Function rope

src/infer.cpp:648–668

}

static void rope(float* buf, float* vec, int d, int head_dim, int pos, float theta) {
  // For some reason, DeepSeek-V2 was trained using rope output 
  // layout transposed compared to the input. This means we need a buffer
  // to hold intermediate results.
  assert(d % 2 == 0);
  for (int i = 0; i < d; i += 2) {
    int j_head = i % head_dim;
    float freq = 1.0f / powf(theta, (float)j_head / (float)head_dim);
    float val = pos * freq;
    float fcr = cosf(val);
    float fci = sinf(val);

    float v0 = vec[i];
    float v1 = vec[i + 1];
    buf[i/2] = v0 * fcr - v1 * fci;
    buf[i/2 + d/2] = v0 * fci + v1 * fcr;
  }
  for (int i = 0; i < d; i++) {
    vec[i] = buf[i];
  }
}

static void rope_v3(float* vec, int d, int head_dim, int pos, float theta) {
  int rotary_dim = head_dim;