
(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 (* x (* tau (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 := x \cdot \left(tau \cdot \mathsf{PI}\left(\right)\right)\\
\frac{\sin t\_1 \cdot \frac{\sin t\_2}{t\_2}}{t\_1}
\end{array}
\end{array}
Initial program 97.7%
lift-*.f32N/A
lift-/.f32N/A
associate-*r/N/A
lower-/.f32N/A
Applied rewrites97.6%
lift-*.f32N/A
lift-*.f32N/A
*-commutativeN/A
associate-*r*N/A
lower-*.f32N/A
lower-*.f3297.1
Applied rewrites97.1%
lift-*.f32N/A
*-commutativeN/A
lift-*.f32N/A
*-commutativeN/A
associate-*l*N/A
lift-*.f32N/A
lift-*.f3297.6
lower-*.f32N/A
*-commutativeN/A
lift-/.f32N/A
clear-numN/A
lift-*.f32N/A
lift-*.f32N/A
*-commutativeN/A
lift-*.f32N/A
associate-*r/N/A
Applied rewrites97.7%
Final simplification97.7%
(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 97.7%
Final simplification97.7%
(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 97.7%
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 rewrites97.5%
Final simplification97.5%
(FPCore (x tau) :precision binary32 (let* ((t_1 (* x (PI))) (t_2 (* x (* tau (PI))))) (/ (* (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 := x \cdot \left(tau \cdot \mathsf{PI}\left(\right)\right)\\
\frac{\sin t\_1 \cdot \sin t\_2}{t\_1 \cdot t\_2}
\end{array}
\end{array}
Initial program 97.7%
lift-*.f32N/A
lift-/.f32N/A
associate-*r/N/A
lower-/.f32N/A
Applied rewrites97.6%
lift-/.f32N/A
lift-*.f32N/A
*-commutativeN/A
associate-/l*N/A
*-rgt-identityN/A
clear-numN/A
div-invN/A
*-rgt-identityN/A
lower-/.f32N/A
Applied rewrites97.5%
Applied rewrites97.4%
Final simplification97.4%
(FPCore (x tau) :precision binary32 (let* ((t_1 (* x (PI))) (t_2 (* t_1 tau))) (/ (/ t_1 t_1) (/ t_2 (sin t_2)))))
\begin{array}{l}
\\
\begin{array}{l}
t_1 := x \cdot \mathsf{PI}\left(\right)\\
t_2 := t\_1 \cdot tau\\
\frac{\frac{t\_1}{t\_1}}{\frac{t\_2}{\sin t\_2}}
\end{array}
\end{array}
Initial program 97.7%
lift-*.f32N/A
*-commutativeN/A
lift-/.f32N/A
lift-*.f32N/A
associate-/r*N/A
lift-PI.f32N/A
add-sqr-sqrtN/A
associate-/r*N/A
lift-/.f32N/A
frac-timesN/A
lower-/.f32N/A
Applied rewrites96.7%
Taylor expanded in x around 0
*-commutativeN/A
lower-*.f32N/A
lower-PI.f3268.8
Applied rewrites68.8%
lift-/.f32N/A
lift-*.f32N/A
lift-*.f32N/A
times-fracN/A
lift-*.f32N/A
*-commutativeN/A
lift-*.f32N/A
*-commutativeN/A
lift-*.f32N/A
lift-*.f32N/A
lift-*.f32N/A
Applied rewrites69.0%
Final simplification69.0%
(FPCore (x tau) :precision binary32 (let* ((t_1 (sqrt (PI))) (t_2 (* (* x (PI)) tau))) (/ (* t_1 (sin t_2)) (* t_1 t_2))))
\begin{array}{l}
\\
\begin{array}{l}
t_1 := \sqrt{\mathsf{PI}\left(\right)}\\
t_2 := \left(x \cdot \mathsf{PI}\left(\right)\right) \cdot tau\\
\frac{t\_1 \cdot \sin t\_2}{t\_1 \cdot t\_2}
\end{array}
\end{array}
Initial program 97.7%
lift-*.f32N/A
*-commutativeN/A
lift-/.f32N/A
lift-*.f32N/A
associate-/r*N/A
lift-PI.f32N/A
add-sqr-sqrtN/A
associate-/r*N/A
lift-/.f32N/A
frac-timesN/A
lower-/.f32N/A
Applied rewrites96.7%
Taylor expanded in x around 0
lower-sqrt.f32N/A
lower-PI.f3269.0
Applied rewrites69.0%
Final simplification69.0%
(FPCore (x tau) :precision binary32 (let* ((t_1 (* x (PI))) (t_2 (* x (* tau (PI))))) (/ t_1 (* (/ t_2 (sin t_2)) t_1))))
\begin{array}{l}
\\
\begin{array}{l}
t_1 := x \cdot \mathsf{PI}\left(\right)\\
t_2 := x \cdot \left(tau \cdot \mathsf{PI}\left(\right)\right)\\
\frac{t\_1}{\frac{t\_2}{\sin t\_2} \cdot t\_1}
\end{array}
\end{array}
Initial program 97.7%
lift-*.f32N/A
*-commutativeN/A
lift-/.f32N/A
lift-*.f32N/A
associate-/r*N/A
lift-PI.f32N/A
add-sqr-sqrtN/A
associate-/r*N/A
lift-/.f32N/A
frac-timesN/A
lower-/.f32N/A
Applied rewrites96.7%
Taylor expanded in x around 0
*-commutativeN/A
lower-*.f32N/A
lower-PI.f3268.8
Applied rewrites68.8%
Applied rewrites68.7%
lift-/.f32N/A
lift-neg.f32N/A
lift-/.f32N/A
distribute-neg-fracN/A
associate-/l/N/A
lower-/.f32N/A
lower-neg.f32N/A
lower-*.f3268.7
Applied rewrites69.0%
Final simplification69.0%
(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 97.7%
lift-*.f32N/A
lift-/.f32N/A
associate-*r/N/A
lower-/.f32N/A
Applied rewrites97.6%
lift-/.f32N/A
lift-*.f32N/A
*-commutativeN/A
associate-/l*N/A
*-rgt-identityN/A
clear-numN/A
div-invN/A
*-rgt-identityN/A
lower-/.f32N/A
Applied rewrites97.5%
Taylor expanded in x around 0
*-commutativeN/A
lower-*.f32N/A
*-commutativeN/A
lower-*.f32N/A
lower-PI.f3268.9
Applied rewrites68.9%
Final simplification68.9%
(FPCore (x tau) :precision binary32 (+ (* (fma tau tau 1.0) (* (pow (* x (PI)) 2.0) -0.16666666666666666)) 1.0))
\begin{array}{l}
\\
\mathsf{fma}\left(tau, tau, 1\right) \cdot \left({\left(x \cdot \mathsf{PI}\left(\right)\right)}^{2} \cdot -0.16666666666666666\right) + 1
\end{array}
Initial program 97.7%
lift-*.f32N/A
lift-/.f32N/A
associate-*r/N/A
lower-/.f32N/A
Applied rewrites97.6%
lift-*.f32N/A
lift-/.f32N/A
associate-*l/N/A
lower-/.f32N/A
*-commutativeN/A
lower-*.f3297.6
lift-*.f32N/A
*-commutativeN/A
lower-*.f3297.6
lift-*.f32N/A
*-commutativeN/A
lower-*.f3297.6
lift-*.f32N/A
*-commutativeN/A
lower-*.f3297.6
Applied rewrites97.6%
Taylor expanded in x around 0
+-commutativeN/A
*-commutativeN/A
lower-fma.f32N/A
Applied rewrites60.7%
Applied rewrites37.4%
Final simplification39.8%
(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.f3261.8
Applied rewrites61.8%
Final simplification61.8%
(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 97.7%
Taylor expanded in x around 0
Applied rewrites61.1%
herbie shell --seed 2024283
(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)))))