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

```asm
<testLU>:
  endbr64
  push   %r13
  push   %r12
  push   %rbp
  push   %rbx
  sub    $0x48,%rsp
  mov    %fs:0x28,%rax
  mov    %rax,0x38(%rsp)
  xor    %eax,%eax
  mov    %rsp,%rdx
  mov    $0x2,%esi
  mov    $0x2,%edi
  call   <zeros@plt>
  mov    D56(%rip),%rbp
  mov    (%rsp),%rax
  mov    %rbp,(%rax)
  mov    (%rsp),%rax
  mov    D47(%rip),%rbx
  mov    %rbx,0x8(%rax)
  mov    D58(%rip),%rcx
  mov    %rcx,0x10(%rax)
  mov    D79(%rip),%rcx
  mov    %rcx,0x18(%rax)
  lea    0x8(%rsp),%rdx
  mov    $0x1,%esi
  mov    $0x2,%edi
  call   <zeros@plt>
  mov    0x8(%rsp),%rax
  mov    %rbp,(%rax)
  mov    0x8(%rsp),%rax
  mov    %rbx,0x8(%rax)
  lea    0x10(%rsp),%r12
  mov    %r12,%rdx
  mov    $0x2,%esi
  mov    $0x2,%edi
  call   <zeros@plt>
  lea    0x18(%rsp),%r13
  mov    %r13,%rdx
  mov    $0x2,%esi
  mov    $0x2,%edi
  call   <zeros@plt>
  lea    0x20(%rsp),%rbp
  mov    %rbp,%rdx
  mov    $0x1,%esi
  mov    $0x2,%edi
  call   <zeros@plt>
  lea    0x28(%rsp),%rbx
  mov    %rbx,%rdx
  mov    $0x1,%esi
  mov    $0x2,%edi
  call   <zeros@plt>
  lea    D54(%rip),%rdi
  call   <printf@plt>
  mov    $0x2,%edx
  mov    $0x2,%esi
  mov    (%rsp),%rdi
  call   <print@plt>
  lea    D26(%rip),%rdi
  call   <printf@plt>
  mov    $0x1,%edx
  mov    $0x2,%esi
  mov    0x8(%rsp),%rdi
  call   <print@plt>
  mov    %r13,%rcx
  mov    %r12,%rdx
  mov    $0x2,%esi
  mov    (%rsp),%rdi
  call   <LUDecomposition@plt>
  lea    D5(%rip),%rdi
  call   <printf@plt>
  mov    $0x2,%edx
  mov    $0x2,%esi
  mov    0x10(%rsp),%rdi
  call   <print@plt>
  lea    D15(%rip),%rdi
  call   <printf@plt>
  mov    $0x2,%edx
  mov    $0x2,%esi
  mov    0x18(%rsp),%rdi
  call   <print@plt>
  mov    $0x1,%r8d
  mov    %rbp,%rcx
  mov    $0x2,%edx
  mov    0x8(%rsp),%rsi
  mov    0x10(%rsp),%rdi
  call   <BackSubstitution@plt>
  mov    $0x0,%r8d
  mov    %rbx,%rcx
  mov    $0x2,%edx
  mov    0x20(%rsp),%rsi
  mov    0x18(%rsp),%rdi
  call   <BackSubstitution@plt>
  lea    D73(%rip),%rdi
  call   <printf@plt>
  mov    $0x1,%edx
  mov    $0x2,%esi
  mov    0x28(%rsp),%rdi
  call   <print@plt>
  lea    0x30(%rsp),%rbx
  mov    %rbx,%rdx
  mov    $0x1,%esi
  mov    $0x2,%edi
  call   <zeros@plt>
  sub    $0x8,%rsp
  push   %rbx
  mov    $0x1,%r9d
  mov    $0x2,%r8d
  mov    $0x2,%ecx
  mov    $0x2,%edx
  mov    0x38(%rsp),%rsi
  mov    0x10(%rsp),%rdi
  call   <mult@plt>
  mov    $0x1,%edx
  mov    $0x2,%esi
  mov    0x40(%rsp),%rdi
  call   <print@plt>
  add    $0x10,%rsp
  mov    0x38(%rsp),%rax
  sub    %fs:0x28,%rax
  jne    L9
  add    $0x48,%rsp
  pop    %rbx
  pop    %rbp
  pop    %r12
  pop    %r13
  ret
L9:
  call   <__stack_chk_fail@plt>
```

tool_calls: name: retrieve_data
arguments: tag: D56
type_guessed: byte[8]
name: retrieve_data
arguments: tag: D47
type_guessed: byte[8]
name: retrieve_data
arguments: tag: D58
type_guessed: byte[8]
name: retrieve_data
arguments: tag: D79
type_guessed: byte[8]
name: retrieve_data
arguments: tag: D54
type_guessed: string
name: retrieve_data
arguments: tag: D26
type_guessed: string
name: retrieve_data
arguments: tag: D5
type_guessed: string
name: retrieve_data
arguments: tag: D15
type_guessed: string
name: retrieve_data
arguments: tag: D73
type_guessed: string

tool: {"D56": [0x00,0x00,0x00,0x00,0x00,0x00,0xf0,0x3f]}

tool: {"D47": [0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x40]}

tool: {"D58": [0x00,0x00,0x00,0x00,0x00,0x00,0x08,0x40]}

tool: {"D79": [0x00,0x00,0x00,0x00,0x00,0x00,0x10,0x40]}

tool: D54: A


tool: D26: B


tool: D5: L


tool: D15: U


tool: D73: x


assistant: ```c
void testLU() {
  double *mat;
  zeros(2, 2, &mat);
  mat[0] = 1;
  mat[1] = 2;
  mat[1 * 2] = 3;
  mat[1 * 2 + 1] = 4;
  double *b;
  zeros(2, 1, &b);
  b[0] = 1;
  b[1] = 2;
  double *L, *U, *z, *x;
  zeros(2, 2, &L);
  zeros(2, 2, &U);
  zeros(2, 1, &z);
  zeros(2, 1, &x);
  printf("A\n");
  print(mat, 2, 2);
  printf("B\n");
  print(b, 2, 1);
  LUDecomposition(mat, 2, &L, &U);
  printf("L\n");
  print(L, 2, 2);
  printf("U\n");
  print(U, 2, 2);
  BackSubstitution(L, b, 2, &z, 1);
  BackSubstitution(U, z, 2, &x, 0);
  printf("x\n");
  print(x, 2, 1);
  double *bstar;
  zeros(2, 1, &bstar);
  mult(mat, x, 2, 2, 2, 1, &bstar);
  print(bstar, 2, 1);
}
```