
(FPCore (cosTheta c)
:precision binary32
:pre (and (and (< 0.0 cosTheta) (< cosTheta 0.9999))
(and (< -1.0 c) (< c 1.0)))
(/
1.0
(+
(+ 1.0 c)
(*
(*
(/ 1.0 (sqrt PI))
(/ (sqrt (- (- 1.0 cosTheta) cosTheta)) cosTheta))
(exp (* (- cosTheta) cosTheta))))))float code(float cosTheta, float c) {
return 1.0f / ((1.0f + c) + (((1.0f / sqrtf(((float) M_PI))) * (sqrtf(((1.0f - cosTheta) - cosTheta)) / cosTheta)) * expf((-cosTheta * cosTheta))));
}
function code(cosTheta, c) return Float32(Float32(1.0) / Float32(Float32(Float32(1.0) + c) + Float32(Float32(Float32(Float32(1.0) / sqrt(Float32(pi))) * Float32(sqrt(Float32(Float32(Float32(1.0) - cosTheta) - cosTheta)) / cosTheta)) * exp(Float32(Float32(-cosTheta) * cosTheta))))) end
function tmp = code(cosTheta, c) tmp = single(1.0) / ((single(1.0) + c) + (((single(1.0) / sqrt(single(pi))) * (sqrt(((single(1.0) - cosTheta) - cosTheta)) / cosTheta)) * exp((-cosTheta * cosTheta)))); end
\frac{1}{\left(1 + c\right) + \left(\frac{1}{\sqrt{\pi}} \cdot \frac{\sqrt{\left(1 - cosTheta\right) - cosTheta}}{cosTheta}\right) \cdot e^{\left(-cosTheta\right) \cdot cosTheta}}
Herbie found 8 alternatives:
| Alternative | Accuracy | Speedup |
|---|
(FPCore (cosTheta c)
:precision binary32
:pre (and (and (< 0.0 cosTheta) (< cosTheta 0.9999))
(and (< -1.0 c) (< c 1.0)))
(/
1.0
(+
(+ 1.0 c)
(*
(*
(/ 1.0 (sqrt PI))
(/ (sqrt (- (- 1.0 cosTheta) cosTheta)) cosTheta))
(exp (* (- cosTheta) cosTheta))))))float code(float cosTheta, float c) {
return 1.0f / ((1.0f + c) + (((1.0f / sqrtf(((float) M_PI))) * (sqrtf(((1.0f - cosTheta) - cosTheta)) / cosTheta)) * expf((-cosTheta * cosTheta))));
}
function code(cosTheta, c) return Float32(Float32(1.0) / Float32(Float32(Float32(1.0) + c) + Float32(Float32(Float32(Float32(1.0) / sqrt(Float32(pi))) * Float32(sqrt(Float32(Float32(Float32(1.0) - cosTheta) - cosTheta)) / cosTheta)) * exp(Float32(Float32(-cosTheta) * cosTheta))))) end
function tmp = code(cosTheta, c) tmp = single(1.0) / ((single(1.0) + c) + (((single(1.0) / sqrt(single(pi))) * (sqrt(((single(1.0) - cosTheta) - cosTheta)) / cosTheta)) * exp((-cosTheta * cosTheta)))); end
\frac{1}{\left(1 + c\right) + \left(\frac{1}{\sqrt{\pi}} \cdot \frac{\sqrt{\left(1 - cosTheta\right) - cosTheta}}{cosTheta}\right) \cdot e^{\left(-cosTheta\right) \cdot cosTheta}}
(FPCore (cosTheta c)
:precision binary32
:pre (and (and (< 0.0 cosTheta) (< cosTheta 0.9999))
(and (< -1.0 c) (< c 1.0)))
(let* ((t_0 (exp (* cosTheta cosTheta))))
(*
cosTheta
(/
t_0
(fma
(* t_0 cosTheta)
(- c -1.0)
(sqrt (/ (fma -2.0 cosTheta 1.0) PI)))))))float code(float cosTheta, float c) {
float t_0 = expf((cosTheta * cosTheta));
return cosTheta * (t_0 / fmaf((t_0 * cosTheta), (c - -1.0f), sqrtf((fmaf(-2.0f, cosTheta, 1.0f) / ((float) M_PI)))));
}
function code(cosTheta, c) t_0 = exp(Float32(cosTheta * cosTheta)) return Float32(cosTheta * Float32(t_0 / fma(Float32(t_0 * cosTheta), Float32(c - Float32(-1.0)), sqrt(Float32(fma(Float32(-2.0), cosTheta, Float32(1.0)) / Float32(pi)))))) end
\begin{array}{l}
t_0 := e^{cosTheta \cdot cosTheta}\\
cosTheta \cdot \frac{t\_0}{\mathsf{fma}\left(t\_0 \cdot cosTheta, c - -1, \sqrt{\frac{\mathsf{fma}\left(-2, cosTheta, 1\right)}{\pi}}\right)}
\end{array}
Initial program 97.9%
Applied rewrites98.0%
Applied rewrites98.0%
Applied rewrites98.8%
(FPCore (cosTheta c)
:precision binary32
:pre (and (and (< 0.0 cosTheta) (< cosTheta 0.9999))
(and (< -1.0 c) (< c 1.0)))
(/
1.0
(+
(+ 1.0 c)
(/
(sqrt (fma -2.0 cosTheta 1.0))
(* (exp (* cosTheta cosTheta)) (* 1.7724539041519165 cosTheta))))))float code(float cosTheta, float c) {
return 1.0f / ((1.0f + c) + (sqrtf(fmaf(-2.0f, cosTheta, 1.0f)) / (expf((cosTheta * cosTheta)) * (1.7724539041519165f * cosTheta))));
}
function code(cosTheta, c) return Float32(Float32(1.0) / Float32(Float32(Float32(1.0) + c) + Float32(sqrt(fma(Float32(-2.0), cosTheta, Float32(1.0))) / Float32(exp(Float32(cosTheta * cosTheta)) * Float32(Float32(1.7724539041519165) * cosTheta))))) end
\frac{1}{\left(1 + c\right) + \frac{\sqrt{\mathsf{fma}\left(-2, cosTheta, 1\right)}}{e^{cosTheta \cdot cosTheta} \cdot \left(1.7724539041519165 \cdot cosTheta\right)}}
Initial program 97.9%
Applied rewrites98.5%
Evaluated real constant98.5%
(FPCore (cosTheta c)
:precision binary32
:pre (and (and (< 0.0 cosTheta) (< cosTheta 0.9999))
(and (< -1.0 c) (< c 1.0)))
(/
1.0
(fma
0.564189612865448
(/
(sqrt (fma -2.0 cosTheta 1.0))
(* (exp (* cosTheta cosTheta)) cosTheta))
(- c -1.0))))float code(float cosTheta, float c) {
return 1.0f / fmaf(0.564189612865448f, (sqrtf(fmaf(-2.0f, cosTheta, 1.0f)) / (expf((cosTheta * cosTheta)) * cosTheta)), (c - -1.0f));
}
function code(cosTheta, c) return Float32(Float32(1.0) / fma(Float32(0.564189612865448), Float32(sqrt(fma(Float32(-2.0), cosTheta, Float32(1.0))) / Float32(exp(Float32(cosTheta * cosTheta)) * cosTheta)), Float32(c - Float32(-1.0)))) end
\frac{1}{\mathsf{fma}\left(0.564189612865448, \frac{\sqrt{\mathsf{fma}\left(-2, cosTheta, 1\right)}}{e^{cosTheta \cdot cosTheta} \cdot cosTheta}, c - -1\right)}
Initial program 97.9%
Evaluated real constant97.9%
Applied rewrites98.0%
(FPCore (cosTheta c)
:precision binary32
:pre (and (and (< 0.0 cosTheta) (< cosTheta 0.9999))
(and (< -1.0 c) (< c 1.0)))
(/
1.0
(+
(-
(fma
(fma cosTheta 0.282094806432724 -0.846284419298172)
cosTheta
c)
-0.435810387134552)
(/ 0.564189612865448 cosTheta))))float code(float cosTheta, float c) {
return 1.0f / ((fmaf(fmaf(cosTheta, 0.282094806432724f, -0.846284419298172f), cosTheta, c) - -0.435810387134552f) + (0.564189612865448f / cosTheta));
}
function code(cosTheta, c) return Float32(Float32(1.0) / Float32(Float32(fma(fma(cosTheta, Float32(0.282094806432724), Float32(-0.846284419298172)), cosTheta, c) - Float32(-0.435810387134552)) + Float32(Float32(0.564189612865448) / cosTheta))) end
\frac{1}{\left(\mathsf{fma}\left(\mathsf{fma}\left(cosTheta, 0.282094806432724, -0.846284419298172\right), cosTheta, c\right) - -0.435810387134552\right) + \frac{0.564189612865448}{cosTheta}}
Initial program 97.9%
Evaluated real constant97.9%
Taylor expanded in cosTheta around 0
Applied rewrites97.1%
Applied rewrites97.1%
(FPCore (cosTheta c)
:precision binary32
:pre (and (and (< 0.0 cosTheta) (< cosTheta 0.9999))
(and (< -1.0 c) (< c 1.0)))
(/
1.0
(+
(- (fma cosTheta -0.846284419298172 c) -0.435810387134552)
(/ 0.564189612865448 cosTheta))))float code(float cosTheta, float c) {
return 1.0f / ((fmaf(cosTheta, -0.846284419298172f, c) - -0.435810387134552f) + (0.564189612865448f / cosTheta));
}
function code(cosTheta, c) return Float32(Float32(1.0) / Float32(Float32(fma(cosTheta, Float32(-0.846284419298172), c) - Float32(-0.435810387134552)) + Float32(Float32(0.564189612865448) / cosTheta))) end
\frac{1}{\left(\mathsf{fma}\left(cosTheta, -0.846284419298172, c\right) - -0.435810387134552\right) + \frac{0.564189612865448}{cosTheta}}
Initial program 97.9%
Evaluated real constant97.9%
Taylor expanded in cosTheta around 0
Applied rewrites96.5%
Applied rewrites96.5%
(FPCore (cosTheta c)
:precision binary32
:pre (and (and (< 0.0 cosTheta) (< cosTheta 0.9999))
(and (< -1.0 c) (< c 1.0)))
(*
cosTheta
(+
1.7724537588012759
(* -3.141592327088772 (* cosTheta (+ 0.435810387134552 c))))))float code(float cosTheta, float c) {
return cosTheta * (1.7724537588012759f + (-3.141592327088772f * (cosTheta * (0.435810387134552f + c))));
}
real(4) function code(costheta, c)
use fmin_fmax_functions
real(4), intent (in) :: costheta
real(4), intent (in) :: c
code = costheta * (1.7724537588012759e0 + ((-3.141592327088772e0) * (costheta * (0.435810387134552e0 + c))))
end function
function code(cosTheta, c) return Float32(cosTheta * Float32(Float32(1.7724537588012759) + Float32(Float32(-3.141592327088772) * Float32(cosTheta * Float32(Float32(0.435810387134552) + c))))) end
function tmp = code(cosTheta, c) tmp = cosTheta * (single(1.7724537588012759) + (single(-3.141592327088772) * (cosTheta * (single(0.435810387134552) + c)))); end
cosTheta \cdot \left(1.7724537588012759 + -3.141592327088772 \cdot \left(cosTheta \cdot \left(0.435810387134552 + c\right)\right)\right)
Initial program 97.9%
Evaluated real constant97.9%
Taylor expanded in cosTheta around 0
Applied rewrites95.6%
(FPCore (cosTheta c)
:precision binary32
:pre (and (and (< 0.0 cosTheta) (< cosTheta 0.9999))
(and (< -1.0 c) (< c 1.0)))
(* cosTheta (+ 1.7724537588012759 (* -1.3691385682874957 cosTheta))))float code(float cosTheta, float c) {
return cosTheta * (1.7724537588012759f + (-1.3691385682874957f * cosTheta));
}
real(4) function code(costheta, c)
use fmin_fmax_functions
real(4), intent (in) :: costheta
real(4), intent (in) :: c
code = costheta * (1.7724537588012759e0 + ((-1.3691385682874957e0) * costheta))
end function
function code(cosTheta, c) return Float32(cosTheta * Float32(Float32(1.7724537588012759) + Float32(Float32(-1.3691385682874957) * cosTheta))) end
function tmp = code(cosTheta, c) tmp = cosTheta * (single(1.7724537588012759) + (single(-1.3691385682874957) * cosTheta)); end
cosTheta \cdot \left(1.7724537588012759 + -1.3691385682874957 \cdot cosTheta\right)
Initial program 97.9%
Evaluated real constant97.9%
Taylor expanded in cosTheta around 0
Applied rewrites95.6%
Taylor expanded in c around 0
Applied rewrites95.4%
(FPCore (cosTheta c)
:precision binary32
:pre (and (and (< 0.0 cosTheta) (< cosTheta 0.9999))
(and (< -1.0 c) (< c 1.0)))
(* 1.7724537588012759 cosTheta))float code(float cosTheta, float c) {
return 1.7724537588012759f * cosTheta;
}
real(4) function code(costheta, c)
use fmin_fmax_functions
real(4), intent (in) :: costheta
real(4), intent (in) :: c
code = 1.7724537588012759e0 * costheta
end function
function code(cosTheta, c) return Float32(Float32(1.7724537588012759) * cosTheta) end
function tmp = code(cosTheta, c) tmp = single(1.7724537588012759) * cosTheta; end
1.7724537588012759 \cdot cosTheta
Initial program 97.9%
Evaluated real constant97.9%
Taylor expanded in cosTheta around 0
Applied rewrites92.9%
herbie shell --seed 2026089 +o generate:egglog
(FPCore (cosTheta c)
:name "Beckmann Sample, normalization factor"
:precision binary32
:pre (and (and (< 0.0 cosTheta) (< cosTheta 0.9999)) (and (< -1.0 c) (< c 1.0)))
(/ 1.0 (+ (+ 1.0 c) (* (* (/ 1.0 (sqrt PI)) (/ (sqrt (- (- 1.0 cosTheta) cosTheta)) cosTheta)) (exp (* (- cosTheta) cosTheta))))))