > (std::basic_ostream<char, std::char_traits<char> >&, char)

        mov     esi, OFFSET FLAT:.LC0

        mov     rdi, rax

        call    std::basic_ostream<char, std::char_traits<char> >& std::operator<< <std::char_traits<char> > (std::basic_ostream<char, std::char_traits<char> >&, char const*)

        add     DWORD PTR [rbp-8], 1

        jmp     .L9

.L8:

        mov     esi, OFFSET FLAT:_ZSt4endlIcSt11char_traitsIcEERSt13basic_ostreamIT_T0_ES6_

        mov     edi, OFFSET FLAT:_ZSt4cout

        call    std::basic_ostream<char, std::char_traits<char> >::operator<<(std::basic_ostream<char, std::char_t raits<char> >& (*)(std::basic_ostream<char, std::char_traits<char> >&))

        add     DWORD PTR [rbp-4], 1

        jmp     .L10

.L11:

        nop

        leave

        ret

Thank You.