Average Error: 1.0 → 1.0
Time: 12.8s
Precision: binary64
\[\sqrt{\frac{1}{2} \cdot \left(1 + \frac{1}{\sqrt{1 + {\left(\frac{2 \cdot \ell}{Om}\right)}^{2} \cdot \left({\sin kx}^{2} + {\sin ky}^{2}\right)}}\right)} \]
↓
\[\sqrt{0.5 + \sqrt{0.5} \cdot \sqrt{\frac{0.5}{\mathsf{fma}\left({\left(\frac{2 \cdot \ell}{Om}\right)}^{2}, {\sin kx}^{2} + {\sin ky}^{2}, 1\right)}}} \]
\sqrt{\frac{1}{2} \cdot \left(1 + \frac{1}{\sqrt{1 + {\left(\frac{2 \cdot \ell}{Om}\right)}^{2} \cdot \left({\sin kx}^{2} + {\sin ky}^{2}\right)}}\right)}
↓
\sqrt{0.5 + \sqrt{0.5} \cdot \sqrt{\frac{0.5}{\mathsf{fma}\left({\left(\frac{2 \cdot \ell}{Om}\right)}^{2}, {\sin kx}^{2} + {\sin ky}^{2}, 1\right)}}}

(FPCore (l Om kx ky)
 :precision binary64
 (sqrt
  (*
   (/ 1.0 2.0)
   (+
    1.0
    (/
     1.0
     (sqrt
      (+
       1.0
       (*
        (pow (/ (* 2.0 l) Om) 2.0)
        (+ (pow (sin kx) 2.0) (pow (sin ky) 2.0))))))))))
↓
(FPCore (l Om kx ky)
 :precision binary64
 (sqrt
  (+
   0.5
   (*
    (sqrt 0.5)
    (sqrt
     (/
      0.5
      (fma
       (pow (/ (* 2.0 l) Om) 2.0)
       (+ (pow (sin kx) 2.0) (pow (sin ky) 2.0))
       1.0)))))))
double code(double l, double Om, double kx, double ky) {
	return sqrt(((1.0 / 2.0) * (1.0 + (1.0 / sqrt((1.0 + (pow(((2.0 * l) / Om), 2.0) * (pow(sin(kx), 2.0) + pow(sin(ky), 2.0)))))))));
}
↓
double code(double l, double Om, double kx, double ky) {
	return sqrt((0.5 + (sqrt(0.5) * sqrt((0.5 / fma(pow(((2.0 * l) / Om), 2.0), (pow(sin(kx), 2.0) + pow(sin(ky), 2.0)), 1.0))))));
}

Error

Bits error versus l

Bits error versus Om

Bits error versus kx

Bits error versus ky

Derivation

  1. Initial program 1.0

    \[\sqrt{\frac{1}{2} \cdot \left(1 + \frac{1}{\sqrt{1 + {\left(\frac{2 \cdot \ell}{Om}\right)}^{2} \cdot \left({\sin kx}^{2} + {\sin ky}^{2}\right)}}\right)} \]

  2. Simplified1.0

    \[\leadsto \color{blue}{\sqrt{0.5 + \frac{0.5}{\sqrt{\mathsf{fma}\left({\left(\frac{2 \cdot \ell}{Om}\right)}^{2}, {\sin kx}^{2} + {\sin ky}^{2}, 1\right)}}}} \]

  3. Applied *-un-lft-identity_binary641.0

    \[\leadsto \sqrt{0.5 + \frac{0.5}{\sqrt{\color{blue}{1 \cdot \mathsf{fma}\left({\left(\frac{2 \cdot \ell}{Om}\right)}^{2}, {\sin kx}^{2} + {\sin ky}^{2}, 1\right)}}}} \]

  4. Applied sqrt-prod_binary641.0

    \[\leadsto \sqrt{0.5 + \frac{0.5}{\color{blue}{\sqrt{1} \cdot \sqrt{\mathsf{fma}\left({\left(\frac{2 \cdot \ell}{Om}\right)}^{2}, {\sin kx}^{2} + {\sin ky}^{2}, 1\right)}}}} \]

  5. Applied add-sqr-sqrt_binary641.0

    \[\leadsto \sqrt{0.5 + \frac{\color{blue}{\sqrt{0.5} \cdot \sqrt{0.5}}}{\sqrt{1} \cdot \sqrt{\mathsf{fma}\left({\left(\frac{2 \cdot \ell}{Om}\right)}^{2}, {\sin kx}^{2} + {\sin ky}^{2}, 1\right)}}} \]

  6. Applied times-frac_binary641.0

    \[\leadsto \sqrt{0.5 + \color{blue}{\frac{\sqrt{0.5}}{\sqrt{1}} \cdot \frac{\sqrt{0.5}}{\sqrt{\mathsf{fma}\left({\left(\frac{2 \cdot \ell}{Om}\right)}^{2}, {\sin kx}^{2} + {\sin ky}^{2}, 1\right)}}}} \]

  7. Simplified1.0

    \[\leadsto \sqrt{0.5 + \color{blue}{\sqrt{0.5}} \cdot \frac{\sqrt{0.5}}{\sqrt{\mathsf{fma}\left({\left(\frac{2 \cdot \ell}{Om}\right)}^{2}, {\sin kx}^{2} + {\sin ky}^{2}, 1\right)}}} \]

  8. Applied sqrt-undiv_binary641.0

    \[\leadsto \sqrt{0.5 + \sqrt{0.5} \cdot \color{blue}{\sqrt{\frac{0.5}{\mathsf{fma}\left({\left(\frac{2 \cdot \ell}{Om}\right)}^{2}, {\sin kx}^{2} + {\sin ky}^{2}, 1\right)}}}} \]

  9. Final simplification1.0

    \[\leadsto \sqrt{0.5 + \sqrt{0.5} \cdot \sqrt{\frac{0.5}{\mathsf{fma}\left({\left(\frac{2 \cdot \ell}{Om}\right)}^{2}, {\sin kx}^{2} + {\sin ky}^{2}, 1\right)}}} \]

Reproduce

herbie shell --seed 2022160 
(FPCore (l Om kx ky)
  :name "Toniolo and Linder, Equation (3a)"
  :precision binary64
  (sqrt (* (/ 1.0 2.0) (+ 1.0 (/ 1.0 (sqrt (+ 1.0 (* (pow (/ (* 2.0 l) Om) 2.0) (+ (pow (sin kx) 2.0) (pow (sin ky) 2.0))))))))))