
(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 65.1%
associate-+l-79.0%
sub-neg79.0%
log1p-define84.8%
neg-sub084.8%
associate-+l-84.8%
neg-sub084.8%
+-commutative84.8%
unsub-neg84.8%
*-rgt-identity84.8%
distribute-lft-out--84.8%
expm1-define98.0%
Simplified98.0%
Final simplification98.0%
(FPCore (x y z t) :precision binary64 (if (<= (exp z) 0.99999998) (+ x (/ 1.0 (* t (/ (- (/ 1.0 (- 1.0 (exp z))) (* y 0.5)) y)))) (- x (* y (/ (expm1 z) t)))))
double code(double x, double y, double z, double t) {
double tmp;
if (exp(z) <= 0.99999998) {
tmp = x + (1.0 / (t * (((1.0 / (1.0 - exp(z))) - (y * 0.5)) / y)));
} else {
tmp = x - (y * (expm1(z) / t));
}
return tmp;
}
public static double code(double x, double y, double z, double t) {
double tmp;
if (Math.exp(z) <= 0.99999998) {
tmp = x + (1.0 / (t * (((1.0 / (1.0 - Math.exp(z))) - (y * 0.5)) / y)));
} else {
tmp = x - (y * (Math.expm1(z) / t));
}
return tmp;
}
def code(x, y, z, t): tmp = 0 if math.exp(z) <= 0.99999998: tmp = x + (1.0 / (t * (((1.0 / (1.0 - math.exp(z))) - (y * 0.5)) / y))) else: tmp = x - (y * (math.expm1(z) / t)) return tmp
function code(x, y, z, t) tmp = 0.0 if (exp(z) <= 0.99999998) tmp = Float64(x + Float64(1.0 / Float64(t * Float64(Float64(Float64(1.0 / Float64(1.0 - exp(z))) - Float64(y * 0.5)) / y)))); else tmp = Float64(x - Float64(y * Float64(expm1(z) / t))); end return tmp end
code[x_, y_, z_, t_] := If[LessEqual[N[Exp[z], $MachinePrecision], 0.99999998], N[(x + N[(1.0 / N[(t * N[(N[(N[(1.0 / N[(1.0 - N[Exp[z], $MachinePrecision]), $MachinePrecision]), $MachinePrecision] - N[(y * 0.5), $MachinePrecision]), $MachinePrecision] / y), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision], N[(x - N[(y * N[(N[(Exp[z] - 1), $MachinePrecision] / t), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;e^{z} \leq 0.99999998:\\
\;\;\;\;x + \frac{1}{t \cdot \frac{\frac{1}{1 - e^{z}} - y \cdot 0.5}{y}}\\
\mathbf{else}:\\
\;\;\;\;x - y \cdot \frac{\mathsf{expm1}\left(z\right)}{t}\\
\end{array}
\end{array}
if (exp.f64 z) < 0.999999980000000011Initial program 82.8%
associate-+l-82.8%
sub-neg82.8%
log1p-define99.7%
neg-sub099.7%
associate-+l-99.7%
neg-sub099.7%
+-commutative99.7%
unsub-neg99.7%
*-rgt-identity99.7%
distribute-lft-out--99.7%
expm1-define99.9%
Simplified99.9%
clear-num99.7%
associate-/r/99.8%
Applied egg-rr99.8%
associate-*l/99.9%
*-un-lft-identity99.9%
clear-num99.7%
Applied egg-rr99.7%
div-inv99.8%
Applied egg-rr99.8%
Taylor expanded in y around 0 79.6%
if 0.999999980000000011 < (exp.f64 z) Initial program 56.3%
associate-+l-77.1%
sub-neg77.1%
log1p-define77.5%
neg-sub077.5%
associate-+l-77.5%
neg-sub077.5%
+-commutative77.5%
unsub-neg77.5%
*-rgt-identity77.5%
distribute-lft-out--77.5%
expm1-define97.0%
Simplified97.0%
Taylor expanded in y around 0 77.5%
associate-/l*77.5%
expm1-define92.8%
Simplified92.8%
Final simplification88.4%
(FPCore (x y z t) :precision binary64 (if (<= y -3.4e+211) (/ (log1p (* y (expm1 z))) (- t)) (- x (* y (/ (expm1 z) t)))))
double code(double x, double y, double z, double t) {
double tmp;
if (y <= -3.4e+211) {
tmp = log1p((y * expm1(z))) / -t;
} else {
tmp = x - (y * (expm1(z) / t));
}
return tmp;
}
public static double code(double x, double y, double z, double t) {
double tmp;
if (y <= -3.4e+211) {
tmp = Math.log1p((y * Math.expm1(z))) / -t;
} else {
tmp = x - (y * (Math.expm1(z) / t));
}
return tmp;
}
def code(x, y, z, t): tmp = 0 if y <= -3.4e+211: tmp = math.log1p((y * math.expm1(z))) / -t else: tmp = x - (y * (math.expm1(z) / t)) return tmp
function code(x, y, z, t) tmp = 0.0 if (y <= -3.4e+211) tmp = Float64(log1p(Float64(y * expm1(z))) / Float64(-t)); else tmp = Float64(x - Float64(y * Float64(expm1(z) / t))); end return tmp end
code[x_, y_, z_, t_] := If[LessEqual[y, -3.4e+211], N[(N[Log[1 + N[(y * N[(Exp[z] - 1), $MachinePrecision]), $MachinePrecision]], $MachinePrecision] / (-t)), $MachinePrecision], N[(x - N[(y * N[(N[(Exp[z] - 1), $MachinePrecision] / t), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;y \leq -3.4 \cdot 10^{+211}:\\
\;\;\;\;\frac{\mathsf{log1p}\left(y \cdot \mathsf{expm1}\left(z\right)\right)}{-t}\\
\mathbf{else}:\\
\;\;\;\;x - y \cdot \frac{\mathsf{expm1}\left(z\right)}{t}\\
\end{array}
\end{array}
if y < -3.3999999999999999e211Initial program 76.7%
associate-+l-82.7%
sub-neg82.7%
log1p-define82.7%
neg-sub082.7%
associate-+l-82.7%
neg-sub082.7%
+-commutative82.7%
unsub-neg82.7%
*-rgt-identity82.7%
distribute-lft-out--82.7%
expm1-define99.8%
Simplified99.8%
Taylor expanded in x around 0 48.3%
mul-1-neg48.3%
expm1-define64.0%
log1p-undefine65.3%
distribute-frac-neg265.3%
Simplified65.3%
if -3.3999999999999999e211 < y Initial program 64.2%
associate-+l-78.7%
sub-neg78.7%
log1p-define85.0%
neg-sub085.0%
associate-+l-85.0%
neg-sub085.0%
+-commutative85.0%
unsub-neg85.0%
*-rgt-identity85.0%
distribute-lft-out--85.0%
expm1-define97.8%
Simplified97.8%
Taylor expanded in y around 0 79.9%
associate-/l*79.9%
expm1-define91.3%
Simplified91.3%
Final simplification89.6%
(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 65.1%
associate-+l-79.0%
sub-neg79.0%
log1p-define84.8%
neg-sub084.8%
associate-+l-84.8%
neg-sub084.8%
+-commutative84.8%
unsub-neg84.8%
*-rgt-identity84.8%
distribute-lft-out--84.8%
expm1-define98.0%
Simplified98.0%
Taylor expanded in y around 0 76.0%
associate-/l*76.0%
expm1-define86.3%
Simplified86.3%
Final simplification86.3%
(FPCore (x y z t) :precision binary64 (if (<= z -3900000.0) x (+ x (* y (/ (* z (- -1.0 (* z 0.5))) t)))))
double code(double x, double y, double z, double t) {
double tmp;
if (z <= -3900000.0) {
tmp = x;
} 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 <= (-3900000.0d0)) then
tmp = x
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 <= -3900000.0) {
tmp = x;
} else {
tmp = x + (y * ((z * (-1.0 - (z * 0.5))) / t));
}
return tmp;
}
def code(x, y, z, t): tmp = 0 if z <= -3900000.0: tmp = x else: tmp = x + (y * ((z * (-1.0 - (z * 0.5))) / t)) return tmp
function code(x, y, z, t) tmp = 0.0 if (z <= -3900000.0) tmp = x; else tmp = Float64(x + Float64(y * Float64(Float64(z * 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 <= -3900000.0) tmp = x; else tmp = x + (y * ((z * (-1.0 - (z * 0.5))) / t)); end tmp_2 = tmp; end
code[x_, y_, z_, t_] := If[LessEqual[z, -3900000.0], x, N[(x + N[(y * N[(N[(z * N[(-1.0 - N[(z * 0.5), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] / t), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;z \leq -3900000:\\
\;\;\;\;x\\
\mathbf{else}:\\
\;\;\;\;x + y \cdot \frac{z \cdot \left(-1 - z \cdot 0.5\right)}{t}\\
\end{array}
\end{array}
if z < -3.9e6Initial program 82.2%
associate-+l-82.2%
sub-neg82.2%
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 59.8%
if -3.9e6 < z Initial program 57.1%
associate-+l-77.5%
sub-neg77.5%
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-define97.0%
Simplified97.0%
Taylor expanded in y around 0 77.4%
Taylor expanded in z around 0 90.4%
*-commutative90.4%
Simplified90.4%
Taylor expanded in z around 0 90.3%
Taylor expanded in y around 0 90.3%
associate-/l*92.4%
*-commutative92.4%
Simplified92.4%
Final simplification82.1%
(FPCore (x y z t) :precision binary64 (if (<= z -3.6e+14) x (- x (* y (/ z t)))))
double code(double x, double y, double z, double t) {
double tmp;
if (z <= -3.6e+14) {
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 <= (-3.6d+14)) 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 <= -3.6e+14) {
tmp = x;
} else {
tmp = x - (y * (z / t));
}
return tmp;
}
def code(x, y, z, t): tmp = 0 if z <= -3.6e+14: tmp = x else: tmp = x - (y * (z / t)) return tmp
function code(x, y, z, t) tmp = 0.0 if (z <= -3.6e+14) 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 <= -3.6e+14) tmp = x; else tmp = x - (y * (z / t)); end tmp_2 = tmp; end
code[x_, y_, z_, t_] := If[LessEqual[z, -3.6e+14], x, N[(x - N[(y * N[(z / t), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;z \leq -3.6 \cdot 10^{+14}:\\
\;\;\;\;x\\
\mathbf{else}:\\
\;\;\;\;x - y \cdot \frac{z}{t}\\
\end{array}
\end{array}
if z < -3.6e14Initial program 82.9%
associate-+l-82.9%
sub-neg82.9%
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 61.2%
if -3.6e14 < z Initial program 57.1%
associate-+l-77.2%
sub-neg77.2%
log1p-define78.1%
neg-sub078.1%
associate-+l-78.1%
neg-sub078.1%
+-commutative78.1%
unsub-neg78.1%
*-rgt-identity78.1%
distribute-lft-out--78.1%
expm1-define97.1%
Simplified97.1%
Taylor expanded in z around 0 89.2%
associate-/l*91.2%
Simplified91.2%
Final simplification82.0%
(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 65.1%
associate-+l-79.0%
sub-neg79.0%
log1p-define84.8%
neg-sub084.8%
associate-+l-84.8%
neg-sub084.8%
+-commutative84.8%
unsub-neg84.8%
*-rgt-identity84.8%
distribute-lft-out--84.8%
expm1-define98.0%
Simplified98.0%
Taylor expanded in x around inf 71.6%
Final simplification71.6%
(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 2024067
(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)))