user: What is the c source code of the assembly code below:

```asm
<bitrv2>:
  endbr64
  push   %r15
  push   %r14
  push   %r13
  push   %r12
  push   %rbp
  push   %rbx
  mov    %rsi,-0x28(%rsp)
  mov    %rdx,%rax
  mov    %edi,%edx
  sar    $0x2,%edx
  cmp    $0x23,%edi
  jle    L149
  mov    $0x1,%r8d
L84:
  add    %r8d,%r8d
  sar    $0x2,%edx
  cmp    $0x8,%edx
  jg     L84
  sar    %edi
  mov    %edi,-0x30(%rsp)
  lea    0x0(,%r8,4),%ecx
  cmp    $0x8,%edx
  je     L16
L125:
  test   %r8d,%r8d
  jle    L147
  mov    %r8d,-0x14(%rsp)
  lea    0x0(,%r8,4),%edi
  mov    %edi,-0x20(%rsp)
  movslq %r8d,%r8
  mov    -0x28(%rsp),%rdi
  lea    (%rdi,%r8,4),%rbx
  mov    $0x4,%r8d
  mov    $0x1,%r11d
  mov    -0x30(%rsp),%edi
  mov    %rbx,-0x30(%rsp)
  jmp    L160
L16:
  test   %r8d,%r8d
  jle    L147
L27:
  lea    0x0(,%r8,8),%esi
  lea    -0x2(%rcx,%rcx,1),%edi
  mov    %edi,-0x14(%rsp)
  mov    %r8d,-0x4(%rsp)
  lea    (%r8,%r8,1),%edi
  mov    %edi,-0x10(%rsp)
  movslq %r8d,%r8
  mov    -0x28(%rsp),%rdi
  lea    (%rdi,%r8,4),%rdi
  mov    %rdi,-0x20(%rsp)
  mov    $0x2,%r9d
  mov    $0x1,%r15d
  mov    -0x30(%rsp),%edi
  lea    0x2(%rdi),%edx
  mov    %edx,-0xc(%rsp)
  sub    %ecx,%edi
  mov    %edi,-0x8(%rsp)
  jmp    L100
L154:
  mov    $0x1,%r8d
  mov    $0x4,%ecx
  jmp    L27
L92:
  mov    -0x4(%rsp),%edi
  lea    (%rdi,%r15,1),%edx
  movslq %edx,%rdx
  mov    -0x28(%rsp),%rdi
  lea    (%rdi,%rdx,4),%r11
  mov    %r9d,%r10d
  mov    -0x20(%rsp),%r8
  mov    $0x0,%edi
L158:
  mov    %edi,%ebp
  add    (%r11),%ebp
  add    %ebp,%ebp
  mov    %r10d,%edx
  add    (%r8),%edx
  add    %edx,%edx
  movslq %ebp,%rbx
  lea    (%rax,%rbx,8),%r14
  movsd  (%r14),%xmm1
  lea    0x8(%rax,%rbx,8),%r13
  movsd  0x0(%r13),%xmm0
  movslq %edx,%rbx
  lea    (%rax,%rbx,8),%r12
  movsd  (%r12),%xmm3
  lea    0x8(%rax,%rbx,8),%rbx
  movsd  (%rbx),%xmm2
  movsd  %xmm3,(%r14)
  movsd  %xmm2,0x0(%r13)
  movsd  %xmm1,(%r12)
  movsd  %xmm0,(%rbx)
  add    %ecx,%ebp
  add    %esi,%edx
  movslq %ebp,%rbx
  shl    $0x3,%rbx
  lea    (%rax,%rbx,1),%r14
  movsd  (%r14),%xmm1
  lea    0x8(%rax,%rbx,1),%r13
  movsd  0x0(%r13),%xmm0
  movslq %edx,%rbx
  shl    $0x3,%rbx
  lea    (%rax,%rbx,1),%r12
  movsd  (%r12),%xmm3
  lea    0x8(%rax,%rbx,1),%rbx
  movsd  (%rbx),%xmm2
  movsd  %xmm3,(%r14)
  movsd  %xmm2,0x0(%r13)
  movsd  %xmm1,(%r12)
  movsd  %xmm0,(%rbx)
  add    %ecx,%ebp
  sub    %ecx,%edx
  movslq %ebp,%rbx
  shl    $0x3,%rbx
  lea    (%rax,%rbx,1),%r14
  movsd  (%r14),%xmm1
  lea    0x8(%rax,%rbx,1),%r13
  movsd  0x0(%r13),%xmm0
  movslq %edx,%rbx
  shl    $0x3,%rbx
  lea    (%rax,%rbx,1),%r12
  movsd  (%r12),%xmm3
  lea    0x8(%rax,%rbx,1),%rbx
  movsd  (%rbx),%xmm2
  movsd  %xmm3,(%r14)
  movsd  %xmm2,0x0(%r13)
  movsd  %xmm1,(%r12)
  movsd  %xmm0,(%rbx)
  add    %ecx,%ebp
  add    %esi,%edx
  movslq %ebp,%rbx
  shl    $0x3,%rbx
  lea    (%rax,%rbx,1),%r14
  movsd  (%r14),%xmm1
  lea    0x8(%rax,%rbx,1),%r13
  movsd  0x0(%r13),%xmm0
  movslq %edx,%rbx
  shl    $0x3,%rbx
  lea    (%rax,%rbx,1),%r12
  movsd  (%r12),%xmm3
  lea    0x8(%rax,%rbx,1),%rbx
  movsd  (%rbx),%xmm2
  movsd  %xmm3,(%r14)
  movsd  %xmm2,0x0(%r13)
  movsd  %xmm1,(%r12)
  movsd  %xmm0,(%rbx)
  add    -0x30(%rsp),%ebp
  add    $0x2,%edx
  movslq %ebp,%rbx
  shl    $0x3,%rbx
  lea    (%rax,%rbx,1),%r14
  movsd  (%r14),%xmm1
  lea    0x8(%rax,%rbx,1),%r13
  movsd  0x0(%r13),%xmm0
  movslq %edx,%rbx
  shl    $0x3,%rbx
  lea    (%rax,%rbx,1),%r12
  movsd  (%r12),%xmm3
  lea    0x8(%rax,%rbx,1),%rbx
  movsd  (%rbx),%xmm2
  movsd  %xmm3,(%r14)
  movsd  %xmm2,0x0(%r13)
  movsd  %xmm1,(%r12)
  movsd  %xmm0,(%rbx)
  sub    %ecx,%ebp
  sub    %esi,%edx
  movslq %ebp,%rbx
  shl    $0x3,%rbx
  lea    (%rax,%rbx,1),%r14
  movsd  (%r14),%xmm1
  lea    0x8(%rax,%rbx,1),%r13
  movsd  0x0(%r13),%xmm0
  movslq %edx,%rbx
  shl    $0x3,%rbx
  lea    (%rax,%rbx,1),%r12
  movsd  (%r12),%xmm3
  lea    0x8(%rax,%rbx,1),%rbx
  movsd  (%rbx),%xmm2
  movsd  %xmm3,(%r14)
  movsd  %xmm2,0x0(%r13)
  movsd  %xmm1,(%r12)
  movsd  %xmm0,(%rbx)
  sub    %ecx,%ebp
  add    %ecx,%edx
  movslq %ebp,%rbx
  shl    $0x3,%rbx
  lea    (%rax,%rbx,1),%r14
  movsd  (%r14),%xmm1
  lea    0x8(%rax,%rbx,1),%r13
  movsd  0x0(%r13),%xmm0
  movslq %edx,%rbx
  shl    $0x3,%rbx
  lea    (%rax,%rbx,1),%r12
  movsd  (%r12),%xmm3
  lea    0x8(%rax,%rbx,1),%rbx
  movsd  (%rbx),%xmm2
  movsd  %xmm3,(%r14)
  movsd  %xmm2,0x0(%r13)
  movsd  %xmm1,(%r12)
  movsd  %xmm0,(%rbx)
  sub    %ecx,%ebp
  sub    %esi,%edx
  movslq %ebp,%rbx
  shl    $0x3,%rbx
  lea    (%rax,%rbx,1),%r14
  movsd  (%r14),%xmm1
  lea    0x8(%rax,%rbx,1),%r13
  movsd  0x0(%r13),%xmm0
  movslq %edx,%rbx
  shl    $0x3,%rbx
  lea    (%rax,%rbx,1),%r12
  movsd  (%r12),%xmm3
  lea    0x8(%rax,%rbx,1),%rbx
  movsd  (%rbx),%xmm2
  movsd  %xmm3,(%r14)
  movsd  %xmm2,0x0(%r13)
  movsd  %xmm1,(%r12)
  movsd  %xmm0,(%rbx)
  add    $0x2,%ebp
  add    -0x30(%rsp),%edx
  movslq %ebp,%rbx
  shl    $0x3,%rbx
  lea    (%rax,%rbx,1),%r14
  movsd  (%r14),%xmm1
  lea    0x8(%rax,%rbx,1),%r13
  movsd  0x0(%r13),%xmm0
  movslq %edx,%rbx
  shl    $0x3,%rbx
  lea    (%rax,%rbx,1),%r12
  movsd  (%r12),%xmm3
  lea    0x8(%rax,%rbx,1),%rbx
  movsd  (%rbx),%xmm2
  movsd  %xmm3,(%r14)
  movsd  %xmm2,0x0(%r13)
  movsd  %xmm1,(%r12)
  movsd  %xmm0,(%rbx)
  add    %ecx,%ebp
  add    %esi,%edx
  movslq %ebp,%rbx
  shl    $0x3,%rbx
  lea    (%rax,%rbx,1),%r14
  movsd  (%r14),%xmm1
  lea    0x8(%rax,%rbx,1),%r13
  movsd  0x0(%r13),%xmm0
  movslq %edx,%rbx
  shl    $0x3,%rbx
  lea    (%rax,%rbx,1),%r12
  movsd  (%r12),%xmm3
  lea    0x8(%rax,%rbx,1),%rbx
  movsd  (%rbx),%xmm2
  movsd  %xmm3,(%r14)
  movsd  %xmm2,0x0(%r13)
  movsd  %xmm1,(%r12)
  movsd  %xmm0,(%rbx)
  add    %ecx,%ebp
  sub    %ecx,%edx
  movslq %ebp,%rbx
  shl    $0x3,%rbx
  lea    (%rax,%rbx,1),%r14
  movsd  (%r14),%xmm1
  lea    0x8(%rax,%rbx,1),%r13
  movsd  0x0(%r13),%xmm0
  movslq %edx,%rbx
  shl    $0x3,%rbx
  lea    (%rax,%rbx,1),%r12
  movsd  (%r12),%xmm3
  lea    0x8(%rax,%rbx,1),%rbx
  movsd  (%rbx),%xmm2
  movsd  %xmm3,(%r14)
  movsd  %xmm2,0x0(%r13)
  movsd  %xmm1,(%r12)
  movsd  %xmm0,(%rbx)
  add    %ecx,%ebp
  add    %esi,%edx
  movslq %ebp,%rbx
  shl    $0x3,%rbx
  lea    (%rax,%rbx,1),%r14
  movsd  (%r14),%xmm1
  lea    0x8(%rax,%rbx,1),%r13
  movsd  0x0(%r13),%xmm0
  movslq %edx,%rbx
  shl    $0x3,%rbx
  lea    (%rax,%rbx,1),%r12
  movsd  (%r12),%xmm3
  lea    0x8(%rax,%rbx,1),%rbx
  movsd  (%rbx),%xmm2
  movsd  %xmm3,(%r14)
  movsd  %xmm2,0x0(%r13)
  movsd  %xmm1,(%r12)
  movsd  %xmm0,(%rbx)
  sub    -0x30(%rsp),%ebp
  sub    $0x2,%edx
  movslq %ebp,%rbx
  shl    $0x3,%rbx
  lea    (%rax,%rbx,1),%r14
  movsd  (%r14),%xmm1
  lea    0x8(%rax,%rbx,1),%r13
  movsd  0x0(%r13),%xmm0
  movslq %edx,%rbx
  shl    $0x3,%rbx
  lea    (%rax,%rbx,1),%r12
  movsd  (%r12),%xmm3
  lea    0x8(%rax,%rbx,1),%rbx
  movsd  (%rbx),%xmm2
  movsd  %xmm3,(%r14)
  movsd  %xmm2,0x0(%r13)
  movsd  %xmm1,(%r12)
  movsd  %xmm0,(%rbx)
  sub    %ecx,%ebp
  sub    %esi,%edx
  movslq %ebp,%rbx
  shl    $0x3,%rbx
  lea    (%rax,%rbx,1),%r14
  movsd  (%r14),%xmm1
  lea    0x8(%rax,%rbx,1),%r13
  movsd  0x0(%r13),%xmm0
  movslq %edx,%rbx
  shl    $0x3,%rbx
  lea    (%rax,%rbx,1),%r12
  movsd  (%r12),%xmm3
  lea    0x8(%rax,%rbx,1),%rbx
  movsd  (%rbx),%xmm2
  movsd  %xmm3,(%r14)
  movsd  %xmm2,0x0(%r13)
  movsd  %xmm1,(%r12)
  movsd  %xmm0,(%rbx)
  sub    %ecx,%ebp
  add    %ecx,%edx
  movslq %ebp,%rbx
  shl    $0x3,%rbx
  lea    (%rax,%rbx,1),%r14
  movsd  (%r14),%xmm1
  lea    0x8(%rax,%rbx,1),%r13
  movsd  0x0(%r13),%xmm0
  movslq %edx,%rbx
  shl    $0x3,%rbx
  lea    (%rax,%rbx,1),%r12
  movsd  (%r12),%xmm3
  lea    0x8(%rax,%rbx,1),%rbx
  movsd  (%rbx),%xmm2
  movsd  %xmm3,(%r14)
  movsd  %xmm2,0x0(%r13)
  movsd  %xmm1,(%r12)
  movsd  %xmm0,(%rbx)
  sub    %ecx,%ebp
  movslq %ebp,%rbp
  shl    $0x3,%rbp
  lea    (%rax,%rbp,1),%rbx
  movsd  (%rbx),%xmm1
  lea    0x8(%rax,%rbp,1),%rbp
  movsd  0x0(%rbp),%xmm0
  sub    %esi,%edx
  movslq %edx,%rdx
  shl    $0x3,%rdx
  lea    (%rax,%rdx,1),%r12
  movsd  (%r12),%xmm3
  lea    0x8(%rax,%rdx,1),%rdx
  movsd  (%rdx),%xmm2
  movsd  %xmm3,(%rbx)
  movsd  %xmm2,0x0(%rbp)
  movsd  %xmm1,(%r12)
  movsd  %xmm0,(%rdx)
  add    $0x2,%edi
  add    $0x4,%r8
  cmp    %edi,%r9d
  jne    L158
L122:
  add    $0x1,%r15
  add    $0x2,%r9d
L100:
  mov    -0x20(%rsp),%rdi
  mov    -0x4(%rdi,%r15,4),%edx
  lea    -0x2(%r9,%rdx,1),%edx
  add    %edx,%edx
  lea    0x2(%rdx),%edi
  mov    -0x30(%rsp),%r14d
  add    %r14d,%edx
  movslq %edi,%r8
  lea    (%rax,%r8,8),%rbx
  movsd  (%rbx),%xmm1
  lea    0x8(%rax,%r8,8),%r11
  movsd  (%r11),%xmm0
  movslq %edx,%r8
  shl    $0x3,%r8
  lea    (%rax,%r8,1),%r10
  movsd  (%r10),%xmm3
  lea    0x8(%rax,%r8,1),%r8
  movsd  (%r8),%xmm2
  movsd  %xmm3,(%rbx)
  movsd  %xmm2,(%r11)
  movsd  %xmm1,(%r10)
  movsd  %xmm0,(%r8)
  add    %ecx,%edi
  add    %esi,%edx
  movslq %edi,%r8
  shl    $0x3,%r8
  lea    (%rax,%r8,1),%rbx
  movsd  (%rbx),%xmm1
  lea    0x8(%rax,%r8,1),%r11
  movsd  (%r11),%xmm0
  movslq %edx,%r8
  shl    $0x3,%r8
  lea    (%rax,%r8,1),%r10
  movsd  (%r10),%xmm3
  lea    0x8(%rax,%r8,1),%r8
  movsd  (%r8),%xmm2
  movsd  %xmm3,(%rbx)
  movsd  %xmm2,(%r11)
  movsd  %xmm1,(%r10)
  movsd  %xmm0,(%r8)
  add    %ecx,%edi
  sub    %ecx,%edx
  movslq %edi,%r8
  shl    $0x3,%r8
  lea    (%rax,%r8,1),%rbx
  movsd  (%rbx),%xmm1
  lea    0x8(%rax,%r8,1),%r11
  movsd  (%r11),%xmm0
  movslq %edx,%r8
  shl    $0x3,%r8
  lea    (%rax,%r8,1),%r10
  movsd  (%r10),%xmm3
  lea    0x8(%rax,%r8,1),%r8
  movsd  (%r8),%xmm2
  movsd  %xmm3,(%rbx)
  movsd  %xmm2,(%r11)
  movsd  %xmm1,(%r10)
  movsd  %xmm0,(%r8)
  sub    $0x2,%edi
  movslq %edi,%r8
  shl    $0x3,%r8
  lea    (%rax,%r8,1),%rbx
  movsd  (%rbx),%xmm1
  lea    0x8(%rax,%r8,1),%r11
  movsd  (%r11),%xmm0
  mov    %edx,%r8d
  sub    %r14d,%r8d
  movslq %r8d,%r8
  shl    $0x3,%r8
  lea    (%rax,%r8,1),%r10
  movsd  (%r10),%xmm3
  lea    0x8(%rax,%r8,1),%r8
  movsd  (%r8),%xmm2
  movsd  %xmm3,(%rbx)
  movsd  %xmm2,(%r11)
  movsd  %xmm1,(%r10)
  movsd  %xmm0,(%r8)
  add    -0xc(%rsp),%edi
  add    $0x2,%edx
  movslq %edi,%r8
  shl    $0x3,%r8
  lea    (%rax,%r8,1),%rbx
  movsd  (%rbx),%xmm1
  lea    0x8(%rax,%r8,1),%r11
  movsd  (%r11),%xmm0
  movslq %edx,%r8
  shl    $0x3,%r8
  lea    (%rax,%r8,1),%r10
  movsd  (%r10),%xmm3
  lea    0x8(%rax,%r8,1),%r8
  movsd  (%r8),%xmm2
  movsd  %xmm3,(%rbx)
  movsd  %xmm2,(%r11)
  movsd  %xmm1,(%r10)
  movsd  %xmm0,(%r8)
  sub    -0x8(%rsp),%edi
  movslq %edi,%rdi
  shl    $0x3,%rdi
  lea    (%rax,%rdi,1),%r8
  movsd  (%r8),%xmm1
  lea    0x8(%rax,%rdi,1),%rdi
  movsd  (%rdi),%xmm0
  add    -0x14(%rsp),%edx
  movslq %edx,%rdx
  shl    $0x3,%rdx
  lea    (%rax,%rdx,1),%r10
  movsd  (%r10),%xmm3
  lea    0x8(%rax,%rdx,1),%rdx
  movsd  (%rdx),%xmm2
  movsd  %xmm3,(%r8)
  movsd  %xmm2,(%rdi)
  movsd  %xmm1,(%r10)
  movsd  %xmm0,(%rdx)
  cmp    -0x10(%rsp),%r9d
  je     L147
  test   %r15d,%r15d
  jg     L92
  jmp    L122
L109:
  mov    -0x14(%rsp),%esi
  lea    (%rsi,%r11,1),%edx
  movslq %edx,%rdx
  mov    -0x28(%rsp),%rsi
  lea    (%rsi,%rdx,4),%rbx
  mov    %r8d,%r10d
  mov    -0x30(%rsp),%r9
  mov    $0x0,%esi
L80:
  mov    %esi,%ebp
  add    (%rbx),%ebp
  mov    %r10d,%edx
  add    (%r9),%edx
  movslq %ebp,%r12
  shl    $0x3,%r12
  lea    (%rax,%r12,1),%r14
  movsd  (%r14),%xmm1
  lea    0x8(%rax,%r12,1),%r15
  movsd  (%r15),%xmm0
  movslq %edx,%r12
  shl    $0x3,%r12
  lea    (%rax,%r12,1),%r13
  movsd  0x0(%r13),%xmm3
  lea    0x8(%rax,%r12,1),%r12
  movsd  (%r12),%xmm2
  movsd  %xmm3,(%r14)
  movsd  %xmm2,(%r15)
  movsd  %xmm1,0x0(%r13)
  movsd  %xmm0,(%r12)
  add    %ecx,%ebp
  add    %ecx,%edx
  movslq %ebp,%r12
  shl    $0x3,%r12
  lea    (%rax,%r12,1),%r14
  movsd  (%r14),%xmm1
  lea    0x8(%rax,%r12,1),%r15
  movsd  (%r15),%xmm0
  movslq %edx,%r12
  shl    $0x3,%r12
  lea    (%rax,%r12,1),%r13
  movsd  0x0(%r13),%xmm3
  lea    0x8(%rax,%r12,1),%r12
  movsd  (%r12),%xmm2
  movsd  %xmm3,(%r14)
  movsd  %xmm2,(%r15)
  movsd  %xmm1,0x0(%r13)
  movsd  %xmm0,(%r12)
  add    %edi,%ebp
  add    $0x2,%edx
  movslq %ebp,%r12
  shl    $0x3,%r12
  lea    (%rax,%r12,1),%r14
  movsd  (%r14),%xmm1
  lea    0x8(%rax,%r12,1),%r15
  movsd  (%r15),%xmm0
  movslq %edx,%r12
  shl    $0x3,%r12
  lea    (%rax,%r12,1),%r13
  movsd  0x0(%r13),%xmm3
  lea    0x8(%rax,%r12,1),%r12
  movsd  (%r12),%xmm2
  movsd  %xmm3,(%r14)
  movsd  %xmm2,(%r15)
  movsd  %xmm1,0x0(%r13)
  movsd  %xmm0,(%r12)
  sub    %ecx,%ebp
  sub    %ecx,%edx
  movslq %ebp,%r12
  shl    $0x3,%r12
  lea    (%rax,%r12,1),%r14
  movsd  (%r14),%xmm1
  lea    0x8(%rax,%r12,1),%r15
  movsd  (%r15),%xmm0
  movslq %edx,%r12
  shl    $0x3,%r12
  lea    (%rax,%r12,1),%r13
  movsd  0x0(%r13),%xmm3
  lea    0x8(%rax,%r12,1),%r12
  movsd  (%r12),%xmm2
  movsd  %xmm3,(%r14)
  movsd  %xmm2,(%r15)
  movsd  %xmm1,0x0(%r13)
  movsd  %xmm0,(%r12)
  add    $0x2,%ebp
  add    %edi,%edx
  movslq %ebp,%r12
  shl    $0x3,%r12
  lea    (%rax,%r12,1),%r14
  movsd  (%r14),%xmm1
  lea    0x8(%rax,%r12,1),%r15
  movsd  (%r15),%xmm0
  movslq %edx,%r12
  shl    $0x3,%r12
  lea    (%rax,%r12,1),%r13
  movsd  0x0(%r13),%xmm3
  lea    0x8(%rax,%r12,1),%r12
  movsd  (%r12),%xmm2
  movsd  %xmm3,(%r14)
  movsd  %xmm2,(%r15)
  movsd  %xmm1,0x0(%r13)
  movsd  %xmm0,(%r12)
  add    %ecx,%ebp
  add    %ecx,%edx
  movslq %ebp,%r12
  shl    $0x3,%r12
  lea    (%rax,%r12,1),%r14
  movsd  (%r14),%xmm1
  lea    0x8(%rax,%r12,1),%r15
  movsd  (%r15),%xmm0
  movslq %edx,%r12
  shl    $0x3,%r12
  lea    (%rax,%r12,1),%r13
  movsd  0x0(%r13),%xmm3
  lea    0x8(%rax,%r12,1),%r12
  movsd  (%r12),%xmm2
  movsd  %xmm3,(%r14)
  movsd  %xmm2,(%r15)
  movsd  %xmm1,0x0(%r13)
  movsd  %xmm0,(%r12)
  sub    %edi,%ebp
  sub    $0x2,%edx
  movslq %ebp,%r12
  shl    $0x3,%r12
  lea    (%rax,%r12,1),%r14
  movsd  (%r14),%xmm1
  lea    0x8(%rax,%r12,1),%r15
  movsd  (%r15),%xmm0
  movslq %edx,%r12
  shl    $0x3,%r12
  lea    (%rax,%r12,1),%r13
  movsd  0x0(%r13),%xmm3
  lea    0x8(%rax,%r12,1),%r12
  movsd  (%r12),%xmm2
  movsd  %xmm3,(%r14)
  movsd  %xmm2,(%r15)
  movsd  %xmm1,0x0(%r13)
  movsd  %xmm0,(%r12)
  sub    %ecx,%ebp
  movslq %ebp,%rbp
  shl    $0x3,%rbp
  lea    (%rax,%rbp,1),%r12
  movsd  (%r12),%xmm1
  lea    0x8(%rax,%rbp,1),%rbp
  movsd  0x0(%rbp),%xmm0
  sub    %ecx,%edx
  movslq %edx,%rdx
  shl    $0x3,%rdx
  lea    (%rax,%rdx,1),%r13
  movsd  0x0(%r13),%xmm3
  lea    0x8(%rax,%rdx,1),%rdx
  movsd  (%rdx),%xmm2
  movsd  %xmm3,(%r12)
  movsd  %xmm2,0x0(%rbp)
  movsd  %xmm1,0x0(%r13)
  movsd  %xmm0,(%rdx)
  add    $0x4,%esi
  add    $0x4,%r9
  cmp    %r8d,%esi
  jne    L80
L64:
  add    $0x1,%r11
  add    $0x4,%r8d
L160:
  mov    -0x30(%rsp),%rsi
  mov    -0x4(%rsi,%r11,4),%edx
  lea    -0x4(%r8,%rdx,1),%edx
  lea    0x2(%rdx),%esi
  add    %edi,%edx
  movslq %esi,%r9
  shl    $0x3,%r9
  lea    (%rax,%r9,1),%rbx
  movsd  (%rbx),%xmm1
  lea    0x8(%rax,%r9,1),%rbp
  movsd  0x0(%rbp),%xmm0
  movslq %edx,%r9
  shl    $0x3,%r9
  lea    (%rax,%r9,1),%r10
  movsd  (%r10),%xmm3
  lea    0x8(%rax,%r9,1),%r9
  movsd  (%r9),%xmm2
  movsd  %xmm3,(%rbx)
  movsd  %xmm2,0x0(%rbp)
  movsd  %xmm1,(%r10)
  movsd  %xmm0,(%r9)
  add    %ecx,%esi
  movslq %esi,%rsi
  shl    $0x3,%rsi
  lea    (%rax,%rsi,1),%r9
  movsd  (%r9),%xmm1
  lea    0x8(%rax,%rsi,1),%rsi
  movsd  (%rsi),%xmm0
  add    %ecx,%edx
  movslq %edx,%rdx
  shl    $0x3,%rdx
  lea    (%rax,%rdx,1),%r10
  movsd  (%r10),%xmm3
  lea    0x8(%rax,%rdx,1),%rdx
  movsd  (%rdx),%xmm2
  movsd  %xmm3,(%r9)
  movsd  %xmm2,(%rsi)
  movsd  %xmm1,(%r10)
  movsd  %xmm0,(%rdx)
  cmp    -0x20(%rsp),%r8d
  je     L147
  test   %r11d,%r11d
  jg     L109
  jmp    L64
L149:
  sar    %edi
  mov    %edi,-0x30(%rsp)
  cmp    $0x8,%edx
  je     L154
  mov    $0x1,%r8d
  mov    $0x4,%ecx
  jmp    L125
L147:
  pop    %rbx
  pop    %rbp
  pop    %r12
  pop    %r13
  pop    %r14
  pop    %r15
  ret
```

assistant: ```c
void bitrv2(int n, int *ip, double *a) {
  int j, j1, k, k1, l, m, nh, nm;
  double xr, xi, yr, yi;
  m = 1;
  for (l = n >> 2; l > 8; l >>= 2) {
    m <<= 1;
  }
  nh = n >> 1;
  nm = 4 * m;
  if (l == 8) {
    for (k = 0; k < m; k++) {
      for (j = 0; j < k; j++) {
        j1 = 4 * j + 2 * ip[m + k];
        k1 = 4 * k + 2 * ip[m + j];
        xr = a[j1];
        xi = a[j1 + 1];
        yr = a[k1];
        yi = a[k1 + 1];
        a[j1] = yr;
        a[j1 + 1] = yi;
        a[k1] = xr;
        a[k1 + 1] = xi;
        j1 += nm;
        k1 += 2 * nm;
        xr = a[j1];
        xi = a[j1 + 1];
        yr = a[k1];
        yi = a[k1 + 1];
        a[j1] = yr;
        a[j1 + 1] = yi;
        a[k1] = xr;
        a[k1 + 1] = xi;
        j1 += nm;
        k1 -= nm;
        xr = a[j1];
        xi = a[j1 + 1];
        yr = a[k1];
        yi = a[k1 + 1];
        a[j1] = yr;
        a[j1 + 1] = yi;
        a[k1] = xr;
        a[k1 + 1] = xi;
        j1 += nm;
        k1 += 2 * nm;
        xr = a[j1];
        xi = a[j1 + 1];
        yr = a[k1];
        yi = a[k1 + 1];
        a[j1] = yr;
        a[j1 + 1] = yi;
        a[k1] = xr;
        a[k1 + 1] = xi;
        j1 += nh;
        k1 += 2;
        xr = a[j1];
        xi = a[j1 + 1];
        yr = a[k1];
        yi = a[k1 + 1];
        a[j1] = yr;
        a[j1 + 1] = yi;
        a[k1] = xr;
        a[k1 + 1] = xi;
        j1 -= nm;
        k1 -= 2 * nm;
        xr = a[j1];
        xi = a[j1 + 1];
        yr = a[k1];
        yi = a[k1 + 1];
        a[j1] = yr;
        a[j1 + 1] = yi;
        a[k1] = xr;
        a[k1 + 1] = xi;
        j1 -= nm;
        k1 += nm;
        xr = a[j1];
        xi = a[j1 + 1];
        yr = a[k1];
        yi = a[k1 + 1];
        a[j1] = yr;
        a[j1 + 1] = yi;
        a[k1] = xr;
        a[k1 + 1] = xi;
        j1 -= nm;
        k1 -= 2 * nm;
        xr = a[j1];
        xi = a[j1 + 1];
        yr = a[k1];
        yi = a[k1 + 1];
        a[j1] = yr;
        a[j1 + 1] = yi;
        a[k1] = xr;
        a[k1 + 1] = xi;
        j1 += 2;
        k1 += nh;
        xr = a[j1];
        xi = a[j1 + 1];
        yr = a[k1];
        yi = a[k1 + 1];
        a[j1] = yr;
        a[j1 + 1] = yi;
        a[k1] = xr;
        a[k1 + 1] = xi;
        j1 += nm;
        k1 += 2 * nm;
        xr = a[j1];
        xi = a[j1 + 1];
        yr = a[k1];
        yi = a[k1 + 1];
        a[j1] = yr;
        a[j1 + 1] = yi;
        a[k1] = xr;
        a[k1 + 1] = xi;
        j1 += nm;
        k1 -= nm;
        xr = a[j1];
        xi = a[j1 + 1];
        yr = a[k1];
        yi = a[k1 + 1];
        a[j1] = yr;
        a[j1 + 1] = yi;
        a[k1] = xr;
        a[k1 + 1] = xi;
        j1 += nm;
        k1 += 2 * nm;
        xr = a[j1];
        xi = a[j1 + 1];
        yr = a[k1];
        yi = a[k1 + 1];
        a[j1] = yr;
        a[j1 + 1] = yi;
        a[k1] = xr;
        a[k1 + 1] = xi;
        j1 -= nh;
        k1 -= 2;
        xr = a[j1];
        xi = a[j1 + 1];
        yr = a[k1];
        yi = a[k1 + 1];
        a[j1] = yr;
        a[j1 + 1] = yi;
        a[k1] = xr;
        a[k1 + 1] = xi;
        j1 -= nm;
        k1 -= 2 * nm;
        xr = a[j1];
        xi = a[j1 + 1];
        yr = a[k1];
        yi = a[k1 + 1];
        a[j1] = yr;
        a[j1 + 1] = yi;
        a[k1] = xr;
        a[k1 + 1] = xi;
        j1 -= nm;
        k1 += nm;
        xr = a[j1];
        xi = a[j1 + 1];
        yr = a[k1];
        yi = a[k1 + 1];
        a[j1] = yr;
        a[j1 + 1] = yi;
        a[k1] = xr;
        a[k1 + 1] = xi;
        j1 -= nm;
        k1 -= 2 * nm;
        xr = a[j1];
        xi = a[j1 + 1];
        yr = a[k1];
        yi = a[k1 + 1];
        a[j1] = yr;
        a[j1 + 1] = yi;
        a[k1] = xr;
        a[k1 + 1] = xi;
      }
      k1 = 4 * k + 2 * ip[m + k];
      j1 = k1 + 2;
      k1 += nh;
      xr = a[j1];
      xi = a[j1 + 1];
      yr = a[k1];
      yi = a[k1 + 1];
      a[j1] = yr;
      a[j1 + 1] = yi;
      a[k1] = xr;
      a[k1 + 1] = xi;
      j1 += nm;
      k1 += 2 * nm;
      xr = a[j1];
      xi = a[j1 + 1];
      yr = a[k1];
      yi = a[k1 + 1];
      a[j1] = yr;
      a[j1 + 1] = yi;
      a[k1] = xr;
      a[k1 + 1] = xi;
      j1 += nm;
      k1 -= nm;
      xr = a[j1];
      xi = a[j1 + 1];
      yr = a[k1];
      yi = a[k1 + 1];
      a[j1] = yr;
      a[j1 + 1] = yi;
      a[k1] = xr;
      a[k1 + 1] = xi;
      j1 -= 2;
      k1 -= nh;
      xr = a[j1];
      xi = a[j1 + 1];
      yr = a[k1];
      yi = a[k1 + 1];
      a[j1] = yr;
      a[j1 + 1] = yi;
      a[k1] = xr;
      a[k1 + 1] = xi;
      j1 += nh + 2;
      k1 += nh + 2;
      xr = a[j1];
      xi = a[j1 + 1];
      yr = a[k1];
      yi = a[k1 + 1];
      a[j1] = yr;
      a[j1 + 1] = yi;
      a[k1] = xr;
      a[k1 + 1] = xi;
      j1 -= nh - nm;
      k1 += 2 * nm - 2;
      xr = a[j1];
      xi = a[j1 + 1];
      yr = a[k1];
      yi = a[k1 + 1];
      a[j1] = yr;
      a[j1 + 1] = yi;
      a[k1] = xr;
      a[k1 + 1] = xi;
    }
  } else {
    for (k = 0; k < m; k++) {
      for (j = 0; j < k; j++) {
        j1 = 4 * j + ip[m + k];
        k1 = 4 * k + ip[m + j];
        xr = a[j1];
        xi = a[j1 + 1];
        yr = a[k1];
        yi = a[k1 + 1];
        a[j1] = yr;
        a[j1 + 1] = yi;
        a[k1] = xr;
        a[k1 + 1] = xi;
        j1 += nm;
        k1 += nm;
        xr = a[j1];
        xi = a[j1 + 1];
        yr = a[k1];
        yi = a[k1 + 1];
        a[j1] = yr;
        a[j1 + 1] = yi;
        a[k1] = xr;
        a[k1 + 1] = xi;
        j1 += nh;
        k1 += 2;
        xr = a[j1];
        xi = a[j1 + 1];
        yr = a[k1];
        yi = a[k1 + 1];
        a[j1] = yr;
        a[j1 + 1] = yi;
        a[k1] = xr;
        a[k1 + 1] = xi;
        j1 -= nm;
        k1 -= nm;
        xr = a[j1];
        xi = a[j1 + 1];
        yr = a[k1];
        yi = a[k1 + 1];
        a[j1] = yr;
        a[j1 + 1] = yi;
        a[k1] = xr;
        a[k1 + 1] = xi;
        j1 += 2;
        k1 += nh;
        xr = a[j1];
        xi = a[j1 + 1];
        yr = a[k1];
        yi = a[k1 + 1];
        a[j1] = yr;
        a[j1 + 1] = yi;
        a[k1] = xr;
        a[k1 + 1] = xi;
        j1 += nm;
        k1 += nm;
        xr = a[j1];
        xi = a[j1 + 1];
        yr = a[k1];
        yi = a[k1 + 1];
        a[j1] = yr;
        a[j1 + 1] = yi;
        a[k1] = xr;
        a[k1 + 1] = xi;
        j1 -= nh;
        k1 -= 2;
        xr = a[j1];
        xi = a[j1 + 1];
        yr = a[k1];
        yi = a[k1 + 1];
        a[j1] = yr;
        a[j1 + 1] = yi;
        a[k1] = xr;
        a[k1 + 1] = xi;
        j1 -= nm;
        k1 -= nm;
        xr = a[j1];
        xi = a[j1 + 1];
        yr = a[k1];
        yi = a[k1 + 1];
        a[j1] = yr;
        a[j1 + 1] = yi;
        a[k1] = xr;
        a[k1 + 1] = xi;
      }
      k1 = 4 * k + ip[m + k];
      j1 = k1 + 2;
      k1 += nh;
      xr = a[j1];
      xi = a[j1 + 1];
      yr = a[k1];
      yi = a[k1 + 1];
      a[j1] = yr;
      a[j1 + 1] = yi;
      a[k1] = xr;
      a[k1 + 1] = xi;
      j1 += nm;
      k1 += nm;
      xr = a[j1];
      xi = a[j1 + 1];
      yr = a[k1];
      yi = a[k1 + 1];
      a[j1] = yr;
      a[j1 + 1] = yi;
      a[k1] = xr;
      a[k1 + 1] = xi;
    }
  }
}
```