user: Demonstrate the C code that generates the assembly output below:

```asm
<effective_transpose>:
  endbr64
  push   %r15
  mov    %edx,%eax
  push   %r14
  sub    $0xf,%eax
  push   %r13
  push   %r12
  push   %rbp
  push   %rbx
  sub    $0x30,%rsp
  mov    %rdi,-0x10(%rsp)
  mov    %rsi,-0x20(%rsp)
  mov    %edx,-0x30(%rsp)
  mov    %eax,-0x2c(%rsp)
  test   %eax,%eax
  jle    L77
  movq   $0x0,-0x18(%rsp)
  mov    -0x30(%rsp),%ebx
  mov    %rdi,%rcx
  movq   $0x0,0x10(%rsp)
  mov    %ebx,%eax
  shl    $0x4,%eax
  movslq %eax,%rdx
  lea    0x0(,%rbx,4),%eax
  cltq
  add    %rdx,%rcx
  mov    %rdx,0x8(%rsp)
  mov    %rax,0x18(%rsp)
  movslq %ebx,%rax
  mov    %rax,%rbx
  mov    %rcx,-0x38(%rsp)
  shl    $0x5,%rbx
  mov    %rax,-0x8(%rsp)
  neg    %rax
  add    %rbx,%rcx
  mov    %rbx,0x20(%rsp)
  lea    0x0(,%rdx,4),%rbx
  lea    0x0(,%rax,4),%r15
  mov    %rbx,-0x28(%rsp)
  mov    %rax,%rbx
  mov    %r15,%r14
  shl    $0x4,%rbx
  mov    %rcx,(%rsp)
  mov    %rbx,0x28(%rsp)
L100:
  mov    -0x20(%rsp),%rax
  mov    0x10(%rsp),%rbx
  mov    %r14,-0x48(%rsp)
  mov    -0x38(%rsp),%rdx
  mov    (%rsp),%r13
  movl   $0x0,-0x3c(%rsp)
  lea    (%rax,%rbx,4),%rcx
  mov    0x28(%rsp),%rax
  mov    0x18(%rsp),%r11
  mov    %rax,%rbp
  add    %rdx,%r11
  add    %r13,%rax
  add    %rdx,%rbp
  mov    %rax,%r9
  mov    %r11,%r15
  mov    %r13,%rdx
  mov    %rbp,%rbx
  sub    %r14,%r15
  sub    %r14,%r9
  sub    %r14,%rdx
  sub    %r14,%rbx
  mov    %r9,%r8
  mov    %rdx,%rsi
  mov    %rax,%r10
  mov    %rbx,%r12
  sub    %r14,%r8
  sub    %r14,%rsi
  sub    %r14,%r12
  mov    %r8,%rax
  mov    %r12,%rdi
  sub    %r14,%rax
  sub    %r14,%rdi
  mov    %rax,-0x68(%rsp)
  mov    %rsi,%rax
  mov    %rdi,-0x50(%rsp)
  mov    %r15,%rdi
  sub    %r14,%rax
  sub    %r14,%rdi
  mov    %rax,%r14
  mov    %rdi,-0x60(%rsp)
  mov    %rdx,%rdi
  mov    -0x38(%rsp),%rdx
  mov    %rdx,-0x58(%rsp)
L40:
  mov    %rsi,-0x78(%rsp)
  xor    %eax,%eax
  xor    %edx,%edx
  mov    %rdi,-0x70(%rsp)
  nopl   0x0(%rax,%rax,1)
L35:
  mov    (%rcx,%rdx,1),%esi
  mov    %esi,0x0(%rbp,%rax,1)
  mov    0x4(%rcx,%rdx,1),%esi
  mov    %esi,(%rbx,%rax,1)
  mov    0x8(%rcx,%rdx,1),%esi
  mov    %esi,(%r12,%rax,1)
  mov    -0x50(%rsp),%rsi
  mov    0xc(%rcx,%rdx,1),%edi
  mov    %edi,(%rsi,%rax,1)
  mov    -0x58(%rsp),%rdi
  mov    0x10(%rcx,%rdx,1),%esi
  mov    %esi,(%rdi,%rax,1)
  mov    0x14(%rcx,%rdx,1),%edi
  mov    %edi,(%r11,%rax,1)
  mov    0x18(%rcx,%rdx,1),%edi
  mov    %edi,(%r15,%rax,1)
  mov    -0x60(%rsp),%rdi
  mov    0x1c(%rcx,%rdx,1),%esi
  mov    %esi,(%rdi,%rax,1)
  mov    0x20(%rcx,%rdx,1),%edi
  mov    %edi,(%r10,%rax,1)
  mov    0x24(%rcx,%rdx,1),%edi
  mov    %edi,(%r9,%rax,1)
  mov    0x28(%rcx,%rdx,1),%esi
  mov    -0x68(%rsp),%rdi
  mov    %esi,(%r8,%rax,1)
  mov    0x2c(%rcx,%rdx,1),%esi
  mov    %esi,(%rdi,%rax,1)
  mov    0x30(%rcx,%rdx,1),%edi
  mov    %edi,0x0(%r13,%rax,1)
  mov    -0x70(%rsp),%rdi
  mov    0x34(%rcx,%rdx,1),%esi
  mov    %esi,(%rdi,%rax,1)
  mov    0x38(%rcx,%rdx,1),%edi
  mov    -0x78(%rsp),%rsi
  mov    %edi,(%rsi,%rax,1)
  mov    0x3c(%rcx,%rdx,1),%esi
  sub    -0x48(%rsp),%rdx
  mov    %esi,(%r14,%rax,1)
  add    $0x4,%rax
  cmp    $0x40,%rax
  jne    L35
  mov    -0x28(%rsp),%rax
  mov    -0x78(%rsp),%rsi
  add    $0x40,%rcx
  mov    -0x70(%rsp),%rdi
  addl   $0x10,-0x3c(%rsp)
  add    %rax,-0x50(%rsp)
  mov    -0x3c(%rsp),%edx
  add    %rax,%rbp
  add    %rax,%rbx
  add    %rax,-0x58(%rsp)
  add    %rax,%r12
  add    %rax,%r11
  add    %rax,%r15
  add    %rax,-0x60(%rsp)
  add    %rax,%r10
  add    %rax,%r9
  add    %rax,%r8
  add    %rax,-0x68(%rsp)
  add    %rax,%r13
  add    %rax,%rdi
  add    %rax,%rsi
  add    %rax,%r14
  cmp    -0x2c(%rsp),%edx
  jl     L40
  addq   $0x10,-0x18(%rsp)
  mov    0x8(%rsp),%rbx
  addq   $0x40,-0x38(%rsp)
  mov    -0x48(%rsp),%r14
  add    %rbx,0x10(%rsp)
  mov    -0x18(%rsp),%rax
  addq   $0x40,(%rsp)
  cmp    %eax,-0x2c(%rsp)
  jg     L100
  mov    -0x30(%rsp),%ebx
  mov    %r14,%r15
  lea    -0x10(%rbx),%eax
  and    $0xfffffff0,%eax
  lea    0x10(%rax),%esi
  cmp    %esi,%ebx
  jle    L84
  mov    -0x8(%rsp),%r11
  movslq %esi,%r10
  mov    -0x10(%rsp),%rcx
  imul   %esi,%ebx
  mov    %esi,-0x70(%rsp)
  mov    %esi,%r12d
  lea    (%r10,%r11,1),%rax
  lea    (%r11,%r11,2),%rdi
  mov    %r10,-0x68(%rsp)
  mov    -0x28(%rsp),%r10
  lea    (%rcx,%rax,4),%rbp
  lea    -0x1(%rsi),%eax
  mov    0x8(%rsp),%rsi
  movslq %ebx,%rbx
  shr    $0x4,%eax
  lea    (%r11,%r11,4),%r8
  lea    0x0(,%rdi,4),%r9
  shl    $0x3,%rdi
  shl    $0x4,%rax
  shl    $0x2,%r8
  mov    %rax,%r14
  mov    -0x20(%rsp),%rax
  lea    0x40(%rax),%r13
L122:
  mov    -0x20(%rsp),%rax
  mov    0x20(%rsp),%rcx
  lea    (%rbx,%r14,1),%rdx
  mov    %rbx,-0x60(%rsp)
  lea    0x0(%r13,%rdx,4),%rdx
  mov    %rdx,-0x78(%rsp)
  lea    (%rax,%rbx,4),%rax
  add    %rbp,%rcx
  mov    %rbp,%rdx
L50:
  mov    (%rax),%ebx
  add    $0x40,%rax
  mov    %ebx,(%rdx,%r15,1)
  mov    -0x3c(%rax),%ebx
  mov    %ebx,(%rdx)
  mov    -0x38(%rax),%ebx
  mov    %ebx,(%rdx,%r11,4)
  mov    -0x34(%rax),%ebx
  mov    %ebx,(%rdx,%r11,8)
  mov    -0x30(%rax),%ebx
  mov    %ebx,(%rdx,%r9,1)
  mov    -0x2c(%rax),%ebx
  mov    %ebx,(%rdx,%rsi,1)
  mov    -0x28(%rax),%ebx
  mov    %ebx,(%rdx,%r8,1)
  mov    -0x24(%rax),%ebx
  mov    %ebx,(%rdx,%rdi,1)
  mov    -0x20(%rax),%ebx
  add    %r10,%rdx
  mov    %ebx,(%rcx,%r15,1)
  mov    -0x1c(%rax),%ebx
  mov    %ebx,(%rcx)
  mov    -0x18(%rax),%ebx
  mov    %ebx,(%rcx,%r11,4)
  mov    -0x14(%rax),%ebx
  mov    %ebx,(%rcx,%r11,8)
  mov    -0x10(%rax),%ebx
  mov    %ebx,(%rcx,%r9,1)
  mov    -0xc(%rax),%ebx
  mov    %ebx,(%rcx,%rsi,1)
  mov    -0x8(%rax),%ebx
  mov    %ebx,(%rcx,%r8,1)
  mov    -0x4(%rax),%ebx
  mov    %ebx,(%rcx,%rdi,1)
  add    %r10,%rcx
  cmp    %rax,-0x78(%rsp)
  jne    L50
  mov    -0x60(%rsp),%rbx
  add    $0x1,%r12d
  add    $0x4,%rbp
  add    %r11,%rbx
  cmp    %r12d,-0x30(%rsp)
  jne    L122
  mov    -0x70(%rsp),%esi
  mov    -0x68(%rsp),%r10
L70:
  mov    -0x30(%rsp),%ebx
  mov    -0x10(%rsp),%rdx
  xor    %r8d,%r8d
  mov    -0x20(%rsp),%rcx
  mov    -0x8(%rsp),%rdi
  mov    %ebx,%eax
  imul   %esi,%eax
  lea    (%rcx,%r10,4),%r9
  shl    $0x2,%rdi
  cltq
  lea    (%rdx,%rax,4),%r11
  lea    -0x1(%rbx),%eax
  sub    %esi,%eax
  add    %r10,%rax
  lea    0x4(%rcx,%rax,4),%rcx
L99:
  mov    %r11,%rdx
  mov    %r9,%rax
L102:
  mov    (%rax),%esi
  add    $0x4,%rax
  mov    %esi,(%rdx)
  add    %rdi,%rdx
  cmp    %rcx,%rax
  jne    L102
  add    $0x1,%r8d
  add    %rdi,%r9
  add    $0x4,%r11
  add    %rdi,%rcx
  cmp    %r8d,-0x30(%rsp)
  jne    L99
L19:
  add    $0x30,%rsp
  pop    %rbx
  pop    %rbp
  pop    %r12
  pop    %r13
  pop    %r14
  pop    %r15
  ret
L77:
  movslq %edx,%rbx
  xor    %esi,%esi
  xor    %r10d,%r10d
  mov    %rbx,-0x8(%rsp)
  test   %ebx,%ebx
  jg     L70
  jmp    L19
L84:
  mov    -0x30(%rsp),%eax
  test   %eax,%eax
  jle    L19
  cmp    %esi,-0x30(%rsp)
  jle    L19
  movslq %esi,%r10
  jmp    L70
```

assistant: ```c
void effective_transpose(int *dst, int *src, int N) {
  int i, j, a, b;
  for (i = 0; i <= N - 16; i += 16)
    for (j = 0; j <= N - 16; j += 16)
      for (a = i; a < i + 16; a++)
        for (b = j; b < j + 16; b++)
          dst[b * N + a] = src[a * N + b];
  int offset = i;
  for (i = offset; i <= N - 1; i++)
    for (j = 0; j < offset; j += 16)
      for (b = j; b < j + 16; b++)
        dst[b * N + i] = src[i * N + b];
  for (i = 0; i <= N - 1; i++)
    for (j = offset; j <= N - 1; j++)
      dst[j * N + i] = src[i * N + j];
}
```