user: 下面的汇编指令对应的C源代码是什么:

```asm
<gsa_walk>:
  endbr64
  push   %r15
  push   %r14
  push   %r13
  push   %r12
  push   %rbp
  push   %rbx
  sub    $0x38,%rsp
  mov    %rdi,%r13
  mov    %esi,%ebx
  mov    %edx,%r15d
  mov    %rcx,0x18(%rsp)
  mov    %fs:0x28,%rax
  mov    %rax,0x28(%rsp)
  xor    %eax,%eax
  movslq %esi,%rbp
  mov    %esi,%edi
  imul   %esi,%edi
  shl    $0x2,%edi
  call   <malloc@plt>
  mov    %rax,%r14
  test   %ebx,%ebx
  setg   %al
  test   %r15d,%r15d
  setg   %dil
  movzbl %dil,%edi
  and    %eax,%edi
  call   <assert@plt>
  test   %r14,%r14
  je     L76
L62:
  test   %ebx,%ebx
  jle    L56
  lea    0x0(,%rbp,4),%rdi
  mov    %ebx,%eax
  lea    (%r14,%rax,4),%rdx
  mov    $0x0,%ecx
  mov    %ebx,%esi
  neg    %rsi
  shl    $0x2,%rsi
L10:
  lea    (%rsi,%rdx,1),%rax
L17:
  movl   $0x0,(%rax)
  add    $0x4,%rax
  cmp    %rax,%rdx
  jne    L17
  add    $0x1,%ecx
  add    %rdi,%rdx
  cmp    %ecx,%ebx
  jne    L10
L56:
  mov    %ebx,%r12d
  shr    $0x1f,%r12d
  add    %ebx,%r12d
  sar    %r12d
  mov    %r12d,0x24(%rsp)
  mov    %r12d,0x20(%rsp)
  movslq %r12d,%rax
  imul   %rax,%rbp
  shl    $0x2,%rax
  lea    (%rax,%rbp,4),%rax
  movl   $0x1,(%r14,%rax,1)
  test   %r15d,%r15d
  jle    L8
  pxor   %xmm3,%xmm3
  movsd  %xmm3,0x8(%rsp)
  mov    $0x0,%ebp
  jmp    L66
L76:
  lea    D7(%rip),%rdi
  call   <perror@plt>
  mov    $0x0,%eax
  call   <abort@plt>
  jmp    L62
L67:
  mov    0x20(%rsp),%edi
  sub    %r12d,%edi
  mov    $0x2,%esi
  call   <pow@plt>
  mov    %rax,0x10(%rsp)
  mov    0x24(%rsp),%edi
  sub    %r12d,%edi
  mov    $0x2,%esi
  call   <pow@plt>
  add    0x10(%rsp),%rax
  pxor   %xmm0,%xmm0
  cvtsi2sd %rax,%xmm0
  addsd  0x8(%rsp),%xmm0
  movsd  %xmm0,0x8(%rsp)
  lea    0x24(%rsp),%rcx
  lea    0x20(%rsp),%rdx
  mov    %ebx,%esi
  mov    %r14,%rdi
  call   <take_next_step@plt>
  add    $0x1,%ebp
  test   %eax,%eax
  je     L2
  cmp    %ebp,%r15d
  jle    L2
L66:
  test   %r13,%r13
  je     L67
  mov    0x24(%rsp),%ecx
  mov    0x20(%rsp),%edx
  lea    D4(%rip),%rsi
  mov    %r13,%rdi
  call   <fprintf@plt>
  jmp    L67
L8:
  pxor   %xmm4,%xmm4
  movsd  %xmm4,0x8(%rsp)
  mov    $0x0,%ebp
L2:
  mov    0x18(%rsp),%rax
  test   %rax,%rax
  je     L52
  pxor   %xmm1,%xmm1
  cvtsi2sd %ebp,%xmm1
  movsd  0x8(%rsp),%xmm0
  divsd  %xmm1,%xmm0
  movsd  %xmm0,(%rax)
L52:
  mov    %r14,%rdi
  call   <free@plt>
  mov    0x28(%rsp),%rax
  sub    %fs:0x28,%rax
  jne    L70
  mov    %ebp,%eax
  add    $0x38,%rsp
  pop    %rbx
  pop    %rbp
  pop    %r12
  pop    %r13
  pop    %r14
  pop    %r15
  ret
L70:
  call   <__stack_chk_fail@plt>
```

tool_calls: name: disassemble_data
arguments: label: D7
data_type: string
name: disassemble_data
arguments: label: D4
data_type: string

tool: D7: malloc() lattice

tool: D4: %d %d


assistant: ```c
int gsa_walk(FILE *fout, int dim, int nsteps, double *pdist) {
  bool(*lattice)[dim] = malloc(dim * dim * sizeof(bool));
  int asteps;
  int i, j;
  int last_x, last_y;
  double sum_r2;
  bool alive;
  assert(dim > 0 && nsteps > 0);
  if (lattice == NULL) {
    perror("malloc() lattice");
    abort();
  }
  for (i = 0; i < dim; i++) {
    for (j = 0; j < dim; j++) {
      lattice[i][j] = false;
    }
  }
  alive = true;
  last_x = last_y = dim / 2;
  lattice[last_x][last_y] = true;
  asteps = 0;
  sum_r2 = 0;
  while (alive && asteps < nsteps) {
    if (fout != NULL) {
      fprintf(fout, "%d %d\n", last_x, last_y);
    }
    sum_r2 += pow(last_x - dim / 2, 2) + pow(last_y - dim / 2, 2);
    alive = take_next_step((bool *)lattice, dim, &last_x, &last_y);
    asteps++;
  }
  if (pdist != NULL) {
    *pdist = sum_r2 / asteps;
  }
  free(lattice);
  return asteps;
}
```