user: 下面的汇编指令对应的C源代码是什么:

```asm
<dftixb>:
  endbr64
  push   %r15
  mov    %r9,%r15
  push   %r14
  mov    %r8,%r14
  push   %r13
  mov    %ecx,%r13d
  push   %r12
  mov    %rsi,%r12
  push   %rbp
  mov    %rdi,%rbp
  push   %rbx
  sub    $0x18,%rsp
  mov    %fs:0x28,%rax
  mov    %rax,0x8(%rsp)
  xor    %eax,%eax
  cmp    %edx,%ecx
  jg     L19
L27:
  lea    0x0(,%r13,8),%edx
  xor    %esi,%esi
  mov    %rbp,%rdi
  movslq %r13d,%rbx
  call   <memset@plt>
  lea    0x0(%r13,%r13,1),%ecx
  lea    -0x1(%rcx),%edx
  test   %r13d,%r13d
  jle    L67
  movslq %edx,%rdx
  xor    %eax,%eax
  movss  D3(%rip),%xmm1
  shl    $0x2,%rdx
L50:
  movss  0x0(%rbp,%rax,4),%xmm0
  movss  %xmm0,0x0(%rbp,%rdx,1)
  movss  (%r12,%rax,4),%xmm0
  add    $0x1,%rax
  xorps  %xmm1,%xmm0
  movss  %xmm0,(%r12,%rdx,1)
  sub    $0x4,%rdx
  cmp    %rbx,%rax
  jne    L50
  mov    %ecx,0x4(%rsp)
  lea    0x4(%rsp),%rdx
  mov    %r12,%rsi
  mov    %rbp,%rdi
  push   %r15
  mov    $0x1,%ecx
  xor    %r9d,%r9d
  xor    %r8d,%r8d
  push   %r14
  call   <fourt@plt>
  lea    0x0(,%rbx,4),%rdx
  pop    %rsi
  xor    %eax,%eax
  lea    0x0(%rbp,%rdx,1),%rcx
  pop    %rdi
  add    %r12,%rdx
  nop
L70:
  movss  (%rcx,%rax,4),%xmm0
  movss  %xmm0,0x0(%rbp,%rax,4)
  movss  (%rdx,%rax,4),%xmm0
  movss  %xmm0,(%r12,%rax,4)
  add    $0x1,%rax
  cmp    %rbx,%rax
  jne    L70
  pxor   %xmm1,%xmm1
  movsd  D12(%rip),%xmm0
  xor    %eax,%eax
  cvtsi2sd %r13d,%xmm1
  divsd  %xmm1,%xmm0
  cvtsd2ss %xmm0,%xmm0
  nopw   0x0(%rax,%rax,1)
L56:
  movss  0x0(%rbp,%rax,4),%xmm1
  mulss  %xmm0,%xmm1
  movss  %xmm1,0x0(%rbp,%rax,4)
  movss  (%r12,%rax,4),%xmm1
  mulss  %xmm0,%xmm1
  movss  %xmm1,(%r12,%rax,4)
  add    $0x1,%rax
  cmp    %rbx,%rax
  jne    L56
L37:
  mov    0x8(%rsp),%rax
  sub    %fs:0x28,%rax
  jne    L40
  add    $0x18,%rsp
  mov    %r13d,%eax
  pop    %rbx
  pop    %rbp
  pop    %r12
  pop    %r13
  pop    %r14
  pop    %r15
  ret
  nopl   0x0(%rax,%rax,1)
L19:
  mov    %ecx,%r8d
  sub    %edx,%r8d
  movslq %edx,%rdx
  shl    $0x2,%r8d
  lea    (%rsi,%rdx,4),%rdi
  xor    %esi,%esi
  mov    %r8d,%edx
  call   <memset@plt>
  jmp    L27
L67:
  mov    %ecx,0x4(%rsp)
  lea    0x4(%rsp),%rdx
  xor    %r9d,%r9d
  xor    %r8d,%r8d
  push   %r15
  mov    $0x1,%ecx
  mov    %r12,%rsi
  mov    %rbp,%rdi
  push   %r14
  call   <fourt@plt>
  pop    %rax
  pop    %rdx
  jmp    L37
L40:
  call   <__stack_chk_fail@plt>
```

tool_calls: name: extract_symbolic_data
arguments: data_tag: D3
type: byte[4]
name: extract_symbolic_data
arguments: data_tag: D12
type: f64

tool: {"D3": [0x00,0x00,0x00,0x80]}

tool: D12: 1

assistant: ```c
int dftixb(float *xrr, float *xri, int isize, int ntot, float *workr, float *worki) {
  int i, ntotp1;
  float scale;
  if (ntot > isize)
    memset(xri + isize, 0, sizeof(float) * (ntot - isize));
  memset(xrr, 0, sizeof(float) * ntot * 2);
  ntotp1 = 2 * ntot - 1;
  for (i = 0; i < ntot; i++) {
    xrr[ntotp1 - i] = xrr[i];
    xri[ntotp1 - i] = -xri[i];
  }
  ntotp1 = ntot * 2;
  fourt(xrr, xri, &ntotp1, 1, 0, 0, workr, worki);
  for (i = 0; i < ntot; i++) {
    xrr[i] = xrr[i + ntot];
    xri[i] = xri[i + ntot];
  }
  scale = 1.0 / ntot;
  for (i = 0; i < ntot; i++) {
    xrr[i] *= scale;
    xri[i] *= scale;
  }
  return ntot;
}
```