user: 这段汇编代码用C语言表示是什么样的:

```asm
<computeBWT>:
  endbr64
  push   %r15
  push   %r14
  push   %r13
  push   %r12
  mov    %rcx,%r12
  push   %rbp
  mov    %rdi,%rbp
  push   %rbx
  mov    %rsi,%rbx
  sub    $0x48,%rsp
  mov    %rdx,0x20(%rsp)
  mov    %r8d,0x2c(%rsp)
  mov    %r9d,0x34(%rsp)
  cmp    %rcx,%rdx
  je     L128
L18:
  mov    0x34(%rsp),%edx
  mov    0x20(%rsp),%rdi
  xor    %ecx,%ecx
  mov    %r12,%rsi
  call   <getBuckets@plt>
  mov    0x2c(%rsp),%eax
  sub    $0x1,%eax
  cmpl   $0x4,0x80(%rsp)
  mov    %eax,0x30(%rsp)
  movslq %eax,%r13
  je     L195
  movzbl 0x0(%rbp,%r13,1),%r10d
  movslq (%r12,%r10,4),%rax
  lea    (%rbx,%rax,4),%rdx
  mov    0x30(%rsp),%eax
  test   %eax,%eax
  jle    L31
  movzbl -0x1(%rbp,%r13,1),%ecx
L37:
  mov    0x2c(%rsp),%eax
  neg    %eax
  cmp    %r10d,%ecx
  cmovge 0x30(%rsp),%eax
L31:
  movslq 0x2c(%rsp),%rsi
  mov    %eax,(%rdx)
  lea    0x4(%rdx),%r11
  xor    %r15d,%r15d
  mov    %rsi,0x10(%rsp)
  test   %esi,%esi
  jle    L286
  mov    %r12,0x18(%rsp)
  mov    %rbx,%r12
  mov    %r10d,%ebx
  mov    %r11,(%rsp)
  mov    %r13,0x38(%rsp)
  jmp    L253
L212:
  lea    -0x1(%r13),%r14d
  cmpl   $0x4,0x80(%rsp)
  movslq %r14d,%rax
  mov    %rax,0x8(%rsp)
  movslq %r13d,%rax
  je     L147
  movslq %r14d,%rsi
  movzbl 0x0(%rbp,%rax,1),%eax
  lea    0x0(%rbp,%rsi,1),%rdx
  cmp    %al,(%rdx)
  mov    %rdx,0x8(%rsp)
  setae  %dil
  movzbl %dil,%edi
  call   <assert@plt>
  mov    0x8(%rsp),%rdx
  movzbl (%rdx),%r8d
L256:
  mov    %r8d,%eax
  mov    (%rsp),%rdx
  not    %eax
  mov    %eax,(%r12,%r15,4)
  cmp    %ebx,%r8d
  je     L170
  mov    0x18(%rsp),%rcx
  sub    %r12,%rdx
  movslq %ebx,%r10
  movslq %r8d,%rax
  sar    $0x2,%rdx
  mov    %edx,(%rcx,%r10,4)
  movslq (%rcx,%rax,4),%rax
  lea    (%r12,%rax,4),%rdx
L170:
  mov    %rdx,%rax
  xor    %edi,%edi
  mov    %r8d,0x8(%rsp)
  sub    %r12,%rax
  mov    %rdx,(%rsp)
  sar    $0x2,%rax
  cmp    %r15,%rax
  setg   %dil
  call   <assert@plt>
  test   %r14d,%r14d
  mov    (%rsp),%rdx
  mov    0x8(%rsp),%r8d
  je     L247
  cmpl   $0x4,0x80(%rsp)
  movslq %r14d,%rax
  je     L295
  movzbl -0x1(%rbp,%rax,1),%eax
L254:
  mov    %r13d,%ecx
  neg    %ecx
  cmp    %eax,%r8d
  cmovg  %ecx,%r14d
L247:
  lea    0x4(%rdx),%rax
  mov    %r14d,(%rdx)
  mov    %r8d,%ebx
  mov    %rax,(%rsp)
L103:
  add    $0x1,%r15
  cmp    %r15,0x10(%rsp)
  je     L191
L253:
  mov    (%r12,%r15,4),%r13d
  test   %r13d,%r13d
  jg     L212
  je     L103
  mov    %r13d,%ecx
  not    %ecx
  mov    %ecx,(%r12,%r15,4)
  add    $0x1,%r15
  cmp    %r15,0x10(%rsp)
  jne    L253
L191:
  mov    %r12,%rbx
  mov    0x38(%rsp),%r13
  mov    0x18(%rsp),%r12
L286:
  cmp    %r12,0x20(%rsp)
  je     L325
L133:
  mov    0x34(%rsp),%edx
  mov    0x20(%rsp),%rdi
  mov    $0x1,%ecx
  mov    %r12,%rsi
  call   <getBuckets@plt>
  movslq (%r12),%rax
  lea    (%rbx,%rax,4),%rcx
  mov    0x30(%rsp),%eax
  test   %eax,%eax
  js     L220
  xor    %r15d,%r15d
  mov    %r12,0x10(%rsp)
  movl   $0xffffffff,0x18(%rsp)
  mov    %r15d,%r12d
  mov    %rcx,(%rsp)
  jmp    L15
  nopw   0x0(%rax,%rax,1)
L241:
  lea    -0x1(%rax),%r14d
  cmpl   $0x4,0x80(%rsp)
  movslq %r14d,%rcx
  mov    %rcx,0x8(%rsp)
  je     L77
  movslq %r14d,%rsi
  movzbl 0x0(%rbp,%rax,1),%eax
  xor    %edi,%edi
  lea    0x0(%rbp,%rsi,1),%r15
  cmp    %al,(%r15)
  setbe  %dil
  call   <assert@plt>
  movzbl (%r15),%esi
L233:
  mov    %esi,(%rbx,%r13,4)
  mov    (%rsp),%r15
  cmp    %r12d,%esi
  je     L266
  mov    0x10(%rsp),%rcx
  sub    %rbx,%r15
  movslq %r12d,%r8
  movslq %esi,%rax
  sar    $0x2,%r15
  mov    %r15d,(%rcx,%r8,4)
  movslq (%rcx,%rax,4),%rax
  lea    (%rbx,%rax,4),%r15
L266:
  mov    %r15,%rax
  xor    %edi,%edi
  mov    %esi,(%rsp)
  sub    %rbx,%rax
  sar    $0x2,%rax
  cmp    %r13,%rax
  setle  %dil
  call   <assert@plt>
  test   %r14d,%r14d
  mov    (%rsp),%esi
  je     L169
  cmpl   $0x4,0x80(%rsp)
  movslq %r14d,%rax
  je     L245
  movzbl -0x1(%rbp,%rax,1),%eax
  mov    %eax,%ecx
  cmp    %eax,%esi
  not    %ecx
  cmovl  %ecx,%r14d
L169:
  lea    -0x4(%r15),%rax
  mov    %r14d,-0x4(%r15)
  mov    %esi,%r12d
  mov    %rax,(%rsp)
L48:
  sub    $0x1,%r13
  test   %r13d,%r13d
  js     L51
L15:
  movslq (%rbx,%r13,4),%rax
  test   %eax,%eax
  jg     L241
  je     L67
  not    %eax
  mov    %eax,(%rbx,%r13,4)
  sub    $0x1,%r13
  test   %r13d,%r13d
  jns    L15
L51:
  mov    0x18(%rsp),%eax
  add    $0x48,%rsp
  pop    %rbx
  pop    %rbp
  pop    %r12
  pop    %r13
  pop    %r14
  pop    %r15
  ret
  nopw   0x0(%rax,%rax,1)
L147:
  movslq %r14d,%rax
  shl    $0x2,%rax
  lea    0x0(%rbp,%rax,1),%rdx
  mov    0x4(%rbp,%rax,1),%eax
  cmp    %eax,(%rdx)
  mov    %rdx,0x8(%rsp)
  setge  %dil
  movzbl %dil,%edi
  call   <assert@plt>
  mov    0x8(%rsp),%rdx
  mov    (%rdx),%r8d
  jmp    L256
  nopl   0x0(%rax)
L67:
  mov    %r13d,0x18(%rsp)
  jmp    L48
  nopw   0x0(%rax,%rax,1)
L77:
  mov    %rcx,%rax
  xor    %edi,%edi
  shl    $0x2,%rax
  lea    0x0(%rbp,%rax,1),%r15
  mov    0x4(%rbp,%rax,1),%eax
  cmp    %eax,(%r15)
  setle  %dil
  call   <assert@plt>
  mov    (%r15),%esi
  jmp    L233
  xchg   %ax,%ax
L245:
  mov    -0x4(%rbp,%rax,4),%eax
  mov    %eax,%ecx
  cmp    %eax,%esi
  not    %ecx
  cmovl  %ecx,%r14d
  jmp    L169
  nopl   0x0(%rax,%rax,1)
L295:
  mov    -0x4(%rbp,%rax,4),%eax
  jmp    L254
  nopl   0x0(%rax)
L195:
  movslq 0x0(%rbp,%r13,4),%rax
  lea    0x0(,%r13,4),%rcx
  mov    %rax,%r10
  movslq (%r12,%rax,4),%rax
  lea    (%rbx,%rax,4),%rdx
  mov    0x30(%rsp),%eax
  test   %eax,%eax
  jle    L31
  mov    -0x4(%rbp,%rcx,1),%ecx
  jmp    L37
  nopl   (%rax)
L128:
  mov    %r8d,%edx
  mov    0x20(%rsp),%rsi
  mov    0x80(%rsp),%r8d
  mov    %r9d,%ecx
  call   <getCounts@plt>
  jmp    L18
  nopl   (%rax)
L325:
  mov    0x80(%rsp),%r8d
  mov    0x34(%rsp),%ecx
  mov    %rbp,%rdi
  mov    0x2c(%rsp),%edx
  mov    0x20(%rsp),%rsi
  call   <getCounts@plt>
  jmp    L133
  nopw   0x0(%rax,%rax,1)
L220:
  movl   $0xffffffff,0x18(%rsp)
  jmp    L51
```

assistant: ```c
off_t computeBWT(const void *T, off_t *SA, off_t *C, off_t *B, off_t n, off_t k, int cs) {
  off_t *b, i, j, pidx = -1;
  off_t c0, c1;
  if (C == B) {
    getCounts(T, C, n, k, cs);
  }
  getBuckets(C, B, k, 0);
  j = n - 1;
  b = SA + B[c1 = (cs == sizeof(off_t) ? ((const off_t *)T)[(j)] : ((const unsigned char *)T)[(j)])];
  *b++ = ((0 < j) && ((cs == sizeof(off_t) ? ((const off_t *)T)[(j - 1)] : ((const unsigned char *)T)[(j - 1)]) < c1)) ? ~j : j;
  for (i = 0; i < n; ++i) {
    if (0 < (j = SA[i])) {
      --j;
      assert((cs == sizeof(off_t) ? ((const off_t *)T)[(j)] : ((const unsigned char *)T)[(j)]) >= (cs == sizeof(off_t) ? ((const off_t *)T)[(j + 1)] : ((const unsigned char *)T)[(j + 1)]));
      SA[i] = ~((off_t)(c0 = (cs == sizeof(off_t) ? ((const off_t *)T)[(j)] : ((const unsigned char *)T)[(j)])));
      if (c0 != c1) {
        B[c1] = b - SA;
        b = SA + B[c1 = c0];
      }
      assert(i < (b - SA));
      *b++ = ((0 < j) && ((cs == sizeof(off_t) ? ((const off_t *)T)[(j - 1)] : ((const unsigned char *)T)[(j - 1)]) < c1)) ? ~j : j;
    } else if (j != 0) {
      SA[i] = ~j;
    }
  }
  if (C == B) {
    getCounts(T, C, n, k, cs);
  }
  getBuckets(C, B, k, 1);
  for (i = n - 1, b = SA + B[c1 = 0]; 0 <= i; --i) {
    if (0 < (j = SA[i])) {
      --j;
      assert((cs == sizeof(off_t) ? ((const off_t *)T)[(j)] : ((const unsigned char *)T)[(j)]) <= (cs == sizeof(off_t) ? ((const off_t *)T)[(j + 1)] : ((const unsigned char *)T)[(j + 1)]));
      SA[i] = (c0 = (cs == sizeof(off_t) ? ((const off_t *)T)[(j)] : ((const unsigned char *)T)[(j)]));
      if (c0 != c1) {
        B[c1] = b - SA;
        b = SA + B[c1 = c0];
      }
      assert((b - SA) <= i);
      *--b = ((0 < j) && ((cs == sizeof(off_t) ? ((const off_t *)T)[(j - 1)] : ((const unsigned char *)T)[(j - 1)]) > c1)) ? ~((off_t)(cs == sizeof(off_t) ? ((const off_t *)T)[(j - 1)] : ((const unsigned char *)T)[(j - 1)])) : j;
    } else if (j != 0) {
      SA[i] = ~j;
    } else {
      pidx = i;
    }
  }
  return pidx;
}
```