
(FPCore (cosTheta_i cosTheta_O sinTheta_i sinTheta_O v)
:precision binary32
(exp
(+
(+
(-
(- (/ (* cosTheta_i cosTheta_O) v) (/ (* sinTheta_i sinTheta_O) v))
(/ 1.0 v))
0.6931)
(log (/ 1.0 (* 2.0 v))))))
float code(float cosTheta_i, float cosTheta_O, float sinTheta_i, float sinTheta_O, float v) {
return expf(((((((cosTheta_i * cosTheta_O) / v) - ((sinTheta_i * sinTheta_O) / v)) - (1.0f / v)) + 0.6931f) + logf((1.0f / (2.0f * v)))));
}
real(4) function code(costheta_i, costheta_o, sintheta_i, sintheta_o, v)
real(4), intent (in) :: costheta_i
real(4), intent (in) :: costheta_o
real(4), intent (in) :: sintheta_i
real(4), intent (in) :: sintheta_o
real(4), intent (in) :: v
code = exp(((((((costheta_i * costheta_o) / v) - ((sintheta_i * sintheta_o) / v)) - (1.0e0 / v)) + 0.6931e0) + log((1.0e0 / (2.0e0 * v)))))
end function
function code(cosTheta_i, cosTheta_O, sinTheta_i, sinTheta_O, v) return exp(Float32(Float32(Float32(Float32(Float32(Float32(cosTheta_i * cosTheta_O) / v) - Float32(Float32(sinTheta_i * sinTheta_O) / v)) - Float32(Float32(1.0) / v)) + Float32(0.6931)) + log(Float32(Float32(1.0) / Float32(Float32(2.0) * v))))) end
function tmp = code(cosTheta_i, cosTheta_O, sinTheta_i, sinTheta_O, v) tmp = exp(((((((cosTheta_i * cosTheta_O) / v) - ((sinTheta_i * sinTheta_O) / v)) - (single(1.0) / v)) + single(0.6931)) + log((single(1.0) / (single(2.0) * v))))); end
\begin{array}{l}
\\
e^{\left(\left(\left(\frac{cosTheta\_i \cdot cosTheta\_O}{v} - \frac{sinTheta\_i \cdot sinTheta\_O}{v}\right) - \frac{1}{v}\right) + 0.6931\right) + \log \left(\frac{1}{2 \cdot v}\right)}
\end{array}
Sampling outcomes in binary32 precision:
Herbie found 13 alternatives:
| Alternative | Accuracy | Speedup |
|---|
(FPCore (cosTheta_i cosTheta_O sinTheta_i sinTheta_O v)
:precision binary32
(exp
(+
(+
(-
(- (/ (* cosTheta_i cosTheta_O) v) (/ (* sinTheta_i sinTheta_O) v))
(/ 1.0 v))
0.6931)
(log (/ 1.0 (* 2.0 v))))))
float code(float cosTheta_i, float cosTheta_O, float sinTheta_i, float sinTheta_O, float v) {
return expf(((((((cosTheta_i * cosTheta_O) / v) - ((sinTheta_i * sinTheta_O) / v)) - (1.0f / v)) + 0.6931f) + logf((1.0f / (2.0f * v)))));
}
real(4) function code(costheta_i, costheta_o, sintheta_i, sintheta_o, v)
real(4), intent (in) :: costheta_i
real(4), intent (in) :: costheta_o
real(4), intent (in) :: sintheta_i
real(4), intent (in) :: sintheta_o
real(4), intent (in) :: v
code = exp(((((((costheta_i * costheta_o) / v) - ((sintheta_i * sintheta_o) / v)) - (1.0e0 / v)) + 0.6931e0) + log((1.0e0 / (2.0e0 * v)))))
end function
function code(cosTheta_i, cosTheta_O, sinTheta_i, sinTheta_O, v) return exp(Float32(Float32(Float32(Float32(Float32(Float32(cosTheta_i * cosTheta_O) / v) - Float32(Float32(sinTheta_i * sinTheta_O) / v)) - Float32(Float32(1.0) / v)) + Float32(0.6931)) + log(Float32(Float32(1.0) / Float32(Float32(2.0) * v))))) end
function tmp = code(cosTheta_i, cosTheta_O, sinTheta_i, sinTheta_O, v) tmp = exp(((((((cosTheta_i * cosTheta_O) / v) - ((sinTheta_i * sinTheta_O) / v)) - (single(1.0) / v)) + single(0.6931)) + log((single(1.0) / (single(2.0) * v))))); end
\begin{array}{l}
\\
e^{\left(\left(\left(\frac{cosTheta\_i \cdot cosTheta\_O}{v} - \frac{sinTheta\_i \cdot sinTheta\_O}{v}\right) - \frac{1}{v}\right) + 0.6931\right) + \log \left(\frac{1}{2 \cdot v}\right)}
\end{array}
(FPCore (cosTheta_i cosTheta_O sinTheta_i sinTheta_O v)
:precision binary32
(let* ((t_0 (log (* 2.0 v)))
(t_1
(+
(/ (- (fma cosTheta_i cosTheta_O -1.0) (* sinTheta_i sinTheta_O)) v)
(+ t_0 0.6931)))
(t_2 (+ (/ (fma cosTheta_i cosTheta_O -1.0) v) 0.6931))
(t_3 (/ t_0 t_1)))
(/ (/ (exp (/ (* t_2 t_2) t_1)) (pow v t_3)) (pow 2.0 t_3))))
float code(float cosTheta_i, float cosTheta_O, float sinTheta_i, float sinTheta_O, float v) {
float t_0 = logf((2.0f * v));
float t_1 = ((fmaf(cosTheta_i, cosTheta_O, -1.0f) - (sinTheta_i * sinTheta_O)) / v) + (t_0 + 0.6931f);
float t_2 = (fmaf(cosTheta_i, cosTheta_O, -1.0f) / v) + 0.6931f;
float t_3 = t_0 / t_1;
return (expf(((t_2 * t_2) / t_1)) / powf(v, t_3)) / powf(2.0f, t_3);
}
function code(cosTheta_i, cosTheta_O, sinTheta_i, sinTheta_O, v) t_0 = log(Float32(Float32(2.0) * v)) t_1 = Float32(Float32(Float32(fma(cosTheta_i, cosTheta_O, Float32(-1.0)) - Float32(sinTheta_i * sinTheta_O)) / v) + Float32(t_0 + Float32(0.6931))) t_2 = Float32(Float32(fma(cosTheta_i, cosTheta_O, Float32(-1.0)) / v) + Float32(0.6931)) t_3 = Float32(t_0 / t_1) return Float32(Float32(exp(Float32(Float32(t_2 * t_2) / t_1)) / (v ^ t_3)) / (Float32(2.0) ^ t_3)) end
\begin{array}{l}
\\
\begin{array}{l}
t_0 := \log \left(2 \cdot v\right)\\
t_1 := \frac{\mathsf{fma}\left(cosTheta\_i, cosTheta\_O, -1\right) - sinTheta\_i \cdot sinTheta\_O}{v} + \left(t\_0 + 0.6931\right)\\
t_2 := \frac{\mathsf{fma}\left(cosTheta\_i, cosTheta\_O, -1\right)}{v} + 0.6931\\
t_3 := \frac{t\_0}{t\_1}\\
\frac{\frac{e^{\frac{t\_2 \cdot t\_2}{t\_1}}}{{v}^{t\_3}}}{{2}^{t\_3}}
\end{array}
\end{array}
Initial program 99.7%
Applied rewrites99.7%
lift-exp.f32N/A
lift-/.f32N/A
lift-pow.f32N/A
unpow2N/A
associate-/l*N/A
lift-log.f32N/A
lift-*.f32N/A
*-commutativeN/A
metadata-evalN/A
div-invN/A
exp-to-powN/A
lower-pow.f32N/A
Applied rewrites99.7%
Taylor expanded in sinTheta_O around 0
unpow2N/A
lower-*.f32N/A
associate--l+N/A
div-subN/A
lower-+.f32N/A
lower-/.f32N/A
sub-negN/A
metadata-evalN/A
lower-fma.f32N/A
associate--l+N/A
div-subN/A
lower-+.f32N/A
lower-/.f32N/A
sub-negN/A
metadata-evalN/A
lower-fma.f3299.7
Applied rewrites99.7%
Applied rewrites99.8%
Final simplification99.8%
(FPCore (cosTheta_i cosTheta_O sinTheta_i sinTheta_O v)
:precision binary32
(let* ((t_0 (+ (/ (fma cosTheta_O cosTheta_i -1.0) v) 0.6931))
(t_1 (log (* 2.0 v))))
(/
(exp
(/
(* t_0 t_0)
(+
(+
(/ (- (- (* cosTheta_i cosTheta_O) (* sinTheta_i sinTheta_O)) 1.0) v)
0.6931)
t_1)))
(pow
(* 2.0 v)
(/
t_1
(+
(/ (- (fma cosTheta_i cosTheta_O -1.0) (* sinTheta_i sinTheta_O)) v)
(+ t_1 0.6931)))))))
float code(float cosTheta_i, float cosTheta_O, float sinTheta_i, float sinTheta_O, float v) {
float t_0 = (fmaf(cosTheta_O, cosTheta_i, -1.0f) / v) + 0.6931f;
float t_1 = logf((2.0f * v));
return expf(((t_0 * t_0) / ((((((cosTheta_i * cosTheta_O) - (sinTheta_i * sinTheta_O)) - 1.0f) / v) + 0.6931f) + t_1))) / powf((2.0f * v), (t_1 / (((fmaf(cosTheta_i, cosTheta_O, -1.0f) - (sinTheta_i * sinTheta_O)) / v) + (t_1 + 0.6931f))));
}
function code(cosTheta_i, cosTheta_O, sinTheta_i, sinTheta_O, v) t_0 = Float32(Float32(fma(cosTheta_O, cosTheta_i, Float32(-1.0)) / v) + Float32(0.6931)) t_1 = log(Float32(Float32(2.0) * v)) return Float32(exp(Float32(Float32(t_0 * t_0) / Float32(Float32(Float32(Float32(Float32(Float32(cosTheta_i * cosTheta_O) - Float32(sinTheta_i * sinTheta_O)) - Float32(1.0)) / v) + Float32(0.6931)) + t_1))) / (Float32(Float32(2.0) * v) ^ Float32(t_1 / Float32(Float32(Float32(fma(cosTheta_i, cosTheta_O, Float32(-1.0)) - Float32(sinTheta_i * sinTheta_O)) / v) + Float32(t_1 + Float32(0.6931)))))) end
\begin{array}{l}
\\
\begin{array}{l}
t_0 := \frac{\mathsf{fma}\left(cosTheta\_O, cosTheta\_i, -1\right)}{v} + 0.6931\\
t_1 := \log \left(2 \cdot v\right)\\
\frac{e^{\frac{t\_0 \cdot t\_0}{\left(\frac{\left(cosTheta\_i \cdot cosTheta\_O - sinTheta\_i \cdot sinTheta\_O\right) - 1}{v} + 0.6931\right) + t\_1}}}{{\left(2 \cdot v\right)}^{\left(\frac{t\_1}{\frac{\mathsf{fma}\left(cosTheta\_i, cosTheta\_O, -1\right) - sinTheta\_i \cdot sinTheta\_O}{v} + \left(t\_1 + 0.6931\right)}\right)}}
\end{array}
\end{array}
Initial program 99.6%
Applied rewrites99.4%
lift-exp.f32N/A
lift-/.f32N/A
lift-pow.f32N/A
unpow2N/A
associate-/l*N/A
lift-log.f32N/A
lift-*.f32N/A
*-commutativeN/A
metadata-evalN/A
div-invN/A
exp-to-powN/A
lower-pow.f32N/A
Applied rewrites99.4%
Taylor expanded in sinTheta_O around 0
unpow2N/A
lower-*.f32N/A
associate--l+N/A
div-subN/A
lower-+.f32N/A
lower-/.f32N/A
sub-negN/A
metadata-evalN/A
lower-fma.f32N/A
associate--l+N/A
div-subN/A
lower-+.f32N/A
lower-/.f32N/A
sub-negN/A
metadata-evalN/A
lower-fma.f3299.4
Applied rewrites99.4%
Final simplification99.4%
herbie shell --seed 2024229
(FPCore (cosTheta_i cosTheta_O sinTheta_i sinTheta_O v)
:name "HairBSDF, Mp, lower"
:precision binary32
:pre (and (and (and (and (and (<= -1.0 cosTheta_i) (<= cosTheta_i 1.0)) (and (<= -1.0 cosTheta_O) (<= cosTheta_O 1.0))) (and (<= -1.0 sinTheta_i) (<= sinTheta_i 1.0))) (and (<= -1.0 sinTheta_O) (<= sinTheta_O 1.0))) (and (<= -1.5707964 v) (<= v 0.1)))
(exp (+ (+ (- (- (/ (* cosTheta_i cosTheta_O) v) (/ (* sinTheta_i sinTheta_O) v)) (/ 1.0 v)) 0.6931) (log (/ 1.0 (* 2.0 v))))))