
(FPCore (ux uy maxCos) :precision binary32 (+ (- 1.0 ux) (* ux maxCos)))
float code(float ux, float uy, float maxCos) {
return (1.0f - ux) + (ux * maxCos);
}
real(4) function code(ux, uy, maxcos)
real(4), intent (in) :: ux
real(4), intent (in) :: uy
real(4), intent (in) :: maxcos
code = (1.0e0 - ux) + (ux * maxcos)
end function
function code(ux, uy, maxCos) return Float32(Float32(Float32(1.0) - ux) + Float32(ux * maxCos)) end
function tmp = code(ux, uy, maxCos) tmp = (single(1.0) - ux) + (ux * maxCos); end
\begin{array}{l}
\\
\left(1 - ux\right) + ux \cdot maxCos
\end{array}
Sampling outcomes in binary32 precision:
Herbie found 5 alternatives:
| Alternative | Accuracy | Speedup |
|---|
(FPCore (ux uy maxCos) :precision binary32 (+ (- 1.0 ux) (* ux maxCos)))
float code(float ux, float uy, float maxCos) {
return (1.0f - ux) + (ux * maxCos);
}
real(4) function code(ux, uy, maxcos)
real(4), intent (in) :: ux
real(4), intent (in) :: uy
real(4), intent (in) :: maxcos
code = (1.0e0 - ux) + (ux * maxcos)
end function
function code(ux, uy, maxCos) return Float32(Float32(Float32(1.0) - ux) + Float32(ux * maxCos)) end
function tmp = code(ux, uy, maxCos) tmp = (single(1.0) - ux) + (ux * maxCos); end
\begin{array}{l}
\\
\left(1 - ux\right) + ux \cdot maxCos
\end{array}
(FPCore (ux uy maxCos) :precision binary32 (+ 1.0 (+ ux (+ (* ux -2.0) (* ux maxCos)))))
float code(float ux, float uy, float maxCos) {
return 1.0f + (ux + ((ux * -2.0f) + (ux * maxCos)));
}
real(4) function code(ux, uy, maxcos)
real(4), intent (in) :: ux
real(4), intent (in) :: uy
real(4), intent (in) :: maxcos
code = 1.0e0 + (ux + ((ux * (-2.0e0)) + (ux * maxcos)))
end function
function code(ux, uy, maxCos) return Float32(Float32(1.0) + Float32(ux + Float32(Float32(ux * Float32(-2.0)) + Float32(ux * maxCos)))) end
function tmp = code(ux, uy, maxCos) tmp = single(1.0) + (ux + ((ux * single(-2.0)) + (ux * maxCos))); end
\begin{array}{l}
\\
1 + \left(ux + \left(ux \cdot -2 + ux \cdot maxCos\right)\right)
\end{array}
Initial program 99.9%
associate-+l-100.0%
flip--98.9%
metadata-eval98.9%
*-un-lft-identity98.9%
*-commutative98.9%
distribute-rgt-out--98.9%
*-un-lft-identity98.9%
*-commutative98.9%
distribute-rgt-out--98.9%
*-un-lft-identity98.9%
*-commutative98.9%
distribute-rgt-out--98.9%
Applied egg-rr98.9%
Taylor expanded in maxCos around inf 98.5%
distribute-rgt-out98.5%
distribute-lft-in98.5%
metadata-eval98.5%
neg-mul-198.5%
Simplified98.5%
Taylor expanded in maxCos around 0 100.0%
Final simplification100.0%
(FPCore (ux uy maxCos) :precision binary32 (+ (- 1.0 ux) (* ux maxCos)))
float code(float ux, float uy, float maxCos) {
return (1.0f - ux) + (ux * maxCos);
}
real(4) function code(ux, uy, maxcos)
real(4), intent (in) :: ux
real(4), intent (in) :: uy
real(4), intent (in) :: maxcos
code = (1.0e0 - ux) + (ux * maxcos)
end function
function code(ux, uy, maxCos) return Float32(Float32(Float32(1.0) - ux) + Float32(ux * maxCos)) end
function tmp = code(ux, uy, maxCos) tmp = (single(1.0) - ux) + (ux * maxCos); end
\begin{array}{l}
\\
\left(1 - ux\right) + ux \cdot maxCos
\end{array}
Initial program 99.9%
Final simplification99.9%
(FPCore (ux uy maxCos) :precision binary32 (- 1.0 (* ux (- 1.0 maxCos))))
float code(float ux, float uy, float maxCos) {
return 1.0f - (ux * (1.0f - maxCos));
}
real(4) function code(ux, uy, maxcos)
real(4), intent (in) :: ux
real(4), intent (in) :: uy
real(4), intent (in) :: maxcos
code = 1.0e0 - (ux * (1.0e0 - maxcos))
end function
function code(ux, uy, maxCos) return Float32(Float32(1.0) - Float32(ux * Float32(Float32(1.0) - maxCos))) end
function tmp = code(ux, uy, maxCos) tmp = single(1.0) - (ux * (single(1.0) - maxCos)); end
\begin{array}{l}
\\
1 - ux \cdot \left(1 - maxCos\right)
\end{array}
Initial program 99.9%
associate-+l-100.0%
*-un-lft-identity100.0%
*-commutative100.0%
distribute-rgt-out--100.0%
Applied egg-rr100.0%
Final simplification100.0%
(FPCore (ux uy maxCos) :precision binary32 (- 1.0 ux))
float code(float ux, float uy, float maxCos) {
return 1.0f - ux;
}
real(4) function code(ux, uy, maxcos)
real(4), intent (in) :: ux
real(4), intent (in) :: uy
real(4), intent (in) :: maxcos
code = 1.0e0 - ux
end function
function code(ux, uy, maxCos) return Float32(Float32(1.0) - ux) end
function tmp = code(ux, uy, maxCos) tmp = single(1.0) - ux; end
\begin{array}{l}
\\
1 - ux
\end{array}
Initial program 99.9%
Taylor expanded in maxCos around 0 98.0%
Final simplification98.0%
(FPCore (ux uy maxCos) :precision binary32 1.0)
float code(float ux, float uy, float maxCos) {
return 1.0f;
}
real(4) function code(ux, uy, maxcos)
real(4), intent (in) :: ux
real(4), intent (in) :: uy
real(4), intent (in) :: maxcos
code = 1.0e0
end function
function code(ux, uy, maxCos) return Float32(1.0) end
function tmp = code(ux, uy, maxCos) tmp = single(1.0); end
\begin{array}{l}
\\
1
\end{array}
Initial program 99.9%
Taylor expanded in ux around 0 72.1%
Final simplification72.1%
herbie shell --seed 2023322
(FPCore (ux uy maxCos)
:name "UniformSampleCone, z"
:precision binary32
:pre (and (and (and (<= 2.328306437e-10 ux) (<= ux 1.0)) (and (<= 2.328306437e-10 uy) (<= uy 1.0))) (and (<= 0.0 maxCos) (<= maxCos 1.0)))
(+ (- 1.0 ux) (* ux maxCos)))