
(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 60.7%
associate-+l-78.9%
sub-neg78.9%
log1p-define83.7%
neg-sub083.7%
associate-+l-83.7%
neg-sub083.7%
+-commutative83.7%
unsub-neg83.7%
*-rgt-identity83.7%
distribute-lft-out--83.7%
expm1-define98.7%
Simplified98.7%
(FPCore (x y z t) :precision binary64 (if (<= y -900000.0) (+ x (/ y (* t (- (/ -1.0 z) (* y 0.5))))) (if (<= y 6.2e-9) (- x (/ (* y (expm1 z)) t)) (- x (/ (log1p (* y z)) t)))))
double code(double x, double y, double z, double t) {
double tmp;
if (y <= -900000.0) {
tmp = x + (y / (t * ((-1.0 / z) - (y * 0.5))));
} else if (y <= 6.2e-9) {
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 (y <= -900000.0) {
tmp = x + (y / (t * ((-1.0 / z) - (y * 0.5))));
} else if (y <= 6.2e-9) {
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 y <= -900000.0: tmp = x + (y / (t * ((-1.0 / z) - (y * 0.5)))) elif y <= 6.2e-9: 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 (y <= -900000.0) tmp = Float64(x + Float64(y / Float64(t * Float64(Float64(-1.0 / z) - Float64(y * 0.5))))); elseif (y <= 6.2e-9) 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[y, -900000.0], N[(x + N[(y / N[(t * N[(N[(-1.0 / z), $MachinePrecision] - N[(y * 0.5), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision], If[LessEqual[y, 6.2e-9], 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}\;y \leq -900000:\\
\;\;\;\;x + \frac{y}{t \cdot \left(\frac{-1}{z} - y \cdot 0.5\right)}\\
\mathbf{elif}\;y \leq 6.2 \cdot 10^{-9}:\\
\;\;\;\;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 y < -9e5Initial program 44.2%
associate-+l-80.5%
sub-neg80.5%
log1p-define80.5%
neg-sub080.5%
associate-+l-80.5%
neg-sub080.5%
+-commutative80.5%
unsub-neg80.5%
*-rgt-identity80.5%
distribute-lft-out--80.5%
expm1-define99.9%
Simplified99.9%
Taylor expanded in z around 0 74.5%
clear-num74.5%
inv-pow74.5%
Applied egg-rr74.5%
unpow-174.5%
Simplified74.5%
Taylor expanded in y around 0 76.6%
Taylor expanded in t around 0 82.6%
if -9e5 < y < 6.2000000000000001e-9Initial program 82.9%
associate-+l-83.0%
sub-neg83.0%
log1p-define91.6%
neg-sub091.6%
associate-+l-91.6%
neg-sub091.6%
+-commutative91.6%
unsub-neg91.6%
*-rgt-identity91.6%
distribute-lft-out--91.6%
expm1-define97.8%
Simplified97.8%
Taylor expanded in y around 0 91.2%
expm1-define97.4%
Simplified97.4%
if 6.2000000000000001e-9 < y Initial program 12.4%
associate-+l-62.8%
sub-neg62.8%
log1p-define62.8%
neg-sub062.8%
associate-+l-62.8%
neg-sub062.8%
+-commutative62.8%
unsub-neg62.8%
*-rgt-identity62.8%
distribute-lft-out--62.8%
expm1-define99.9%
Simplified99.9%
Taylor expanded in z around 0 99.9%
Final simplification93.9%
(FPCore (x y z t) :precision binary64 (if (<= z -1.5e+84) x (- x (/ (log1p (* y z)) t))))
double code(double x, double y, double z, double t) {
double tmp;
if (z <= -1.5e+84) {
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 <= -1.5e+84) {
tmp = x;
} else {
tmp = x - (Math.log1p((y * z)) / t);
}
return tmp;
}
def code(x, y, z, t): tmp = 0 if z <= -1.5e+84: tmp = x else: tmp = x - (math.log1p((y * z)) / t) return tmp
function code(x, y, z, t) tmp = 0.0 if (z <= -1.5e+84) tmp = x; else tmp = Float64(x - Float64(log1p(Float64(y * z)) / t)); end return tmp end
code[x_, y_, z_, t_] := If[LessEqual[z, -1.5e+84], 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 -1.5 \cdot 10^{+84}:\\
\;\;\;\;x\\
\mathbf{else}:\\
\;\;\;\;x - \frac{\mathsf{log1p}\left(y \cdot z\right)}{t}\\
\end{array}
\end{array}
if z < -1.49999999999999998e84Initial program 86.0%
associate-+l-86.0%
sub-neg86.0%
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 x around inf 73.3%
if -1.49999999999999998e84 < z Initial program 51.5%
associate-+l-76.3%
sub-neg76.3%
log1p-define77.9%
neg-sub077.9%
associate-+l-77.9%
neg-sub077.9%
+-commutative77.9%
unsub-neg77.9%
*-rgt-identity77.9%
distribute-lft-out--77.9%
expm1-define98.2%
Simplified98.2%
Taylor expanded in z around 0 96.4%
(FPCore (x y z t) :precision binary64 (if (<= z -2.45e+85) x (+ x (/ y (* t (- (/ -1.0 z) (* y 0.5)))))))
double code(double x, double y, double z, double t) {
double tmp;
if (z <= -2.45e+85) {
tmp = x;
} else {
tmp = x + (y / (t * ((-1.0 / z) - (y * 0.5))));
}
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 <= (-2.45d+85)) then
tmp = x
else
tmp = x + (y / (t * (((-1.0d0) / z) - (y * 0.5d0))))
end if
code = tmp
end function
public static double code(double x, double y, double z, double t) {
double tmp;
if (z <= -2.45e+85) {
tmp = x;
} else {
tmp = x + (y / (t * ((-1.0 / z) - (y * 0.5))));
}
return tmp;
}
def code(x, y, z, t): tmp = 0 if z <= -2.45e+85: tmp = x else: tmp = x + (y / (t * ((-1.0 / z) - (y * 0.5)))) return tmp
function code(x, y, z, t) tmp = 0.0 if (z <= -2.45e+85) tmp = x; else tmp = Float64(x + Float64(y / Float64(t * Float64(Float64(-1.0 / z) - Float64(y * 0.5))))); end return tmp end
function tmp_2 = code(x, y, z, t) tmp = 0.0; if (z <= -2.45e+85) tmp = x; else tmp = x + (y / (t * ((-1.0 / z) - (y * 0.5)))); end tmp_2 = tmp; end
code[x_, y_, z_, t_] := If[LessEqual[z, -2.45e+85], x, N[(x + N[(y / N[(t * N[(N[(-1.0 / z), $MachinePrecision] - N[(y * 0.5), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;z \leq -2.45 \cdot 10^{+85}:\\
\;\;\;\;x\\
\mathbf{else}:\\
\;\;\;\;x + \frac{y}{t \cdot \left(\frac{-1}{z} - y \cdot 0.5\right)}\\
\end{array}
\end{array}
if z < -2.4499999999999998e85Initial program 85.8%
associate-+l-85.8%
sub-neg85.8%
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 x around inf 72.9%
if -2.4499999999999998e85 < z Initial program 51.8%
associate-+l-76.4%
sub-neg76.4%
log1p-define78.0%
neg-sub078.0%
associate-+l-78.0%
neg-sub078.0%
+-commutative78.0%
unsub-neg78.0%
*-rgt-identity78.0%
distribute-lft-out--78.0%
expm1-define98.2%
Simplified98.2%
Taylor expanded in z around 0 95.8%
clear-num95.8%
inv-pow95.8%
Applied egg-rr95.8%
unpow-195.8%
Simplified95.8%
Taylor expanded in y around 0 88.9%
Taylor expanded in t around 0 92.6%
Final simplification87.4%
(FPCore (x y z t) :precision binary64 (if (<= z -1.26e-76) x (- x (* y (/ z t)))))
double code(double x, double y, double z, double t) {
double tmp;
if (z <= -1.26e-76) {
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 <= (-1.26d-76)) 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 <= -1.26e-76) {
tmp = x;
} else {
tmp = x - (y * (z / t));
}
return tmp;
}
def code(x, y, z, t): tmp = 0 if z <= -1.26e-76: tmp = x else: tmp = x - (y * (z / t)) return tmp
function code(x, y, z, t) tmp = 0.0 if (z <= -1.26e-76) 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 <= -1.26e-76) tmp = x; else tmp = x - (y * (z / t)); end tmp_2 = tmp; end
code[x_, y_, z_, t_] := If[LessEqual[z, -1.26e-76], x, N[(x - N[(y * N[(z / t), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;z \leq -1.26 \cdot 10^{-76}:\\
\;\;\;\;x\\
\mathbf{else}:\\
\;\;\;\;x - y \cdot \frac{z}{t}\\
\end{array}
\end{array}
if z < -1.26e-76Initial program 79.2%
associate-+l-86.7%
sub-neg86.7%
log1p-define97.7%
neg-sub097.7%
associate-+l-97.7%
neg-sub097.7%
+-commutative97.7%
unsub-neg97.7%
*-rgt-identity97.7%
distribute-lft-out--97.7%
expm1-define100.0%
Simplified100.0%
Taylor expanded in x around inf 76.9%
if -1.26e-76 < z Initial program 48.0%
associate-+l-73.5%
sub-neg73.5%
log1p-define74.2%
neg-sub074.2%
associate-+l-74.2%
neg-sub074.2%
+-commutative74.2%
unsub-neg74.2%
*-rgt-identity74.2%
distribute-lft-out--74.2%
expm1-define97.8%
Simplified97.8%
Taylor expanded in z around 0 89.5%
associate-/l*92.8%
Simplified92.8%
(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 60.7%
associate-+l-78.9%
sub-neg78.9%
log1p-define83.7%
neg-sub083.7%
associate-+l-83.7%
neg-sub083.7%
+-commutative83.7%
unsub-neg83.7%
*-rgt-identity83.7%
distribute-lft-out--83.7%
expm1-define98.7%
Simplified98.7%
Taylor expanded in x around inf 74.9%
(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 2024110
(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)))