
(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 5 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 (* 0.5 (/ (exp 0.6931) (* v (pow (exp (fma sinTheta_O sinTheta_i 1.0)) (/ 1.0 v))))))
float code(float cosTheta_i, float cosTheta_O, float sinTheta_i, float sinTheta_O, float v) {
return 0.5f * (expf(0.6931f) / (v * powf(expf(fmaf(sinTheta_O, sinTheta_i, 1.0f)), (1.0f / v))));
}
function code(cosTheta_i, cosTheta_O, sinTheta_i, sinTheta_O, v) return Float32(Float32(0.5) * Float32(exp(Float32(0.6931)) / Float32(v * (exp(fma(sinTheta_O, sinTheta_i, Float32(1.0))) ^ Float32(Float32(1.0) / v))))) end
\begin{array}{l}
\\
0.5 \cdot \frac{e^{0.6931}}{v \cdot {\left(e^{\mathsf{fma}\left(sinTheta\_O, sinTheta\_i, 1\right)}\right)}^{\left(\frac{1}{v}\right)}}
\end{array}
Initial program 99.3%
associate-+l+99.3%
associate--l-99.3%
associate-/l*99.3%
associate-/l*99.3%
associate-/r*99.3%
metadata-eval99.3%
Simplified99.3%
Taylor expanded in cosTheta_i around 0 99.3%
exp-diff99.1%
+-commutative99.1%
associate-/l*99.1%
fma-undefine99.1%
frac-2neg99.1%
prod-exp99.1%
add-exp-log99.1%
Applied egg-rr99.1%
associate-*r/99.1%
associate-*l/98.7%
distribute-rgt-neg-in98.7%
metadata-eval98.7%
fma-define98.7%
+-commutative98.7%
associate-*r/98.7%
associate-*r/98.7%
*-lft-identity98.7%
metadata-eval98.7%
cancel-sign-sub-inv98.7%
associate-*r/98.7%
associate-*r/98.7%
div-sub98.8%
neg-mul-198.8%
distribute-lft-neg-in98.8%
cancel-sign-sub98.8%
+-commutative98.8%
fma-define98.8%
Simplified98.8%
Taylor expanded in v around 0 99.6%
div-inv99.5%
exp-prod99.6%
+-commutative99.6%
fma-undefine99.6%
Applied egg-rr99.6%
Final simplification99.6%
(FPCore (cosTheta_i cosTheta_O sinTheta_i sinTheta_O v) :precision binary32 (* 0.5 (/ (exp (+ 0.6931 (/ -1.0 v))) v)))
float code(float cosTheta_i, float cosTheta_O, float sinTheta_i, float sinTheta_O, float v) {
return 0.5f * (expf((0.6931f + (-1.0f / v))) / 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 = 0.5e0 * (exp((0.6931e0 + ((-1.0e0) / v))) / v)
end function
function code(cosTheta_i, cosTheta_O, sinTheta_i, sinTheta_O, v) return Float32(Float32(0.5) * Float32(exp(Float32(Float32(0.6931) + Float32(Float32(-1.0) / v))) / v)) end
function tmp = code(cosTheta_i, cosTheta_O, sinTheta_i, sinTheta_O, v) tmp = single(0.5) * (exp((single(0.6931) + (single(-1.0) / v))) / v); end
\begin{array}{l}
\\
0.5 \cdot \frac{e^{0.6931 + \frac{-1}{v}}}{v}
\end{array}
Initial program 99.3%
+-commutative99.3%
exp-sum99.4%
rem-exp-log99.4%
associate-/r*99.4%
metadata-eval99.4%
+-rgt-identity99.4%
metadata-eval99.4%
metadata-eval99.4%
+-rgt-identity99.4%
+-commutative99.4%
associate--l-99.4%
associate-+r-99.4%
Simplified99.4%
Taylor expanded in sinTheta_i around 0 99.6%
Taylor expanded in cosTheta_O around 0 99.6%
Final simplification99.6%
(FPCore (cosTheta_i cosTheta_O sinTheta_i sinTheta_O v) :precision binary32 (* 0.5 (/ (pow E (/ -1.0 v)) v)))
float code(float cosTheta_i, float cosTheta_O, float sinTheta_i, float sinTheta_O, float v) {
return 0.5f * (powf(((float) M_E), (-1.0f / v)) / v);
}
function code(cosTheta_i, cosTheta_O, sinTheta_i, sinTheta_O, v) return Float32(Float32(0.5) * Float32((Float32(exp(1)) ^ Float32(Float32(-1.0) / v)) / v)) end
function tmp = code(cosTheta_i, cosTheta_O, sinTheta_i, sinTheta_O, v) tmp = single(0.5) * ((single(2.71828182845904523536) ^ (single(-1.0) / v)) / v); end
\begin{array}{l}
\\
0.5 \cdot \frac{{e}^{\left(\frac{-1}{v}\right)}}{v}
\end{array}
Initial program 99.3%
+-commutative99.3%
exp-sum99.4%
rem-exp-log99.4%
associate-/r*99.4%
metadata-eval99.4%
+-rgt-identity99.4%
metadata-eval99.4%
metadata-eval99.4%
+-rgt-identity99.4%
+-commutative99.4%
associate--l-99.4%
associate-+r-99.4%
Simplified99.4%
Taylor expanded in sinTheta_i around 0 99.6%
Taylor expanded in cosTheta_O around 0 99.6%
Taylor expanded in v around 0 98.6%
*-un-lft-identity98.6%
exp-prod98.6%
e-exp-198.6%
Applied egg-rr98.6%
Final simplification98.6%
(FPCore (cosTheta_i cosTheta_O sinTheta_i sinTheta_O v) :precision binary32 (* 0.5 (/ (exp (/ -1.0 v)) v)))
float code(float cosTheta_i, float cosTheta_O, float sinTheta_i, float sinTheta_O, float v) {
return 0.5f * (expf((-1.0f / v)) / 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 = 0.5e0 * (exp(((-1.0e0) / v)) / v)
end function
function code(cosTheta_i, cosTheta_O, sinTheta_i, sinTheta_O, v) return Float32(Float32(0.5) * Float32(exp(Float32(Float32(-1.0) / v)) / v)) end
function tmp = code(cosTheta_i, cosTheta_O, sinTheta_i, sinTheta_O, v) tmp = single(0.5) * (exp((single(-1.0) / v)) / v); end
\begin{array}{l}
\\
0.5 \cdot \frac{e^{\frac{-1}{v}}}{v}
\end{array}
Initial program 99.3%
+-commutative99.3%
exp-sum99.4%
rem-exp-log99.4%
associate-/r*99.4%
metadata-eval99.4%
+-rgt-identity99.4%
metadata-eval99.4%
metadata-eval99.4%
+-rgt-identity99.4%
+-commutative99.4%
associate--l-99.4%
associate-+r-99.4%
Simplified99.4%
Taylor expanded in sinTheta_i around 0 99.6%
Taylor expanded in cosTheta_O around 0 99.6%
Taylor expanded in v around 0 98.6%
Final simplification98.6%
(FPCore (cosTheta_i cosTheta_O sinTheta_i sinTheta_O v) :precision binary32 (* 0.5 (/ 1.0 v)))
float code(float cosTheta_i, float cosTheta_O, float sinTheta_i, float sinTheta_O, float v) {
return 0.5f * (1.0f / 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 = 0.5e0 * (1.0e0 / v)
end function
function code(cosTheta_i, cosTheta_O, sinTheta_i, sinTheta_O, v) return Float32(Float32(0.5) * Float32(Float32(1.0) / v)) end
function tmp = code(cosTheta_i, cosTheta_O, sinTheta_i, sinTheta_O, v) tmp = single(0.5) * (single(1.0) / v); end
\begin{array}{l}
\\
0.5 \cdot \frac{1}{v}
\end{array}
Initial program 99.3%
+-commutative99.3%
exp-sum99.4%
rem-exp-log99.4%
associate-/r*99.4%
metadata-eval99.4%
+-rgt-identity99.4%
metadata-eval99.4%
metadata-eval99.4%
+-rgt-identity99.4%
+-commutative99.4%
associate--l-99.4%
associate-+r-99.4%
Simplified99.4%
Taylor expanded in sinTheta_i around 0 99.6%
Taylor expanded in cosTheta_O around 0 99.6%
Taylor expanded in v around 0 98.6%
Taylor expanded in v around inf 4.6%
Final simplification4.6%
herbie shell --seed 2024040
(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))))))