2014-09-17

#include <iostream>
using namespace std;
struct st1 { char vc[4]; }; struct st2 { int vd[4]; };
class cl
{   st1 s; int v[4];
public:
    cl(char c, st2& s2);
    void elab1(st1 s1, st2 s2);
    void stampa()
    {   int i;
        for (i=0;i<4;i++) cout << s.vc[i] << ' '; cout << endl;
        for (i=0;i<4;i++) cout << v[i] << ' '; cout << endl << endl;
    }
};


#include "cc.h"
cl::cl(char c, st2& s2) {
    for (int i = 0; i < 4; i++) {
        s.vc[i] = c + i;
        v[i] = s2.vd[i] + s.vc[i];
    }
}
void cl::elab1(st1 s1, st2 s2) {
    cl cla('a', s2);
    for (int i = 0; i < 4; i++) {
        if (s.vc[i] <= s1.vc[i]) {
            s.vc[i] = cla.s.vc[i];
            v[i] = cla.v[i];
        }
    }
}

SOLUZIONE

.global _ZN2clC1EcR3st2

_ZN2clC1EcR3st2:

  # RECORD DI ATTIVAZIONE
  # &s2   -24
  # i   |   c     -16
  # this      -8

.set s2,    -24
.set i,   -12
.set c,   -16
.set this,  -8

  # PROLOGO
  pushq %rsp
  movq %rsp,    %rbp
  subq $24,   %rsp

  # COPIO PARAMETRI
  movq %rdi,    this(%rbp)
  movb %sil,    c(%rbp)
  movq %rdx,    s2(%rbp)

  movl $0,    i(%rbp)
for:
  cmpl $4,    i(%rbp)
  jge finefor

  movq this(%rbp),    %rdi
  movslq  i(%rbp),    %rcx
  movb c(%rbp),   %al
  addb %cl,    %al
  movb %al,   (%rdi,  %rcx)           # (%rdi,  %rcx) = s.vc[i]

  movq s2(%rbp, %rcx, 4),    %r9      # s2.vd[i]
  addq  (%rdi,  %rcx),    %r9
  movq %r9,   4(%rdi,  %rcx, 4)

  incl i(%rbp)
  jmp for
finefor:

  leave
  ret


# ELAB1

.global _ZN2cl5elab13st13st2

_ZN2cl5elab1E3st13st2:

  # RECORD DI ATTIVAZIONE
  # cla.s   |    _ _ _ _    -64
  # cla.v[1]    |   cla.v[0]    -56
  # cla.v[3]    |   cla.v[2]    -48
  # cla     -40
  # s2[1]   |   s2[0]   -32
  # s2[3]   |   s2[2]   -24
  # i   |   s1   -16
  # this    -8

.set this, -8
.set i, -12
.set s1, -16
.set s2, -32
.set cla, -64

  # PROLOGO
  pushq %rsp
  movq %rsp,    %rbp
  subq $64,   %rsp

  # COPIO PARAMETRI
  movl %esi,  s1(%rbp)
  movq %rdi,  this(%rbp)
  movq %rdx,  s2(%rbp)          # parte più significativa di s2
  movq %rcx,  s2+8(%rbp)        # parte meno significativa di s2

  # CREO CLA
  leaq cla(%rbp),   %rdi
  movb $'a',    %sil
  leaq s2(%rbp),    %rdx
  call _ZN2clC1EcR3st2

  movl $0,    i(%rbp)
for1:
  cmpl $4,    i(%rbp)
  jge finefor

  movslq i(%rbp),    %rcx
  movq this(%rbp),    %r8
  leaq cla(%rbp),   %r9

if:
  movb (%r8,  %rcx),    %al     # al prende s.vc[i]
  cmpb s1(%rbp, %rcx),    %al    # confronto  s1.vc[i] con s.vc[i]
  jg fineif

  movb (%r9, %rcx), %al       # in al ho salvato l'indrizzo di s.vc[i], quindi
                              # sposto cla.s.vc[i] in s.vc[i]
  movq 4(%r9, %rcx, 4),     %rax
  movq %rax,    4(%r8, %rcx, 4)
fineif:
  incl i(%rbp)
  jmp for1
finefor1:
  leave
  ret