예제 #1
0
파일: vrsqrteQf32.c 프로젝트: 0day-ci/gcc
void test_vrsqrteQf32 (void)
{
  float32x4_t out_float32x4_t;
  float32x4_t arg0_float32x4_t;

  out_float32x4_t = vrsqrteq_f32 (arg0_float32x4_t);
}
예제 #2
0
inline float32x4_t cv_vrsqrtq_f32(float32x4_t val)
{
    float32x4_t e = vrsqrteq_f32(val);
    e = vmulq_f32(vrsqrtsq_f32(vmulq_f32(e, e), val), e);
    e = vmulq_f32(vrsqrtsq_f32(vmulq_f32(e, e), val), e);
    return e;
}
예제 #3
0
static float32x4_t vsqrtq_f32(float32x4_t s) {
  int i;
  float32x4_t x = vrsqrteq_f32(s);

  // Code to handle sqrt(0).
  // If the input to sqrtf() is zero, a zero will be returned.
  // If the input to vrsqrteq_f32() is zero, positive infinity is returned.
  const uint32x4_t vec_p_inf = vdupq_n_u32(0x7F800000);
  // check for divide by zero
  const uint32x4_t div_by_zero = vceqq_u32(vec_p_inf, vreinterpretq_u32_f32(x));
  // zero out the positive infinity results
  x = vreinterpretq_f32_u32(vandq_u32(vmvnq_u32(div_by_zero),
                                      vreinterpretq_u32_f32(x)));
  // from arm documentation
  // The Newton-Raphson iteration:
  //     x[n+1] = x[n] * (3 - d * (x[n] * x[n])) / 2)
  // converges to (1/√d) if x0 is the result of VRSQRTE applied to d.
  //
  // Note: The precision did not improve after 2 iterations.
  for (i = 0; i < 2; i++) {
    x = vmulq_f32(vrsqrtsq_f32(vmulq_f32(x, x), s), x);
  }
  // sqrt(s) = s * 1/sqrt(s)
  return vmulq_f32(s, x);;
}
예제 #4
0
inline v_float32x4 v_invsqrt(const v_float32x4& x)
{
    float32x4_t e = vrsqrteq_f32(x.val);
    e = vmulq_f32(vrsqrtsq_f32(vmulq_f32(x.val, e), e), e);
    e = vmulq_f32(vrsqrtsq_f32(vmulq_f32(x.val, e), e), e);
    return v_float32x4(e);
}
예제 #5
0
inline v_float32x4 v_sqrt(const v_float32x4& x)
{
    float32x4_t x1 = vmaxq_f32(x.val, vdupq_n_f32(FLT_MIN));
    float32x4_t e = vrsqrteq_f32(x1);
    e = vmulq_f32(vrsqrtsq_f32(vmulq_f32(x1, e), e), e);
    e = vmulq_f32(vrsqrtsq_f32(vmulq_f32(x1, e), e), e);
    return v_float32x4(vmulq_f32(x.val, e));
}
예제 #6
0
float32x4_t test_vrsqrteq_f32(float32x4_t in) {
  // CHECK-LABEL: @test_vrsqrteq_f32
  // CHECK: call <4 x float> @llvm.arm64.neon.frsqrte.v4f32(<4 x float> %in)
  return vrsqrteq_f32(in);
}