
(FPCore (x y z t) :precision binary64 (- x (/ (log (+ (- 1.0 y) (* y (exp z)))) t)))
double code(double x, double y, double z, double t) {
return x - (log(((1.0 - y) + (y * exp(z)))) / t);
}
real(8) function code(x, y, z, t)
real(8), intent (in) :: x
real(8), intent (in) :: y
real(8), intent (in) :: z
real(8), intent (in) :: t
code = x - (log(((1.0d0 - y) + (y * exp(z)))) / t)
end function
public static double code(double x, double y, double z, double t) {
return x - (Math.log(((1.0 - y) + (y * Math.exp(z)))) / t);
}
def code(x, y, z, t): return x - (math.log(((1.0 - y) + (y * math.exp(z)))) / t)
function code(x, y, z, t) return Float64(x - Float64(log(Float64(Float64(1.0 - y) + Float64(y * exp(z)))) / t)) end
function tmp = code(x, y, z, t) tmp = x - (log(((1.0 - y) + (y * exp(z)))) / t); end
code[x_, y_, z_, t_] := N[(x - N[(N[Log[N[(N[(1.0 - y), $MachinePrecision] + N[(y * N[Exp[z], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]], $MachinePrecision] / t), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
x - \frac{\log \left(\left(1 - y\right) + y \cdot e^{z}\right)}{t}
\end{array}
Sampling outcomes in binary64 precision:
Herbie found 7 alternatives:
| Alternative | Accuracy | Speedup |
|---|
(FPCore (x y z t) :precision binary64 (- x (/ (log (+ (- 1.0 y) (* y (exp z)))) t)))
double code(double x, double y, double z, double t) {
return x - (log(((1.0 - y) + (y * exp(z)))) / t);
}
real(8) function code(x, y, z, t)
real(8), intent (in) :: x
real(8), intent (in) :: y
real(8), intent (in) :: z
real(8), intent (in) :: t
code = x - (log(((1.0d0 - y) + (y * exp(z)))) / t)
end function
public static double code(double x, double y, double z, double t) {
return x - (Math.log(((1.0 - y) + (y * Math.exp(z)))) / t);
}
def code(x, y, z, t): return x - (math.log(((1.0 - y) + (y * math.exp(z)))) / t)
function code(x, y, z, t) return Float64(x - Float64(log(Float64(Float64(1.0 - y) + Float64(y * exp(z)))) / t)) end
function tmp = code(x, y, z, t) tmp = x - (log(((1.0 - y) + (y * exp(z)))) / t); end
code[x_, y_, z_, t_] := N[(x - N[(N[Log[N[(N[(1.0 - y), $MachinePrecision] + N[(y * N[Exp[z], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]], $MachinePrecision] / t), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
x - \frac{\log \left(\left(1 - y\right) + y \cdot e^{z}\right)}{t}
\end{array}
(FPCore (x y z t) :precision binary64 (- x (/ (log1p (* y (expm1 z))) t)))
double code(double x, double y, double z, double t) {
return x - (log1p((y * expm1(z))) / t);
}
public static double code(double x, double y, double z, double t) {
return x - (Math.log1p((y * Math.expm1(z))) / t);
}
def code(x, y, z, t): return x - (math.log1p((y * math.expm1(z))) / t)
function code(x, y, z, t) return Float64(x - Float64(log1p(Float64(y * expm1(z))) / t)) end
code[x_, y_, z_, t_] := N[(x - N[(N[Log[1 + N[(y * N[(Exp[z] - 1), $MachinePrecision]), $MachinePrecision]], $MachinePrecision] / t), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
x - \frac{\mathsf{log1p}\left(y \cdot \mathsf{expm1}\left(z\right)\right)}{t}
\end{array}
Initial program 60.5%
associate-+l-77.5%
sub-neg77.5%
log1p-define82.8%
neg-sub082.8%
associate-+l-82.8%
neg-sub082.8%
+-commutative82.8%
unsub-neg82.8%
*-rgt-identity82.8%
distribute-lft-out--82.8%
expm1-define98.3%
Simplified98.3%
(FPCore (x y z t)
:precision binary64
(if (<= (exp z) 0.0)
(- x (/ (* y (expm1 z)) t))
(-
x
(/
(log1p (* z (+ y (* z (+ (* 0.16666666666666666 (* y z)) (* y 0.5))))))
t))))
double code(double x, double y, double z, double t) {
double tmp;
if (exp(z) <= 0.0) {
tmp = x - ((y * expm1(z)) / t);
} else {
tmp = x - (log1p((z * (y + (z * ((0.16666666666666666 * (y * z)) + (y * 0.5)))))) / t);
}
return tmp;
}
public static double code(double x, double y, double z, double t) {
double tmp;
if (Math.exp(z) <= 0.0) {
tmp = x - ((y * Math.expm1(z)) / t);
} else {
tmp = x - (Math.log1p((z * (y + (z * ((0.16666666666666666 * (y * z)) + (y * 0.5)))))) / t);
}
return tmp;
}
def code(x, y, z, t): tmp = 0 if math.exp(z) <= 0.0: tmp = x - ((y * math.expm1(z)) / t) else: tmp = x - (math.log1p((z * (y + (z * ((0.16666666666666666 * (y * z)) + (y * 0.5)))))) / t) return tmp
function code(x, y, z, t) tmp = 0.0 if (exp(z) <= 0.0) tmp = Float64(x - Float64(Float64(y * expm1(z)) / t)); else tmp = Float64(x - Float64(log1p(Float64(z * Float64(y + Float64(z * Float64(Float64(0.16666666666666666 * Float64(y * z)) + Float64(y * 0.5)))))) / t)); end return tmp end
code[x_, y_, z_, t_] := If[LessEqual[N[Exp[z], $MachinePrecision], 0.0], N[(x - N[(N[(y * N[(Exp[z] - 1), $MachinePrecision]), $MachinePrecision] / t), $MachinePrecision]), $MachinePrecision], N[(x - N[(N[Log[1 + N[(z * N[(y + N[(z * N[(N[(0.16666666666666666 * N[(y * z), $MachinePrecision]), $MachinePrecision] + N[(y * 0.5), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]], $MachinePrecision] / t), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;e^{z} \leq 0:\\
\;\;\;\;x - \frac{y \cdot \mathsf{expm1}\left(z\right)}{t}\\
\mathbf{else}:\\
\;\;\;\;x - \frac{\mathsf{log1p}\left(z \cdot \left(y + z \cdot \left(0.16666666666666666 \cdot \left(y \cdot z\right) + y \cdot 0.5\right)\right)\right)}{t}\\
\end{array}
\end{array}
if (exp.f64 z) < 0.0Initial program 81.4%
associate-+l-81.4%
sub-neg81.4%
log1p-define100.0%
neg-sub0100.0%
associate-+l-100.0%
neg-sub0100.0%
+-commutative100.0%
unsub-neg100.0%
*-rgt-identity100.0%
distribute-lft-out--100.0%
expm1-define100.0%
Simplified100.0%
Taylor expanded in y around 0 82.7%
expm1-define82.7%
Simplified82.7%
if 0.0 < (exp.f64 z) Initial program 53.2%
associate-+l-76.1%
sub-neg76.1%
log1p-define76.9%
neg-sub076.9%
associate-+l-76.9%
neg-sub076.9%
+-commutative76.9%
unsub-neg76.9%
*-rgt-identity76.9%
distribute-lft-out--76.9%
expm1-define97.7%
Simplified97.7%
Taylor expanded in z around 0 98.2%
Final simplification94.2%
(FPCore (x y z t) :precision binary64 (if (<= (exp z) 0.99999996) (- x (/ (* y (expm1 z)) t)) (- x (/ (log1p (* z (+ y (* (* y z) 0.5)))) t))))
double code(double x, double y, double z, double t) {
double tmp;
if (exp(z) <= 0.99999996) {
tmp = x - ((y * expm1(z)) / t);
} else {
tmp = x - (log1p((z * (y + ((y * z) * 0.5)))) / t);
}
return tmp;
}
public static double code(double x, double y, double z, double t) {
double tmp;
if (Math.exp(z) <= 0.99999996) {
tmp = x - ((y * Math.expm1(z)) / t);
} else {
tmp = x - (Math.log1p((z * (y + ((y * z) * 0.5)))) / t);
}
return tmp;
}
def code(x, y, z, t): tmp = 0 if math.exp(z) <= 0.99999996: tmp = x - ((y * math.expm1(z)) / t) else: tmp = x - (math.log1p((z * (y + ((y * z) * 0.5)))) / t) return tmp
function code(x, y, z, t) tmp = 0.0 if (exp(z) <= 0.99999996) tmp = Float64(x - Float64(Float64(y * expm1(z)) / t)); else tmp = Float64(x - Float64(log1p(Float64(z * Float64(y + Float64(Float64(y * z) * 0.5)))) / t)); end return tmp end
code[x_, y_, z_, t_] := If[LessEqual[N[Exp[z], $MachinePrecision], 0.99999996], N[(x - N[(N[(y * N[(Exp[z] - 1), $MachinePrecision]), $MachinePrecision] / t), $MachinePrecision]), $MachinePrecision], N[(x - N[(N[Log[1 + N[(z * N[(y + N[(N[(y * z), $MachinePrecision] * 0.5), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]], $MachinePrecision] / t), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;e^{z} \leq 0.99999996:\\
\;\;\;\;x - \frac{y \cdot \mathsf{expm1}\left(z\right)}{t}\\
\mathbf{else}:\\
\;\;\;\;x - \frac{\mathsf{log1p}\left(z \cdot \left(y + \left(y \cdot z\right) \cdot 0.5\right)\right)}{t}\\
\end{array}
\end{array}
if (exp.f64 z) < 0.99999996000000002Initial program 80.9%
associate-+l-80.9%
sub-neg80.9%
log1p-define99.5%
neg-sub099.5%
associate-+l-99.5%
neg-sub099.5%
+-commutative99.5%
unsub-neg99.5%
*-rgt-identity99.5%
distribute-lft-out--99.5%
expm1-define100.0%
Simplified100.0%
Taylor expanded in y around 0 83.0%
expm1-define83.4%
Simplified83.4%
if 0.99999996000000002 < (exp.f64 z) Initial program 53.0%
associate-+l-76.2%
sub-neg76.2%
log1p-define76.7%
neg-sub076.7%
associate-+l-76.7%
neg-sub076.7%
+-commutative76.7%
unsub-neg76.7%
*-rgt-identity76.7%
distribute-lft-out--76.7%
expm1-define97.6%
Simplified97.6%
Taylor expanded in z around 0 98.2%
Final simplification94.2%
(FPCore (x y z t) :precision binary64 (- x (* y (/ (expm1 z) t))))
double code(double x, double y, double z, double t) {
return x - (y * (expm1(z) / t));
}
public static double code(double x, double y, double z, double t) {
return x - (y * (Math.expm1(z) / t));
}
def code(x, y, z, t): return x - (y * (math.expm1(z) / t))
function code(x, y, z, t) return Float64(x - Float64(y * Float64(expm1(z) / t))) end
code[x_, y_, z_, t_] := N[(x - N[(y * N[(N[(Exp[z] - 1), $MachinePrecision] / t), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
x - y \cdot \frac{\mathsf{expm1}\left(z\right)}{t}
\end{array}
Initial program 60.5%
associate-+l-77.5%
sub-neg77.5%
log1p-define82.8%
neg-sub082.8%
associate-+l-82.8%
neg-sub082.8%
+-commutative82.8%
unsub-neg82.8%
*-rgt-identity82.8%
distribute-lft-out--82.8%
expm1-define98.3%
Simplified98.3%
Taylor expanded in y around 0 77.4%
associate-/l*77.4%
expm1-define87.1%
Simplified87.1%
(FPCore (x y z t) :precision binary64 (if (<= z -5e-53) (+ x (/ -1.0 (/ (+ (* -0.5 (/ (* z t) y)) (/ t y)) z))) (+ x (* y (* z (/ (- -1.0 (* z 0.5)) t))))))
double code(double x, double y, double z, double t) {
double tmp;
if (z <= -5e-53) {
tmp = x + (-1.0 / (((-0.5 * ((z * t) / y)) + (t / y)) / z));
} else {
tmp = x + (y * (z * ((-1.0 - (z * 0.5)) / t)));
}
return tmp;
}
real(8) function code(x, y, z, t)
real(8), intent (in) :: x
real(8), intent (in) :: y
real(8), intent (in) :: z
real(8), intent (in) :: t
real(8) :: tmp
if (z <= (-5d-53)) then
tmp = x + ((-1.0d0) / ((((-0.5d0) * ((z * t) / y)) + (t / y)) / z))
else
tmp = x + (y * (z * (((-1.0d0) - (z * 0.5d0)) / t)))
end if
code = tmp
end function
public static double code(double x, double y, double z, double t) {
double tmp;
if (z <= -5e-53) {
tmp = x + (-1.0 / (((-0.5 * ((z * t) / y)) + (t / y)) / z));
} else {
tmp = x + (y * (z * ((-1.0 - (z * 0.5)) / t)));
}
return tmp;
}
def code(x, y, z, t): tmp = 0 if z <= -5e-53: tmp = x + (-1.0 / (((-0.5 * ((z * t) / y)) + (t / y)) / z)) else: tmp = x + (y * (z * ((-1.0 - (z * 0.5)) / t))) return tmp
function code(x, y, z, t) tmp = 0.0 if (z <= -5e-53) tmp = Float64(x + Float64(-1.0 / Float64(Float64(Float64(-0.5 * Float64(Float64(z * t) / y)) + Float64(t / y)) / z))); else tmp = Float64(x + Float64(y * Float64(z * Float64(Float64(-1.0 - Float64(z * 0.5)) / t)))); end return tmp end
function tmp_2 = code(x, y, z, t) tmp = 0.0; if (z <= -5e-53) tmp = x + (-1.0 / (((-0.5 * ((z * t) / y)) + (t / y)) / z)); else tmp = x + (y * (z * ((-1.0 - (z * 0.5)) / t))); end tmp_2 = tmp; end
code[x_, y_, z_, t_] := If[LessEqual[z, -5e-53], N[(x + N[(-1.0 / N[(N[(N[(-0.5 * N[(N[(z * t), $MachinePrecision] / y), $MachinePrecision]), $MachinePrecision] + N[(t / y), $MachinePrecision]), $MachinePrecision] / z), $MachinePrecision]), $MachinePrecision]), $MachinePrecision], N[(x + N[(y * N[(z * N[(N[(-1.0 - N[(z * 0.5), $MachinePrecision]), $MachinePrecision] / t), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;z \leq -5 \cdot 10^{-53}:\\
\;\;\;\;x + \frac{-1}{\frac{-0.5 \cdot \frac{z \cdot t}{y} + \frac{t}{y}}{z}}\\
\mathbf{else}:\\
\;\;\;\;x + y \cdot \left(z \cdot \frac{-1 - z \cdot 0.5}{t}\right)\\
\end{array}
\end{array}
if z < -5e-53Initial program 77.3%
associate-+l-77.4%
sub-neg77.4%
log1p-define93.0%
neg-sub093.0%
associate-+l-93.0%
neg-sub093.0%
+-commutative93.0%
unsub-neg93.0%
*-rgt-identity93.0%
distribute-lft-out--93.0%
expm1-define99.9%
Simplified99.9%
Taylor expanded in y around 0 77.2%
expm1-define82.9%
Simplified82.9%
clear-num82.9%
inv-pow82.9%
Applied egg-rr82.9%
unpow-182.9%
expm1-define77.2%
associate-/r*77.1%
expm1-define82.9%
Simplified82.9%
Taylor expanded in z around 0 72.2%
if -5e-53 < z Initial program 52.3%
associate-+l-77.5%
sub-neg77.5%
log1p-define77.8%
neg-sub077.8%
associate-+l-77.8%
neg-sub077.8%
+-commutative77.8%
unsub-neg77.8%
*-rgt-identity77.8%
distribute-lft-out--77.8%
expm1-define97.4%
Simplified97.4%
Taylor expanded in z around 0 77.7%
associate-*r*77.7%
mul-1-neg77.7%
Simplified77.7%
Taylor expanded in y around 0 88.3%
associate-/l*89.2%
associate-/l*89.2%
*-commutative89.2%
Simplified89.2%
Final simplification83.6%
(FPCore (x y z t) :precision binary64 (+ x (* y (* z (/ -1.0 t)))))
double code(double x, double y, double z, double t) {
return x + (y * (z * (-1.0 / t)));
}
real(8) function code(x, y, z, t)
real(8), intent (in) :: x
real(8), intent (in) :: y
real(8), intent (in) :: z
real(8), intent (in) :: t
code = x + (y * (z * ((-1.0d0) / t)))
end function
public static double code(double x, double y, double z, double t) {
return x + (y * (z * (-1.0 / t)));
}
def code(x, y, z, t): return x + (y * (z * (-1.0 / t)))
function code(x, y, z, t) return Float64(x + Float64(y * Float64(z * Float64(-1.0 / t)))) end
function tmp = code(x, y, z, t) tmp = x + (y * (z * (-1.0 / t))); end
code[x_, y_, z_, t_] := N[(x + N[(y * N[(z * N[(-1.0 / t), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
x + y \cdot \left(z \cdot \frac{-1}{t}\right)
\end{array}
Initial program 60.5%
associate-+l-77.5%
sub-neg77.5%
log1p-define82.8%
neg-sub082.8%
associate-+l-82.8%
neg-sub082.8%
+-commutative82.8%
unsub-neg82.8%
*-rgt-identity82.8%
distribute-lft-out--82.8%
expm1-define98.3%
Simplified98.3%
Taylor expanded in z around 0 64.0%
associate-*r*64.0%
mul-1-neg64.0%
Simplified64.0%
Taylor expanded in y around 0 69.9%
associate-/l*70.1%
associate-/l*72.0%
*-commutative72.0%
Simplified72.0%
Taylor expanded in z around 0 76.0%
Final simplification76.0%
(FPCore (x y z t) :precision binary64 (- x (* y (/ z t))))
double code(double x, double y, double z, double t) {
return x - (y * (z / t));
}
real(8) function code(x, y, z, t)
real(8), intent (in) :: x
real(8), intent (in) :: y
real(8), intent (in) :: z
real(8), intent (in) :: t
code = x - (y * (z / t))
end function
public static double code(double x, double y, double z, double t) {
return x - (y * (z / t));
}
def code(x, y, z, t): return x - (y * (z / t))
function code(x, y, z, t) return Float64(x - Float64(y * Float64(z / t))) end
function tmp = code(x, y, z, t) tmp = x - (y * (z / t)); end
code[x_, y_, z_, t_] := N[(x - N[(y * N[(z / t), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
x - y \cdot \frac{z}{t}
\end{array}
Initial program 60.5%
associate-+l-77.5%
sub-neg77.5%
log1p-define82.8%
neg-sub082.8%
associate-+l-82.8%
neg-sub082.8%
+-commutative82.8%
unsub-neg82.8%
*-rgt-identity82.8%
distribute-lft-out--82.8%
expm1-define98.3%
Simplified98.3%
Taylor expanded in z around 0 75.7%
associate-/l*76.0%
Simplified76.0%
(FPCore (x y z t)
:precision binary64
(let* ((t_1 (/ (- 0.5) (* y t))))
(if (< z -2.8874623088207947e+119)
(- (- x (/ t_1 (* z z))) (* t_1 (/ (/ 2.0 z) (* z z))))
(- x (/ (log (+ 1.0 (* z y))) t)))))
double code(double x, double y, double z, double t) {
double t_1 = -0.5 / (y * t);
double tmp;
if (z < -2.8874623088207947e+119) {
tmp = (x - (t_1 / (z * z))) - (t_1 * ((2.0 / z) / (z * z)));
} else {
tmp = x - (log((1.0 + (z * y))) / t);
}
return tmp;
}
real(8) function code(x, y, z, t)
real(8), intent (in) :: x
real(8), intent (in) :: y
real(8), intent (in) :: z
real(8), intent (in) :: t
real(8) :: t_1
real(8) :: tmp
t_1 = -0.5d0 / (y * t)
if (z < (-2.8874623088207947d+119)) then
tmp = (x - (t_1 / (z * z))) - (t_1 * ((2.0d0 / z) / (z * z)))
else
tmp = x - (log((1.0d0 + (z * y))) / t)
end if
code = tmp
end function
public static double code(double x, double y, double z, double t) {
double t_1 = -0.5 / (y * t);
double tmp;
if (z < -2.8874623088207947e+119) {
tmp = (x - (t_1 / (z * z))) - (t_1 * ((2.0 / z) / (z * z)));
} else {
tmp = x - (Math.log((1.0 + (z * y))) / t);
}
return tmp;
}
def code(x, y, z, t): t_1 = -0.5 / (y * t) tmp = 0 if z < -2.8874623088207947e+119: tmp = (x - (t_1 / (z * z))) - (t_1 * ((2.0 / z) / (z * z))) else: tmp = x - (math.log((1.0 + (z * y))) / t) return tmp
function code(x, y, z, t) t_1 = Float64(Float64(-0.5) / Float64(y * t)) tmp = 0.0 if (z < -2.8874623088207947e+119) tmp = Float64(Float64(x - Float64(t_1 / Float64(z * z))) - Float64(t_1 * Float64(Float64(2.0 / z) / Float64(z * z)))); else tmp = Float64(x - Float64(log(Float64(1.0 + Float64(z * y))) / t)); end return tmp end
function tmp_2 = code(x, y, z, t) t_1 = -0.5 / (y * t); tmp = 0.0; if (z < -2.8874623088207947e+119) tmp = (x - (t_1 / (z * z))) - (t_1 * ((2.0 / z) / (z * z))); else tmp = x - (log((1.0 + (z * y))) / t); end tmp_2 = tmp; end
code[x_, y_, z_, t_] := Block[{t$95$1 = N[((-0.5) / N[(y * t), $MachinePrecision]), $MachinePrecision]}, If[Less[z, -2.8874623088207947e+119], N[(N[(x - N[(t$95$1 / N[(z * z), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] - N[(t$95$1 * N[(N[(2.0 / z), $MachinePrecision] / N[(z * z), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision], N[(x - N[(N[Log[N[(1.0 + N[(z * y), $MachinePrecision]), $MachinePrecision]], $MachinePrecision] / t), $MachinePrecision]), $MachinePrecision]]]
\begin{array}{l}
\\
\begin{array}{l}
t_1 := \frac{-0.5}{y \cdot t}\\
\mathbf{if}\;z < -2.8874623088207947 \cdot 10^{+119}:\\
\;\;\;\;\left(x - \frac{t\_1}{z \cdot z}\right) - t\_1 \cdot \frac{\frac{2}{z}}{z \cdot z}\\
\mathbf{else}:\\
\;\;\;\;x - \frac{\log \left(1 + z \cdot y\right)}{t}\\
\end{array}
\end{array}
herbie shell --seed 2024085
(FPCore (x y z t)
:name "System.Random.MWC.Distributions:truncatedExp from mwc-random-0.13.3.2"
:precision binary64
:alt
(if (< z -2.8874623088207947e+119) (- (- x (/ (/ (- 0.5) (* y t)) (* z z))) (* (/ (- 0.5) (* y t)) (/ (/ 2.0 z) (* z z)))) (- x (/ (log (+ 1.0 (* z y))) t)))
(- x (/ (log (+ (- 1.0 y) (* y (exp z)))) t)))