
(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 11 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 (* 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(x * Float32(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 := x \cdot \left(\pi \cdot tau\right)\\
\frac{\sin t\_1}{t\_1} \cdot \frac{\sin \left(x \cdot \pi\right)}{x \cdot \pi}
\end{array}
\end{array}
Initial program 98.2%
associate-*l*97.5%
associate-*l*98.2%
Simplified98.2%
Final simplification98.2%
(FPCore (x tau) :precision binary32 (* (/ (sin (* x PI)) (* x PI)) (/ (sin (* tau (* x PI))) (* PI (* x tau)))))
float code(float x, float tau) {
return (sinf((x * ((float) M_PI))) / (x * ((float) M_PI))) * (sinf((tau * (x * ((float) M_PI)))) / (((float) M_PI) * (x * tau)));
}
function code(x, tau) return Float32(Float32(sin(Float32(x * Float32(pi))) / Float32(x * Float32(pi))) * Float32(sin(Float32(tau * Float32(x * Float32(pi)))) / Float32(Float32(pi) * Float32(x * tau)))) end
function tmp = code(x, tau) tmp = (sin((x * single(pi))) / (x * single(pi))) * (sin((tau * (x * single(pi)))) / (single(pi) * (x * tau))); end
\begin{array}{l}
\\
\frac{\sin \left(x \cdot \pi\right)}{x \cdot \pi} \cdot \frac{\sin \left(tau \cdot \left(x \cdot \pi\right)\right)}{\pi \cdot \left(x \cdot tau\right)}
\end{array}
Initial program 98.2%
*-commutative98.2%
associate-*l*97.1%
*-commutative97.1%
associate-*l*98.0%
Simplified98.0%
Taylor expanded in x around 0 97.1%
Final simplification97.1%
(FPCore (x tau) :precision binary32 (* (/ (sin (* x PI)) (* x PI)) (/ (sin (* x (* PI tau))) (* PI (* x tau)))))
float code(float x, float tau) {
return (sinf((x * ((float) M_PI))) / (x * ((float) M_PI))) * (sinf((x * (((float) M_PI) * tau))) / (((float) M_PI) * (x * tau)));
}
function code(x, tau) return Float32(Float32(sin(Float32(x * Float32(pi))) / Float32(x * Float32(pi))) * Float32(sin(Float32(x * Float32(Float32(pi) * tau))) / Float32(Float32(pi) * Float32(x * tau)))) end
function tmp = code(x, tau) tmp = (sin((x * single(pi))) / (x * single(pi))) * (sin((x * (single(pi) * tau))) / (single(pi) * (x * tau))); end
\begin{array}{l}
\\
\frac{\sin \left(x \cdot \pi\right)}{x \cdot \pi} \cdot \frac{\sin \left(x \cdot \left(\pi \cdot tau\right)\right)}{\pi \cdot \left(x \cdot tau\right)}
\end{array}
Initial program 98.2%
*-commutative98.2%
associate-*l*97.1%
*-commutative97.1%
associate-*l*98.0%
Simplified98.0%
Taylor expanded in x around 0 97.1%
*-commutative97.1%
associate-*l*97.4%
*-commutative97.4%
Simplified97.4%
Final simplification97.4%
(FPCore (x tau)
:precision binary32
(let* ((t_1 (* x (* PI tau))))
(*
(/ (sin t_1) t_1)
(+ 1.0 (* -0.16666666666666666 (* PI (* x (* x PI))))))))
float code(float x, float tau) {
float t_1 = x * (((float) M_PI) * tau);
return (sinf(t_1) / t_1) * (1.0f + (-0.16666666666666666f * (((float) M_PI) * (x * (x * ((float) M_PI))))));
}
function code(x, tau) t_1 = Float32(x * Float32(Float32(pi) * tau)) return Float32(Float32(sin(t_1) / t_1) * Float32(Float32(1.0) + Float32(Float32(-0.16666666666666666) * Float32(Float32(pi) * Float32(x * Float32(x * Float32(pi))))))) end
function tmp = code(x, tau) t_1 = x * (single(pi) * tau); tmp = (sin(t_1) / t_1) * (single(1.0) + (single(-0.16666666666666666) * (single(pi) * (x * (x * single(pi)))))); end
\begin{array}{l}
\\
\begin{array}{l}
t_1 := x \cdot \left(\pi \cdot tau\right)\\
\frac{\sin t\_1}{t\_1} \cdot \left(1 + -0.16666666666666666 \cdot \left(\pi \cdot \left(x \cdot \left(x \cdot \pi\right)\right)\right)\right)
\end{array}
\end{array}
Initial program 98.2%
associate-/r*97.9%
div-inv97.8%
Applied egg-rr97.8%
Taylor expanded in x around 0 86.2%
unpow286.2%
unpow286.2%
swap-sqr86.2%
unpow286.2%
Simplified86.2%
unpow286.2%
associate-*r*86.2%
Applied egg-rr86.2%
Taylor expanded in x around inf 86.2%
*-commutative86.2%
associate-*r*85.4%
*-commutative85.4%
associate-*r*86.2%
Simplified86.2%
Final simplification86.2%
(FPCore (x tau)
:precision binary32
(let* ((t_1 (* tau (* x PI))))
(*
(/ (sin t_1) t_1)
(+ 1.0 (* -0.16666666666666666 (* PI (* x (* x PI))))))))
float code(float x, float tau) {
float t_1 = tau * (x * ((float) M_PI));
return (sinf(t_1) / t_1) * (1.0f + (-0.16666666666666666f * (((float) M_PI) * (x * (x * ((float) M_PI))))));
}
function code(x, tau) t_1 = Float32(tau * Float32(x * Float32(pi))) return Float32(Float32(sin(t_1) / t_1) * Float32(Float32(1.0) + Float32(Float32(-0.16666666666666666) * Float32(Float32(pi) * Float32(x * Float32(x * Float32(pi))))))) end
function tmp = code(x, tau) t_1 = tau * (x * single(pi)); tmp = (sin(t_1) / t_1) * (single(1.0) + (single(-0.16666666666666666) * (single(pi) * (x * (x * single(pi)))))); end
\begin{array}{l}
\\
\begin{array}{l}
t_1 := tau \cdot \left(x \cdot \pi\right)\\
\frac{\sin t\_1}{t\_1} \cdot \left(1 + -0.16666666666666666 \cdot \left(\pi \cdot \left(x \cdot \left(x \cdot \pi\right)\right)\right)\right)
\end{array}
\end{array}
Initial program 98.2%
associate-/r*97.9%
div-inv97.8%
Applied egg-rr97.8%
Taylor expanded in x around 0 86.2%
unpow286.2%
unpow286.2%
swap-sqr86.2%
unpow286.2%
Simplified86.2%
unpow286.2%
associate-*r*86.2%
Applied egg-rr86.2%
Final simplification86.2%
(FPCore (x tau)
:precision binary32
(let* ((t_1 (* tau (* x PI))))
(*
(/ (sin t_1) t_1)
(+ 1.0 (* -0.16666666666666666 (* x (* PI (* x PI))))))))
float code(float x, float tau) {
float t_1 = tau * (x * ((float) M_PI));
return (sinf(t_1) / t_1) * (1.0f + (-0.16666666666666666f * (x * (((float) M_PI) * (x * ((float) M_PI))))));
}
function code(x, tau) t_1 = Float32(tau * Float32(x * Float32(pi))) return Float32(Float32(sin(t_1) / t_1) * Float32(Float32(1.0) + Float32(Float32(-0.16666666666666666) * Float32(x * Float32(Float32(pi) * Float32(x * Float32(pi))))))) end
function tmp = code(x, tau) t_1 = tau * (x * single(pi)); tmp = (sin(t_1) / t_1) * (single(1.0) + (single(-0.16666666666666666) * (x * (single(pi) * (x * single(pi)))))); end
\begin{array}{l}
\\
\begin{array}{l}
t_1 := tau \cdot \left(x \cdot \pi\right)\\
\frac{\sin t\_1}{t\_1} \cdot \left(1 + -0.16666666666666666 \cdot \left(x \cdot \left(\pi \cdot \left(x \cdot \pi\right)\right)\right)\right)
\end{array}
\end{array}
Initial program 98.2%
associate-/r*97.9%
div-inv97.8%
Applied egg-rr97.8%
Taylor expanded in x around 0 86.2%
unpow286.2%
unpow286.2%
swap-sqr86.2%
unpow286.2%
Simplified86.2%
unpow286.2%
*-commutative86.2%
associate-*r*86.2%
Applied egg-rr86.2%
Final simplification86.2%
(FPCore (x tau) :precision binary32 (let* ((t_1 (* tau (* x PI)))) (/ (sin t_1) t_1)))
float code(float x, float tau) {
float t_1 = tau * (x * ((float) M_PI));
return sinf(t_1) / t_1;
}
function code(x, tau) t_1 = Float32(tau * Float32(x * Float32(pi))) return Float32(sin(t_1) / t_1) end
function tmp = code(x, tau) t_1 = tau * (x * single(pi)); tmp = sin(t_1) / t_1; end
\begin{array}{l}
\\
\begin{array}{l}
t_1 := tau \cdot \left(x \cdot \pi\right)\\
\frac{\sin t\_1}{t\_1}
\end{array}
\end{array}
Initial program 98.2%
associate-/r*97.9%
div-inv97.8%
Applied egg-rr97.8%
Taylor expanded in x around 0 70.3%
Final simplification70.3%
(FPCore (x tau) :precision binary32 (/ 1.0 (/ (* x PI) (sin (* x PI)))))
float code(float x, float tau) {
return 1.0f / ((x * ((float) M_PI)) / sinf((x * ((float) M_PI))));
}
function code(x, tau) return Float32(Float32(1.0) / Float32(Float32(x * Float32(pi)) / sin(Float32(x * Float32(pi))))) end
function tmp = code(x, tau) tmp = single(1.0) / ((x * single(pi)) / sin((x * single(pi)))); end
\begin{array}{l}
\\
\frac{1}{\frac{x \cdot \pi}{\sin \left(x \cdot \pi\right)}}
\end{array}
Initial program 98.2%
associate-*l*97.5%
associate-*l*98.2%
Simplified98.2%
Taylor expanded in x around 0 63.7%
div-inv63.8%
associate-/r*63.7%
Applied egg-rr63.7%
*-commutative63.7%
associate-*l/63.6%
associate-*r/63.7%
Simplified63.7%
frac-times63.7%
associate-/l*63.8%
Applied egg-rr63.8%
Final simplification63.8%
(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 98.2%
associate-*l*97.5%
associate-*l*98.2%
Simplified98.2%
Taylor expanded in x around 0 63.7%
Final simplification63.7%
(FPCore (x tau) :precision binary32 (/ (* x PI) (* x PI)))
float code(float x, float tau) {
return (x * ((float) M_PI)) / (x * ((float) M_PI));
}
function code(x, tau) return Float32(Float32(x * Float32(pi)) / Float32(x * Float32(pi))) end
function tmp = code(x, tau) tmp = (x * single(pi)) / (x * single(pi)); end
\begin{array}{l}
\\
\frac{x \cdot \pi}{x \cdot \pi}
\end{array}
Initial program 98.2%
associate-*l*97.5%
associate-*l*98.2%
Simplified98.2%
Taylor expanded in x around 0 63.7%
Taylor expanded in x around 0 62.9%
Final simplification62.9%
(FPCore (x tau) :precision binary32 (* x (/ 1.0 x)))
float code(float x, float tau) {
return x * (1.0f / x);
}
real(4) function code(x, tau)
real(4), intent (in) :: x
real(4), intent (in) :: tau
code = x * (1.0e0 / x)
end function
function code(x, tau) return Float32(x * Float32(Float32(1.0) / x)) end
function tmp = code(x, tau) tmp = x * (single(1.0) / x); end
\begin{array}{l}
\\
x \cdot \frac{1}{x}
\end{array}
Initial program 98.2%
associate-*l*97.5%
associate-*l*98.2%
Simplified98.2%
Taylor expanded in x around 0 63.7%
div-inv63.8%
associate-/r*63.7%
Applied egg-rr63.7%
*-commutative63.7%
associate-*l/63.6%
associate-*r/63.7%
Simplified63.7%
Taylor expanded in x around 0 62.9%
Final simplification62.9%
herbie shell --seed 2024039
(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))))