
(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 9 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 98.0%
*-commutative98.0%
associate-*l*97.4%
*-commutative97.4%
associate-*l*98.0%
Simplified98.0%
Taylor expanded in x around inf 98.0%
associate-*r*97.3%
*-commutative97.3%
associate-*r*97.5%
associate-*r*97.6%
*-commutative97.6%
associate-*r*98.1%
Simplified98.1%
Final simplification98.1%
(FPCore (x tau) :precision binary32 (* (/ (sin (* x PI)) (* (* x PI) (* x (* tau PI)))) (sin (* tau (* x PI)))))
float code(float x, float tau) {
return (sinf((x * ((float) M_PI))) / ((x * ((float) M_PI)) * (x * (tau * ((float) M_PI))))) * sinf((tau * (x * ((float) M_PI))));
}
function code(x, tau) return Float32(Float32(sin(Float32(x * Float32(pi))) / Float32(Float32(x * Float32(pi)) * Float32(x * Float32(tau * Float32(pi))))) * sin(Float32(tau * Float32(x * Float32(pi))))) end
function tmp = code(x, tau) tmp = (sin((x * single(pi))) / ((x * single(pi)) * (x * (tau * single(pi))))) * sin((tau * (x * single(pi)))); end
\begin{array}{l}
\\
\frac{\sin \left(x \cdot \pi\right)}{\left(x \cdot \pi\right) \cdot \left(x \cdot \left(tau \cdot \pi\right)\right)} \cdot \sin \left(tau \cdot \left(x \cdot \pi\right)\right)
\end{array}
Initial program 98.0%
associate-*l/97.9%
associate-/l*97.8%
associate-*l*97.4%
associate-/l/97.4%
associate-*l*97.8%
Simplified97.8%
Taylor expanded in x around inf 97.3%
Final simplification97.3%
(FPCore (x tau) :precision binary32 (let* ((t_1 (* x (* tau PI)))) (* (sin t_1) (/ (sin (* x PI)) (* PI (* x t_1))))))
float code(float x, float tau) {
float t_1 = x * (tau * ((float) M_PI));
return sinf(t_1) * (sinf((x * ((float) M_PI))) / (((float) M_PI) * (x * t_1)));
}
function code(x, tau) t_1 = Float32(x * Float32(tau * Float32(pi))) return Float32(sin(t_1) * Float32(sin(Float32(x * Float32(pi))) / Float32(Float32(pi) * Float32(x * t_1)))) end
function tmp = code(x, tau) t_1 = x * (tau * single(pi)); tmp = sin(t_1) * (sin((x * single(pi))) / (single(pi) * (x * t_1))); end
\begin{array}{l}
\\
\begin{array}{l}
t_1 := x \cdot \left(tau \cdot \pi\right)\\
\sin t\_1 \cdot \frac{\sin \left(x \cdot \pi\right)}{\pi \cdot \left(x \cdot t\_1\right)}
\end{array}
\end{array}
Initial program 98.0%
associate-*l/97.9%
associate-/l*97.8%
associate-*l*97.4%
associate-/l/97.4%
*-commutative97.4%
*-commutative97.4%
associate-*l*97.3%
associate-*l*97.3%
Simplified97.3%
Final simplification97.3%
(FPCore (x tau) :precision binary32 (let* ((t_1 (* x (* tau PI)))) (* (sin t_1) (/ (sin (* x PI)) (* (* x PI) t_1)))))
float code(float x, float tau) {
float t_1 = x * (tau * ((float) M_PI));
return sinf(t_1) * (sinf((x * ((float) M_PI))) / ((x * ((float) M_PI)) * t_1));
}
function code(x, tau) t_1 = Float32(x * Float32(tau * Float32(pi))) return Float32(sin(t_1) * Float32(sin(Float32(x * Float32(pi))) / Float32(Float32(x * Float32(pi)) * t_1))) end
function tmp = code(x, tau) t_1 = x * (tau * single(pi)); tmp = sin(t_1) * (sin((x * single(pi))) / ((x * single(pi)) * t_1)); end
\begin{array}{l}
\\
\begin{array}{l}
t_1 := x \cdot \left(tau \cdot \pi\right)\\
\sin t\_1 \cdot \frac{\sin \left(x \cdot \pi\right)}{\left(x \cdot \pi\right) \cdot t\_1}
\end{array}
\end{array}
Initial program 98.0%
associate-*l/97.9%
associate-/l*97.8%
associate-*l*97.4%
associate-/l/97.4%
associate-*l*97.8%
Simplified97.8%
Final simplification97.8%
(FPCore (x tau) :precision binary32 (let* ((t_1 (* PI (* x tau)))) (/ (* (/ (* x PI) t_1) (sin t_1)) (* x PI))))
float code(float x, float tau) {
float t_1 = ((float) M_PI) * (x * tau);
return (((x * ((float) M_PI)) / t_1) * sinf(t_1)) / (x * ((float) M_PI));
}
function code(x, tau) t_1 = Float32(Float32(pi) * Float32(x * tau)) return Float32(Float32(Float32(Float32(x * Float32(pi)) / t_1) * sin(t_1)) / Float32(x * Float32(pi))) end
function tmp = code(x, tau) t_1 = single(pi) * (x * tau); tmp = (((x * single(pi)) / t_1) * sin(t_1)) / (x * single(pi)); end
\begin{array}{l}
\\
\begin{array}{l}
t_1 := \pi \cdot \left(x \cdot tau\right)\\
\frac{\frac{x \cdot \pi}{t\_1} \cdot \sin t\_1}{x \cdot \pi}
\end{array}
\end{array}
Initial program 98.0%
associate-*l/97.9%
associate-/l*97.8%
associate-*l*97.4%
associate-/l/97.4%
*-commutative97.4%
*-commutative97.4%
associate-*l*97.3%
associate-*l*97.3%
Simplified97.3%
associate-*r*97.3%
associate-*r*97.4%
*-commutative97.4%
*-commutative97.4%
associate-*r*97.8%
*-commutative97.8%
Applied egg-rr97.7%
Taylor expanded in x around 0 73.6%
Final simplification73.6%
(FPCore (x tau) :precision binary32 (let* ((t_1 (* PI (* x tau)))) (* (/ (sin t_1) t_1) (* x (/ 1.0 x)))))
float code(float x, float tau) {
float t_1 = ((float) M_PI) * (x * tau);
return (sinf(t_1) / t_1) * (x * (1.0f / x));
}
function code(x, tau) t_1 = Float32(Float32(pi) * Float32(x * tau)) return Float32(Float32(sin(t_1) / t_1) * Float32(x * Float32(Float32(1.0) / x))) end
function tmp = code(x, tau) t_1 = single(pi) * (x * tau); tmp = (sin(t_1) / t_1) * (x * (single(1.0) / x)); end
\begin{array}{l}
\\
\begin{array}{l}
t_1 := \pi \cdot \left(x \cdot tau\right)\\
\frac{\sin t\_1}{t\_1} \cdot \left(x \cdot \frac{1}{x}\right)
\end{array}
\end{array}
Initial program 98.0%
*-commutative98.0%
associate-*l*97.4%
*-commutative97.4%
associate-*l*98.0%
Simplified98.0%
*-un-lft-identity98.0%
times-frac97.4%
Applied egg-rr97.4%
Taylor expanded in x around 0 73.6%
Final simplification73.6%
(FPCore (x tau) :precision binary32 (/ (* (sin (* PI (* x tau))) (/ 1.0 tau)) (* x PI)))
float code(float x, float tau) {
return (sinf((((float) M_PI) * (x * tau))) * (1.0f / tau)) / (x * ((float) M_PI));
}
function code(x, tau) return Float32(Float32(sin(Float32(Float32(pi) * Float32(x * tau))) * Float32(Float32(1.0) / tau)) / Float32(x * Float32(pi))) end
function tmp = code(x, tau) tmp = (sin((single(pi) * (x * tau))) * (single(1.0) / tau)) / (x * single(pi)); end
\begin{array}{l}
\\
\frac{\sin \left(\pi \cdot \left(x \cdot tau\right)\right) \cdot \frac{1}{tau}}{x \cdot \pi}
\end{array}
Initial program 98.0%
associate-*l/97.9%
associate-/l*97.8%
associate-*l*97.4%
associate-/l/97.4%
*-commutative97.4%
*-commutative97.4%
associate-*l*97.3%
associate-*l*97.3%
Simplified97.3%
associate-*r*97.3%
associate-*r*97.4%
*-commutative97.4%
*-commutative97.4%
associate-*r*97.8%
*-commutative97.8%
Applied egg-rr97.7%
Taylor expanded in x around 0 73.4%
Final simplification73.4%
(FPCore (x tau) :precision binary32 (/ (sin (* x PI)) (* x PI)))
float code(float x, float tau) {
return sinf((x * ((float) M_PI))) / (x * ((float) M_PI));
}
function code(x, tau) return Float32(sin(Float32(x * Float32(pi))) / Float32(x * Float32(pi))) end
function tmp = code(x, tau) tmp = sin((x * single(pi))) / (x * single(pi)); end
\begin{array}{l}
\\
\frac{\sin \left(x \cdot \pi\right)}{x \cdot \pi}
\end{array}
Initial program 98.0%
associate-*l/97.9%
associate-/l*97.8%
associate-*l*97.4%
associate-/l/97.4%
*-commutative97.4%
*-commutative97.4%
associate-*l*97.3%
associate-*l*97.3%
Simplified97.3%
Taylor expanded in tau around 0 67.5%
Final simplification67.5%
(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 98.0%
associate-*l/97.9%
associate-/l*97.8%
associate-*l*97.4%
associate-/l/97.4%
*-commutative97.4%
*-commutative97.4%
associate-*l*97.3%
associate-*l*97.3%
Simplified97.3%
Taylor expanded in x around 0 66.7%
Final simplification66.7%
herbie shell --seed 2024100
(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))))