
(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 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}
Initial program 98.1%
Final simplification98.1%
(FPCore (x tau) :precision binary32 (let* ((t_1 (* x (* PI tau)))) (* (sin t_1) (/ (sin (* x PI)) (* PI (* x t_1))))))
float code(float x, float tau) {
float t_1 = x * (((float) M_PI) * tau);
return sinf(t_1) * (sinf((x * ((float) M_PI))) / (((float) M_PI) * (x * t_1)));
}
function code(x, tau) t_1 = Float32(x * Float32(Float32(pi) * tau)) 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 * (single(pi) * tau); 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(\pi \cdot tau\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 98.1%
associate-*l/97.9%
associate-/l*97.9%
associate-*l*97.3%
associate-/l/97.2%
*-commutative97.2%
*-commutative97.2%
associate-*l*97.2%
associate-*l*97.7%
Simplified97.7%
Final simplification97.7%
(FPCore (x tau) :precision binary32 (let* ((t_1 (* x (* PI tau)))) (* (sin t_1) (/ (sin (* x PI)) (* (* x PI) t_1)))))
float code(float x, float tau) {
float t_1 = x * (((float) M_PI) * tau);
return sinf(t_1) * (sinf((x * ((float) M_PI))) / ((x * ((float) M_PI)) * t_1));
}
function code(x, tau) t_1 = Float32(x * Float32(Float32(pi) * tau)) 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 * (single(pi) * tau); 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(\pi \cdot tau\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 98.1%
associate-*l/97.9%
associate-/l*97.9%
associate-*l*97.3%
associate-/l/97.2%
associate-*l*97.9%
Simplified97.9%
Final simplification97.9%
(FPCore (x tau) :precision binary32 (let* ((t_1 (* PI (* x tau)))) (* (/ (sin (* x PI)) (* x PI)) (/ (sin t_1) t_1))))
float code(float x, float tau) {
float t_1 = ((float) M_PI) * (x * tau);
return (sinf((x * ((float) M_PI))) / (x * ((float) M_PI))) * (sinf(t_1) / t_1);
}
function code(x, tau) t_1 = Float32(Float32(pi) * Float32(x * tau)) return Float32(Float32(sin(Float32(x * Float32(pi))) / Float32(x * Float32(pi))) * Float32(sin(t_1) / t_1)) end
function tmp = code(x, tau) t_1 = single(pi) * (x * tau); tmp = (sin((x * single(pi))) / (x * single(pi))) * (sin(t_1) / 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)}{x \cdot \pi} \cdot \frac{\sin t\_1}{t\_1}
\end{array}
\end{array}
Initial program 98.1%
*-commutative98.1%
associate-*l*97.4%
*-commutative97.4%
associate-*l*98.0%
Simplified98.0%
Final simplification98.0%
(FPCore (x tau) :precision binary32 (* (sin (* x (* PI tau))) (/ 1.0 (* (* x PI) tau))))
float code(float x, float tau) {
return sinf((x * (((float) M_PI) * tau))) * (1.0f / ((x * ((float) M_PI)) * tau));
}
function code(x, tau) return Float32(sin(Float32(x * Float32(Float32(pi) * tau))) * Float32(Float32(1.0) / Float32(Float32(x * Float32(pi)) * tau))) end
function tmp = code(x, tau) tmp = sin((x * (single(pi) * tau))) * (single(1.0) / ((x * single(pi)) * tau)); end
\begin{array}{l}
\\
\sin \left(x \cdot \left(\pi \cdot tau\right)\right) \cdot \frac{1}{\left(x \cdot \pi\right) \cdot tau}
\end{array}
Initial program 98.1%
associate-*l/97.9%
associate-/l*97.9%
associate-*l*97.3%
associate-/l/97.2%
*-commutative97.2%
*-commutative97.2%
associate-*l*97.2%
associate-*l*97.7%
Simplified97.7%
Taylor expanded in x around 0 72.7%
Final simplification72.7%
(FPCore (x tau) :precision binary32 (* (sin (* x (* PI tau))) (/ (/ 1.0 tau) (* x PI))))
float code(float x, float tau) {
return sinf((x * (((float) M_PI) * tau))) * ((1.0f / tau) / (x * ((float) M_PI)));
}
function code(x, tau) return Float32(sin(Float32(x * Float32(Float32(pi) * tau))) * Float32(Float32(Float32(1.0) / tau) / Float32(x * Float32(pi)))) end
function tmp = code(x, tau) tmp = sin((x * (single(pi) * tau))) * ((single(1.0) / tau) / (x * single(pi))); end
\begin{array}{l}
\\
\sin \left(x \cdot \left(\pi \cdot tau\right)\right) \cdot \frac{\frac{1}{tau}}{x \cdot \pi}
\end{array}
Initial program 98.1%
associate-*l/97.9%
associate-/l*97.9%
associate-*l*97.3%
associate-/l/97.2%
*-commutative97.2%
*-commutative97.2%
associate-*l*97.2%
associate-*l*97.7%
Simplified97.7%
Taylor expanded in x around 0 72.7%
associate-/r*72.7%
Simplified72.7%
Final simplification72.7%
(FPCore (x tau) :precision binary32 (* (sin (* x (* PI tau))) (/ (/ 1.0 x) (* PI tau))))
float code(float x, float tau) {
return sinf((x * (((float) M_PI) * tau))) * ((1.0f / x) / (((float) M_PI) * tau));
}
function code(x, tau) return Float32(sin(Float32(x * Float32(Float32(pi) * tau))) * Float32(Float32(Float32(1.0) / x) / Float32(Float32(pi) * tau))) end
function tmp = code(x, tau) tmp = sin((x * (single(pi) * tau))) * ((single(1.0) / x) / (single(pi) * tau)); end
\begin{array}{l}
\\
\sin \left(x \cdot \left(\pi \cdot tau\right)\right) \cdot \frac{\frac{1}{x}}{\pi \cdot tau}
\end{array}
Initial program 98.1%
associate-*l/97.9%
associate-/l*97.9%
associate-*l*97.3%
associate-/l/97.2%
*-commutative97.2%
*-commutative97.2%
associate-*l*97.2%
associate-*l*97.7%
Simplified97.7%
Taylor expanded in x around 0 72.7%
associate-/l/72.7%
*-commutative72.7%
associate-/l/72.7%
associate-/l/72.8%
Simplified72.8%
Final simplification72.8%
(FPCore (x tau) :precision binary32 (let* ((t_1 (* (* x PI) tau))) (/ (sin t_1) t_1)))
float code(float x, float tau) {
float t_1 = (x * ((float) M_PI)) * tau;
return sinf(t_1) / t_1;
}
function code(x, tau) t_1 = Float32(Float32(x * Float32(pi)) * tau) return Float32(sin(t_1) / t_1) end
function tmp = code(x, tau) t_1 = (x * single(pi)) * tau; tmp = sin(t_1) / t_1; end
\begin{array}{l}
\\
\begin{array}{l}
t_1 := \left(x \cdot \pi\right) \cdot tau\\
\frac{\sin t\_1}{t\_1}
\end{array}
\end{array}
Initial program 98.1%
add-log-exp97.5%
Applied egg-rr97.5%
rem-log-exp98.1%
associate-/r*97.9%
Applied egg-rr97.9%
Taylor expanded in x around 0 73.0%
Final simplification73.0%
(FPCore (x tau) :precision binary32 (fma -0.16666666666666666 (* PI (* x (* x PI))) 1.0))
float code(float x, float tau) {
return fmaf(-0.16666666666666666f, (((float) M_PI) * (x * (x * ((float) M_PI)))), 1.0f);
}
function code(x, tau) return fma(Float32(-0.16666666666666666), Float32(Float32(pi) * Float32(x * Float32(x * Float32(pi)))), Float32(1.0)) end
\begin{array}{l}
\\
\mathsf{fma}\left(-0.16666666666666666, \pi \cdot \left(x \cdot \left(x \cdot \pi\right)\right), 1\right)
\end{array}
Initial program 98.1%
associate-*l/97.9%
associate-/l*97.9%
associate-*l*97.3%
associate-/l/97.2%
*-commutative97.2%
*-commutative97.2%
associate-*l*97.2%
associate-*l*97.7%
Simplified97.7%
Taylor expanded in tau around 0 66.5%
Taylor expanded in x around 0 66.8%
+-commutative66.8%
fma-define66.8%
unpow266.8%
unpow266.8%
swap-sqr66.8%
unpow266.8%
Simplified66.8%
unpow266.8%
associate-*r*66.8%
Applied egg-rr66.8%
Final simplification66.8%
(FPCore (x tau) :precision binary32 (+ 1.0 (* -0.16666666666666666 (pow (* x PI) 2.0))))
float code(float x, float tau) {
return 1.0f + (-0.16666666666666666f * powf((x * ((float) M_PI)), 2.0f));
}
function code(x, tau) return Float32(Float32(1.0) + Float32(Float32(-0.16666666666666666) * (Float32(x * Float32(pi)) ^ Float32(2.0)))) end
function tmp = code(x, tau) tmp = single(1.0) + (single(-0.16666666666666666) * ((x * single(pi)) ^ single(2.0))); end
\begin{array}{l}
\\
1 + -0.16666666666666666 \cdot {\left(x \cdot \pi\right)}^{2}
\end{array}
Initial program 98.1%
associate-*l/97.9%
associate-/l*97.9%
associate-*l*97.3%
associate-/l/97.2%
*-commutative97.2%
*-commutative97.2%
associate-*l*97.2%
associate-*l*97.7%
Simplified97.7%
Taylor expanded in tau around 0 66.5%
Taylor expanded in x around 0 66.8%
+-commutative66.8%
fma-define66.8%
unpow266.8%
unpow266.8%
swap-sqr66.8%
unpow266.8%
Simplified66.8%
fma-undefine66.8%
*-commutative66.8%
Applied egg-rr66.8%
Final simplification66.8%
(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 98.1%
associate-*l/97.9%
associate-/l*97.9%
associate-*l*97.3%
associate-/l/97.2%
*-commutative97.2%
*-commutative97.2%
associate-*l*97.2%
associate-*l*97.7%
Simplified97.7%
Taylor expanded in tau around 0 66.5%
Final simplification66.5%
(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 98.1%
associate-*r/98.0%
times-frac97.6%
associate-/l/97.5%
associate-*l*97.1%
associate-*l*97.5%
Simplified97.5%
Taylor expanded in x around 0 66.3%
Taylor expanded in x around 0 65.6%
Taylor expanded in x around 0 65.7%
Final simplification65.7%
herbie shell --seed 2024096
(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))))