user: Demonstrate the C code that generates the assembly output below:

```asm
<step_forward_k>:
  endbr64
  push   %r15
  mov    %ecx,%r15d
  push   %r14
  mov    %r8d,%r14d
  push   %r13
  mov    %rdi,%r13
  push   %r12
  mov    %r8d,%r12d
  push   %rbp
  imul   %ecx,%r12d
  lea    0x1(%r9),%ebp
  push   %rbx
  mov    %rsi,%rbx
  shl    $0x2,%r12d
  sub    $0x88,%rsp
  mov    %rdi,0x30(%rsp)
  mov    %r12d,%edi
  mov    %rdx,0x28(%rsp)
  mov    %r8d,0x60(%rsp)
  movss  %xmm0,0x38(%rsp)
  movss  %xmm1,0x3c(%rsp)
  movss  %xmm3,0x50(%rsp)
  movss  %xmm4,0x64(%rsp)
  movss  %xmm5,0x68(%rsp)
  movss  %xmm6,0x6c(%rsp)
  mov    %ebp,(%rsp)
  call   <malloc@plt>
  mov    %r12d,%edx
  mov    %r13,%rsi
  mov    %rax,%rdi
  mov    %rax,0x58(%rsp)
  call   <memcpy@plt>
  mov    %r14d,%eax
  sub    %ebp,%eax
  cmp    %eax,%ebp
  jge    L30
  mov    (%rsp),%esi
  mov    0x58(%rsp),%rdx
  mov    0x28(%rsp),%rcx
  mov    %esi,%eax
  mov    %esi,0x54(%rsp)
  imul   %r15d,%eax
  mov    %eax,0x20(%rsp)
  movslq %r15d,%rax
  mov    %rax,0x70(%rsp)
  shl    $0x2,%rax
  mov    %rax,0x40(%rsp)
  sub    %rdx,%rax
  lea    (%rcx,%rax,1),%r14
  add    %rbx,%rax
  mov    %rax,0x78(%rsp)
  mov    %rdx,%rax
  neg    %rax
  mov    %rax,0x8(%rsp)
  mov    %rbx,%rax
  sub    %rdx,%rax
  mov    %rax,0x48(%rsp)
  mov    %r15d,%eax
  sub    %esi,%eax
  cmp    %esi,%eax
  jle    L30
  nopl   0x0(%rax)
L69:
  movss  0x6c(%rsp),%xmm1
  movss  0x68(%rsp),%xmm0
  call   <fmaxf@plt>
  mulss  0x64(%rsp),%xmm0
  movslq 0x20(%rsp),%rdx
  movslq (%rsp),%rax
  mov    0x58(%rsp),%rsi
  mov    0x78(%rsp),%r13
  mov    (%rsp),%edi
  lea    (%rax,%rdx,1),%rcx
  sub    0x70(%rsp),%rax
  add    %rdx,%rax
  lea    (%rsi,%rcx,4),%r12
  lea    (%rsi,%rax,4),%rbp
  movss  %xmm0,0x24(%rsp)
  jmp    L38
  nopl   0x0(%rax)
L58:
  mov    0x18(%rsp),%r12
L38:
  movss  (%r14,%rbp,1),%xmm0
  pxor   %xmm6,%xmm6
  add    0x20(%rsp),%edi
  ucomiss %xmm0,%xmm6
  ja     L79
  sqrtss %xmm0,%xmm0
L21:
  mulss  0x50(%rsp),%xmm0
  mov    %edi,0x10(%rsp)
  divss  0x24(%rsp),%xmm0
  call   <floor@plt>
  pxor   %xmm0,%xmm0
  mov    0x10(%rsp),%edi
  mov    %eax,%edx
  lea    0x1(%rax),%eax
  movss  0x38(%rsp),%xmm3
  mov    0x30(%rsp),%r11
  mov    %eax,%ecx
  lea    0x2(%rdx),%esi
  movss  0x3c(%rsp),%xmm6
  add    0x8(%rsp),%r11
  imul   %eax,%ecx
  mov    %esi,0x4(%rsp)
  lea    (%rdi,%rax,1),%esi
  movss  D18(%rip),%xmm4
  movslq %esi,%r10
  mov    %r11,0x10(%rsp)
  lea    (%r15,%rsi,1),%r11d
  sub    %r15d,%esi
  movslq %r11d,%r11
  movslq %esi,%rsi
  mov    %r15d,%r8d
  movss  0x0(%r13,%rbp,1),%xmm2
  cvtsi2ss %ecx,%xmm0
  mov    %edi,%ecx
  movss  D6(%rip),%xmm5
  imul   %eax,%r8d
  mulss  %xmm4,%xmm2
  sub    %eax,%ecx
  mov    %edi,%eax
  movslq %ecx,%r9
  addss  0x4(%r13,%rbp,1),%xmm2
  addss  0x0(%r13,%r12,1),%xmm2
  movss  (%rbx,%r9,4),%xmm1
  addss  -0x4(%r13,%rbp,1),%xmm2
  divss  %xmm0,%xmm3
  lea    (%rdi,%r8,1),%edx
  lea    0x4(%r12),%rdi
  sub    %r8d,%eax
  mulss  %xmm4,%xmm1
  movslq %edx,%r8
  mov    %rdi,0x18(%rsp)
  mov    0x48(%rsp),%rdi
  addss  0x4(%rbx,%r9,4),%xmm1
  addss  (%rdi,%rbp,1),%xmm2
  movslq %eax,%rdi
  movss  (%rbx,%rdi,4),%xmm7
  mulss  %xmm4,%xmm7
  mulss  %xmm5,%xmm2
  divss  %xmm0,%xmm6
  movss  (%rbx,%r10,4),%xmm0
  mulss  %xmm4,%xmm0
  addss  0x4(%rbx,%r10,4),%xmm0
  addss  (%rbx,%r11,4),%xmm0
  addss  -0x4(%rbx,%r10,4),%xmm0
  addss  (%rbx,%rsi,4),%xmm0
  lea    (%r15,%rcx,1),%esi
  sub    %r15d,%ecx
  movslq %ecx,%rcx
  movslq %esi,%rsi
  addss  (%rbx,%rsi,4),%xmm1
  addss  -0x4(%rbx,%r9,4),%xmm1
  mulss  %xmm5,%xmm0
  addss  (%rbx,%rcx,4),%xmm1
  lea    (%r15,%rdx,1),%ecx
  sub    %r15d,%edx
  movslq %edx,%rdx
  movslq %ecx,%rcx
  mulss  %xmm5,%xmm1
  addss  %xmm1,%xmm0
  movss  (%rbx,%r8,4),%xmm1
  mulss  %xmm4,%xmm1
  addss  0x4(%rbx,%r8,4),%xmm1
  addss  (%rbx,%rcx,4),%xmm1
  mulss  %xmm3,%xmm0
  addss  -0x4(%rbx,%r8,4),%xmm1
  addss  (%rbx,%rdx,4),%xmm1
  lea    (%r15,%rax,1),%edx
  sub    %r15d,%eax
  addss  0x4(%rbx,%rdi,4),%xmm7
  addl   $0x1,(%rsp)
  cltq
  movslq %edx,%rdx
  addss  %xmm6,%xmm3
  mov    0x10(%rsp),%r11
  addss  (%rbx,%rdx,4),%xmm7
  addss  -0x4(%rbx,%rdi,4),%xmm7
  mulss  %xmm5,%xmm1
  addss  (%rbx,%rax,4),%xmm7
  mov    0x28(%rsp),%rax
  addss  %xmm3,%xmm3
  add    0x8(%rsp),%rax
  mov    (%rsp),%edi
  mulss  %xmm5,%xmm7
  mulss  %xmm2,%xmm3
  addss  %xmm2,%xmm2
  addss  %xmm7,%xmm1
  mulss  %xmm6,%xmm1
  addss  %xmm1,%xmm0
  movss  (%r14,%rbp,1),%xmm1
  mulss  %xmm4,%xmm1
  addss  0x4(%r14,%rbp,1),%xmm1
  addss  (%r14,%r12,1),%xmm1
  addss  -0x4(%r14,%rbp,1),%xmm1
  addss  (%rax,%rbp,1),%xmm1
  add    $0x4,%rbp
  subss  %xmm3,%xmm0
  mov    0x40(%rsp),%rax
  mulss  %xmm5,%xmm1
  mulss  %xmm1,%xmm0
  movss  (%r12),%xmm1
  mulss  %xmm4,%xmm1
  addss  0x4(%r12),%xmm1
  addss  (%rax,%r12,1),%xmm1
  mov    %r15d,%eax
  addss  -0x4(%r12),%xmm1
  addss  -0x4(%rbp),%xmm1
  sub    0x4(%rsp),%eax
  mulss  %xmm5,%xmm1
  subss  %xmm1,%xmm2
  addss  %xmm2,%xmm0
  movss  %xmm0,(%r11,%r12,1)
  cmp    %edi,%eax
  jg     L58
  addl   $0x1,0x54(%rsp)
  mov    0x54(%rsp),%esi
  mov    0x60(%rsp),%eax
  sub    0x4(%rsp),%eax
  cmp    %eax,%esi
  jge    L30
  mov    0x4(%rsp),%eax
  add    %r15d,0x20(%rsp)
  mov    %eax,%esi
  mov    %eax,(%rsp)
  mov    %r15d,%eax
  sub    %esi,%eax
  cmp    %esi,%eax
  jg     L69
L30:
  mov    0x58(%rsp),%rdi
  call   <free@plt>
  add    $0x88,%rsp
  xor    %eax,%eax
  pop    %rbx
  pop    %rbp
  pop    %r12
  pop    %r13
  pop    %r14
  pop    %r15
  ret
L79:
  mov    %edi,0x4(%rsp)
  call   <sqrtf@plt>
  mov    0x4(%rsp),%edi
  jmp    L21
```

tool_calls: name: unpack_data
arguments: data_label: D18
type_guessed: byte[4]
name: unpack_data
arguments: data_label: D6
type_guessed: byte[4]

tool: {"D18": [0x00,0x00,0x80,0x40]}

tool: {"D6": [0x00,0x00,0x00,0x3e]}

assistant: ```c
int step_forward_k(float *tgt_p, float *src_p, float *v, int nz, int nx, float rz, float rx, float s, int k, float dt, float CFL, float dx, float dz) {
  int iz;
  int ix;
  int ioff;
  float two = 2.0;
  float k2 = k * k, k_rz = rz / k2, k_rx = rx / k2, k_s = 2.f * (k_rz + k_rx);
  int k_nz = k * nz, k1_nz = (k - 1) * nz, k1 = k - 1, kp1 = k + 1;
  float src_iz_plus_1, src_iz_minus_1, src_ix_iz, src_ix_plus_1, src_ix_minus_1, tgt_ix_iz, vel;
  int ioffkzp, ioffkzm, ioffkxp, ioffkxm, num_cfl = 0;
  float *tgt = (float *)malloc(nx * nz * sizeof(float));
  memcpy(tgt, tgt_p, nx * nz * sizeof(float));
  for (ix = kp1; ix < nx - kp1; ix++) {
    for (iz = kp1; iz < nz - kp1; iz++) {
      ioff = iz + ix * nz;
      vel = sqrtf(v[ioff]);
      k = floor(vel * dt / (CFL * fmaxf(dx, dz))) + 1;
      k2 = k * k;
      k_rz = rz / k2;
      k_rx = rx / k2;
      k_s = 2.f * (k_rz + k_rx);
      k_nz = k * nz;
      k1_nz = (k - 1) * nz;
      k1 = k - 1;
      kp1 = k + 1;
      ioffkzp = ioff + k;
      ioffkzm = ioff - k;
      ioffkxp = ioff + k_nz;
      ioffkxm = ioff - k_nz;
      tgt_ix_iz = 0.125f * (4.f * tgt[ioff] + tgt[ioff + 1] + tgt[ioff + nz] + tgt[ioff - 1] + tgt[ioff - nz]);
      src_ix_iz = 0.125f * (4.f * src_p[ioff] + src_p[ioff + 1] + src_p[ioff + nz] + src_p[ioff - 1] + src_p[ioff - nz]);
      src_ix_plus_1 = 0.125f * (4.f * src_p[ioffkxp] + src_p[ioffkxp + 1] + src_p[ioffkxp + nz] + src_p[ioffkxp - 1] + src_p[ioffkxp - nz]);
      src_ix_minus_1 = 0.125f * (4.f * src_p[ioffkxm] + src_p[ioffkxm + 1] + src_p[ioffkxm + nz] + src_p[ioffkxm - 1] + src_p[ioffkxm - nz]);
      src_iz_plus_1 = 0.125f * (4.f * src_p[ioffkzp] + src_p[ioffkzp + 1] + src_p[ioffkzp + nz] + src_p[ioffkzp - 1] + src_p[ioffkzp - nz]);
      src_iz_minus_1 = 0.125f * (4.f * src_p[ioffkzm] + src_p[ioffkzm + 1] + src_p[ioffkzm + nz] + src_p[ioffkzm - 1] + src_p[ioffkzm - nz]);
      vel = 0.125f * (4.f * v[ioff] + v[ioff + 1] + v[ioff + nz] + v[ioff - 1] + v[ioff - nz]);
      tgt_p[ioff] = two * src_ix_iz - tgt_ix_iz + vel * (k_rz * (src_iz_plus_1 + src_iz_minus_1) + k_rx * (src_ix_plus_1 + src_ix_minus_1) - k_s * src_ix_iz);
    }
  }
  free(tgt);
  return num_cfl;
}
```