
(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 6 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 64.8%
associate-+l-80.0%
sub-neg80.0%
log1p-define88.3%
neg-sub088.3%
associate-+l-88.3%
neg-sub088.3%
+-commutative88.3%
unsub-neg88.3%
*-rgt-identity88.3%
distribute-lft-out--88.3%
expm1-define98.7%
Simplified98.7%
(FPCore (x y z t) :precision binary64 (if (<= z -2.5e-8) (- x (/ (* y (expm1 z)) t)) (- x (/ (log1p (* y z)) t))))
double code(double x, double y, double z, double t) {
double tmp;
if (z <= -2.5e-8) {
tmp = x - ((y * expm1(z)) / t);
} else {
tmp = x - (log1p((y * z)) / t);
}
return tmp;
}
public static double code(double x, double y, double z, double t) {
double tmp;
if (z <= -2.5e-8) {
tmp = x - ((y * Math.expm1(z)) / t);
} else {
tmp = x - (Math.log1p((y * z)) / t);
}
return tmp;
}
def code(x, y, z, t): tmp = 0 if z <= -2.5e-8: tmp = x - ((y * math.expm1(z)) / t) else: tmp = x - (math.log1p((y * z)) / t) return tmp
function code(x, y, z, t) tmp = 0.0 if (z <= -2.5e-8) tmp = Float64(x - Float64(Float64(y * expm1(z)) / t)); else tmp = Float64(x - Float64(log1p(Float64(y * z)) / t)); end return tmp end
code[x_, y_, z_, t_] := If[LessEqual[z, -2.5e-8], N[(x - N[(N[(y * N[(Exp[z] - 1), $MachinePrecision]), $MachinePrecision] / t), $MachinePrecision]), $MachinePrecision], N[(x - N[(N[Log[1 + N[(y * z), $MachinePrecision]], $MachinePrecision] / t), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;z \leq -2.5 \cdot 10^{-8}:\\
\;\;\;\;x - \frac{y \cdot \mathsf{expm1}\left(z\right)}{t}\\
\mathbf{else}:\\
\;\;\;\;x - \frac{\mathsf{log1p}\left(y \cdot z\right)}{t}\\
\end{array}
\end{array}
if z < -2.4999999999999999e-8Initial program 74.3%
associate-+l-74.3%
sub-neg74.3%
log1p-define99.2%
neg-sub099.2%
associate-+l-99.2%
neg-sub099.2%
+-commutative99.2%
unsub-neg99.2%
*-rgt-identity99.2%
distribute-lft-out--99.3%
expm1-define99.9%
Simplified99.9%
Taylor expanded in y around 0 86.2%
expm1-define86.9%
Simplified86.9%
if -2.4999999999999999e-8 < z Initial program 60.1%
associate-+l-82.8%
sub-neg82.8%
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-define98.1%
Simplified98.1%
Taylor expanded in z around 0 98.1%
(FPCore (x y z t) :precision binary64 (if (<= z -1.06e+30) x (- x (/ (log1p (* y z)) t))))
double code(double x, double y, double z, double t) {
double tmp;
if (z <= -1.06e+30) {
tmp = x;
} else {
tmp = x - (log1p((y * z)) / t);
}
return tmp;
}
public static double code(double x, double y, double z, double t) {
double tmp;
if (z <= -1.06e+30) {
tmp = x;
} else {
tmp = x - (Math.log1p((y * z)) / t);
}
return tmp;
}
def code(x, y, z, t): tmp = 0 if z <= -1.06e+30: tmp = x else: tmp = x - (math.log1p((y * z)) / t) return tmp
function code(x, y, z, t) tmp = 0.0 if (z <= -1.06e+30) tmp = x; else tmp = Float64(x - Float64(log1p(Float64(y * z)) / t)); end return tmp end
code[x_, y_, z_, t_] := If[LessEqual[z, -1.06e+30], x, N[(x - N[(N[Log[1 + N[(y * z), $MachinePrecision]], $MachinePrecision] / t), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;z \leq -1.06 \cdot 10^{+30}:\\
\;\;\;\;x\\
\mathbf{else}:\\
\;\;\;\;x - \frac{\mathsf{log1p}\left(y \cdot z\right)}{t}\\
\end{array}
\end{array}
if z < -1.06e30Initial program 76.0%
associate-+l-76.0%
sub-neg76.0%
log1p-define99.9%
neg-sub099.9%
associate-+l-99.9%
neg-sub099.9%
+-commutative99.9%
unsub-neg99.9%
*-rgt-identity99.9%
distribute-lft-out--99.9%
expm1-define99.9%
Simplified99.9%
Taylor expanded in x around inf 66.6%
if -1.06e30 < z Initial program 60.2%
associate-+l-81.6%
sub-neg81.6%
log1p-define83.5%
neg-sub083.5%
associate-+l-83.5%
neg-sub083.5%
+-commutative83.5%
unsub-neg83.5%
*-rgt-identity83.5%
distribute-lft-out--83.5%
expm1-define98.2%
Simplified98.2%
Taylor expanded in z around 0 95.4%
(FPCore (x y z t) :precision binary64 (if (<= z -190.0) x (+ x (* y (* z (+ (* -0.5 (/ z t)) (/ -1.0 t)))))))
double code(double x, double y, double z, double t) {
double tmp;
if (z <= -190.0) {
tmp = x;
} else {
tmp = x + (y * (z * ((-0.5 * (z / t)) + (-1.0 / 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 <= (-190.0d0)) then
tmp = x
else
tmp = x + (y * (z * (((-0.5d0) * (z / t)) + ((-1.0d0) / t))))
end if
code = tmp
end function
public static double code(double x, double y, double z, double t) {
double tmp;
if (z <= -190.0) {
tmp = x;
} else {
tmp = x + (y * (z * ((-0.5 * (z / t)) + (-1.0 / t))));
}
return tmp;
}
def code(x, y, z, t): tmp = 0 if z <= -190.0: tmp = x else: tmp = x + (y * (z * ((-0.5 * (z / t)) + (-1.0 / t)))) return tmp
function code(x, y, z, t) tmp = 0.0 if (z <= -190.0) tmp = x; else tmp = Float64(x + Float64(y * Float64(z * Float64(Float64(-0.5 * Float64(z / t)) + Float64(-1.0 / t))))); end return tmp end
function tmp_2 = code(x, y, z, t) tmp = 0.0; if (z <= -190.0) tmp = x; else tmp = x + (y * (z * ((-0.5 * (z / t)) + (-1.0 / t)))); end tmp_2 = tmp; end
code[x_, y_, z_, t_] := If[LessEqual[z, -190.0], x, N[(x + N[(y * N[(z * N[(N[(-0.5 * N[(z / t), $MachinePrecision]), $MachinePrecision] + N[(-1.0 / t), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;z \leq -190:\\
\;\;\;\;x\\
\mathbf{else}:\\
\;\;\;\;x + y \cdot \left(z \cdot \left(-0.5 \cdot \frac{z}{t} + \frac{-1}{t}\right)\right)\\
\end{array}
\end{array}
if z < -190Initial program 75.7%
associate-+l-75.7%
sub-neg75.7%
log1p-define99.9%
neg-sub099.9%
associate-+l-99.9%
neg-sub099.9%
+-commutative99.9%
unsub-neg99.9%
*-rgt-identity99.9%
distribute-lft-out--99.9%
expm1-define99.9%
Simplified99.9%
Taylor expanded in x around inf 63.6%
if -190 < z Initial program 59.7%
associate-+l-82.0%
sub-neg82.0%
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-define98.1%
Simplified98.1%
Taylor expanded in z around 0 80.0%
+-commutative80.0%
fma-define80.0%
*-commutative80.0%
associate-/l*78.3%
associate-*l*78.3%
metadata-eval78.3%
distribute-rgt-neg-in78.3%
*-commutative78.3%
distribute-lft-neg-in78.3%
metadata-eval78.3%
mul-1-neg78.3%
unsub-neg78.3%
Simplified78.3%
Taylor expanded in y around 0 92.5%
Final simplification83.2%
(FPCore (x y z t) :precision binary64 (if (<= z -16200000.0) x (- x (* y (/ z t)))))
double code(double x, double y, double z, double t) {
double tmp;
if (z <= -16200000.0) {
tmp = x;
} else {
tmp = x - (y * (z / 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 <= (-16200000.0d0)) then
tmp = x
else
tmp = x - (y * (z / t))
end if
code = tmp
end function
public static double code(double x, double y, double z, double t) {
double tmp;
if (z <= -16200000.0) {
tmp = x;
} else {
tmp = x - (y * (z / t));
}
return tmp;
}
def code(x, y, z, t): tmp = 0 if z <= -16200000.0: tmp = x else: tmp = x - (y * (z / t)) return tmp
function code(x, y, z, t) tmp = 0.0 if (z <= -16200000.0) tmp = x; else tmp = Float64(x - Float64(y * Float64(z / t))); end return tmp end
function tmp_2 = code(x, y, z, t) tmp = 0.0; if (z <= -16200000.0) tmp = x; else tmp = x - (y * (z / t)); end tmp_2 = tmp; end
code[x_, y_, z_, t_] := If[LessEqual[z, -16200000.0], x, N[(x - N[(y * N[(z / t), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;z \leq -16200000:\\
\;\;\;\;x\\
\mathbf{else}:\\
\;\;\;\;x - y \cdot \frac{z}{t}\\
\end{array}
\end{array}
if z < -1.62e7Initial program 75.4%
associate-+l-75.4%
sub-neg75.4%
log1p-define99.9%
neg-sub099.9%
associate-+l-99.9%
neg-sub099.9%
+-commutative99.9%
unsub-neg99.9%
*-rgt-identity99.9%
distribute-lft-out--99.9%
expm1-define99.9%
Simplified99.9%
Taylor expanded in x around inf 64.4%
if -1.62e7 < z Initial program 59.9%
associate-+l-82.1%
sub-neg82.1%
log1p-define82.9%
neg-sub082.9%
associate-+l-82.9%
neg-sub082.9%
+-commutative82.9%
unsub-neg82.9%
*-rgt-identity82.9%
distribute-lft-out--82.9%
expm1-define98.1%
Simplified98.1%
Taylor expanded in z around 0 90.3%
associate-/l*91.6%
Simplified91.6%
(FPCore (x y z t) :precision binary64 x)
double code(double x, double y, double z, double t) {
return x;
}
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
end function
public static double code(double x, double y, double z, double t) {
return x;
}
def code(x, y, z, t): return x
function code(x, y, z, t) return x end
function tmp = code(x, y, z, t) tmp = x; end
code[x_, y_, z_, t_] := x
\begin{array}{l}
\\
x
\end{array}
Initial program 64.8%
associate-+l-80.0%
sub-neg80.0%
log1p-define88.3%
neg-sub088.3%
associate-+l-88.3%
neg-sub088.3%
+-commutative88.3%
unsub-neg88.3%
*-rgt-identity88.3%
distribute-lft-out--88.3%
expm1-define98.7%
Simplified98.7%
Taylor expanded in x around inf 76.1%
(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 2024186
(FPCore (x y z t)
:name "System.Random.MWC.Distributions:truncatedExp from mwc-random-0.13.3.2"
:precision binary64
:alt
(! :herbie-platform default (if (< z -288746230882079470000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000) (- (- x (/ (/ (- 1/2) (* y t)) (* z z))) (* (/ (- 1/2) (* y t)) (/ (/ 2 z) (* z z)))) (- x (/ (log (+ 1 (* z y))) t))))
(- x (/ (log (+ (- 1.0 y) (* y (exp z)))) t)))