
(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 10 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 (* t_1 tau))) (/ (/ (sin t_2) t_1) (/ t_2 (sin t_1)))))
\begin{array}{l}
\\
\begin{array}{l}
t_1 := x \cdot \mathsf{PI}\left(\right)\\
t_2 := t\_1 \cdot tau\\
\frac{\frac{\sin t\_2}{t\_1}}{\frac{t\_2}{\sin t\_1}}
\end{array}
\end{array}
Initial program 97.7%
lift-*.f32N/A
lift-/.f32N/A
clear-numN/A
un-div-invN/A
lift-/.f32N/A
lift-*.f32N/A
associate-/r*N/A
associate-/r*N/A
lower-/.f32N/A
Applied rewrites97.8%
Final simplification97.8%
(FPCore (x tau) :precision binary32 (let* ((t_1 (* x (PI))) (t_2 (* t_1 tau))) (/ (* (sin 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 := t\_1 \cdot tau\\
\frac{\sin t\_1 \cdot \frac{\sin t\_2}{t\_1}}{t\_2}
\end{array}
\end{array}
Initial program 97.7%
lift-*.f32N/A
lift-/.f32N/A
associate-*l/N/A
lower-/.f32N/A
Applied rewrites97.7%
Final simplification97.7%
(FPCore (x tau) :precision binary32 (let* ((t_1 (* x (PI))) (t_2 (* (* x tau) (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(x \cdot tau\right) \cdot \mathsf{PI}\left(\right)\\
\frac{\sin t\_1}{t\_1} \cdot \frac{\sin t\_2}{t\_2}
\end{array}
\end{array}
Initial program 97.7%
lift-*.f32N/A
*-commutativeN/A
lift-*.f32N/A
associate-*r*N/A
lower-*.f32N/A
lower-*.f3297.0
Applied rewrites97.0%
lift-*.f32N/A
*-commutativeN/A
lift-*.f32N/A
associate-*l*N/A
lift-*.f32N/A
lift-*.f3297.7
lift-*.f32N/A
*-commutativeN/A
lower-*.f3297.7
Applied rewrites97.7%
Final simplification97.7%
(FPCore (x tau) :precision binary32 (let* ((t_1 (* x (PI))) (t_2 (* t_1 tau))) (/ (* (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 := t\_1 \cdot tau\\
\frac{\sin t\_1 \cdot \sin t\_2}{t\_2 \cdot t\_1}
\end{array}
\end{array}
Initial program 97.7%
lift-*.f32N/A
lift-/.f32N/A
clear-numN/A
un-div-invN/A
lift-/.f32N/A
lift-*.f32N/A
associate-/r*N/A
associate-/r*N/A
lower-/.f32N/A
Applied rewrites97.8%
lift-/.f32N/A
lift-/.f32N/A
associate-/l/N/A
div-invN/A
lift-/.f32N/A
lift-*.f32N/A
lift-*.f32N/A
*-commutativeN/A
lift-*.f32N/A
*-commutativeN/A
lift-*.f32N/A
lift-*.f32N/A
*-commutativeN/A
lift-*.f32N/A
Applied rewrites97.7%
lift-/.f32N/A
lift-*.f32N/A
associate-/l*N/A
lift-/.f32N/A
lift-*.f32N/A
*-commutativeN/A
lift-*.f32N/A
lift-*.f32N/A
*-commutativeN/A
lower-*.f32N/A
lift-*.f32N/A
*-commutativeN/A
lift-*.f32N/A
Applied rewrites97.6%
Final simplification97.6%
(FPCore (x tau) :precision binary32 (* (- (sin (* x (PI)))) (- (* (* (* tau tau) (PI)) (* 0.16666666666666666 x)) (/ (/ 1.0 (PI)) x))))
\begin{array}{l}
\\
\left(-\sin \left(x \cdot \mathsf{PI}\left(\right)\right)\right) \cdot \left(\left(\left(tau \cdot tau\right) \cdot \mathsf{PI}\left(\right)\right) \cdot \left(0.16666666666666666 \cdot x\right) - \frac{\frac{1}{\mathsf{PI}\left(\right)}}{x}\right)
\end{array}
Initial program 97.7%
lift-*.f32N/A
lift-/.f32N/A
clear-numN/A
un-div-invN/A
frac-2negN/A
associate-/r/N/A
lower-*.f32N/A
Applied rewrites97.6%
Taylor expanded in tau around 0
sub-negN/A
associate-*r*N/A
*-commutativeN/A
associate-*r*N/A
associate-*r*N/A
lower-fma.f32N/A
*-commutativeN/A
lower-*.f32N/A
*-commutativeN/A
unpow2N/A
associate-*r*N/A
*-commutativeN/A
lower-*.f32N/A
lower-*.f32N/A
lower-PI.f32N/A
associate-/l/N/A
distribute-frac-negN/A
Applied rewrites27.4%
Applied rewrites78.2%
Final simplification78.2%
(FPCore (x tau) :precision binary32 (let* ((t_1 (* (* x (PI)) tau))) (* 1.0 (/ (sin t_1) t_1))))
\begin{array}{l}
\\
\begin{array}{l}
t_1 := \left(x \cdot \mathsf{PI}\left(\right)\right) \cdot tau\\
1 \cdot \frac{\sin t\_1}{t\_1}
\end{array}
\end{array}
Initial program 97.7%
Taylor expanded in x around 0
Applied rewrites70.4%
Final simplification70.4%
(FPCore (x tau) :precision binary32 (* (/ (sin (* (* x (PI)) tau)) (* (* x tau) (PI))) 1.0))
\begin{array}{l}
\\
\frac{\sin \left(\left(x \cdot \mathsf{PI}\left(\right)\right) \cdot tau\right)}{\left(x \cdot tau\right) \cdot \mathsf{PI}\left(\right)} \cdot 1
\end{array}
Initial program 97.7%
lift-*.f32N/A
*-commutativeN/A
lift-*.f32N/A
associate-*r*N/A
lower-*.f32N/A
lower-*.f3297.0
Applied rewrites97.0%
Taylor expanded in x around 0
Applied rewrites70.1%
Final simplification70.1%
(FPCore (x tau) :precision binary32 (+ (* (pow (* x (PI)) 2.0) (* -0.16666666666666666 (fma tau tau 1.0))) 1.0))
\begin{array}{l}
\\
{\left(x \cdot \mathsf{PI}\left(\right)\right)}^{2} \cdot \left(-0.16666666666666666 \cdot \mathsf{fma}\left(tau, tau, 1\right)\right) + 1
\end{array}
Initial program 97.7%
lift-*.f32N/A
lift-/.f32N/A
clear-numN/A
un-div-invN/A
lift-/.f32N/A
lift-*.f32N/A
associate-/r*N/A
associate-/r*N/A
lower-/.f32N/A
Applied rewrites97.8%
lift-/.f32N/A
lift-/.f32N/A
associate-/l/N/A
div-invN/A
lift-/.f32N/A
lift-*.f32N/A
lift-*.f32N/A
*-commutativeN/A
lift-*.f32N/A
*-commutativeN/A
lift-*.f32N/A
lift-*.f32N/A
*-commutativeN/A
lift-*.f32N/A
Applied rewrites97.7%
Taylor expanded in x around 0
+-commutativeN/A
distribute-rgt-inN/A
associate-*r*N/A
associate-*l*N/A
*-commutativeN/A
associate-*r*N/A
*-commutativeN/A
associate-*l*N/A
*-commutativeN/A
associate-*l*N/A
*-commutativeN/A
distribute-lft1-inN/A
Applied rewrites62.6%
Applied rewrites42.2%
Final simplification42.1%
(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 97.7%
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.f3263.7
Applied rewrites63.7%
Final simplification63.7%
(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 97.7%
Taylor expanded in x around 0
Applied rewrites62.9%
herbie shell --seed 2024271
(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)))))