
(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 13 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 (* tau (* PI x)))) (* (/ (sin (* PI x)) (* PI x)) (/ (sin t_1) t_1))))
float code(float x, float tau) {
float t_1 = tau * (((float) M_PI) * x);
return (sinf((((float) M_PI) * x)) / (((float) M_PI) * x)) * (sinf(t_1) / t_1);
}
function code(x, tau) t_1 = Float32(tau * Float32(Float32(pi) * x)) return Float32(Float32(sin(Float32(Float32(pi) * x)) / Float32(Float32(pi) * x)) * Float32(sin(t_1) / t_1)) end
function tmp = code(x, tau) t_1 = tau * (single(pi) * x); tmp = (sin((single(pi) * x)) / (single(pi) * x)) * (sin(t_1) / t_1); end
\begin{array}{l}
\\
\begin{array}{l}
t_1 := tau \cdot \left(\pi \cdot x\right)\\
\frac{\sin \left(\pi \cdot x\right)}{\pi \cdot x} \cdot \frac{\sin t\_1}{t\_1}
\end{array}
\end{array}
Initial program 97.8%
Final simplification97.8%
(FPCore (x tau) :precision binary32 (let* ((t_1 (* tau (* PI x)))) (/ (* (sin (* PI x)) (sin t_1)) (* t_1 (* PI x)))))
float code(float x, float tau) {
float t_1 = tau * (((float) M_PI) * x);
return (sinf((((float) M_PI) * x)) * sinf(t_1)) / (t_1 * (((float) M_PI) * x));
}
function code(x, tau) t_1 = Float32(tau * Float32(Float32(pi) * x)) return Float32(Float32(sin(Float32(Float32(pi) * x)) * sin(t_1)) / Float32(t_1 * Float32(Float32(pi) * x))) end
function tmp = code(x, tau) t_1 = tau * (single(pi) * x); tmp = (sin((single(pi) * x)) * sin(t_1)) / (t_1 * (single(pi) * x)); end
\begin{array}{l}
\\
\begin{array}{l}
t_1 := tau \cdot \left(\pi \cdot x\right)\\
\frac{\sin \left(\pi \cdot x\right) \cdot \sin t\_1}{t\_1 \cdot \left(\pi \cdot x\right)}
\end{array}
\end{array}
Initial program 97.8%
lift-*.f32N/A
lift-/.f32N/A
associate-*l/N/A
frac-2negN/A
distribute-frac-neg2N/A
lower-neg.f32N/A
lower-/.f32N/A
Applied rewrites97.7%
lift-neg.f32N/A
lift-/.f32N/A
distribute-neg-frac2N/A
lift-*.f32N/A
lift-/.f32N/A
associate-*l/N/A
associate-/l/N/A
Applied rewrites97.6%
lift-*.f32N/A
lift-*.f32N/A
associate-*l*N/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
lift-*.f32N/A
lower-*.f3297.6
Applied rewrites97.6%
Final simplification97.6%
(FPCore (x tau) :precision binary32 (let* ((t_1 (* tau (* PI x)))) (* (/ (sin (* PI x)) (* (* t_1 PI) x)) (sin t_1))))
float code(float x, float tau) {
float t_1 = tau * (((float) M_PI) * x);
return (sinf((((float) M_PI) * x)) / ((t_1 * ((float) M_PI)) * x)) * sinf(t_1);
}
function code(x, tau) t_1 = Float32(tau * Float32(Float32(pi) * x)) return Float32(Float32(sin(Float32(Float32(pi) * x)) / Float32(Float32(t_1 * Float32(pi)) * x)) * sin(t_1)) end
function tmp = code(x, tau) t_1 = tau * (single(pi) * x); tmp = (sin((single(pi) * x)) / ((t_1 * single(pi)) * x)) * sin(t_1); end
\begin{array}{l}
\\
\begin{array}{l}
t_1 := tau \cdot \left(\pi \cdot x\right)\\
\frac{\sin \left(\pi \cdot x\right)}{\left(t\_1 \cdot \pi\right) \cdot x} \cdot \sin t\_1
\end{array}
\end{array}
Initial program 97.8%
lift-*.f32N/A
lift-/.f32N/A
associate-*l/N/A
frac-2negN/A
distribute-frac-neg2N/A
lower-neg.f32N/A
lower-/.f32N/A
Applied rewrites97.7%
lift-neg.f32N/A
lift-/.f32N/A
distribute-neg-frac2N/A
lift-*.f32N/A
lift-/.f32N/A
associate-*l/N/A
associate-/l/N/A
Applied rewrites97.6%
lift-/.f32N/A
lift-*.f32N/A
associate-/l*N/A
*-commutativeN/A
lower-*.f32N/A
Applied rewrites97.5%
Final simplification97.5%
(FPCore (x tau) :precision binary32 (let* ((t_1 (* tau (* PI x)))) (* (/ (sin (* PI x)) (* (* t_1 x) PI)) (sin t_1))))
float code(float x, float tau) {
float t_1 = tau * (((float) M_PI) * x);
return (sinf((((float) M_PI) * x)) / ((t_1 * x) * ((float) M_PI))) * sinf(t_1);
}
function code(x, tau) t_1 = Float32(tau * Float32(Float32(pi) * x)) return Float32(Float32(sin(Float32(Float32(pi) * x)) / Float32(Float32(t_1 * x) * Float32(pi))) * sin(t_1)) end
function tmp = code(x, tau) t_1 = tau * (single(pi) * x); tmp = (sin((single(pi) * x)) / ((t_1 * x) * single(pi))) * sin(t_1); end
\begin{array}{l}
\\
\begin{array}{l}
t_1 := tau \cdot \left(\pi \cdot x\right)\\
\frac{\sin \left(\pi \cdot x\right)}{\left(t\_1 \cdot x\right) \cdot \pi} \cdot \sin t\_1
\end{array}
\end{array}
Initial program 97.8%
Taylor expanded in tau around inf
associate-/l*N/A
*-commutativeN/A
lower-*.f32N/A
Applied rewrites97.4%
Final simplification97.4%
(FPCore (x tau) :precision binary32 (let* ((t_1 (* tau (* PI x)))) (* (fma (* (* -0.16666666666666666 x) x) (* PI PI) 1.0) (/ (sin t_1) t_1))))
float code(float x, float tau) {
float t_1 = tau * (((float) M_PI) * x);
return fmaf(((-0.16666666666666666f * x) * x), (((float) M_PI) * ((float) M_PI)), 1.0f) * (sinf(t_1) / t_1);
}
function code(x, tau) t_1 = Float32(tau * Float32(Float32(pi) * x)) return Float32(fma(Float32(Float32(Float32(-0.16666666666666666) * x) * x), Float32(Float32(pi) * Float32(pi)), Float32(1.0)) * Float32(sin(t_1) / t_1)) end
\begin{array}{l}
\\
\begin{array}{l}
t_1 := tau \cdot \left(\pi \cdot x\right)\\
\mathsf{fma}\left(\left(-0.16666666666666666 \cdot x\right) \cdot x, \pi \cdot \pi, 1\right) \cdot \frac{\sin t\_1}{t\_1}
\end{array}
\end{array}
Initial program 97.8%
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.f3285.5
Applied rewrites85.5%
Final simplification85.5%
(FPCore (x tau) :precision binary32 (let* ((t_1 (* tau (* PI x)))) (* (/ (fma (* PI PI) (* (* -0.16666666666666666 x) x) 1.0) t_1) (sin t_1))))
float code(float x, float tau) {
float t_1 = tau * (((float) M_PI) * x);
return (fmaf((((float) M_PI) * ((float) M_PI)), ((-0.16666666666666666f * x) * x), 1.0f) / t_1) * sinf(t_1);
}
function code(x, tau) t_1 = Float32(tau * Float32(Float32(pi) * x)) return Float32(Float32(fma(Float32(Float32(pi) * Float32(pi)), Float32(Float32(Float32(-0.16666666666666666) * x) * x), Float32(1.0)) / t_1) * sin(t_1)) end
\begin{array}{l}
\\
\begin{array}{l}
t_1 := tau \cdot \left(\pi \cdot x\right)\\
\frac{\mathsf{fma}\left(\pi \cdot \pi, \left(-0.16666666666666666 \cdot x\right) \cdot x, 1\right)}{t\_1} \cdot \sin t\_1
\end{array}
\end{array}
Initial program 97.8%
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.f3285.5
Applied rewrites85.5%
lift-*.f32N/A
lift-/.f32N/A
associate-*l/N/A
lift-*.f32N/A
*-commutativeN/A
lift-*.f32N/A
associate-/l*N/A
lower-*.f32N/A
Applied rewrites85.4%
Final simplification85.4%
(FPCore (x tau)
:precision binary32
(fma
(fma
(*
(fma
0.008333333333333333
(fma (* tau tau) (* tau tau) 1.0)
(* 0.027777777777777776 (* tau tau)))
(* (* (* PI PI) PI) PI))
(* x x)
(* (* (fma tau tau 1.0) -0.16666666666666666) (* PI PI)))
(* x x)
1.0))
float code(float x, float tau) {
return fmaf(fmaf((fmaf(0.008333333333333333f, fmaf((tau * tau), (tau * tau), 1.0f), (0.027777777777777776f * (tau * tau))) * (((((float) M_PI) * ((float) M_PI)) * ((float) M_PI)) * ((float) M_PI))), (x * x), ((fmaf(tau, tau, 1.0f) * -0.16666666666666666f) * (((float) M_PI) * ((float) M_PI)))), (x * x), 1.0f);
}
function code(x, tau) return fma(fma(Float32(fma(Float32(0.008333333333333333), fma(Float32(tau * tau), Float32(tau * tau), Float32(1.0)), Float32(Float32(0.027777777777777776) * Float32(tau * tau))) * Float32(Float32(Float32(Float32(pi) * Float32(pi)) * Float32(pi)) * Float32(pi))), Float32(x * x), Float32(Float32(fma(tau, tau, Float32(1.0)) * Float32(-0.16666666666666666)) * Float32(Float32(pi) * Float32(pi)))), Float32(x * x), Float32(1.0)) end
\begin{array}{l}
\\
\mathsf{fma}\left(\mathsf{fma}\left(\mathsf{fma}\left(0.008333333333333333, \mathsf{fma}\left(tau \cdot tau, tau \cdot tau, 1\right), 0.027777777777777776 \cdot \left(tau \cdot tau\right)\right) \cdot \left(\left(\left(\pi \cdot \pi\right) \cdot \pi\right) \cdot \pi\right), x \cdot x, \left(\mathsf{fma}\left(tau, tau, 1\right) \cdot -0.16666666666666666\right) \cdot \left(\pi \cdot \pi\right)\right), x \cdot x, 1\right)
\end{array}
Initial program 97.8%
Taylor expanded in x around 0
Applied rewrites84.8%
Applied rewrites84.8%
Final simplification84.8%
(FPCore (x tau)
:precision binary32
(fma
(*
(fma
(* (fma tau tau 1.0) -0.16666666666666666)
(* PI PI)
(*
(* x x)
(*
(fma
0.008333333333333333
(fma (* tau tau) (* tau tau) 1.0)
(* 0.027777777777777776 (* tau tau)))
(* (* (* PI PI) PI) PI))))
x)
x
1.0))
float code(float x, float tau) {
return fmaf((fmaf((fmaf(tau, tau, 1.0f) * -0.16666666666666666f), (((float) M_PI) * ((float) M_PI)), ((x * x) * (fmaf(0.008333333333333333f, fmaf((tau * tau), (tau * tau), 1.0f), (0.027777777777777776f * (tau * tau))) * (((((float) M_PI) * ((float) M_PI)) * ((float) M_PI)) * ((float) M_PI))))) * x), x, 1.0f);
}
function code(x, tau) return fma(Float32(fma(Float32(fma(tau, tau, Float32(1.0)) * Float32(-0.16666666666666666)), Float32(Float32(pi) * Float32(pi)), Float32(Float32(x * x) * Float32(fma(Float32(0.008333333333333333), fma(Float32(tau * tau), Float32(tau * tau), Float32(1.0)), Float32(Float32(0.027777777777777776) * Float32(tau * tau))) * Float32(Float32(Float32(Float32(pi) * Float32(pi)) * Float32(pi)) * Float32(pi))))) * x), x, Float32(1.0)) end
\begin{array}{l}
\\
\mathsf{fma}\left(\mathsf{fma}\left(\mathsf{fma}\left(tau, tau, 1\right) \cdot -0.16666666666666666, \pi \cdot \pi, \left(x \cdot x\right) \cdot \left(\mathsf{fma}\left(0.008333333333333333, \mathsf{fma}\left(tau \cdot tau, tau \cdot tau, 1\right), 0.027777777777777776 \cdot \left(tau \cdot tau\right)\right) \cdot \left(\left(\left(\pi \cdot \pi\right) \cdot \pi\right) \cdot \pi\right)\right)\right) \cdot x, x, 1\right)
\end{array}
Initial program 97.8%
Taylor expanded in x around 0
Applied rewrites84.8%
Applied rewrites84.8%
Final simplification84.8%
(FPCore (x tau) :precision binary32 (* (fma (* (* (* x x) tau) tau) (* (* PI PI) -0.16666666666666666) 1.0) (fma (* (* -0.16666666666666666 x) x) (* PI PI) 1.0)))
float code(float x, float tau) {
return fmaf((((x * x) * tau) * tau), ((((float) M_PI) * ((float) M_PI)) * -0.16666666666666666f), 1.0f) * fmaf(((-0.16666666666666666f * x) * x), (((float) M_PI) * ((float) M_PI)), 1.0f);
}
function code(x, tau) return Float32(fma(Float32(Float32(Float32(x * x) * tau) * tau), Float32(Float32(Float32(pi) * Float32(pi)) * Float32(-0.16666666666666666)), Float32(1.0)) * fma(Float32(Float32(Float32(-0.16666666666666666) * x) * x), Float32(Float32(pi) * Float32(pi)), Float32(1.0))) end
\begin{array}{l}
\\
\mathsf{fma}\left(\left(\left(x \cdot x\right) \cdot tau\right) \cdot tau, \left(\pi \cdot \pi\right) \cdot -0.16666666666666666, 1\right) \cdot \mathsf{fma}\left(\left(-0.16666666666666666 \cdot x\right) \cdot x, \pi \cdot \pi, 1\right)
\end{array}
Initial program 97.8%
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.f3285.5
Applied rewrites85.5%
Taylor expanded in tau around 0
Applied rewrites65.2%
Taylor expanded in tau around 0
+-commutativeN/A
*-commutativeN/A
associate-*r*N/A
associate-*l*N/A
*-commutativeN/A
lower-fma.f32N/A
unpow2N/A
associate-*l*N/A
lower-*.f32N/A
*-commutativeN/A
lower-*.f32N/A
unpow2N/A
lower-*.f32N/A
lower-*.f32N/A
unpow2N/A
lower-*.f32N/A
lower-PI.f32N/A
lower-PI.f3280.0
Applied rewrites80.0%
Final simplification80.0%
(FPCore (x tau) :precision binary32 (fma (* (* (* PI PI) -0.16666666666666666) (fma tau tau 1.0)) (* x x) 1.0))
float code(float x, float tau) {
return fmaf((((((float) M_PI) * ((float) M_PI)) * -0.16666666666666666f) * fmaf(tau, tau, 1.0f)), (x * x), 1.0f);
}
function code(x, tau) return fma(Float32(Float32(Float32(Float32(pi) * Float32(pi)) * Float32(-0.16666666666666666)) * fma(tau, tau, Float32(1.0))), Float32(x * x), Float32(1.0)) end
\begin{array}{l}
\\
\mathsf{fma}\left(\left(\left(\pi \cdot \pi\right) \cdot -0.16666666666666666\right) \cdot \mathsf{fma}\left(tau, tau, 1\right), x \cdot x, 1\right)
\end{array}
Initial program 97.8%
Taylor expanded in x around 0
+-commutativeN/A
*-commutativeN/A
lower-fma.f32N/A
Applied rewrites79.4%
Final simplification79.4%
(FPCore (x tau) :precision binary32 (* (fma x (* (* (* PI PI) x) -0.16666666666666666) 1.0) 1.0))
float code(float x, float tau) {
return fmaf(x, (((((float) M_PI) * ((float) M_PI)) * x) * -0.16666666666666666f), 1.0f) * 1.0f;
}
function code(x, tau) return Float32(fma(x, Float32(Float32(Float32(Float32(pi) * Float32(pi)) * x) * Float32(-0.16666666666666666)), Float32(1.0)) * Float32(1.0)) end
\begin{array}{l}
\\
\mathsf{fma}\left(x, \left(\left(\pi \cdot \pi\right) \cdot x\right) \cdot -0.16666666666666666, 1\right) \cdot 1
\end{array}
Initial program 97.8%
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.f3285.5
Applied rewrites85.5%
Taylor expanded in tau around 0
Applied rewrites65.2%
Applied rewrites65.2%
Final simplification65.2%
(FPCore (x tau) :precision binary32 (* (fma -0.16666666666666666 (* (* (* PI PI) x) x) 1.0) 1.0))
float code(float x, float tau) {
return fmaf(-0.16666666666666666f, (((((float) M_PI) * ((float) M_PI)) * x) * x), 1.0f) * 1.0f;
}
function code(x, tau) return Float32(fma(Float32(-0.16666666666666666), Float32(Float32(Float32(Float32(pi) * Float32(pi)) * x) * x), Float32(1.0)) * Float32(1.0)) end
\begin{array}{l}
\\
\mathsf{fma}\left(-0.16666666666666666, \left(\left(\pi \cdot \pi\right) \cdot x\right) \cdot x, 1\right) \cdot 1
\end{array}
Initial program 97.8%
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.f3285.5
Applied rewrites85.5%
Taylor expanded in tau around 0
Applied rewrites65.2%
Applied rewrites65.2%
Final simplification65.2%
(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 rewrites64.0%
herbie shell --seed 2024235
(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))))