
(FPCore (u0 u1 alphax alphay)
:precision binary32
(let* ((t_0
(atan
(*
(/ alphay alphax)
(tan (+ (* (* 2.0 PI) u1) (* 0.5 PI))))))
(t_1 (sin t_0))
(t_2 (cos t_0)))
(/
1.0
(sqrt
(+
1.0
(/
(*
(/
1.0
(+
(/ (* t_2 t_2) (* alphax alphax))
(/ (* t_1 t_1) (* alphay alphay))))
u0)
(- 1.0 u0)))))))float code(float u0, float u1, float alphax, float alphay) {
float t_0 = atanf(((alphay / alphax) * tanf((((2.0f * ((float) M_PI)) * u1) + (0.5f * ((float) M_PI))))));
float t_1 = sinf(t_0);
float t_2 = cosf(t_0);
return 1.0f / sqrtf((1.0f + (((1.0f / (((t_2 * t_2) / (alphax * alphax)) + ((t_1 * t_1) / (alphay * alphay)))) * u0) / (1.0f - u0))));
}
function code(u0, u1, alphax, alphay) t_0 = atan(Float32(Float32(alphay / alphax) * tan(Float32(Float32(Float32(Float32(2.0) * Float32(pi)) * u1) + Float32(Float32(0.5) * Float32(pi)))))) t_1 = sin(t_0) t_2 = cos(t_0) return Float32(Float32(1.0) / sqrt(Float32(Float32(1.0) + Float32(Float32(Float32(Float32(1.0) / Float32(Float32(Float32(t_2 * t_2) / Float32(alphax * alphax)) + Float32(Float32(t_1 * t_1) / Float32(alphay * alphay)))) * u0) / Float32(Float32(1.0) - u0))))) end
function tmp = code(u0, u1, alphax, alphay) t_0 = atan(((alphay / alphax) * tan((((single(2.0) * single(pi)) * u1) + (single(0.5) * single(pi)))))); t_1 = sin(t_0); t_2 = cos(t_0); tmp = single(1.0) / sqrt((single(1.0) + (((single(1.0) / (((t_2 * t_2) / (alphax * alphax)) + ((t_1 * t_1) / (alphay * alphay)))) * u0) / (single(1.0) - u0)))); end
\begin{array}{l}
t_0 := \tan^{-1} \left(\frac{alphay}{alphax} \cdot \tan \left(\left(2 \cdot \pi\right) \cdot u1 + 0.5 \cdot \pi\right)\right)\\
t_1 := \sin t\_0\\
t_2 := \cos t\_0\\
\frac{1}{\sqrt{1 + \frac{\frac{1}{\frac{t\_2 \cdot t\_2}{alphax \cdot alphax} + \frac{t\_1 \cdot t\_1}{alphay \cdot alphay}} \cdot u0}{1 - u0}}}
\end{array}
Herbie found 6 alternatives:
| Alternative | Accuracy | Speedup |
|---|
(FPCore (u0 u1 alphax alphay)
:precision binary32
(let* ((t_0
(atan
(*
(/ alphay alphax)
(tan (+ (* (* 2.0 PI) u1) (* 0.5 PI))))))
(t_1 (sin t_0))
(t_2 (cos t_0)))
(/
1.0
(sqrt
(+
1.0
(/
(*
(/
1.0
(+
(/ (* t_2 t_2) (* alphax alphax))
(/ (* t_1 t_1) (* alphay alphay))))
u0)
(- 1.0 u0)))))))float code(float u0, float u1, float alphax, float alphay) {
float t_0 = atanf(((alphay / alphax) * tanf((((2.0f * ((float) M_PI)) * u1) + (0.5f * ((float) M_PI))))));
float t_1 = sinf(t_0);
float t_2 = cosf(t_0);
return 1.0f / sqrtf((1.0f + (((1.0f / (((t_2 * t_2) / (alphax * alphax)) + ((t_1 * t_1) / (alphay * alphay)))) * u0) / (1.0f - u0))));
}
function code(u0, u1, alphax, alphay) t_0 = atan(Float32(Float32(alphay / alphax) * tan(Float32(Float32(Float32(Float32(2.0) * Float32(pi)) * u1) + Float32(Float32(0.5) * Float32(pi)))))) t_1 = sin(t_0) t_2 = cos(t_0) return Float32(Float32(1.0) / sqrt(Float32(Float32(1.0) + Float32(Float32(Float32(Float32(1.0) / Float32(Float32(Float32(t_2 * t_2) / Float32(alphax * alphax)) + Float32(Float32(t_1 * t_1) / Float32(alphay * alphay)))) * u0) / Float32(Float32(1.0) - u0))))) end
function tmp = code(u0, u1, alphax, alphay) t_0 = atan(((alphay / alphax) * tan((((single(2.0) * single(pi)) * u1) + (single(0.5) * single(pi)))))); t_1 = sin(t_0); t_2 = cos(t_0); tmp = single(1.0) / sqrt((single(1.0) + (((single(1.0) / (((t_2 * t_2) / (alphax * alphax)) + ((t_1 * t_1) / (alphay * alphay)))) * u0) / (single(1.0) - u0)))); end
\begin{array}{l}
t_0 := \tan^{-1} \left(\frac{alphay}{alphax} \cdot \tan \left(\left(2 \cdot \pi\right) \cdot u1 + 0.5 \cdot \pi\right)\right)\\
t_1 := \sin t\_0\\
t_2 := \cos t\_0\\
\frac{1}{\sqrt{1 + \frac{\frac{1}{\frac{t\_2 \cdot t\_2}{alphax \cdot alphax} + \frac{t\_1 \cdot t\_1}{alphay \cdot alphay}} \cdot u0}{1 - u0}}}
\end{array}
(FPCore (u0 u1 alphax alphay)
:precision binary32
(let* ((t_0
(asinh
(*
(tan (fma 6.283185307179586 u1 1.5707963267948966))
(/ alphay alphax)))))
(pow
(-
(/
u0
(*
(- 1.0 u0)
(+
(pow (* (cosh t_0) alphax) -2.0)
(pow (/ (tanh t_0) alphay) 2.0))))
-1.0)
-0.5)))float code(float u0, float u1, float alphax, float alphay) {
float t_0 = asinhf((tanf(fmaf(6.283185307179586f, u1, 1.5707963267948966f)) * (alphay / alphax)));
return powf(((u0 / ((1.0f - u0) * (powf((coshf(t_0) * alphax), -2.0f) + powf((tanhf(t_0) / alphay), 2.0f)))) - -1.0f), -0.5f);
}
function code(u0, u1, alphax, alphay) t_0 = asinh(Float32(tan(fma(Float32(6.283185307179586), u1, Float32(1.5707963267948966))) * Float32(alphay / alphax))) return Float32(Float32(u0 / Float32(Float32(Float32(1.0) - u0) * Float32((Float32(cosh(t_0) * alphax) ^ Float32(-2.0)) + (Float32(tanh(t_0) / alphay) ^ Float32(2.0))))) - Float32(-1.0)) ^ Float32(-0.5) end
\begin{array}{l}
t_0 := \sinh^{-1} \left(\tan \left(\mathsf{fma}\left(6.283185307179586, u1, 1.5707963267948966\right)\right) \cdot \frac{alphay}{alphax}\right)\\
{\left(\frac{u0}{\left(1 - u0\right) \cdot \left({\left(\cosh t\_0 \cdot alphax\right)}^{-2} + {\left(\frac{\tanh t\_0}{alphay}\right)}^{2}\right)} - -1\right)}^{-0.5}
\end{array}
Initial program 99.4%
Applied rewrites99.9%
Evaluated real constant99.9%
Evaluated real constant99.9%
lift-*.f32N/A
*-commutativeN/A
lower-*.f3299.9%
lift-+.f32N/A
+-commutativeN/A
lower-+.f3299.9%
Applied rewrites99.9%
Evaluated real constant99.9%
Evaluated real constant99.9%
(FPCore (u0 u1 alphax alphay)
:precision binary32
(let* ((t_0
(asinh
(*
(tan (fma 6.283185307179586 u1 (* 0.5 PI)))
(/ alphay alphax)))))
(/
1.0
(sqrt
(-
(/
u0
(*
(- 1.0 u0)
(+
(pow (* (cosh t_0) alphax) -2.0)
(pow (/ (tanh t_0) alphay) 2.0))))
-1.0)))))float code(float u0, float u1, float alphax, float alphay) {
float t_0 = asinhf((tanf(fmaf(6.283185307179586f, u1, (0.5f * ((float) M_PI)))) * (alphay / alphax)));
return 1.0f / sqrtf(((u0 / ((1.0f - u0) * (powf((coshf(t_0) * alphax), -2.0f) + powf((tanhf(t_0) / alphay), 2.0f)))) - -1.0f));
}
function code(u0, u1, alphax, alphay) t_0 = asinh(Float32(tan(fma(Float32(6.283185307179586), u1, Float32(Float32(0.5) * Float32(pi)))) * Float32(alphay / alphax))) return Float32(Float32(1.0) / sqrt(Float32(Float32(u0 / Float32(Float32(Float32(1.0) - u0) * Float32((Float32(cosh(t_0) * alphax) ^ Float32(-2.0)) + (Float32(tanh(t_0) / alphay) ^ Float32(2.0))))) - Float32(-1.0)))) end
\begin{array}{l}
t_0 := \sinh^{-1} \left(\tan \left(\mathsf{fma}\left(6.283185307179586, u1, 0.5 \cdot \pi\right)\right) \cdot \frac{alphay}{alphax}\right)\\
\frac{1}{\sqrt{\frac{u0}{\left(1 - u0\right) \cdot \left({\left(\cosh t\_0 \cdot alphax\right)}^{-2} + {\left(\frac{\tanh t\_0}{alphay}\right)}^{2}\right)} - -1}}
\end{array}
Initial program 99.4%
Applied rewrites99.4%
Evaluated real constant99.4%
Evaluated real constant99.4%
lift-*.f32N/A
*-commutativeN/A
lift-+.f32N/A
+-commutativeN/A
Applied rewrites99.4%
(FPCore (u0 u1 alphax alphay)
:precision binary32
(/
1.0
(sqrt
(+
(/
(* u0 (* alphay alphay))
(*
(pow
(tanh
(asinh
(/
(* (sin (* 0.5 PI)) alphay)
(* (cos (fma (+ PI PI) u1 (* 0.5 PI))) alphax))))
2.0)
(- 1.0 u0)))
1.0))))float code(float u0, float u1, float alphax, float alphay) {
return 1.0f / sqrtf((((u0 * (alphay * alphay)) / (powf(tanhf(asinhf(((sinf((0.5f * ((float) M_PI))) * alphay) / (cosf(fmaf((((float) M_PI) + ((float) M_PI)), u1, (0.5f * ((float) M_PI)))) * alphax)))), 2.0f) * (1.0f - u0))) + 1.0f));
}
function code(u0, u1, alphax, alphay) return Float32(Float32(1.0) / sqrt(Float32(Float32(Float32(u0 * Float32(alphay * alphay)) / Float32((tanh(asinh(Float32(Float32(sin(Float32(Float32(0.5) * Float32(pi))) * alphay) / Float32(cos(fma(Float32(Float32(pi) + Float32(pi)), u1, Float32(Float32(0.5) * Float32(pi)))) * alphax)))) ^ Float32(2.0)) * Float32(Float32(1.0) - u0))) + Float32(1.0)))) end
\frac{1}{\sqrt{\frac{u0 \cdot \left(alphay \cdot alphay\right)}{{\tanh \sinh^{-1} \left(\frac{\sin \left(0.5 \cdot \pi\right) \cdot alphay}{\cos \left(\mathsf{fma}\left(\pi + \pi, u1, 0.5 \cdot \pi\right)\right) \cdot alphax}\right)}^{2} \cdot \left(1 - u0\right)} + 1}}
Initial program 99.4%
Taylor expanded in alphax around 0
lower-/.f32N/A
Applied rewrites49.5%
Taylor expanded in alphax around inf
lower-/.f32N/A
Applied rewrites97.9%
Taylor expanded in u1 around 0
lower-sin.f32N/A
lower-*.f32N/A
lower-PI.f3298.4%
Applied rewrites98.4%
Applied rewrites98.4%
(FPCore (u0 u1 alphax alphay)
:precision binary32
(pow
(+
(/
(* (* alphay alphay) u0)
(*
(pow
(tanh
(asinh
(*
(tan (fma (+ PI PI) u1 1.5707963267948966))
(/ alphay alphax))))
2.0)
(- 1.0 u0)))
1.0)
-0.5))float code(float u0, float u1, float alphax, float alphay) {
return powf(((((alphay * alphay) * u0) / (powf(tanhf(asinhf((tanf(fmaf((((float) M_PI) + ((float) M_PI)), u1, 1.5707963267948966f)) * (alphay / alphax)))), 2.0f) * (1.0f - u0))) + 1.0f), -0.5f);
}
function code(u0, u1, alphax, alphay) return Float32(Float32(Float32(Float32(alphay * alphay) * u0) / Float32((tanh(asinh(Float32(tan(fma(Float32(Float32(pi) + Float32(pi)), u1, Float32(1.5707963267948966))) * Float32(alphay / alphax)))) ^ Float32(2.0)) * Float32(Float32(1.0) - u0))) + Float32(1.0)) ^ Float32(-0.5) end
{\left(\frac{\left(alphay \cdot alphay\right) \cdot u0}{{\tanh \sinh^{-1} \left(\tan \left(\mathsf{fma}\left(\pi + \pi, u1, 1.5707963267948966\right)\right) \cdot \frac{alphay}{alphax}\right)}^{2} \cdot \left(1 - u0\right)} + 1\right)}^{-0.5}
Initial program 99.4%
Taylor expanded in alphax around 0
lower-/.f32N/A
Applied rewrites49.5%
Taylor expanded in alphax around inf
lower-/.f32N/A
Applied rewrites97.9%
Applied rewrites98.3%
Evaluated real constant98.3%
(FPCore (u0 u1 alphax alphay)
:precision binary32
(/
1.0
(sqrt
(+
(/
(* (* alphay alphay) u0)
(*
(pow
(tanh
(asinh
(* (tan (fma (+ PI PI) u1 (* 0.5 PI))) (/ alphay alphax))))
2.0)
(- 1.0 u0)))
1.0))))float code(float u0, float u1, float alphax, float alphay) {
return 1.0f / sqrtf(((((alphay * alphay) * u0) / (powf(tanhf(asinhf((tanf(fmaf((((float) M_PI) + ((float) M_PI)), u1, (0.5f * ((float) M_PI)))) * (alphay / alphax)))), 2.0f) * (1.0f - u0))) + 1.0f));
}
function code(u0, u1, alphax, alphay) return Float32(Float32(1.0) / sqrt(Float32(Float32(Float32(Float32(alphay * alphay) * u0) / Float32((tanh(asinh(Float32(tan(fma(Float32(Float32(pi) + Float32(pi)), u1, Float32(Float32(0.5) * Float32(pi)))) * Float32(alphay / alphax)))) ^ Float32(2.0)) * Float32(Float32(1.0) - u0))) + Float32(1.0)))) end
\frac{1}{\sqrt{\frac{\left(alphay \cdot alphay\right) \cdot u0}{{\tanh \sinh^{-1} \left(\tan \left(\mathsf{fma}\left(\pi + \pi, u1, 0.5 \cdot \pi\right)\right) \cdot \frac{alphay}{alphax}\right)}^{2} \cdot \left(1 - u0\right)} + 1}}
Initial program 99.4%
Taylor expanded in alphax around 0
lower-/.f32N/A
Applied rewrites49.5%
Taylor expanded in alphax around inf
lower-/.f32N/A
Applied rewrites97.9%
Applied rewrites97.9%
(FPCore (u0 u1 alphax alphay) :precision binary32 (fma (/ (* (* alphax alphax) u0) 1.0) -0.5 1.0))
float code(float u0, float u1, float alphax, float alphay) {
return fmaf((((alphax * alphax) * u0) / 1.0f), -0.5f, 1.0f);
}
function code(u0, u1, alphax, alphay) return fma(Float32(Float32(Float32(alphax * alphax) * u0) / Float32(1.0)), Float32(-0.5), Float32(1.0)) end
\mathsf{fma}\left(\frac{\left(alphax \cdot alphax\right) \cdot u0}{1}, -0.5, 1\right)
Initial program 99.4%
Taylor expanded in alphax around 0
lower-+.f32N/A
Applied rewrites41.7%
Applied rewrites33.2%
Taylor expanded in alphax around inf
lower--.f3287.9%
Applied rewrites87.9%
Taylor expanded in u0 around 0
Applied rewrites88.1%
herbie shell --seed 2025325
(FPCore (u0 u1 alphax alphay)
:name "Trowbridge-Reitz Sample, sample surface normal, cosTheta"
:precision binary32
:pre (and (and (and (and (<= 2.328306437e-10 u0) (<= u0 1.0)) (and (<= 2.328306437e-10 u1) (<= u1 0.5))) (and (<= 0.0001 alphax) (<= alphax 1.0))) (and (<= 0.0001 alphay) (<= alphay 1.0)))
(/ 1.0 (sqrt (+ 1.0 (/ (* (/ 1.0 (+ (/ (* (cos (atan (* (/ alphay alphax) (tan (+ (* (* 2.0 PI) u1) (* 0.5 PI)))))) (cos (atan (* (/ alphay alphax) (tan (+ (* (* 2.0 PI) u1) (* 0.5 PI))))))) (* alphax alphax)) (/ (* (sin (atan (* (/ alphay alphax) (tan (+ (* (* 2.0 PI) u1) (* 0.5 PI)))))) (sin (atan (* (/ alphay alphax) (tan (+ (* (* 2.0 PI) u1) (* 0.5 PI))))))) (* alphay alphay)))) u0) (- 1.0 u0))))))