
(FPCore (x y z) :precision binary64 (+ (* x 0.5) (* y (+ (- 1.0 z) (log z)))))
double code(double x, double y, double z) {
return (x * 0.5) + (y * ((1.0 - z) + log(z)));
}
real(8) function code(x, y, z)
real(8), intent (in) :: x
real(8), intent (in) :: y
real(8), intent (in) :: z
code = (x * 0.5d0) + (y * ((1.0d0 - z) + log(z)))
end function
public static double code(double x, double y, double z) {
return (x * 0.5) + (y * ((1.0 - z) + Math.log(z)));
}
def code(x, y, z): return (x * 0.5) + (y * ((1.0 - z) + math.log(z)))
function code(x, y, z) return Float64(Float64(x * 0.5) + Float64(y * Float64(Float64(1.0 - z) + log(z)))) end
function tmp = code(x, y, z) tmp = (x * 0.5) + (y * ((1.0 - z) + log(z))); end
code[x_, y_, z_] := N[(N[(x * 0.5), $MachinePrecision] + N[(y * N[(N[(1.0 - z), $MachinePrecision] + N[Log[z], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
x \cdot 0.5 + y \cdot \left(\left(1 - z\right) + \log z\right)
\end{array}
Sampling outcomes in binary64 precision:
Herbie found 8 alternatives:
| Alternative | Accuracy | Speedup |
|---|
(FPCore (x y z) :precision binary64 (+ (* x 0.5) (* y (+ (- 1.0 z) (log z)))))
double code(double x, double y, double z) {
return (x * 0.5) + (y * ((1.0 - z) + log(z)));
}
real(8) function code(x, y, z)
real(8), intent (in) :: x
real(8), intent (in) :: y
real(8), intent (in) :: z
code = (x * 0.5d0) + (y * ((1.0d0 - z) + log(z)))
end function
public static double code(double x, double y, double z) {
return (x * 0.5) + (y * ((1.0 - z) + Math.log(z)));
}
def code(x, y, z): return (x * 0.5) + (y * ((1.0 - z) + math.log(z)))
function code(x, y, z) return Float64(Float64(x * 0.5) + Float64(y * Float64(Float64(1.0 - z) + log(z)))) end
function tmp = code(x, y, z) tmp = (x * 0.5) + (y * ((1.0 - z) + log(z))); end
code[x_, y_, z_] := N[(N[(x * 0.5), $MachinePrecision] + N[(y * N[(N[(1.0 - z), $MachinePrecision] + N[Log[z], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
x \cdot 0.5 + y \cdot \left(\left(1 - z\right) + \log z\right)
\end{array}
(FPCore (x y z) :precision binary64 (+ (* x 0.5) (- (* y (+ 1.0 (log z))) (* y z))))
double code(double x, double y, double z) {
return (x * 0.5) + ((y * (1.0 + log(z))) - (y * z));
}
real(8) function code(x, y, z)
real(8), intent (in) :: x
real(8), intent (in) :: y
real(8), intent (in) :: z
code = (x * 0.5d0) + ((y * (1.0d0 + log(z))) - (y * z))
end function
public static double code(double x, double y, double z) {
return (x * 0.5) + ((y * (1.0 + Math.log(z))) - (y * z));
}
def code(x, y, z): return (x * 0.5) + ((y * (1.0 + math.log(z))) - (y * z))
function code(x, y, z) return Float64(Float64(x * 0.5) + Float64(Float64(y * Float64(1.0 + log(z))) - Float64(y * z))) end
function tmp = code(x, y, z) tmp = (x * 0.5) + ((y * (1.0 + log(z))) - (y * z)); end
code[x_, y_, z_] := N[(N[(x * 0.5), $MachinePrecision] + N[(N[(y * N[(1.0 + N[Log[z], $MachinePrecision]), $MachinePrecision]), $MachinePrecision] - N[(y * z), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
x \cdot 0.5 + \left(y \cdot \left(1 + \log z\right) - y \cdot z\right)
\end{array}
Initial program 99.9%
Taylor expanded in z around 0 99.9%
mul-1-neg99.9%
Applied egg-rr99.9%
+-commutative99.9%
*-commutative99.9%
add-sqr-sqrt51.5%
unpow251.5%
unsub-neg51.5%
unpow251.5%
add-sqr-sqrt99.9%
*-commutative99.9%
Applied egg-rr99.9%
(FPCore (x y z)
:precision binary64
(if (<= (* x 0.5) -2e-82)
(fma y (- z) (* x 0.5))
(if (<= (* x 0.5) 4e-28)
(* y (- (+ 1.0 (log z)) z))
(- (* x 0.5) (* y z)))))
double code(double x, double y, double z) {
double tmp;
if ((x * 0.5) <= -2e-82) {
tmp = fma(y, -z, (x * 0.5));
} else if ((x * 0.5) <= 4e-28) {
tmp = y * ((1.0 + log(z)) - z);
} else {
tmp = (x * 0.5) - (y * z);
}
return tmp;
}
function code(x, y, z) tmp = 0.0 if (Float64(x * 0.5) <= -2e-82) tmp = fma(y, Float64(-z), Float64(x * 0.5)); elseif (Float64(x * 0.5) <= 4e-28) tmp = Float64(y * Float64(Float64(1.0 + log(z)) - z)); else tmp = Float64(Float64(x * 0.5) - Float64(y * z)); end return tmp end
code[x_, y_, z_] := If[LessEqual[N[(x * 0.5), $MachinePrecision], -2e-82], N[(y * (-z) + N[(x * 0.5), $MachinePrecision]), $MachinePrecision], If[LessEqual[N[(x * 0.5), $MachinePrecision], 4e-28], N[(y * N[(N[(1.0 + N[Log[z], $MachinePrecision]), $MachinePrecision] - z), $MachinePrecision]), $MachinePrecision], N[(N[(x * 0.5), $MachinePrecision] - N[(y * z), $MachinePrecision]), $MachinePrecision]]]
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;x \cdot 0.5 \leq -2 \cdot 10^{-82}:\\
\;\;\;\;\mathsf{fma}\left(y, -z, x \cdot 0.5\right)\\
\mathbf{elif}\;x \cdot 0.5 \leq 4 \cdot 10^{-28}:\\
\;\;\;\;y \cdot \left(\left(1 + \log z\right) - z\right)\\
\mathbf{else}:\\
\;\;\;\;x \cdot 0.5 - y \cdot z\\
\end{array}
\end{array}
if (*.f64 x #s(literal 1/2 binary64)) < -2e-82Initial program 100.0%
+-commutative100.0%
fma-define100.0%
Simplified100.0%
Taylor expanded in z around inf 87.9%
neg-mul-187.9%
Simplified87.9%
if -2e-82 < (*.f64 x #s(literal 1/2 binary64)) < 3.99999999999999988e-28Initial program 99.8%
Taylor expanded in y around inf 99.8%
Taylor expanded in x around 0 87.1%
if 3.99999999999999988e-28 < (*.f64 x #s(literal 1/2 binary64)) Initial program 100.0%
Taylor expanded in z around inf 98.3%
associate-*r*98.3%
neg-mul-198.3%
Simplified98.3%
fma-define98.3%
distribute-lft-neg-out98.3%
fmm-undef98.3%
Applied egg-rr98.3%
(FPCore (x y z) :precision binary64 (if (<= z 0.28) (+ (* x 0.5) (* y (+ 1.0 (log z)))) (fma y (- z) (* x 0.5))))
double code(double x, double y, double z) {
double tmp;
if (z <= 0.28) {
tmp = (x * 0.5) + (y * (1.0 + log(z)));
} else {
tmp = fma(y, -z, (x * 0.5));
}
return tmp;
}
function code(x, y, z) tmp = 0.0 if (z <= 0.28) tmp = Float64(Float64(x * 0.5) + Float64(y * Float64(1.0 + log(z)))); else tmp = fma(y, Float64(-z), Float64(x * 0.5)); end return tmp end
code[x_, y_, z_] := If[LessEqual[z, 0.28], N[(N[(x * 0.5), $MachinePrecision] + N[(y * N[(1.0 + N[Log[z], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision], N[(y * (-z) + N[(x * 0.5), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;z \leq 0.28:\\
\;\;\;\;x \cdot 0.5 + y \cdot \left(1 + \log z\right)\\
\mathbf{else}:\\
\;\;\;\;\mathsf{fma}\left(y, -z, x \cdot 0.5\right)\\
\end{array}
\end{array}
if z < 0.28000000000000003Initial program 99.8%
Taylor expanded in z around 0 98.8%
*-commutative98.8%
Simplified98.8%
if 0.28000000000000003 < z Initial program 100.0%
+-commutative100.0%
fma-define100.0%
Simplified100.0%
Taylor expanded in z around inf 99.3%
neg-mul-199.3%
Simplified99.3%
Final simplification99.0%
(FPCore (x y z) :precision binary64 (+ (* x 0.5) (* y (+ (log z) (- 1.0 z)))))
double code(double x, double y, double z) {
return (x * 0.5) + (y * (log(z) + (1.0 - z)));
}
real(8) function code(x, y, z)
real(8), intent (in) :: x
real(8), intent (in) :: y
real(8), intent (in) :: z
code = (x * 0.5d0) + (y * (log(z) + (1.0d0 - z)))
end function
public static double code(double x, double y, double z) {
return (x * 0.5) + (y * (Math.log(z) + (1.0 - z)));
}
def code(x, y, z): return (x * 0.5) + (y * (math.log(z) + (1.0 - z)))
function code(x, y, z) return Float64(Float64(x * 0.5) + Float64(y * Float64(log(z) + Float64(1.0 - z)))) end
function tmp = code(x, y, z) tmp = (x * 0.5) + (y * (log(z) + (1.0 - z))); end
code[x_, y_, z_] := N[(N[(x * 0.5), $MachinePrecision] + N[(y * N[(N[Log[z], $MachinePrecision] + N[(1.0 - z), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
x \cdot 0.5 + y \cdot \left(\log z + \left(1 - z\right)\right)
\end{array}
Initial program 99.9%
Final simplification99.9%
(FPCore (x y z) :precision binary64 (fma y (- z) (* x 0.5)))
double code(double x, double y, double z) {
return fma(y, -z, (x * 0.5));
}
function code(x, y, z) return fma(y, Float64(-z), Float64(x * 0.5)) end
code[x_, y_, z_] := N[(y * (-z) + N[(x * 0.5), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\mathsf{fma}\left(y, -z, x \cdot 0.5\right)
\end{array}
Initial program 99.9%
+-commutative99.9%
fma-define99.9%
Simplified99.9%
Taylor expanded in z around inf 78.3%
neg-mul-178.3%
Simplified78.3%
(FPCore (x y z) :precision binary64 (if (<= z 4.8e+53) (* x 0.5) (* y (- z))))
double code(double x, double y, double z) {
double tmp;
if (z <= 4.8e+53) {
tmp = x * 0.5;
} else {
tmp = y * -z;
}
return tmp;
}
real(8) function code(x, y, z)
real(8), intent (in) :: x
real(8), intent (in) :: y
real(8), intent (in) :: z
real(8) :: tmp
if (z <= 4.8d+53) then
tmp = x * 0.5d0
else
tmp = y * -z
end if
code = tmp
end function
public static double code(double x, double y, double z) {
double tmp;
if (z <= 4.8e+53) {
tmp = x * 0.5;
} else {
tmp = y * -z;
}
return tmp;
}
def code(x, y, z): tmp = 0 if z <= 4.8e+53: tmp = x * 0.5 else: tmp = y * -z return tmp
function code(x, y, z) tmp = 0.0 if (z <= 4.8e+53) tmp = Float64(x * 0.5); else tmp = Float64(y * Float64(-z)); end return tmp end
function tmp_2 = code(x, y, z) tmp = 0.0; if (z <= 4.8e+53) tmp = x * 0.5; else tmp = y * -z; end tmp_2 = tmp; end
code[x_, y_, z_] := If[LessEqual[z, 4.8e+53], N[(x * 0.5), $MachinePrecision], N[(y * (-z)), $MachinePrecision]]
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;z \leq 4.8 \cdot 10^{+53}:\\
\;\;\;\;x \cdot 0.5\\
\mathbf{else}:\\
\;\;\;\;y \cdot \left(-z\right)\\
\end{array}
\end{array}
if z < 4.8e53Initial program 99.8%
Taylor expanded in z around inf 61.8%
associate-*r*61.8%
neg-mul-161.8%
Simplified61.8%
Taylor expanded in x around inf 56.2%
if 4.8e53 < z Initial program 100.0%
Taylor expanded in z around inf 100.0%
associate-*r*100.0%
neg-mul-1100.0%
Simplified100.0%
Taylor expanded in x around 0 76.1%
neg-mul-176.1%
distribute-lft-neg-in76.1%
*-commutative76.1%
Simplified76.1%
Final simplification64.8%
(FPCore (x y z) :precision binary64 (- (* x 0.5) (* y z)))
double code(double x, double y, double z) {
return (x * 0.5) - (y * z);
}
real(8) function code(x, y, z)
real(8), intent (in) :: x
real(8), intent (in) :: y
real(8), intent (in) :: z
code = (x * 0.5d0) - (y * z)
end function
public static double code(double x, double y, double z) {
return (x * 0.5) - (y * z);
}
def code(x, y, z): return (x * 0.5) - (y * z)
function code(x, y, z) return Float64(Float64(x * 0.5) - Float64(y * z)) end
function tmp = code(x, y, z) tmp = (x * 0.5) - (y * z); end
code[x_, y_, z_] := N[(N[(x * 0.5), $MachinePrecision] - N[(y * z), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
x \cdot 0.5 - y \cdot z
\end{array}
Initial program 99.9%
Taylor expanded in z around inf 78.3%
associate-*r*78.3%
neg-mul-178.3%
Simplified78.3%
fma-define78.3%
distribute-lft-neg-out78.3%
fmm-undef78.3%
Applied egg-rr78.3%
(FPCore (x y z) :precision binary64 (* x 0.5))
double code(double x, double y, double z) {
return x * 0.5;
}
real(8) function code(x, y, z)
real(8), intent (in) :: x
real(8), intent (in) :: y
real(8), intent (in) :: z
code = x * 0.5d0
end function
public static double code(double x, double y, double z) {
return x * 0.5;
}
def code(x, y, z): return x * 0.5
function code(x, y, z) return Float64(x * 0.5) end
function tmp = code(x, y, z) tmp = x * 0.5; end
code[x_, y_, z_] := N[(x * 0.5), $MachinePrecision]
\begin{array}{l}
\\
x \cdot 0.5
\end{array}
Initial program 99.9%
Taylor expanded in z around inf 78.3%
associate-*r*78.3%
neg-mul-178.3%
Simplified78.3%
Taylor expanded in x around inf 42.8%
Final simplification42.8%
(FPCore (x y z) :precision binary64 (- (+ y (* 0.5 x)) (* y (- z (log z)))))
double code(double x, double y, double z) {
return (y + (0.5 * x)) - (y * (z - log(z)));
}
real(8) function code(x, y, z)
real(8), intent (in) :: x
real(8), intent (in) :: y
real(8), intent (in) :: z
code = (y + (0.5d0 * x)) - (y * (z - log(z)))
end function
public static double code(double x, double y, double z) {
return (y + (0.5 * x)) - (y * (z - Math.log(z)));
}
def code(x, y, z): return (y + (0.5 * x)) - (y * (z - math.log(z)))
function code(x, y, z) return Float64(Float64(y + Float64(0.5 * x)) - Float64(y * Float64(z - log(z)))) end
function tmp = code(x, y, z) tmp = (y + (0.5 * x)) - (y * (z - log(z))); end
code[x_, y_, z_] := N[(N[(y + N[(0.5 * x), $MachinePrecision]), $MachinePrecision] - N[(y * N[(z - N[Log[z], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\left(y + 0.5 \cdot x\right) - y \cdot \left(z - \log z\right)
\end{array}
herbie shell --seed 2024165
(FPCore (x y z)
:name "System.Random.MWC.Distributions:gamma from mwc-random-0.13.3.2"
:precision binary64
:alt
(! :herbie-platform default (- (+ y (* 1/2 x)) (* y (- z (log z)))))
(+ (* x 0.5) (* y (+ (- 1.0 z) (log z)))))