
(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 (* (PI) x)) (t_2 (* t_1 tau))) (* (/ (sin t_2) t_2) (/ (sin t_1) t_1))))
\begin{array}{l}
\\
\begin{array}{l}
t_1 := \mathsf{PI}\left(\right) \cdot x\\
t_2 := t\_1 \cdot tau\\
\frac{\sin t\_2}{t\_2} \cdot \frac{\sin t\_1}{t\_1}
\end{array}
\end{array}
Initial program 97.8%
lift-*.f32N/A
*-commutativeN/A
lift-/.f32N/A
clear-numN/A
frac-2negN/A
metadata-evalN/A
lift-/.f32N/A
frac-timesN/A
neg-mul-1N/A
lower-/.f32N/A
Applied rewrites97.7%
Applied rewrites97.7%
Applied rewrites97.6%
lift-/.f32N/A
lift-*.f32N/A
*-commutativeN/A
associate-/r*N/A
div-invN/A
lift-/.f32N/A
clear-numN/A
lower-*.f32N/A
Applied rewrites97.8%
Final simplification97.8%
(FPCore (x tau) :precision binary32 (let* ((t_1 (* (PI) x)) (t_2 (* t_1 tau))) (/ (* (sin t_2) (sin t_1)) (* t_2 t_1))))
\begin{array}{l}
\\
\begin{array}{l}
t_1 := \mathsf{PI}\left(\right) \cdot x\\
t_2 := t\_1 \cdot tau\\
\frac{\sin t\_2 \cdot \sin t\_1}{t\_2 \cdot t\_1}
\end{array}
\end{array}
Initial program 97.8%
lift-*.f32N/A
*-commutativeN/A
lift-/.f32N/A
clear-numN/A
frac-2negN/A
metadata-evalN/A
lift-/.f32N/A
frac-timesN/A
neg-mul-1N/A
lower-/.f32N/A
Applied rewrites97.7%
Applied rewrites97.7%
lift-/.f32N/A
frac-2negN/A
Applied rewrites97.6%
lift-*.f32N/A
lift-*.f32N/A
lift-*.f32N/A
lift-neg.f32N/A
distribute-lft-neg-outN/A
*-commutativeN/A
lift-*.f32N/A
distribute-lft-neg-inN/A
lift-*.f32N/A
distribute-rgt-neg-inN/A
distribute-lft-neg-inN/A
lift-*.f32N/A
lift-neg.f32N/A
distribute-lft-neg-outN/A
*-commutativeN/A
lift-*.f32N/A
remove-double-negN/A
lower-*.f3297.6
Applied rewrites97.6%
Final simplification97.6%
(FPCore (x tau) :precision binary32 (let* ((t_1 (* (PI) x)) (t_2 (* t_1 tau))) (/ (* (sin t_2) (sin t_1)) (* (* t_2 x) (PI)))))
\begin{array}{l}
\\
\begin{array}{l}
t_1 := \mathsf{PI}\left(\right) \cdot x\\
t_2 := t\_1 \cdot tau\\
\frac{\sin t\_2 \cdot \sin t\_1}{\left(t\_2 \cdot x\right) \cdot \mathsf{PI}\left(\right)}
\end{array}
\end{array}
Initial program 97.8%
lift-*.f32N/A
*-commutativeN/A
lift-/.f32N/A
clear-numN/A
frac-2negN/A
metadata-evalN/A
lift-/.f32N/A
frac-timesN/A
neg-mul-1N/A
lower-/.f32N/A
Applied rewrites97.7%
Applied rewrites97.7%
Applied rewrites97.3%
Final simplification97.3%
(FPCore (x tau) :precision binary32 (let* ((t_1 (* (PI) x))) (/ (* (sin (* t_1 tau)) (sin t_1)) (* (* (* tau x) t_1) (PI)))))
\begin{array}{l}
\\
\begin{array}{l}
t_1 := \mathsf{PI}\left(\right) \cdot x\\
\frac{\sin \left(t\_1 \cdot tau\right) \cdot \sin t\_1}{\left(\left(tau \cdot x\right) \cdot t\_1\right) \cdot \mathsf{PI}\left(\right)}
\end{array}
\end{array}
Initial program 97.8%
lift-*.f32N/A
*-commutativeN/A
lift-/.f32N/A
clear-numN/A
frac-2negN/A
metadata-evalN/A
lift-/.f32N/A
frac-timesN/A
neg-mul-1N/A
lower-/.f32N/A
Applied rewrites97.7%
Applied rewrites97.7%
lift-/.f32N/A
frac-2negN/A
Applied rewrites97.6%
lift-*.f32N/A
lift-*.f32N/A
associate-*r*N/A
*-commutativeN/A
lift-*.f32N/A
lift-neg.f32N/A
distribute-lft-neg-outN/A
*-commutativeN/A
lift-*.f32N/A
lift-*.f32N/A
lift-neg.f32N/A
distribute-lft-neg-outN/A
*-commutativeN/A
lift-*.f32N/A
sqr-negN/A
associate-*l*N/A
*-commutativeN/A
Applied rewrites97.2%
Final simplification97.2%
(FPCore (x tau) :precision binary32 (let* ((t_1 (* (PI) x)) (t_2 (* t_1 tau))) (/ (sin t_2) (* (/ t_1 t_1) t_2))))
\begin{array}{l}
\\
\begin{array}{l}
t_1 := \mathsf{PI}\left(\right) \cdot x\\
t_2 := t\_1 \cdot tau\\
\frac{\sin t\_2}{\frac{t\_1}{t\_1} \cdot t\_2}
\end{array}
\end{array}
Initial program 97.8%
lift-*.f32N/A
*-commutativeN/A
lift-/.f32N/A
clear-numN/A
frac-2negN/A
metadata-evalN/A
lift-/.f32N/A
frac-timesN/A
neg-mul-1N/A
lower-/.f32N/A
Applied rewrites97.7%
Taylor expanded in x around 0
*-commutativeN/A
lower-*.f32N/A
lower-PI.f3272.2
Applied rewrites72.2%
Final simplification72.2%
(FPCore (x tau) :precision binary32 (let* ((t_1 (* (PI) x)) (t_2 (* t_1 tau))) (/ t_1 (* (/ t_2 (sin t_2)) t_1))))
\begin{array}{l}
\\
\begin{array}{l}
t_1 := \mathsf{PI}\left(\right) \cdot x\\
t_2 := t\_1 \cdot tau\\
\frac{t\_1}{\frac{t\_2}{\sin t\_2} \cdot t\_1}
\end{array}
\end{array}
Initial program 97.8%
lift-*.f32N/A
*-commutativeN/A
lift-/.f32N/A
clear-numN/A
frac-2negN/A
metadata-evalN/A
lift-/.f32N/A
frac-timesN/A
neg-mul-1N/A
lower-/.f32N/A
Applied rewrites97.7%
Applied rewrites97.7%
Applied rewrites97.6%
Taylor expanded in x around 0
*-commutativeN/A
lower-*.f32N/A
lower-PI.f3272.2
Applied rewrites72.2%
(FPCore (x tau) :precision binary32 (let* ((t_1 (* (* (PI) x) tau))) (* (/ 1.0 (* t_1 (PI))) (* (PI) (sin t_1)))))
\begin{array}{l}
\\
\begin{array}{l}
t_1 := \left(\mathsf{PI}\left(\right) \cdot x\right) \cdot tau\\
\frac{1}{t\_1 \cdot \mathsf{PI}\left(\right)} \cdot \left(\mathsf{PI}\left(\right) \cdot \sin t\_1\right)
\end{array}
\end{array}
Initial program 97.8%
lift-*.f32N/A
lift-/.f32N/A
lift-/.f32N/A
lift-*.f32N/A
associate-/r*N/A
frac-timesN/A
div-invN/A
lower-*.f32N/A
Applied rewrites97.4%
Taylor expanded in x around 0
lower-PI.f3272.2
Applied rewrites72.2%
Final simplification72.2%
(FPCore (x tau) :precision binary32 (* (/ (sin (* (PI) x)) (* (* (PI) (PI)) x)) (PI)))
\begin{array}{l}
\\
\frac{\sin \left(\mathsf{PI}\left(\right) \cdot x\right)}{\left(\mathsf{PI}\left(\right) \cdot \mathsf{PI}\left(\right)\right) \cdot x} \cdot \mathsf{PI}\left(\right)
\end{array}
Initial program 97.8%
lift-*.f32N/A
*-commutativeN/A
lift-/.f32N/A
clear-numN/A
frac-2negN/A
metadata-evalN/A
lift-/.f32N/A
frac-timesN/A
neg-mul-1N/A
lower-/.f32N/A
Applied rewrites97.7%
Applied rewrites97.2%
Taylor expanded in x around 0
lower-PI.f3265.7
Applied rewrites65.7%
Final simplification65.7%
(FPCore (x tau) :precision binary32 (let* ((t_1 (* (PI) x))) (/ (sin t_1) t_1)))
\begin{array}{l}
\\
\begin{array}{l}
t_1 := \mathsf{PI}\left(\right) \cdot x\\
\frac{\sin t\_1}{t\_1}
\end{array}
\end{array}
Initial program 97.8%
lift-*.f32N/A
*-commutativeN/A
lift-/.f32N/A
clear-numN/A
frac-2negN/A
metadata-evalN/A
lift-/.f32N/A
frac-timesN/A
neg-mul-1N/A
lower-/.f32N/A
Applied rewrites97.7%
Applied rewrites97.7%
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.f3265.7
Applied rewrites65.7%
(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 97.8%
Taylor expanded in x around 0
Applied rewrites65.0%
herbie shell --seed 2024296
(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)))))