
(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 t_1))) (/ (* (/ (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 := tau \cdot t\_1\\
\frac{\frac{\sin t\_1}{t\_1} \cdot \sin t\_2}{t\_2}
\end{array}
\end{array}
Initial program 98.1%
lift-*.f32N/A
lift-/.f32N/A
associate-*r/N/A
lift-/.f32N/A
div-invN/A
associate-*l*N/A
associate-*l/N/A
clear-numN/A
Applied rewrites98.1%
lift-/.f32N/A
div-invN/A
lift-/.f32N/A
clear-numN/A
lift-/.f32N/A
clear-numN/A
lift-/.f32N/A
frac-timesN/A
*-lft-identityN/A
Applied rewrites98.1%
lift-/.f32N/A
lift-*.f32N/A
associate-/r*N/A
lift-/.f32N/A
associate-/r/N/A
associate-*l/N/A
associate-/r*N/A
frac-timesN/A
Applied rewrites98.2%
Final simplification98.2%
(FPCore (x tau) :precision binary32 (let* ((t_1 (* x (PI))) (t_2 (* tau t_1))) (* (/ (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 := tau \cdot t\_1\\
\frac{\sin t\_1}{t\_1} \cdot \frac{\sin t\_2}{t\_2}
\end{array}
\end{array}
Initial program 98.1%
Final simplification98.1%
(FPCore (x tau) :precision binary32 (let* ((t_1 (* (* tau x) (PI))) (t_2 (* x (PI)))) (* (/ (sin t_1) t_1) (/ (sin t_2) t_2))))
\begin{array}{l}
\\
\begin{array}{l}
t_1 := \left(tau \cdot x\right) \cdot \mathsf{PI}\left(\right)\\
t_2 := x \cdot \mathsf{PI}\left(\right)\\
\frac{\sin t\_1}{t\_1} \cdot \frac{\sin t\_2}{t\_2}
\end{array}
\end{array}
Initial program 98.1%
lift-*.f32N/A
*-commutativeN/A
lift-*.f32N/A
associate-*r*N/A
lower-*.f32N/A
lower-*.f3297.6
Applied rewrites97.6%
lift-*.f32N/A
lift-*.f32N/A
associate-*l*N/A
*-commutativeN/A
associate-*l*N/A
*-commutativeN/A
lift-*.f32N/A
lift-*.f3298.0
Applied rewrites98.0%
(FPCore (x tau) :precision binary32 (let* ((t_1 (* x (PI))) (t_2 (* tau t_1))) (/ (* (sin t_2) (sin t_1)) (* t_2 t_1))))
\begin{array}{l}
\\
\begin{array}{l}
t_1 := x \cdot \mathsf{PI}\left(\right)\\
t_2 := tau \cdot t\_1\\
\frac{\sin t\_2 \cdot \sin t\_1}{t\_2 \cdot t\_1}
\end{array}
\end{array}
Initial program 98.1%
lift-*.f32N/A
lift-/.f32N/A
associate-*r/N/A
lift-/.f32N/A
div-invN/A
associate-*l*N/A
associate-*l/N/A
clear-numN/A
Applied rewrites98.1%
lift-/.f32N/A
div-invN/A
lift-/.f32N/A
clear-numN/A
lift-/.f32N/A
clear-numN/A
lift-/.f32N/A
frac-timesN/A
*-lft-identityN/A
Applied rewrites98.1%
lift-/.f32N/A
lift-*.f32N/A
associate-/r*N/A
lift-/.f32N/A
associate-/r/N/A
associate-*l/N/A
associate-/r*N/A
frac-timesN/A
frac-2negN/A
Applied rewrites97.9%
Final simplification97.9%
(FPCore (x tau) :precision binary32 (let* ((t_1 (* x (PI))) (t_2 (* tau t_1))) (/ (* (sin t_2) (sin t_1)) (* (* t_2 (PI)) x))))
\begin{array}{l}
\\
\begin{array}{l}
t_1 := x \cdot \mathsf{PI}\left(\right)\\
t_2 := tau \cdot t\_1\\
\frac{\sin t\_2 \cdot \sin t\_1}{\left(t\_2 \cdot \mathsf{PI}\left(\right)\right) \cdot x}
\end{array}
\end{array}
Initial program 98.1%
lift-*.f32N/A
lift-/.f32N/A
associate-*r/N/A
lift-/.f32N/A
div-invN/A
associate-*l*N/A
associate-*l/N/A
clear-numN/A
Applied rewrites98.1%
lift-/.f32N/A
div-invN/A
lift-/.f32N/A
clear-numN/A
lift-/.f32N/A
clear-numN/A
lift-/.f32N/A
frac-timesN/A
*-lft-identityN/A
Applied rewrites98.1%
lift-/.f32N/A
lift-*.f32N/A
associate-/r*N/A
lift-/.f32N/A
associate-/r/N/A
associate-*l/N/A
associate-/r*N/A
*-commutativeN/A
Applied rewrites97.7%
Final simplification97.7%
(FPCore (x tau) :precision binary32 (let* ((t_1 (* x (PI)))) (/ (* (sin (* tau t_1)) (sin t_1)) (* (* (* tau (PI)) t_1) x))))
\begin{array}{l}
\\
\begin{array}{l}
t_1 := x \cdot \mathsf{PI}\left(\right)\\
\frac{\sin \left(tau \cdot t\_1\right) \cdot \sin t\_1}{\left(\left(tau \cdot \mathsf{PI}\left(\right)\right) \cdot t\_1\right) \cdot x}
\end{array}
\end{array}
Initial program 98.1%
lift-*.f32N/A
lift-/.f32N/A
associate-*r/N/A
lift-/.f32N/A
div-invN/A
associate-*l*N/A
associate-*l/N/A
clear-numN/A
Applied rewrites98.1%
lift-/.f32N/A
div-invN/A
lift-/.f32N/A
clear-numN/A
lift-/.f32N/A
clear-numN/A
lift-/.f32N/A
frac-timesN/A
*-lft-identityN/A
Applied rewrites98.1%
lift-/.f32N/A
lift-*.f32N/A
associate-/r*N/A
lift-/.f32N/A
associate-/r/N/A
associate-*l/N/A
associate-/r*N/A
frac-timesN/A
Applied rewrites98.2%
Applied rewrites97.2%
Final simplification97.2%
(FPCore (x tau) :precision binary32 (+ (* (+ 1.0 (* tau tau)) (* (pow (* x (PI)) 2.0) -0.16666666666666666)) 1.0))
\begin{array}{l}
\\
\left(1 + tau \cdot tau\right) \cdot \left({\left(x \cdot \mathsf{PI}\left(\right)\right)}^{2} \cdot -0.16666666666666666\right) + 1
\end{array}
Initial program 98.1%
Taylor expanded in x around 0
+-commutativeN/A
*-commutativeN/A
lower-fma.f32N/A
Applied rewrites65.5%
Applied rewrites38.0%
Applied rewrites78.9%
Final simplification78.9%
(FPCore (x tau) :precision binary32 (+ (* (* tau tau) (* (pow (* x (PI)) 2.0) -0.16666666666666666)) 1.0))
\begin{array}{l}
\\
\left(tau \cdot tau\right) \cdot \left({\left(x \cdot \mathsf{PI}\left(\right)\right)}^{2} \cdot -0.16666666666666666\right) + 1
\end{array}
Initial program 98.1%
Taylor expanded in x around 0
+-commutativeN/A
*-commutativeN/A
lower-fma.f32N/A
Applied rewrites65.5%
Applied rewrites38.0%
Taylor expanded in tau around inf
Applied rewrites71.2%
Final simplification71.2%
(FPCore (x tau) :precision binary32 (+ (* (* (* (* x x) (PI)) (PI)) (* (* tau tau) -0.16666666666666666)) 1.0))
\begin{array}{l}
\\
\left(\left(\left(x \cdot x\right) \cdot \mathsf{PI}\left(\right)\right) \cdot \mathsf{PI}\left(\right)\right) \cdot \left(\left(tau \cdot tau\right) \cdot -0.16666666666666666\right) + 1
\end{array}
Initial program 98.1%
Taylor expanded in x around 0
+-commutativeN/A
*-commutativeN/A
lower-fma.f32N/A
Applied rewrites65.5%
Applied rewrites38.0%
Taylor expanded in tau around inf
Applied rewrites71.2%
Final simplification71.2%
(FPCore (x tau) :precision binary32 (+ (* (* (* (* x x) -0.16666666666666666) (PI)) (PI)) 1.0))
\begin{array}{l}
\\
\left(\left(\left(x \cdot x\right) \cdot -0.16666666666666666\right) \cdot \mathsf{PI}\left(\right)\right) \cdot \mathsf{PI}\left(\right) + 1
\end{array}
Initial program 98.1%
Taylor expanded in x around 0
+-commutativeN/A
*-commutativeN/A
lower-fma.f32N/A
Applied rewrites65.5%
Applied rewrites38.0%
Taylor expanded in tau around 0
Applied rewrites66.5%
(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 98.1%
Taylor expanded in x around 0
Applied rewrites65.7%
herbie shell --seed 2024266
(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)))))