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

```asm
<ddst>:
  endbr64
  push   %r15
  mov    %esi,%eax
  push   %r14
  push   %r13
  mov    %rcx,%r13
  push   %r12
  mov    %edi,%r12d
  push   %rbp
  mov    %rdx,%rbp
  push   %rbx
  sub    $0x18,%rsp
  mov    (%rcx),%r14d
  lea    0x0(,%r14,4),%edx
  cmp    %edi,%edx
  jl     L141
L54:
  mov    0x4(%r13),%r15d
  movslq %r14d,%rdx
  lea    (%r8,%rdx,4),%rbx
  cmp    %r15d,%r12d
  jg     L101
L137:
  movslq %r12d,%rdx
  lea    -0x4(%rbp,%rdx,4),%r9
  test   %eax,%eax
  js     L80
  mov    %rbx,%rcx
  mov    %r15d,%edx
  mov    %rbp,%rsi
  mov    %r12d,%edi
  mov    %r8,0x8(%rsp)
  mov    %r9,(%rsp)
  call   <dstsub@plt>
  cmp    $0x4,%r12d
  mov    (%rsp),%r9
  mov    0x8(%rsp),%r8
  jg     L37
  je     L119
  movss  0x0(%rbp),%xmm0
  movss  0x4(%rbp),%xmm1
  movss  D20(%rip),%xmm3
  movaps %xmm0,%xmm4
  addss  %xmm1,%xmm0
  subss  %xmm1,%xmm4
  movss  %xmm0,0x0(%rbp)
  cmp    $0x3,%r12d
  jne    L165
  movss  0x8(%rbp),%xmm1
  movss  0xc(%rbp),%xmm2
  movss  D20(%rip),%xmm3
  movaps %xmm1,%xmm0
  subss  %xmm2,%xmm1
  xorps  %xmm3,%xmm0
  subss  %xmm2,%xmm0
  unpcklps %xmm1,%xmm0
  movlps %xmm0,0x4(%rbp)
L165:
  xorps  %xmm4,%xmm3
  movss  %xmm3,(%r9)
  add    $0x18,%rsp
  pop    %rbx
  pop    %rbp
  pop    %r12
  pop    %r13
  pop    %r14
  pop    %r15
  ret
  nopl   (%rax)
L80:
  lea    -0x2(%r12),%eax
  movss  (%r9),%xmm4
  cmp    $0x1,%eax
  jle    L161
  cltq
  lea    -0x4(%r12),%ecx
  movss  D20(%rip),%xmm3
  lea    0x0(,%rax,4),%rdx
  shr    %ecx
  lea    0x0(%rbp,%rdx,1),%rax
  shl    $0x3,%rcx
  lea    -0x8(%rbp,%rdx,1),%rdx
  sub    %rcx,%rdx
  nopl   0x0(%rax)
L163:
  movss  (%rax),%xmm0
  movss  -0x4(%rax),%xmm2
  sub    $0x8,%rax
  movaps %xmm0,%xmm1
  xorps  %xmm3,%xmm0
  subss  %xmm2,%xmm1
  subss  %xmm2,%xmm0
  unpcklps %xmm0,%xmm1
  movlps %xmm1,0x8(%rax)
  cmp    %rax,%rdx
  jne    L163
L161:
  movss  0x0(%rbp),%xmm0
  movaps %xmm0,%xmm1
  addss  %xmm4,%xmm0
  subss  %xmm4,%xmm1
  unpcklps %xmm0,%xmm1
  movlps %xmm1,0x0(%rbp)
  cmp    $0x4,%r12d
  jg     L104
  je     L103
L50:
  add    $0x18,%rsp
  mov    %rbx,%rcx
  mov    %r15d,%edx
  mov    %rbp,%rsi
  pop    %rbx
  mov    %r12d,%edi
  pop    %rbp
  pop    %r12
  pop    %r13
  pop    %r14
  pop    %r15
  jmp    10e0 <dstsub@plt>
  nopl   (%rax)
L101:
  mov    %rbx,%rdx
  mov    %r13,%rsi
  mov    %r12d,%edi
  mov    %r8,0x8(%rsp)
  mov    %eax,(%rsp)
  mov    %r12d,%r15d
  call   <makect@plt>
  mov    0x8(%rsp),%r8
  mov    (%rsp),%eax
  jmp    L137
  cs nopw 0x0(%rax,%rax,1)
L141:
  mov    %edi,%r14d
  mov    %esi,0x8(%rsp)
  mov    %r8,%rdx
  mov    %rcx,%rsi
  sar    $0x2,%r14d
  mov    %r8,(%rsp)
  mov    %r14d,%edi
  call   <makewt@plt>
  mov    0x8(%rsp),%eax
  mov    (%rsp),%r8
  jmp    L54
  nopw   0x0(%rax,%rax,1)
L37:
  mov    %r14d,%ecx
  mov    %r13,%rdx
  mov    %rbp,%rsi
  mov    %r12d,%edi
  mov    %r9,(%rsp)
  call   <cftfsub@plt>
  mov    %rbx,%rcx
  mov    %r15d,%edx
  mov    %rbp,%rsi
  mov    %r12d,%edi
  call   <rftfsub@plt>
  mov    (%rsp),%r9
L91:
  movss  0x0(%rbp),%xmm1
  movss  0x4(%rbp),%xmm0
  mov    $0x2,%eax
  movss  D20(%rip),%xmm3
  movaps %xmm1,%xmm4
  subss  %xmm0,%xmm4
  addss  %xmm1,%xmm0
  movss  %xmm0,0x0(%rbp)
  nopl   0x0(%rax)
L58:
  movss  0x0(%rbp,%rax,4),%xmm1
  movss  0x4(%rbp,%rax,4),%xmm2
  movaps %xmm1,%xmm0
  subss  %xmm2,%xmm1
  xorps  %xmm3,%xmm0
  subss  %xmm2,%xmm0
  unpcklps %xmm1,%xmm0
  movlps %xmm0,-0x4(%rbp,%rax,4)
  add    $0x2,%rax
  cmp    %eax,%r12d
  jg     L58
  jmp    L165
  nopl   0x0(%rax,%rax,1)
L104:
  mov    %rbx,%rcx
  mov    %r15d,%edx
  mov    %rbp,%rsi
  mov    %r12d,%edi
  mov    %r8,(%rsp)
  call   <rftbsub@plt>
  mov    (%rsp),%r8
  mov    %r14d,%ecx
  mov    %r13,%rdx
  mov    %rbp,%rsi
  mov    %r12d,%edi
  call   <cftbsub@plt>
  jmp    L50
  nop
L119:
  mov    %r14d,%ecx
  mov    %r13,%rdx
  mov    %rbp,%rsi
  mov    $0x4,%edi
  mov    %r9,(%rsp)
  call   <cftfsub@plt>
  mov    (%rsp),%r9
  jmp    L91
L103:
  mov    %r14d,%ecx
  mov    %r13,%rdx
  mov    %rbp,%rsi
  mov    $0x4,%edi
  call   <cftbsub@plt>
  jmp    L50
```

tool_calls: name: parse_data
arguments: data_label: D20
type_guessed: byte[4]

tool: {"D20": [0x00,0x00,0x00,0x80]}

assistant: ```c
void ddst(int n, int isgn, float *a, int *ip, float *w) {
  void makewt(int nw, int *ip, float *w);
  void makect(int nc, int *ip, float *c);
  void cftfsub(int n, float *a, int *ip, int nw, float *w);
  void cftbsub(int n, float *a, int *ip, int nw, float *w);
  void rftfsub(int n, float *a, int nc, float *c);
  void rftbsub(int n, float *a, int nc, float *c);
  void dstsub(int n, float *a, int nc, float *c);
  int j, nw, nc;
  float xr;
  nw = ip[0];
  if (n > (nw << 2)) {
    nw = n >> 2;
    makewt(nw, ip, w);
  }
  nc = ip[1];
  if (n > nc) {
    nc = n;
    makect(nc, ip, w + nw);
  }
  if (isgn < 0) {
    xr = a[n - 1];
    for (j = n - 2; j >= 2; j -= 2) {
      a[j + 1] = -a[j] - a[j - 1];
      a[j] -= a[j - 1];
    }
    a[1] = a[0] + xr;
    a[0] -= xr;
    if (n > 4) {
      rftbsub(n, a, nc, w + nw);
      cftbsub(n, a, ip, nw, w);
    } else if (n == 4) {
      cftbsub(n, a, ip, nw, w);
    }
  }
  dstsub(n, a, nc, w + nw);
  if (isgn >= 0) {
    if (n > 4) {
      cftfsub(n, a, ip, nw, w);
      rftfsub(n, a, nc, w + nw);
    } else if (n == 4) {
      cftfsub(n, a, ip, nw, w);
    }
    xr = a[0] - a[1];
    a[0] += a[1];
    for (j = 2; j < n; j += 2) {
      a[j - 1] = -a[j] - a[j + 1];
      a[j] -= a[j + 1];
    }
    a[n - 1] = -xr;
  }
}
```