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

```asm
<dd_to_string>:
  endbr64
  push   %r15
  push   %r14
  push   %r13
  push   %r12
  push   %rbp
  push   %rbx
  sub    $0x68,%rsp
  mov    %rdi,%r12
  mov    %rsi,%rbx
  mov    %edx,0x8(%rsp)
  mov    %ecx,%ebp
  mov    %r8d,0x20(%rsp)
  mov    %r9d,%r14d
  mov    0xb0(%rsp),%rax
  mov    %rax,0x10(%rsp)
  movzbl 0xa8(%rsp),%r15d
  mov    %fs:0x28,%rax
  mov    %rax,0x58(%rsp)
  xor    %eax,%eax
  movl   $0x0,0x3c(%rsp)
  call   <dd_is_negative@plt>
  mov    %eax,0xc(%rsp)
  cmp    $0x1,%eax
  je     L97
  mov    %rbx,%r13
  movl   $0x0,0xc(%rsp)
  cmp    $0x1,%r14d
  je     L316
L98:
  mov    %r12,%rdi
  call   <dd_is_zero@plt>
  cmp    $0x1,%eax
  je     L170
  cmpl   $0x1,0x20(%rsp)
  je     L297
  mov    0x8(%rsp),%eax
  lea    0x2(%rax),%edi
  mov    $0x1,%esi
  call   <calloc@plt>
  mov    %rax,%r14
  mov    %rax,0x18(%rsp)
  mov    0x8(%rsp),%eax
  lea    0x1(%rax),%ecx
  lea    0x3c(%rsp),%rdx
  mov    %r14,%rsi
  mov    %r12,%rdi
  call   <dd_to_digits@plt>
  movzbl (%r14),%eax
  mov    %al,0x0(%r13)
  cmpl   $0x0,0x8(%rsp)
  jle    L85
  lea    0x2(%r13),%rsi
  movb   $0x2e,0x1(%r13)
  mov    0xc(%rsp),%r12d
  add    $0x2,%r12d
  lea    0x1(%r14),%rax
  mov    0x8(%rsp),%ecx
  lea    -0x1(%rcx),%edx
  lea    0x2(%r14,%rdx,1),%rcx
  sub    %r14,%r13
L22:
  movzbl (%rax),%edx
  mov    %dl,0x1(%r13,%rax,1)
  add    $0x1,%rax
  cmp    %rcx,%rax
  jne    L22
  mov    0x8(%rsp),%edi
  mov    %edi,%eax
  lea    (%rsi,%rax,1),%r14
  add    %edi,%r12d
L28:
  mov    0x18(%rsp),%rdi
  call   <free@plt>
L392:
  cmpl   $0x0,0x20(%rsp)
  jne    L193
  cmpl   $0x1,0xa0(%rsp)
  mov    $0x45,%eax
  mov    $0x65,%edx
  cmovne %edx,%eax
  mov    %al,(%r14)
  mov    0x3c(%rsp),%eax
  test   %eax,%eax
  js     L125
  lea    0x2(%r14),%rdx
  movb   $0x2b,0x1(%r14)
  lea    0x2(%r12),%ecx
L345:
  mov    0x3c(%rsp),%esi
  cmp    $0x63,%esi
  jle    L150
  movslq %esi,%rax
  imul   $0x51eb851f,%rax,%rax
  sar    $0x25,%rax
  mov    %esi,%edx
  sar    $0x1f,%edx
  sub    %edx,%eax
  lea    0x3(%r14),%rdx
  lea    0x30(%rax),%ecx
  mov    %cl,0x2(%r14)
  lea    0x3(%r12),%ecx
  imul   $0xffffff9c,%eax,%eax
  add    %esi,%eax
  mov    %eax,0x3c(%rsp)
L150:
  mov    0x3c(%rsp),%esi
  movslq %esi,%rax
  imul   $0x66666667,%rax,%rax
  sar    $0x22,%rax
  mov    %esi,%edi
  sar    $0x1f,%edi
  sub    %edi,%eax
  lea    0x30(%rax),%edi
  mov    %dil,(%rdx)
  imul   $0xfffffff6,%eax,%eax
  add    %esi,%eax
  mov    %eax,0x3c(%rsp)
  lea    0x2(%rdx),%r14
  add    $0x30,%eax
  mov    %al,0x1(%rdx)
  lea    0x2(%rcx),%r12d
L193:
  cmp    %ebp,%r12d
  jl     L223
  movb   $0x0,(%r14)
  lea    0x1(%r12),%ebp
L243:
  mov    0x10(%rsp),%rax
  mov    %ebp,(%rax)
  mov    0x58(%rsp),%rax
  sub    %fs:0x28,%rax
  jne    L47
  add    $0x68,%rsp
  pop    %rbx
  pop    %rbp
  pop    %r12
  pop    %r13
  pop    %r14
  pop    %r15
  ret
L97:
  lea    0x1(%rbx),%r13
  movb   $0x2d,(%rbx)
  jmp    L98
L316:
  lea    0x1(%rbx),%r13
  movb   $0x2b,(%rbx)
  mov    %r14d,0xc(%rsp)
  jmp    L98
L170:
  movb   $0x30,0x0(%r13)
  cmpl   $0x0,0x8(%rsp)
  jle    L252
  lea    0x2(%r13),%r14
  movb   $0x2e,0x1(%r13)
  mov    0xc(%rsp),%r12d
  add    $0x2,%r12d
  mov    0x8(%rsp),%eax
  lea    -0x1(%rax),%eax
  lea    0x3(%r13,%rax,1),%rdx
  mov    %r14,%rax
L91:
  add    $0x1,%rax
  movb   $0x30,-0x1(%rax)
  cmp    %rdx,%rax
  jne    L91
  mov    0x8(%rsp),%ecx
  mov    %ecx,%eax
  add    %rax,%r14
  add    %ecx,%r12d
  jmp    L392
L252:
  lea    0x1(%r13),%r14
  mov    0xc(%rsp),%r12d
  add    $0x1,%r12d
  jmp    L392
L297:
  lea    0x40(%rsp),%r14
  mov    %r14,%rsi
  mov    %r12,%rdi
  call   <dd_abs@plt>
  mov    %r14,%rsi
  mov    %r14,%rdi
  call   <dd_log10@plt>
  mov    %r14,%rsi
  mov    %r14,%rdi
  call   <dd_floor@plt>
  mov    %r14,%rdi
  call   <dd_to_int@plt>
  mov    %eax,0x2c(%rsp)
  add    $0x1,%eax
  mov    %eax,0x24(%rsp)
  mov    %eax,%esi
  mov    0x8(%rsp),%eax
  add    %eax,%esi
  mov    %esi,0x28(%rsp)
  test   %esi,%esi
  jg     L33
  movb   $0x30,0x0(%r13)
  test   %eax,%eax
  jle    L318
  lea    0x2(%r13),%r14
  movb   $0x2e,0x1(%r13)
  mov    0xc(%rsp),%r12d
  add    $0x2,%r12d
  lea    -0x1(%rax),%eax
  lea    0x3(%r13,%rax,1),%rdx
  mov    %r14,%rax
L93:
  add    $0x1,%rax
  movb   $0x30,-0x1(%rax)
  cmp    %rdx,%rax
  jne    L93
  mov    0x8(%rsp),%ecx
  mov    %ecx,%eax
  add    %rax,%r14
  add    %ecx,%r12d
  jmp    L193
L176:
  movb   $0x30,0x0(%r13)
  lea    0x2(%r13),%r14
  movb   $0x2e,0x1(%r13)
  mov    0xc(%rsp),%r12d
  add    $0x2,%r12d
  cmpl   $0x0,0x24(%rsp)
  js     L0
L171:
  mov    0x28(%rsp),%eax
  test   %eax,%eax
  jle    L28
  lea    -0x1(%rax),%ecx
  lea    0x1(%rcx),%rsi
  mov    $0x0,%eax
  mov    0x18(%rsp),%rdi
L365:
  movzbl (%rdi,%rax,1),%edx
  mov    %dl,(%r14,%rax,1)
  mov    %rax,%rdx
  add    $0x1,%rax
  cmp    %rcx,%rdx
  jne    L365
  add    %rsi,%r14
  add    0x28(%rsp),%r12d
  jmp    L28
L0:
  mov    0x2c(%rsp),%ecx
  not    %ecx
  lea    -0x1(%rcx),%eax
  lea    0x3(%r13,%rax,1),%rdx
  mov    %r14,%rax
L157:
  add    $0x1,%rax
  movb   $0x30,-0x1(%rax)
  cmp    %rdx,%rax
  jne    L157
  mov    %ecx,%eax
  add    %rax,%r14
  add    %ecx,%r12d
  jmp    L171
L85:
  lea    0x1(%r13),%r14
  mov    0xc(%rsp),%r12d
  add    $0x1,%r12d
  jmp    L28
L223:
  mov    %ebp,%edi
  sub    %r12d,%edi
  test   %r12d,%r12d
  jle    L217
  mov    %rbx,%rax
  lea    -0x1(%r12),%edx
  lea    0x1(%rbx,%rdx,1),%rsi
  movslq %edi,%rcx
L92:
  movzbl (%rax),%edx
  mov    %dl,(%rax,%rcx,1)
  add    $0x1,%rax
  cmp    %rsi,%rax
  jne    L92
L217:
  test   %edi,%edi
  jle    L18
  mov    %rbx,%rax
  lea    -0x1(%rdi),%edx
  lea    0x1(%rbx,%rdx,1),%rdx
L267:
  mov    %r15b,(%rax)
  add    $0x1,%rax
  cmp    %rdx,%rax
  jne    L267
L18:
  movslq %ebp,%rax
  movb   $0x0,(%rbx,%rax,1)
  jmp    L243
L125:
  lea    0x2(%r14),%rdx
  movb   $0x2d,0x1(%r14)
  lea    0x2(%r12),%ecx
  neg    %eax
  mov    %eax,0x3c(%rsp)
  jmp    L345
L318:
  lea    0x1(%r13),%r14
  mov    0xc(%rsp),%r12d
  add    $0x1,%r12d
  jmp    L193
L33:
  mov    0x28(%rsp),%r14d
  lea    0x1(%r14),%edi
  mov    $0x1,%esi
  call   <calloc@plt>
  mov    %rax,0x18(%rsp)
  lea    0x3c(%rsp),%rdx
  mov    %r14d,%ecx
  mov    %rax,%rsi
  mov    %r12,%rdi
  call   <dd_to_digits@plt>
  cmpl   $0x0,0x24(%rsp)
  jle    L176
  mov    0x2c(%rsp),%edx
  lea    0x1(%rdx),%r14
  mov    $0x0,%eax
  mov    0x18(%rsp),%rsi
L161:
  movzbl (%rsi,%rax,1),%ecx
  mov    %cl,0x0(%r13,%rax,1)
  mov    %rax,%rcx
  add    $0x1,%rax
  cmp    %rdx,%rcx
  jne    L161
  add    %r13,%r14
  mov    0xc(%rsp),%eax
  mov    %eax,%r12d
  mov    0x24(%rsp),%esi
  add    %esi,%r12d
  add    %r13,%rdx
  lea    -0x1(%rax,%rsi,1),%eax
  mov    0x8(%rsp),%edi
  test   %edi,%edi
  jle    L28
  movb   $0x2e,(%r14)
  lea    0x2(%rax),%r8d
  mov    %edi,%edi
  mov    $0x0,%eax
  movslq %esi,%rsi
  add    0x18(%rsp),%rsi
L87:
  movzbl (%rsi,%rax,1),%ecx
  mov    %cl,0x2(%rdx,%rax,1)
  add    $0x1,%rax
  cmp    %rdi,%rax
  jne    L87
  lea    0x2(%rdx,%rdi,1),%r14
  mov    0x8(%rsp),%r12d
  add    %r8d,%r12d
  jmp    L28
L47:
  call   <__stack_chk_fail@plt>
```

assistant: ```c
void dd_to_string(const double *a, char *s, int precision, int width, int fixed, int showpos, int uppercase, char fill, int *endstring) {
  int sgn = 1;
  int i, e = 0;
  char *p = s;
  int cnt = 0;
  int off, d;
  double acc[2];
  if (dd_is_negative(a) == 1) {
    *(p++) = '-';
    cnt++;
  } else if (showpos == 1) {
    *(p++) = '+';
    cnt++;
  } else
    sgn = 0;
  if (dd_is_zero(a) == 1) {
    *(p++) = '0';
    cnt++;
    if (precision > 0) {
      *(p++) = '.';
      cnt++;
      for (i = 0; i < precision; i++, cnt++)
        *(p++) = '0';
    }
  } else {
    if (fixed != 1)
      off = 1;
    else {
      dd_abs(a, acc);
      dd_log10(acc, acc);
      dd_floor(acc, acc);
      off = dd_to_int(acc) + 1;
    }
    d = precision + off;
    if ((fixed == 1) && (d <= 0)) {
      *(p++) = '0';
      cnt++;
      if (precision > 0) {
        *(p++) = '.';
        cnt++;
        for (i = 0; i < precision; i++, cnt++)
          *(p++) = '0';
      }
    } else {
      char *t = (char *)calloc(d + 1, sizeof(char));
      int j;
      dd_to_digits(a, t, &e, d);
      if (fixed == 1) {
        if (off > 0) {
          for (i = 0; i < off; i++, cnt++)
            *(p++) = t[i];
          if (precision > 0) {
            *(p++) = '.';
            cnt++;
            for (j = 0; j < precision; j++, i++, cnt++)
              *(p++) = t[i];
          }
        } else {
          *(p++) = '0';
          cnt++;
          *(p++) = '.';
          cnt++;
          if (off < 0)
            for (i = 0; i < (-off); i++, cnt++)
              *(p++) = '0';
          for (i = 0; i < d; i++, cnt++)
            *(p++) = t[i];
        }
      } else {
        *(p++) = t[0];
        cnt++;
        if (precision > 0) {
          *(p++) = '.';
          cnt++;
        }
        for (i = 1; i <= precision; i++, cnt++)
          *(p++) = t[i];
      }
      free(t);
    }
  }
  if (fixed == 0) {
    *(p++) = (uppercase == 1) ? 'E' : 'e';
    cnt++;
    *(p++) = (e < 0 ? '-' : '+');
    cnt++;
    if (e < 0)
      e = -e;
    if (e >= 100) {
      i = e / 100;
      *(p++) = '0' + i;
      cnt++;
      e -= 100 * i;
    }
    i = e / 10;
    *(p++) = '0' + i;
    cnt++;
    e -= 10 * i;
    *(p++) = '0' + e;
    cnt++;
  }
  if (cnt >= width) {
    *(p++) = '\0';
    *endstring = cnt + 1;
  } else {
    d = width - cnt;
    for (i = 0; i < cnt; i++)
      s[i + d] = s[i];
    for (i = 0; i < d; i++)
      s[i] = fill;
    s[width] = '\0';
    *endstring = width;
  }
}
```