user: What would the C source look like for the assembly code provided here:

```asm
<matexp>:
  endbr64
  push   %r15
  push   %r14
  push   %r13
  mov    %rdi,%r13
  push   %r12
  mov    %edx,%r12d
  push   %rbp
  push   %rbx
  sub    $0x78,%rsp
  mov    %rsi,0x18(%rsp)
  mov    %ecx,0x3c(%rsp)
  movsd  %xmm0,0x8(%rsp)
  mov    %fs:0x28,%rax
  mov    %rax,0x68(%rsp)
  mov    %ecx,%eax
  sub    $0x2,%eax
  cmp    $0x1d,%eax
  ja     L67
L181:
  mov    %r12d,%eax
  imul   %r12d,%eax
  mov    %eax,%edi
  mov    %eax,0x48(%rsp)
  call   <dvector@plt>
  movq   %rax,%xmm0
  mov    %rax,0x10(%rsp)
  movhps 0x18(%rsp),%xmm0
  movaps %xmm0,0x50(%rsp)
  test   %r12d,%r12d
  jle    L176
  movslq %r12d,%rsi
  mov    0x3c(%rsp),%ebp
  mov    %r12d,0x4c(%rsp)
  lea    0x0(,%rsi,8),%rcx
  mov    %rsi,0x40(%rsp)
  mov    %rax,%rsi
  lea    -0x1(%r12),%eax
  shl    $0x3,%rax
  mov    %rcx,0x20(%rsp)
  neg    %ebp
  mov    %rsi,%r12
  lea    0x8(%r13,%rax,1),%rcx
  add    $0x8,%rax
  mov    %rcx,0x28(%rsp)
  mov    %rax,0x30(%rsp)
  nopl   0x0(%rax)
L99:
  mov    0x0(%r13),%r15
  mov    0x30(%rsp),%rax
  mov    %r12,%r14
  lea    (%rax,%r15,1),%rbx
  nopl   0x0(%rax,%rax,1)
L180:
  movsd  0x8(%rsp),%xmm0
  mov    %ebp,%edi
  add    $0x8,%r15
  add    $0x8,%r14
  mulsd  -0x8(%r15),%xmm0
  call   <ldexp@plt>
  movsd  %xmm0,-0x8(%r14)
  cmp    %rbx,%r15
  jne    L180
  add    $0x8,%r13
  add    0x20(%rsp),%r12
  cmp    0x28(%rsp),%r13
  jne    L99
  mov    0x4c(%rsp),%r12d
  mov    0x10(%rsp),%rsi
  mov    0x18(%rsp),%rdx
  mov    %r12d,%r9d
  mov    %r12d,%r8d
  mov    %r12d,%ecx
  mov    %rsi,%rdi
  call   <matby@plt>
  mov    0x48(%rsp),%edx
  test   %edx,%edx
  je     L72
L12:
  mov    0x18(%rsp),%rdi
  mov    0x10(%rsp),%rsi
  lea    0x8(%rdi),%rax
  cmp    %rax,%rsi
  je     L41
  mov    0x48(%rsp),%eax
  cmp    $0x1,%eax
  jle    L41
  test   %eax,%eax
  mov    $0x1,%ecx
  movapd D9(%rip),%xmm1
  cmovg  %eax,%ecx
  xor    %eax,%eax
  mov    %ecx,%edx
  shr    %edx
  shl    $0x4,%rdx
  nopw   0x0(%rax,%rax,1)
L70:
  movupd (%rdi,%rax,1),%xmm0
  movupd (%rsi,%rax,1),%xmm2
  mulpd  %xmm1,%xmm0
  addpd  %xmm2,%xmm0
  movups %xmm0,(%rsi,%rax,1)
  add    $0x10,%rax
  cmp    %rax,%rdx
  jne    L70
  mov    %ecx,%eax
  and    $0xfffffffe,%eax
  and    $0x1,%ecx
  je     L3
  mov    0x10(%rsp),%rsi
  mov    0x18(%rsp),%rcx
  movsd  D9(%rip),%xmm0
  lea    (%rsi,%rax,8),%rdx
  mulsd  (%rcx,%rax,8),%xmm0
  addsd  (%rdx),%xmm0
  movsd  %xmm0,(%rdx)
L3:
  movslq %r12d,%rax
  mov    %rax,0x40(%rsp)
  test   %r12d,%r12d
  jle    L166
L72:
  mov    0x40(%rsp),%rax
  movsd  D30(%rip),%xmm1
  xor    %edx,%edx
  lea    0x8(,%rax,8),%rcx
  mov    0x10(%rsp),%rax
  nopl   (%rax)
L186:
  movsd  (%rax),%xmm0
  add    $0x1,%edx
  addsd  %xmm1,%xmm0
  movsd  %xmm0,(%rax)
  add    %rcx,%rax
  cmp    %edx,%r12d
  jg     L186
L166:
  mov    0x3c(%rsp),%ecx
  test   %ecx,%ecx
  jle    L110
  mov    0x10(%rsp),%rdi
  mov    0x18(%rsp),%rdx
  xor    %r15d,%r15d
  xor    %r13d,%r13d
  mov    0x3c(%rsp),%r14d
  mov    $0x1,%ebp
  jmp    L160
  nop
L51:
  movslq %r13d,%rax
  mov    0x50(%rsp,%rax,8),%rdx
  mov    %ebp,%eax
  sub    %r13d,%eax
  mov    %ebx,%r13d
  cltq
  mov    0x50(%rsp,%rax,8),%rdi
L160:
  mov    %r13d,%ebx
  mov    %r12d,%r9d
  mov    %r12d,%r8d
  mov    %r12d,%ecx
  mov    %rdi,%rsi
  add    $0x1,%r15d
  xor    $0x1,%ebx
  call   <matby@plt>
  cmp    %r15d,%r14d
  jne    L51
  cmp    $0x1,%r13d
  je     L110
L98:
  mov    0x10(%rsp),%rdi
  call   <free@plt>
  mov    0x68(%rsp),%rax
  sub    %fs:0x28,%rax
  jne    L155
  add    $0x78,%rsp
  xor    %eax,%eax
  pop    %rbx
  pop    %rbp
  pop    %r12
  pop    %r13
  pop    %r14
  pop    %r15
  ret
L67:
  lea    D27(%rip),%rdi
  call   <error@plt>
  jmp    L181
L110:
  mov    0x48(%rsp),%edx
  mov    0x10(%rsp),%rsi
  mov    0x18(%rsp),%rdi
  shl    $0x3,%edx
  call   <memcpy@plt>
  jmp    L98
L41:
  movsd  D9(%rip),%xmm1
  mov    0x48(%rsp),%ecx
  xor    %eax,%eax
  mov    0x10(%rsp),%rdx
  mov    0x18(%rsp),%rsi
  nopl   (%rax)
L92:
  movsd  (%rsi,%rax,8),%xmm0
  mulsd  %xmm1,%xmm0
  addsd  (%rdx,%rax,8),%xmm0
  movsd  %xmm0,(%rdx,%rax,8)
  add    $0x1,%rax
  cmp    %eax,%ecx
  jg     L92
  jmp    L3
L176:
  mov    0x18(%rsp),%rdx
  mov    %rax,%rsi
  mov    %r12d,%r9d
  mov    %r12d,%r8d
  mov    %r12d,%ecx
  mov    %rax,%rdi
  call   <matby@plt>
  mov    0x48(%rsp),%eax
  test   %eax,%eax
  jne    L12
  jmp    L166
L155:
  call   <__stack_chk_fail@plt>
```

tool_calls: name: unpack_data
arguments: label: D9
data_type: byte[16]
name: unpack_data
arguments: label: D30
data_type: byte[8]
name: unpack_data
arguments: label: D27
data_type: string

tool: {"D9": [0x00,0x00,0x00,0x00,0x00,0x00,0xe0,0x3f,0x00,0x00,0x00,0x00,0x00,0x00,0xe0,0x3f]}

tool: {"D30": [0x00,0x00,0x00,0x00,0x00,0x00,0xf0,0x3f]}

tool: D27: TimeSquare not good

assistant: ```c
int matexp(double **Q, double *P, double t, int n, int TimeSquare) {
  int it, i, j;
  double *T[2];
  if (TimeSquare < 2 || TimeSquare > 31)
    error("TimeSquare not good");
  T[0] = dvector(n * n);
  T[1] = P;
  for (i = 0; i < n; i++) {
    for (j = 0; j < n; j++) {
      T[0][i * n + j] = ldexp(Q[i][j] * t, -TimeSquare);
    }
  }
  matby(T[0], T[0], T[1], n, n, n);
  for (i = 0; i < n * n; i++) {
    T[0][i] += T[1][i] / 2;
  }
  for (i = 0; i < n; i++) {
    T[0][i * n + i]++;
  }
  for (i = 0, it = 0; i < TimeSquare; i++) {
    it = !it;
    matby(T[1 - it], T[1 - it], T[it], n, n, n);
  }
  if (it == 0) {
    memcpy(P, T[0], n * n * sizeof(double));
  }
  free(T[0]);
  return (0);
}
```