
(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 (sin 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\_2}{\frac{t\_1}{\sin t\_1} \cdot t\_2}
\end{array}
\end{array}
Initial program 98.0%
lift-*.f32N/A
lift-/.f32N/A
clear-numN/A
un-div-invN/A
lower-/.f32N/A
Applied rewrites98.0%
lift-/.f32N/A
div-invN/A
lift-*.f32N/A
lift-*.f32N/A
*-commutativeN/A
associate-*l*N/A
lift-*.f32N/A
lift-*.f32N/A
lift-*.f32N/A
*-commutativeN/A
lift-*.f32N/A
*-commutativeN/A
lift-*.f32N/A
lift-*.f32N/A
lift-/.f32N/A
Applied rewrites98.0%
lift-*.f32N/A
*-commutativeN/A
lift-/.f32N/A
clear-numN/A
lift-/.f32N/A
frac-timesN/A
*-lft-identityN/A
lower-/.f32N/A
Applied rewrites98.0%
Final simplification98.0%
(FPCore (x tau) :precision binary32 (let* ((t_1 (* x (PI))) (t_2 (* t_1 tau))) (* (/ (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 := t\_1 \cdot tau\\
\frac{\sin t\_1}{t\_1} \cdot \frac{\sin t\_2}{t\_2}
\end{array}
\end{array}
Initial program 98.0%
lift-*.f32N/A
lift-/.f32N/A
clear-numN/A
un-div-invN/A
lower-/.f32N/A
Applied rewrites98.0%
lift-/.f32N/A
div-invN/A
lift-*.f32N/A
lift-*.f32N/A
*-commutativeN/A
associate-*l*N/A
lift-*.f32N/A
lift-*.f32N/A
lift-*.f32N/A
*-commutativeN/A
lift-*.f32N/A
*-commutativeN/A
lift-*.f32N/A
lift-*.f32N/A
lift-/.f32N/A
Applied rewrites98.0%
Final simplification98.0%
(FPCore (x tau) :precision binary32 (let* ((t_1 (* x (PI))) (t_2 (* t_1 tau))) (* (/ (sin t_2) t_1) (/ (sin 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\_2}{t\_1} \cdot \frac{\sin t\_1}{t\_2}
\end{array}
\end{array}
Initial program 98.0%
lift-*.f32N/A
lift-/.f32N/A
lift-/.f32N/A
frac-timesN/A
*-commutativeN/A
times-fracN/A
*-lft-identityN/A
associate-*l/N/A
lower-*.f32N/A
Applied rewrites97.9%
Final simplification97.9%
(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 98.0%
lift-*.f32N/A
lift-/.f32N/A
clear-numN/A
un-div-invN/A
lower-/.f32N/A
Applied rewrites98.0%
lift-/.f32N/A
div-invN/A
lift-*.f32N/A
lift-*.f32N/A
*-commutativeN/A
associate-*l*N/A
lift-*.f32N/A
lift-*.f32N/A
lift-*.f32N/A
*-commutativeN/A
lift-*.f32N/A
*-commutativeN/A
lift-*.f32N/A
lift-*.f32N/A
lift-/.f32N/A
Applied rewrites98.0%
lift-*.f32N/A
*-commutativeN/A
lift-/.f32N/A
clear-numN/A
lift-/.f32N/A
frac-timesN/A
*-lft-identityN/A
lower-/.f32N/A
Applied rewrites98.0%
lift-/.f32N/A
*-rgt-identityN/A
lift-*.f32N/A
*-commutativeN/A
lift-*.f32N/A
*-commutativeN/A
lift-*.f32N/A
*-commutativeN/A
lift-PI.f32N/A
frac-timesN/A
lift-/.f32N/A
Applied rewrites97.8%
Final simplification97.8%
(FPCore (x tau) :precision binary32 (let* ((t_1 (* x (PI)))) (/ (* (sin t_1) (sin (* t_1 tau))) (* (* (* (* (PI) (PI)) x) tau) x))))
\begin{array}{l}
\\
\begin{array}{l}
t_1 := x \cdot \mathsf{PI}\left(\right)\\
\frac{\sin t\_1 \cdot \sin \left(t\_1 \cdot tau\right)}{\left(\left(\left(\mathsf{PI}\left(\right) \cdot \mathsf{PI}\left(\right)\right) \cdot x\right) \cdot tau\right) \cdot x}
\end{array}
\end{array}
Initial program 98.0%
lift-*.f32N/A
lift-/.f32N/A
clear-numN/A
un-div-invN/A
lower-/.f32N/A
Applied rewrites98.0%
lift-/.f32N/A
div-invN/A
lift-*.f32N/A
lift-*.f32N/A
*-commutativeN/A
associate-*l*N/A
lift-*.f32N/A
lift-*.f32N/A
lift-*.f32N/A
*-commutativeN/A
lift-*.f32N/A
*-commutativeN/A
lift-*.f32N/A
lift-*.f32N/A
lift-/.f32N/A
Applied rewrites98.0%
lift-*.f32N/A
*-commutativeN/A
lift-/.f32N/A
clear-numN/A
lift-/.f32N/A
frac-timesN/A
*-lft-identityN/A
lower-/.f32N/A
Applied rewrites98.0%
Applied rewrites96.9%
Final simplification96.9%
(FPCore (x tau) :precision binary32 (let* ((t_1 (* x (PI)))) (/ (* (sin t_1) (sin (* t_1 tau))) (* (* x x) (* (* (PI) tau) (PI))))))
\begin{array}{l}
\\
\begin{array}{l}
t_1 := x \cdot \mathsf{PI}\left(\right)\\
\frac{\sin t\_1 \cdot \sin \left(t\_1 \cdot tau\right)}{\left(x \cdot x\right) \cdot \left(\left(\mathsf{PI}\left(\right) \cdot tau\right) \cdot \mathsf{PI}\left(\right)\right)}
\end{array}
\end{array}
Initial program 98.0%
lift-*.f32N/A
lift-/.f32N/A
clear-numN/A
un-div-invN/A
lower-/.f32N/A
Applied rewrites98.0%
lift-/.f32N/A
div-invN/A
lift-*.f32N/A
lift-*.f32N/A
*-commutativeN/A
associate-*l*N/A
lift-*.f32N/A
lift-*.f32N/A
lift-*.f32N/A
*-commutativeN/A
lift-*.f32N/A
*-commutativeN/A
lift-*.f32N/A
lift-*.f32N/A
lift-/.f32N/A
Applied rewrites98.0%
Applied rewrites96.8%
Final simplification96.8%
(FPCore (x tau)
:precision binary32
(let* ((t_1 (* x (PI))))
(*
(+ 1.0 (* (pow t_1 2.0) -0.16666666666666666))
(/ (sin (* (* x tau) (PI))) (* t_1 tau)))))\begin{array}{l}
\\
\begin{array}{l}
t_1 := x \cdot \mathsf{PI}\left(\right)\\
\left(1 + {t\_1}^{2} \cdot -0.16666666666666666\right) \cdot \frac{\sin \left(\left(x \cdot tau\right) \cdot \mathsf{PI}\left(\right)\right)}{t\_1 \cdot tau}
\end{array}
\end{array}
Initial program 98.0%
lift-*.f32N/A
*-commutativeN/A
lift-*.f32N/A
associate-*r*N/A
lower-*.f32N/A
lower-*.f3297.5
Applied rewrites97.5%
Taylor expanded in x around 0
+-commutativeN/A
associate-*r*N/A
lower-fma.f32N/A
unpow2N/A
associate-*r*N/A
lower-*.f32N/A
lower-*.f32N/A
unpow2N/A
lower-*.f32N/A
lower-PI.f32N/A
lower-PI.f3232.9
Applied rewrites32.9%
Applied rewrites86.1%
Final simplification86.1%
(FPCore (x tau) :precision binary32 (let* ((t_1 (* (* x (PI)) tau))) (/ (sin t_1) t_1)))
\begin{array}{l}
\\
\begin{array}{l}
t_1 := \left(x \cdot \mathsf{PI}\left(\right)\right) \cdot tau\\
\frac{\sin t\_1}{t\_1}
\end{array}
\end{array}
Initial program 98.0%
lift-*.f32N/A
lift-/.f32N/A
clear-numN/A
un-div-invN/A
lower-/.f32N/A
Applied rewrites98.0%
lift-/.f32N/A
div-invN/A
lift-*.f32N/A
lift-*.f32N/A
*-commutativeN/A
associate-*l*N/A
lift-*.f32N/A
lift-*.f32N/A
lift-*.f32N/A
*-commutativeN/A
lift-*.f32N/A
*-commutativeN/A
lift-*.f32N/A
lift-*.f32N/A
lift-/.f32N/A
Applied rewrites98.0%
lift-*.f32N/A
*-commutativeN/A
lift-/.f32N/A
clear-numN/A
lift-/.f32N/A
frac-timesN/A
*-lft-identityN/A
lower-/.f32N/A
Applied rewrites98.0%
Taylor expanded in x around 0
lower-*.f32N/A
*-commutativeN/A
lower-*.f32N/A
lower-PI.f3272.2
Applied rewrites72.2%
Final simplification72.2%
(FPCore (x tau) :precision binary32 (+ (* (* (* -0.16666666666666666 (PI)) (PI)) (* x x)) 1.0))
\begin{array}{l}
\\
\left(\left(-0.16666666666666666 \cdot \mathsf{PI}\left(\right)\right) \cdot \mathsf{PI}\left(\right)\right) \cdot \left(x \cdot x\right) + 1
\end{array}
Initial program 98.0%
Taylor expanded in x around 0
+-commutativeN/A
*-commutativeN/A
lower-fma.f32N/A
Applied rewrites65.7%
Taylor expanded in tau around 0
Applied rewrites64.9%
Applied rewrites66.8%
Final simplification66.8%
(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 98.0%
Taylor expanded in x around 0
Applied rewrites65.7%
herbie shell --seed 2024249
(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)))))