user: 请从给定的汇编指令推导出C源代码:

```asm
<rk4>:
  endbr64
  push   %r15
  push   %r14
  push   %r13
  push   %r12
  push   %rbp
  push   %rbx
  sub    $0x68,%rsp
  mov    %rdi,%r13
  mov    %rsi,%r14
  mov    %edx,%ebp
  movsd  %xmm0,0x40(%rsp)
  movsd  %xmm1,0x28(%rsp)
  mov    %rcx,%r15
  mov    %r8,0x30(%rsp)
  movslq %edx,%rbx
  shl    $0x3,%rbx
  lea    D18(%rip),%rdx
  lea    D20(%rip),%r12
  mov    %r12,%rsi
  mov    %rbx,%rdi
  mov    $0x0,%eax
  call   <mem_alloc@plt>
  mov    %eax,0x50(%rsp)
  cltq
  mov    %rax,0x38(%rsp)
  lea    D3(%rip),%rdx
  mov    %r12,%rsi
  mov    %rbx,%rdi
  mov    $0x0,%eax
  call   <mem_alloc@plt>
  mov    %eax,0x54(%rsp)
  cltq
  mov    %rax,0x20(%rsp)
  lea    D52(%rip),%rdx
  mov    %r12,%rsi
  mov    %rbx,%rdi
  mov    $0x0,%eax
  call   <mem_alloc@plt>
  mov    %eax,%ebx
  cltq
  mov    %rax,0x18(%rsp)
  movsd  0x28(%rsp),%xmm4
  movapd %xmm4,%xmm3
  mulsd  D36(%rip),%xmm3
  movsd  %xmm3,0x8(%rsp)
  divsd  D57(%rip),%xmm4
  movsd  %xmm4,0x10(%rsp)
  addsd  0x40(%rsp),%xmm3
  movsd  %xmm3,0x48(%rsp)
  test   %ebp,%ebp
  jle    L26
  mov    %rax,%rdi
  mov    %ebp,%eax
  lea    (%rdi,%rax,8),%rsi
  mov    %rdi,%rax
  mov    %r14,%rcx
  sub    %rdi,%rcx
  mov    %r13,%rdx
  sub    %rdi,%rdx
L67:
  movsd  0x8(%rsp),%xmm0
  mulsd  (%rcx,%rax,1),%xmm0
  addsd  (%rdx,%rax,1),%xmm0
  movsd  %xmm0,(%rax)
  add    $0x8,%rax
  cmp    %rsi,%rax
  jne    L67
  mov    0x20(%rsp),%rsi
  mov    0x18(%rsp),%rdi
  movsd  0x48(%rsp),%xmm0
  mov    0x30(%rsp),%rax
  call   *%rax
  cmp    $0x1,%ebp
  jle    L4
L46:
  movslq 0x54(%rsp),%r12
  lea    0x8(%r12),%rax
  lea    -0x2(%rbp),%edx
  lea    0x10(,%rdx,8),%rdi
  mov    %rdi,0x58(%rsp)
  lea    (%rdi,%r12,1),%rsi
  movslq %ebx,%rbx
  mov    %rbx,%rcx
  sub    %r12,%rcx
  mov    %r13,%rdx
  sub    %r12,%rdx
L2:
  movsd  0x8(%rsp),%xmm0
  mulsd  (%rax),%xmm0
  addsd  (%rdx,%rax,1),%xmm0
  movsd  %xmm0,(%rcx,%rax,1)
  add    $0x8,%rax
  cmp    %rsi,%rax
  jne    L2
  mov    0x38(%rsp),%rsi
  mov    0x18(%rsp),%rdi
  movsd  0x48(%rsp),%xmm0
  mov    0x30(%rsp),%rax
  call   *%rax
  movslq 0x50(%rsp),%rsi
  lea    0x8(%rsi),%rax
  mov    0x58(%rsp),%rdx
  add    %rsi,%rdx
  sub    %rsi,%rbx
  mov    %r13,%rcx
  sub    %rsi,%rcx
  sub    %rsi,%r12
  movsd  0x28(%rsp),%xmm1
L16:
  movapd %xmm1,%xmm0
  mulsd  (%rax),%xmm0
  addsd  (%rcx,%rax,1),%xmm0
  movsd  %xmm0,(%rbx,%rax,1)
  movsd  (%rax),%xmm0
  addsd  (%r12,%rax,1),%xmm0
  movsd  %xmm0,(%rax)
  add    $0x8,%rax
  cmp    %rdx,%rax
  jne    L16
  movsd  0x28(%rsp),%xmm0
  addsd  0x40(%rsp),%xmm0
  mov    0x20(%rsp),%rsi
  mov    0x18(%rsp),%rdi
  mov    0x30(%rsp),%rax
  call   *%rax
L89:
  movslq 0x54(%rsp),%rsi
  mov    %rsi,%rdx
  mov    $0x0,%eax
  movslq 0x50(%rsp),%rcx
  sub    %rsi,%rcx
L7:
  movsd  (%rcx,%rdx,1),%xmm0
  addsd  %xmm0,%xmm0
  movsd  (%r14,%rax,8),%xmm1
  addsd  (%rdx),%xmm1
  addsd  %xmm1,%xmm0
  mulsd  0x10(%rsp),%xmm0
  addsd  0x0(%r13,%rax,8),%xmm0
  movsd  %xmm0,(%r15,%rax,8)
  add    $0x1,%rax
  add    $0x8,%rdx
  cmp    %eax,%ebp
  jg     L7
L52:
  mov    0x18(%rsp),%rdi
  call   <free@plt>
  mov    0x20(%rsp),%rdi
  call   <free@plt>
  mov    0x38(%rsp),%rdi
  call   <free@plt>
  add    $0x68,%rsp
  pop    %rbx
  pop    %rbp
  pop    %r12
  pop    %r13
  pop    %r14
  pop    %r15
  ret
L26:
  mov    0x20(%rsp),%rsi
  mov    0x18(%rsp),%rdi
  movsd  0x48(%rsp),%xmm0
  mov    0x30(%rsp),%rax
  call   *%rax
  cmp    $0x1,%ebp
  jg     L46
  mov    0x38(%rsp),%rsi
  mov    0x18(%rsp),%r12
  mov    %r12,%rdi
  movsd  0x48(%rsp),%xmm0
  mov    0x30(%rsp),%rbx
  call   *%rbx
  movsd  0x28(%rsp),%xmm0
  addsd  0x40(%rsp),%xmm0
  mov    0x20(%rsp),%rsi
  mov    %r12,%rdi
  call   *%rbx
  cmp    $0x1,%ebp
  jne    L52
  jmp    L89
L4:
  mov    0x38(%rsp),%rsi
  mov    0x18(%rsp),%r12
  mov    %r12,%rdi
  movsd  0x48(%rsp),%xmm0
  mov    0x30(%rsp),%rbx
  call   *%rbx
  movsd  0x28(%rsp),%xmm0
  addsd  0x40(%rsp),%xmm0
  mov    0x20(%rsp),%rsi
  mov    %r12,%rdi
  call   *%rbx
  jmp    L89
```

tool_calls: name: unpack_data
arguments: data_label: D18
type: string
name: unpack_data
arguments: data_label: D20
type: string
name: unpack_data
arguments: data_label: D3
type: string
name: unpack_data
arguments: data_label: D52
type: string
name: unpack_data
arguments: data_label: D36
type: f64
name: unpack_data
arguments: data_label: D57
type: f64

tool: D18: dym[]

tool: D20: rk4(): 

tool: D3: dyt[]

tool: D52: yt[]

tool: D36: 0.5

tool: D57: 6

assistant: ```c
void rk4(double *y, double *dydx, int n, double x, double h, double *yout, void (*derivs)(double, double *, double *)) {
  char *func = {"rk4(): "};
  int i;
  double xh, hh, h6, *dym, *dyt, *yt;
  dym = (double *)mem_alloc((n) * sizeof(double), func, "dym[]");
  dyt = (double *)mem_alloc((n) * sizeof(double), func, "dyt[]");
  yt = (double *)mem_alloc((n) * sizeof(double), func, "yt[]");
  hh = h * 0.5;
  h6 = h / 6.0;
  xh = x + hh;
  for (i = 0; i < n; i++) {
    yt[i] = y[i] + hh * dydx[i];
  }
  (*derivs)(xh, yt, dyt);
  for (i = 1; i < n; i++) {
    yt[i] = y[i] + hh * dyt[i];
  }
  (*derivs)(xh, yt, dym);
  for (i = 1; i < n; i++) {
    yt[i] = y[i] + h * dym[i];
    dym[i] += dyt[i];
  }
  (*derivs)(x + h, yt, dyt);
  for (i = 0; i < n; i++) {
    yout[i] = y[i] + h6 * (dydx[i] + dyt[i] + 2.0 * dym[i]);
  }
  free(yt);
  free(dyt);
  free(dym);
}
```