
(FPCore (x tau) :precision binary32 (let* ((t_1 (* x (PI))) (t_2 (* t_1 tau))) (* (/ (sin t_2) t_2) (/ (sin t_1) t_1))))
\begin{array}{l}
\\
\begin{array}{l}
t_1 := x \cdot \mathsf{PI}\left(\right)\\
t_2 := t\_1 \cdot tau\\
\frac{\sin t\_2}{t\_2} \cdot \frac{\sin t\_1}{t\_1}
\end{array}
\end{array}
Sampling outcomes in binary32 precision:
Herbie found 11 alternatives:
| Alternative | Accuracy | Speedup |
|---|
(FPCore (x tau) :precision binary32 (let* ((t_1 (* x (PI))) (t_2 (* t_1 tau))) (* (/ (sin t_2) t_2) (/ (sin t_1) t_1))))
\begin{array}{l}
\\
\begin{array}{l}
t_1 := x \cdot \mathsf{PI}\left(\right)\\
t_2 := t\_1 \cdot tau\\
\frac{\sin t\_2}{t\_2} \cdot \frac{\sin t\_1}{t\_1}
\end{array}
\end{array}
(FPCore (x tau) :precision binary32 (let* ((t_1 (* x (PI))) (t_2 (* (* tau x) (PI)))) (/ (* (/ (sin t_1) t_1) (sin t_2)) t_2)))
\begin{array}{l}
\\
\begin{array}{l}
t_1 := x \cdot \mathsf{PI}\left(\right)\\
t_2 := \left(tau \cdot x\right) \cdot \mathsf{PI}\left(\right)\\
\frac{\frac{\sin t\_1}{t\_1} \cdot \sin t\_2}{t\_2}
\end{array}
\end{array}
Initial program 97.6%
lift-*.f32N/A
*-commutativeN/A
lift-*.f32N/A
associate-*r*N/A
lower-*.f32N/A
lower-*.f3297.1
Applied rewrites97.1%
lift-*.f32N/A
lift-*.f32N/A
associate-*l*N/A
*-commutativeN/A
associate-*r*N/A
lift-*.f32N/A
*-commutativeN/A
lift-*.f3297.6
lift-*.f32N/A
*-commutativeN/A
lower-*.f3297.6
Applied rewrites97.6%
Applied rewrites97.6%
Final simplification97.6%
(FPCore (x tau) :precision binary32 (let* ((t_1 (* x (PI))) (t_2 (* (* tau x) (PI)))) (/ (* (sin t_1) (sin t_2)) (* t_2 t_1))))
\begin{array}{l}
\\
\begin{array}{l}
t_1 := x \cdot \mathsf{PI}\left(\right)\\
t_2 := \left(tau \cdot x\right) \cdot \mathsf{PI}\left(\right)\\
\frac{\sin t\_1 \cdot \sin t\_2}{t\_2 \cdot t\_1}
\end{array}
\end{array}
Initial program 97.6%
lift-*.f32N/A
*-commutativeN/A
lift-*.f32N/A
associate-*r*N/A
lower-*.f32N/A
lower-*.f3297.1
Applied rewrites97.1%
lift-*.f32N/A
lift-*.f32N/A
associate-*l*N/A
*-commutativeN/A
associate-*r*N/A
lift-*.f32N/A
*-commutativeN/A
lift-*.f3297.6
lift-*.f32N/A
*-commutativeN/A
lower-*.f3297.6
Applied rewrites97.6%
Applied rewrites97.6%
lift-/.f32N/A
Applied rewrites97.6%
Final simplification97.6%
(FPCore (x tau) :precision binary32 (let* ((t_1 (* x (PI)))) (/ (* (sin t_1) (sin (* (* tau x) (PI)))) (* (* (* t_1 (PI)) x) tau))))
\begin{array}{l}
\\
\begin{array}{l}
t_1 := x \cdot \mathsf{PI}\left(\right)\\
\frac{\sin t\_1 \cdot \sin \left(\left(tau \cdot x\right) \cdot \mathsf{PI}\left(\right)\right)}{\left(\left(t\_1 \cdot \mathsf{PI}\left(\right)\right) \cdot x\right) \cdot tau}
\end{array}
\end{array}
Initial program 97.6%
lift-*.f32N/A
*-commutativeN/A
lift-*.f32N/A
associate-*r*N/A
lower-*.f32N/A
lower-*.f3297.1
Applied rewrites97.1%
lift-*.f32N/A
lift-*.f32N/A
associate-*l*N/A
*-commutativeN/A
associate-*r*N/A
lift-*.f32N/A
*-commutativeN/A
lift-*.f3297.6
lift-*.f32N/A
*-commutativeN/A
lower-*.f3297.6
Applied rewrites97.6%
Applied rewrites97.6%
Applied rewrites97.0%
Final simplification97.0%
(FPCore (x tau) :precision binary32 (* (/ (sin (* x (PI))) (* (* (* (* tau (PI)) (PI)) x) x)) (sin (* (* tau x) (PI)))))
\begin{array}{l}
\\
\frac{\sin \left(x \cdot \mathsf{PI}\left(\right)\right)}{\left(\left(\left(tau \cdot \mathsf{PI}\left(\right)\right) \cdot \mathsf{PI}\left(\right)\right) \cdot x\right) \cdot x} \cdot \sin \left(\left(tau \cdot x\right) \cdot \mathsf{PI}\left(\right)\right)
\end{array}
Initial program 97.6%
lift-*.f32N/A
*-commutativeN/A
lift-*.f32N/A
associate-*r*N/A
lower-*.f32N/A
lower-*.f3297.1
Applied rewrites97.1%
lift-*.f32N/A
lift-*.f32N/A
associate-*l*N/A
*-commutativeN/A
associate-*r*N/A
lift-*.f32N/A
*-commutativeN/A
lift-*.f3297.6
lift-*.f32N/A
*-commutativeN/A
lower-*.f3297.6
Applied rewrites97.6%
Applied rewrites97.6%
Applied rewrites96.7%
Final simplification96.7%
(FPCore (x tau) :precision binary32 (let* ((t_1 (* x (PI))) (t_2 (* tau t_1))) (/ (* t_1 (/ (sin t_2) t_1)) t_2)))
\begin{array}{l}
\\
\begin{array}{l}
t_1 := x \cdot \mathsf{PI}\left(\right)\\
t_2 := tau \cdot t\_1\\
\frac{t\_1 \cdot \frac{\sin t\_2}{t\_1}}{t\_2}
\end{array}
\end{array}
Initial program 97.6%
lift-*.f32N/A
lift-/.f32N/A
associate-*l/N/A
lower-/.f32N/A
Applied rewrites97.5%
Taylor expanded in x around 0
*-commutativeN/A
lower-*.f32N/A
lower-PI.f3271.5
Applied rewrites71.5%
Final simplification71.5%
(FPCore (x tau) :precision binary32 (/ (* -1.0 (sin (* (* tau x) (PI)))) (* (* (- tau) x) (PI))))
\begin{array}{l}
\\
\frac{-1 \cdot \sin \left(\left(tau \cdot x\right) \cdot \mathsf{PI}\left(\right)\right)}{\left(\left(-tau\right) \cdot x\right) \cdot \mathsf{PI}\left(\right)}
\end{array}
Initial program 97.6%
lift-*.f32N/A
*-commutativeN/A
lift-*.f32N/A
associate-*r*N/A
lower-*.f32N/A
lower-*.f3297.1
Applied rewrites97.1%
lift-*.f32N/A
lift-*.f32N/A
associate-*l*N/A
*-commutativeN/A
associate-*r*N/A
lift-*.f32N/A
*-commutativeN/A
lift-*.f3297.6
lift-*.f32N/A
*-commutativeN/A
lower-*.f3297.6
Applied rewrites97.6%
Applied rewrites97.6%
Taylor expanded in x around 0
Applied rewrites71.5%
Final simplification71.5%
(FPCore (x tau) :precision binary32 (let* ((t_1 (* x (PI)))) (/ 1.0 (/ t_1 (sin t_1)))))
\begin{array}{l}
\\
\begin{array}{l}
t_1 := x \cdot \mathsf{PI}\left(\right)\\
\frac{1}{\frac{t\_1}{\sin t\_1}}
\end{array}
\end{array}
Initial program 97.6%
lift-*.f32N/A
*-commutativeN/A
lift-/.f32N/A
lift-*.f32N/A
associate-/r*N/A
frac-2negN/A
lift-/.f32N/A
frac-timesN/A
*-rgt-identityN/A
distribute-rgt-neg-inN/A
metadata-evalN/A
associate-*r*N/A
neg-mul-1N/A
Applied rewrites97.1%
Taylor expanded in x around 0
mul-1-negN/A
associate-*r*N/A
distribute-lft-neg-inN/A
lower-*.f32N/A
distribute-lft-neg-inN/A
mul-1-negN/A
lower-*.f32N/A
mul-1-negN/A
lower-neg.f32N/A
unpow2N/A
lower-*.f32N/A
lower-PI.f32N/A
lower-PI.f3264.0
Applied rewrites64.0%
lift-/.f32N/A
lift-*.f32N/A
*-commutativeN/A
associate-/r*N/A
clear-numN/A
lower-/.f32N/A
Applied rewrites64.0%
Taylor expanded in tau around 0
lower-/.f32N/A
*-commutativeN/A
lower-*.f32N/A
lower-PI.f32N/A
lower-sin.f32N/A
*-commutativeN/A
lower-*.f32N/A
lower-PI.f3265.0
Applied rewrites65.0%
Final simplification65.0%
(FPCore (x tau) :precision binary32 (let* ((t_1 (* x (PI)))) (/ (* (PI) (sin t_1)) (* t_1 (PI)))))
\begin{array}{l}
\\
\begin{array}{l}
t_1 := x \cdot \mathsf{PI}\left(\right)\\
\frac{\mathsf{PI}\left(\right) \cdot \sin t\_1}{t\_1 \cdot \mathsf{PI}\left(\right)}
\end{array}
\end{array}
Initial program 97.6%
lift-*.f32N/A
lift-/.f32N/A
associate-*l/N/A
lower-/.f32N/A
Applied rewrites97.5%
lift-/.f32N/A
lift-*.f32N/A
associate-/l*N/A
*-commutativeN/A
lift-/.f32N/A
times-fracN/A
*-commutativeN/A
frac-timesN/A
Applied rewrites97.1%
Taylor expanded in x around 0
lower-PI.f3265.0
Applied rewrites65.0%
(FPCore (x tau) :precision binary32 (let* ((t_1 (* x (PI)))) (/ (* (sin t_1) tau) (* tau t_1))))
\begin{array}{l}
\\
\begin{array}{l}
t_1 := x \cdot \mathsf{PI}\left(\right)\\
\frac{\sin t\_1 \cdot tau}{tau \cdot t\_1}
\end{array}
\end{array}
Initial program 97.6%
lift-*.f32N/A
lift-/.f32N/A
associate-*l/N/A
lower-/.f32N/A
Applied rewrites97.5%
Taylor expanded in tau around 0
*-commutativeN/A
lower-*.f32N/A
lower-sin.f32N/A
*-commutativeN/A
lower-*.f32N/A
lower-PI.f3265.0
Applied rewrites65.0%
Final simplification65.0%
(FPCore (x tau) :precision binary32 (let* ((t_1 (* x (PI)))) (/ (sin t_1) t_1)))
\begin{array}{l}
\\
\begin{array}{l}
t_1 := x \cdot \mathsf{PI}\left(\right)\\
\frac{\sin t\_1}{t\_1}
\end{array}
\end{array}
Initial program 97.6%
lift-*.f32N/A
*-commutativeN/A
lift-*.f32N/A
associate-*r*N/A
lower-*.f32N/A
lower-*.f3297.1
Applied rewrites97.1%
lift-*.f32N/A
lift-*.f32N/A
associate-*l*N/A
*-commutativeN/A
associate-*r*N/A
lift-*.f32N/A
*-commutativeN/A
lift-*.f3297.6
lift-*.f32N/A
*-commutativeN/A
lower-*.f3297.6
Applied rewrites97.6%
Applied rewrites97.6%
Taylor expanded in tau around 0
lower-/.f32N/A
lower-sin.f32N/A
*-commutativeN/A
lower-*.f32N/A
lower-PI.f32N/A
*-commutativeN/A
lower-*.f32N/A
lower-PI.f3265.0
Applied rewrites65.0%
Final simplification65.0%
(FPCore (x tau) :precision binary32 1.0)
float code(float x, float tau) {
return 1.0f;
}
real(4) function code(x, tau)
real(4), intent (in) :: x
real(4), intent (in) :: tau
code = 1.0e0
end function
function code(x, tau) return Float32(1.0) end
function tmp = code(x, tau) tmp = single(1.0); end
\begin{array}{l}
\\
1
\end{array}
Initial program 97.6%
Taylor expanded in x around 0
Applied rewrites64.2%
herbie shell --seed 2024331
(FPCore (x tau)
:name "Lanczos kernel"
:precision binary32
:pre (and (and (<= 1e-5 x) (<= x 1.0)) (and (<= 1.0 tau) (<= tau 5.0)))
(* (/ (sin (* (* x (PI)) tau)) (* (* x (PI)) tau)) (/ (sin (* x (PI))) (* x (PI)))))