
(FPCore (x tau) :precision binary32 (let* ((t_1 (* (* x PI) tau))) (* (/ (sin t_1) t_1) (/ (sin (* x PI)) (* x PI)))))
float code(float x, float tau) {
float t_1 = (x * ((float) M_PI)) * tau;
return (sinf(t_1) / t_1) * (sinf((x * ((float) M_PI))) / (x * ((float) M_PI)));
}
function code(x, tau) t_1 = Float32(Float32(x * Float32(pi)) * tau) return Float32(Float32(sin(t_1) / t_1) * Float32(sin(Float32(x * Float32(pi))) / Float32(x * Float32(pi)))) end
function tmp = code(x, tau) t_1 = (x * single(pi)) * tau; tmp = (sin(t_1) / t_1) * (sin((x * single(pi))) / (x * single(pi))); end
\begin{array}{l}
\\
\begin{array}{l}
t_1 := \left(x \cdot \pi\right) \cdot tau\\
\frac{\sin t\_1}{t\_1} \cdot \frac{\sin \left(x \cdot \pi\right)}{x \cdot \pi}
\end{array}
\end{array}
Sampling outcomes in binary32 precision:
Herbie found 12 alternatives:
| Alternative | Accuracy | Speedup |
|---|
(FPCore (x tau) :precision binary32 (let* ((t_1 (* (* x PI) tau))) (* (/ (sin t_1) t_1) (/ (sin (* x PI)) (* x PI)))))
float code(float x, float tau) {
float t_1 = (x * ((float) M_PI)) * tau;
return (sinf(t_1) / t_1) * (sinf((x * ((float) M_PI))) / (x * ((float) M_PI)));
}
function code(x, tau) t_1 = Float32(Float32(x * Float32(pi)) * tau) return Float32(Float32(sin(t_1) / t_1) * Float32(sin(Float32(x * Float32(pi))) / Float32(x * Float32(pi)))) end
function tmp = code(x, tau) t_1 = (x * single(pi)) * tau; tmp = (sin(t_1) / t_1) * (sin((x * single(pi))) / (x * single(pi))); end
\begin{array}{l}
\\
\begin{array}{l}
t_1 := \left(x \cdot \pi\right) \cdot tau\\
\frac{\sin t\_1}{t\_1} \cdot \frac{\sin \left(x \cdot \pi\right)}{x \cdot \pi}
\end{array}
\end{array}
(FPCore (x tau) :precision binary32 (let* ((t_1 (* x (* tau PI)))) (* (/ (sin t_1) t_1) (/ (sin (* x PI)) (* x PI)))))
float code(float x, float tau) {
float t_1 = x * (tau * ((float) M_PI));
return (sinf(t_1) / t_1) * (sinf((x * ((float) M_PI))) / (x * ((float) M_PI)));
}
function code(x, tau) t_1 = Float32(x * Float32(tau * Float32(pi))) return Float32(Float32(sin(t_1) / t_1) * Float32(sin(Float32(x * Float32(pi))) / Float32(x * Float32(pi)))) end
function tmp = code(x, tau) t_1 = x * (tau * single(pi)); tmp = (sin(t_1) / t_1) * (sin((x * single(pi))) / (x * single(pi))); end
\begin{array}{l}
\\
\begin{array}{l}
t_1 := x \cdot \left(tau \cdot \pi\right)\\
\frac{\sin t\_1}{t\_1} \cdot \frac{\sin \left(x \cdot \pi\right)}{x \cdot \pi}
\end{array}
\end{array}
Initial program 97.6%
Taylor expanded in x around inf
lower-/.f32N/A
lower-sin.f32N/A
*-commutativeN/A
associate-*r*N/A
*-commutativeN/A
lower-*.f32N/A
lower-*.f32N/A
lower-PI.f32N/A
*-commutativeN/A
associate-*r*N/A
*-commutativeN/A
lower-*.f32N/A
lower-*.f32N/A
lower-PI.f3297.7
Applied rewrites97.7%
(FPCore (x tau) :precision binary32 (let* ((t_1 (* PI (* x tau)))) (/ (* (sin (* x PI)) (sin t_1)) (* x (* PI t_1)))))
float code(float x, float tau) {
float t_1 = ((float) M_PI) * (x * tau);
return (sinf((x * ((float) M_PI))) * sinf(t_1)) / (x * (((float) M_PI) * t_1));
}
function code(x, tau) t_1 = Float32(Float32(pi) * Float32(x * tau)) return Float32(Float32(sin(Float32(x * Float32(pi))) * sin(t_1)) / Float32(x * Float32(Float32(pi) * t_1))) end
function tmp = code(x, tau) t_1 = single(pi) * (x * tau); tmp = (sin((x * single(pi))) * sin(t_1)) / (x * (single(pi) * t_1)); end
\begin{array}{l}
\\
\begin{array}{l}
t_1 := \pi \cdot \left(x \cdot tau\right)\\
\frac{\sin \left(x \cdot \pi\right) \cdot \sin t\_1}{x \cdot \left(\pi \cdot t\_1\right)}
\end{array}
\end{array}
Initial program 97.6%
lift-*.f32N/A
lift-/.f32N/A
lift-/.f32N/A
frac-timesN/A
lower-/.f32N/A
Applied rewrites97.2%
Final simplification97.2%
(FPCore (x tau) :precision binary32 (* (sin (* x (* tau PI))) (/ (sin (* x PI)) (* (* tau PI) (* x (* x PI))))))
float code(float x, float tau) {
return sinf((x * (tau * ((float) M_PI)))) * (sinf((x * ((float) M_PI))) / ((tau * ((float) M_PI)) * (x * (x * ((float) M_PI)))));
}
function code(x, tau) return Float32(sin(Float32(x * Float32(tau * Float32(pi)))) * Float32(sin(Float32(x * Float32(pi))) / Float32(Float32(tau * Float32(pi)) * Float32(x * Float32(x * Float32(pi)))))) end
function tmp = code(x, tau) tmp = sin((x * (tau * single(pi)))) * (sin((x * single(pi))) / ((tau * single(pi)) * (x * (x * single(pi))))); end
\begin{array}{l}
\\
\sin \left(x \cdot \left(tau \cdot \pi\right)\right) \cdot \frac{\sin \left(x \cdot \pi\right)}{\left(tau \cdot \pi\right) \cdot \left(x \cdot \left(x \cdot \pi\right)\right)}
\end{array}
Initial program 97.6%
lift-*.f32N/A
*-commutativeN/A
lift-/.f32N/A
div-invN/A
associate-*l*N/A
*-commutativeN/A
lower-*.f32N/A
Applied rewrites97.0%
lift-*.f32N/A
lift-/.f32N/A
associate-*l/N/A
lift-*.f32N/A
lift-*.f32N/A
associate-*r*N/A
lift-*.f32N/A
associate-/r*N/A
Applied rewrites97.1%
Final simplification97.1%
(FPCore (x tau) :precision binary32 (let* ((t_1 (* PI (* x tau)))) (* (sin t_1) (/ (sin (* x PI)) (* x (* PI t_1))))))
float code(float x, float tau) {
float t_1 = ((float) M_PI) * (x * tau);
return sinf(t_1) * (sinf((x * ((float) M_PI))) / (x * (((float) M_PI) * t_1)));
}
function code(x, tau) t_1 = Float32(Float32(pi) * Float32(x * tau)) return Float32(sin(t_1) * Float32(sin(Float32(x * Float32(pi))) / Float32(x * Float32(Float32(pi) * t_1)))) end
function tmp = code(x, tau) t_1 = single(pi) * (x * tau); tmp = sin(t_1) * (sin((x * single(pi))) / (x * (single(pi) * t_1))); end
\begin{array}{l}
\\
\begin{array}{l}
t_1 := \pi \cdot \left(x \cdot tau\right)\\
\sin t\_1 \cdot \frac{\sin \left(x \cdot \pi\right)}{x \cdot \left(\pi \cdot t\_1\right)}
\end{array}
\end{array}
Initial program 97.6%
lift-*.f32N/A
lift-/.f32N/A
div-invN/A
associate-*l*N/A
*-commutativeN/A
lower-*.f32N/A
Applied rewrites97.0%
Final simplification97.0%
(FPCore (x tau) :precision binary32 (/ (* (sin (* x (* tau PI))) (sin (* x PI))) (* (* x x) (* tau (* PI PI)))))
float code(float x, float tau) {
return (sinf((x * (tau * ((float) M_PI)))) * sinf((x * ((float) M_PI)))) / ((x * x) * (tau * (((float) M_PI) * ((float) M_PI))));
}
function code(x, tau) return Float32(Float32(sin(Float32(x * Float32(tau * Float32(pi)))) * sin(Float32(x * Float32(pi)))) / Float32(Float32(x * x) * Float32(tau * Float32(Float32(pi) * Float32(pi))))) end
function tmp = code(x, tau) tmp = (sin((x * (tau * single(pi)))) * sin((x * single(pi)))) / ((x * x) * (tau * (single(pi) * single(pi)))); end
\begin{array}{l}
\\
\frac{\sin \left(x \cdot \left(tau \cdot \pi\right)\right) \cdot \sin \left(x \cdot \pi\right)}{\left(x \cdot x\right) \cdot \left(tau \cdot \left(\pi \cdot \pi\right)\right)}
\end{array}
Initial program 97.6%
lift-*.f32N/A
lift-/.f32N/A
associate-*l/N/A
lower-/.f32N/A
Applied rewrites97.5%
Taylor expanded in x around 0
lower-*.f32N/A
lower-*.f32N/A
lower-PI.f3261.5
Applied rewrites61.5%
lift-*.f32N/A
lift-*.f32N/A
*-commutativeN/A
associate-*r*N/A
lift-*.f32N/A
lower-*.f3261.5
Applied rewrites61.5%
Taylor expanded in x around inf
*-commutativeN/A
associate-*r*N/A
lower-/.f32N/A
lower-*.f32N/A
lower-sin.f32N/A
*-commutativeN/A
associate-*r*N/A
*-commutativeN/A
lower-*.f32N/A
lower-*.f32N/A
lower-PI.f32N/A
lower-sin.f32N/A
lower-*.f32N/A
lower-PI.f32N/A
Applied rewrites96.9%
(FPCore (x tau) :precision binary32 (* (sin (* x (* tau PI))) (/ (sin (* x PI)) (* PI (* PI (* tau (* x x)))))))
float code(float x, float tau) {
return sinf((x * (tau * ((float) M_PI)))) * (sinf((x * ((float) M_PI))) / (((float) M_PI) * (((float) M_PI) * (tau * (x * x)))));
}
function code(x, tau) return Float32(sin(Float32(x * Float32(tau * Float32(pi)))) * Float32(sin(Float32(x * Float32(pi))) / Float32(Float32(pi) * Float32(Float32(pi) * Float32(tau * Float32(x * x)))))) end
function tmp = code(x, tau) tmp = sin((x * (tau * single(pi)))) * (sin((x * single(pi))) / (single(pi) * (single(pi) * (tau * (x * x))))); end
\begin{array}{l}
\\
\sin \left(x \cdot \left(tau \cdot \pi\right)\right) \cdot \frac{\sin \left(x \cdot \pi\right)}{\pi \cdot \left(\pi \cdot \left(tau \cdot \left(x \cdot x\right)\right)\right)}
\end{array}
Initial program 97.6%
Taylor expanded in x around inf
associate-/l*N/A
lower-*.f32N/A
lower-sin.f32N/A
*-commutativeN/A
associate-*r*N/A
*-commutativeN/A
lower-*.f32N/A
lower-*.f32N/A
lower-PI.f32N/A
associate-*r*N/A
unpow2N/A
associate-*r*N/A
associate-/r*N/A
associate-/l/N/A
lower-/.f32N/A
Applied rewrites96.7%
Final simplification96.7%
(FPCore (x tau)
:precision binary32
(*
(/ (sin (* PI (* x tau))) (- x))
(fma
(* x x)
(fma
(* x x)
(/ (* (* PI (* PI PI)) -0.008333333333333333) tau)
(/ (* PI 0.16666666666666666) tau))
(/ -1.0 (* tau PI)))))
float code(float x, float tau) {
return (sinf((((float) M_PI) * (x * tau))) / -x) * fmaf((x * x), fmaf((x * x), (((((float) M_PI) * (((float) M_PI) * ((float) M_PI))) * -0.008333333333333333f) / tau), ((((float) M_PI) * 0.16666666666666666f) / tau)), (-1.0f / (tau * ((float) M_PI))));
}
function code(x, tau) return Float32(Float32(sin(Float32(Float32(pi) * Float32(x * tau))) / Float32(-x)) * fma(Float32(x * x), fma(Float32(x * x), Float32(Float32(Float32(Float32(pi) * Float32(Float32(pi) * Float32(pi))) * Float32(-0.008333333333333333)) / tau), Float32(Float32(Float32(pi) * Float32(0.16666666666666666)) / tau)), Float32(Float32(-1.0) / Float32(tau * Float32(pi))))) end
\begin{array}{l}
\\
\frac{\sin \left(\pi \cdot \left(x \cdot tau\right)\right)}{-x} \cdot \mathsf{fma}\left(x \cdot x, \mathsf{fma}\left(x \cdot x, \frac{\left(\pi \cdot \left(\pi \cdot \pi\right)\right) \cdot -0.008333333333333333}{tau}, \frac{\pi \cdot 0.16666666666666666}{tau}\right), \frac{-1}{tau \cdot \pi}\right)
\end{array}
Initial program 97.6%
lift-*.f32N/A
lift-/.f32N/A
frac-2negN/A
associate-*l/N/A
lift-*.f32N/A
lift-*.f32N/A
associate-*l*N/A
distribute-rgt-neg-inN/A
times-fracN/A
lower-*.f32N/A
Applied rewrites97.1%
Taylor expanded in x around 0
sub-negN/A
lower-fma.f32N/A
Applied rewrites89.7%
Final simplification89.7%
(FPCore (x tau) :precision binary32 (let* ((t_1 (* x (* tau PI)))) (* (/ (sin t_1) t_1) (fma (* PI PI) (* (* x x) -0.16666666666666666) 1.0))))
float code(float x, float tau) {
float t_1 = x * (tau * ((float) M_PI));
return (sinf(t_1) / t_1) * fmaf((((float) M_PI) * ((float) M_PI)), ((x * x) * -0.16666666666666666f), 1.0f);
}
function code(x, tau) t_1 = Float32(x * Float32(tau * Float32(pi))) return Float32(Float32(sin(t_1) / t_1) * fma(Float32(Float32(pi) * Float32(pi)), Float32(Float32(x * x) * Float32(-0.16666666666666666)), Float32(1.0))) end
\begin{array}{l}
\\
\begin{array}{l}
t_1 := x \cdot \left(tau \cdot \pi\right)\\
\frac{\sin t\_1}{t\_1} \cdot \mathsf{fma}\left(\pi \cdot \pi, \left(x \cdot x\right) \cdot -0.16666666666666666, 1\right)
\end{array}
\end{array}
Initial program 97.6%
Taylor expanded in x around inf
lower-/.f32N/A
lower-sin.f32N/A
*-commutativeN/A
associate-*r*N/A
*-commutativeN/A
lower-*.f32N/A
lower-*.f32N/A
lower-PI.f32N/A
*-commutativeN/A
associate-*r*N/A
*-commutativeN/A
lower-*.f32N/A
lower-*.f32N/A
lower-PI.f3297.7
Applied rewrites97.7%
Taylor expanded in x around 0
*-commutativeN/A
associate-*r*N/A
+-commutativeN/A
*-commutativeN/A
associate-*l*N/A
lower-fma.f32N/A
unpow2N/A
lower-*.f32N/A
lower-PI.f32N/A
lower-PI.f32N/A
*-commutativeN/A
lower-*.f32N/A
unpow2N/A
lower-*.f3284.5
Applied rewrites84.5%
(FPCore (x tau) :precision binary32 (* (sin (* x PI)) (fma (* PI (* -0.16666666666666666 (* tau tau))) x (/ 1.0 (* x PI)))))
float code(float x, float tau) {
return sinf((x * ((float) M_PI))) * fmaf((((float) M_PI) * (-0.16666666666666666f * (tau * tau))), x, (1.0f / (x * ((float) M_PI))));
}
function code(x, tau) return Float32(sin(Float32(x * Float32(pi))) * fma(Float32(Float32(pi) * Float32(Float32(-0.16666666666666666) * Float32(tau * tau))), x, Float32(Float32(1.0) / Float32(x * Float32(pi))))) end
\begin{array}{l}
\\
\sin \left(x \cdot \pi\right) \cdot \mathsf{fma}\left(\pi \cdot \left(-0.16666666666666666 \cdot \left(tau \cdot tau\right)\right), x, \frac{1}{x \cdot \pi}\right)
\end{array}
Initial program 97.6%
lift-*.f32N/A
*-commutativeN/A
lift-/.f32N/A
div-invN/A
associate-*l*N/A
*-commutativeN/A
lower-*.f32N/A
Applied rewrites97.0%
Taylor expanded in tau around 0
associate-*r*N/A
*-commutativeN/A
associate-*r*N/A
associate-*r*N/A
lower-fma.f32N/A
associate-*r*N/A
*-commutativeN/A
lower-*.f32N/A
lower-PI.f32N/A
lower-*.f32N/A
unpow2N/A
lower-*.f32N/A
lower-/.f32N/A
lower-*.f32N/A
lower-PI.f3277.9
Applied rewrites77.9%
Final simplification77.9%
(FPCore (x tau) :precision binary32 (fma (* x x) (* (* PI PI) (fma -0.16666666666666666 (* tau tau) -0.16666666666666666)) 1.0))
float code(float x, float tau) {
return fmaf((x * x), ((((float) M_PI) * ((float) M_PI)) * fmaf(-0.16666666666666666f, (tau * tau), -0.16666666666666666f)), 1.0f);
}
function code(x, tau) return fma(Float32(x * x), Float32(Float32(Float32(pi) * Float32(pi)) * fma(Float32(-0.16666666666666666), Float32(tau * tau), Float32(-0.16666666666666666))), Float32(1.0)) end
\begin{array}{l}
\\
\mathsf{fma}\left(x \cdot x, \left(\pi \cdot \pi\right) \cdot \mathsf{fma}\left(-0.16666666666666666, tau \cdot tau, -0.16666666666666666\right), 1\right)
\end{array}
Initial program 97.6%
Taylor expanded in x around 0
+-commutativeN/A
lower-fma.f32N/A
unpow2N/A
lower-*.f32N/A
+-commutativeN/A
associate-*r*N/A
distribute-rgt-outN/A
lower-*.f32N/A
unpow2N/A
lower-*.f32N/A
lower-PI.f32N/A
lower-PI.f32N/A
+-commutativeN/A
lower-fma.f32N/A
unpow2N/A
lower-*.f3277.6
Applied rewrites77.6%
(FPCore (x tau) :precision binary32 (* (/ 1.0 (* x PI)) (* x PI)))
float code(float x, float tau) {
return (1.0f / (x * ((float) M_PI))) * (x * ((float) M_PI));
}
function code(x, tau) return Float32(Float32(Float32(1.0) / Float32(x * Float32(pi))) * Float32(x * Float32(pi))) end
function tmp = code(x, tau) tmp = (single(1.0) / (x * single(pi))) * (x * single(pi)); end
\begin{array}{l}
\\
\frac{1}{x \cdot \pi} \cdot \left(x \cdot \pi\right)
\end{array}
Initial program 97.6%
lift-*.f32N/A
*-commutativeN/A
lift-/.f32N/A
div-invN/A
associate-*l*N/A
*-commutativeN/A
lower-*.f32N/A
Applied rewrites97.0%
Applied rewrites97.3%
Taylor expanded in x around 0
lower-*.f32N/A
lower-PI.f3261.6
Applied rewrites61.6%
Final simplification61.6%
(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 97.6%
Taylor expanded in x around 0
Applied rewrites61.6%
herbie shell --seed 2024233
(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))))