
(FPCore (x y z) :precision binary64 (exp (- (+ x (* y (log y))) z)))
double code(double x, double y, double z) {
return exp(((x + (y * log(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 = exp(((x + (y * log(y))) - z))
end function
public static double code(double x, double y, double z) {
return Math.exp(((x + (y * Math.log(y))) - z));
}
def code(x, y, z): return math.exp(((x + (y * math.log(y))) - z))
function code(x, y, z) return exp(Float64(Float64(x + Float64(y * log(y))) - z)) end
function tmp = code(x, y, z) tmp = exp(((x + (y * log(y))) - z)); end
code[x_, y_, z_] := N[Exp[N[(N[(x + N[(y * N[Log[y], $MachinePrecision]), $MachinePrecision]), $MachinePrecision] - z), $MachinePrecision]], $MachinePrecision]
\begin{array}{l}
\\
e^{\left(x + y \cdot \log y\right) - z}
\end{array}
Sampling outcomes in binary64 precision:
Herbie found 8 alternatives:
| Alternative | Accuracy | Speedup |
|---|
(FPCore (x y z) :precision binary64 (exp (- (+ x (* y (log y))) z)))
double code(double x, double y, double z) {
return exp(((x + (y * log(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 = exp(((x + (y * log(y))) - z))
end function
public static double code(double x, double y, double z) {
return Math.exp(((x + (y * Math.log(y))) - z));
}
def code(x, y, z): return math.exp(((x + (y * math.log(y))) - z))
function code(x, y, z) return exp(Float64(Float64(x + Float64(y * log(y))) - z)) end
function tmp = code(x, y, z) tmp = exp(((x + (y * log(y))) - z)); end
code[x_, y_, z_] := N[Exp[N[(N[(x + N[(y * N[Log[y], $MachinePrecision]), $MachinePrecision]), $MachinePrecision] - z), $MachinePrecision]], $MachinePrecision]
\begin{array}{l}
\\
e^{\left(x + y \cdot \log y\right) - z}
\end{array}
(FPCore (x y z) :precision binary64 (exp (- (+ x (* y (log y))) z)))
double code(double x, double y, double z) {
return exp(((x + (y * log(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 = exp(((x + (y * log(y))) - z))
end function
public static double code(double x, double y, double z) {
return Math.exp(((x + (y * Math.log(y))) - z));
}
def code(x, y, z): return math.exp(((x + (y * math.log(y))) - z))
function code(x, y, z) return exp(Float64(Float64(x + Float64(y * log(y))) - z)) end
function tmp = code(x, y, z) tmp = exp(((x + (y * log(y))) - z)); end
code[x_, y_, z_] := N[Exp[N[(N[(x + N[(y * N[Log[y], $MachinePrecision]), $MachinePrecision]), $MachinePrecision] - z), $MachinePrecision]], $MachinePrecision]
\begin{array}{l}
\\
e^{\left(x + y \cdot \log y\right) - z}
\end{array}
Initial program 100.0%
Final simplification100.0%
(FPCore (x y z) :precision binary64 (let* ((t_0 (* y (log y)))) (if (<= t_0 10.0) (* (pow y y) (exp (- x z))) (exp (- t_0 z)))))
double code(double x, double y, double z) {
double t_0 = y * log(y);
double tmp;
if (t_0 <= 10.0) {
tmp = pow(y, y) * exp((x - z));
} else {
tmp = exp((t_0 - 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) :: t_0
real(8) :: tmp
t_0 = y * log(y)
if (t_0 <= 10.0d0) then
tmp = (y ** y) * exp((x - z))
else
tmp = exp((t_0 - z))
end if
code = tmp
end function
public static double code(double x, double y, double z) {
double t_0 = y * Math.log(y);
double tmp;
if (t_0 <= 10.0) {
tmp = Math.pow(y, y) * Math.exp((x - z));
} else {
tmp = Math.exp((t_0 - z));
}
return tmp;
}
def code(x, y, z): t_0 = y * math.log(y) tmp = 0 if t_0 <= 10.0: tmp = math.pow(y, y) * math.exp((x - z)) else: tmp = math.exp((t_0 - z)) return tmp
function code(x, y, z) t_0 = Float64(y * log(y)) tmp = 0.0 if (t_0 <= 10.0) tmp = Float64((y ^ y) * exp(Float64(x - z))); else tmp = exp(Float64(t_0 - z)); end return tmp end
function tmp_2 = code(x, y, z) t_0 = y * log(y); tmp = 0.0; if (t_0 <= 10.0) tmp = (y ^ y) * exp((x - z)); else tmp = exp((t_0 - z)); end tmp_2 = tmp; end
code[x_, y_, z_] := Block[{t$95$0 = N[(y * N[Log[y], $MachinePrecision]), $MachinePrecision]}, If[LessEqual[t$95$0, 10.0], N[(N[Power[y, y], $MachinePrecision] * N[Exp[N[(x - z), $MachinePrecision]], $MachinePrecision]), $MachinePrecision], N[Exp[N[(t$95$0 - z), $MachinePrecision]], $MachinePrecision]]]
\begin{array}{l}
\\
\begin{array}{l}
t_0 := y \cdot \log y\\
\mathbf{if}\;t\_0 \leq 10:\\
\;\;\;\;{y}^{y} \cdot e^{x - z}\\
\mathbf{else}:\\
\;\;\;\;e^{t\_0 - z}\\
\end{array}
\end{array}
if (*.f64 y (log.f64 y)) < 10Initial program 100.0%
+-commutative100.0%
associate--l+100.0%
exp-sum100.0%
*-commutative100.0%
exp-to-pow100.0%
Simplified100.0%
if 10 < (*.f64 y (log.f64 y)) Initial program 100.0%
Taylor expanded in x around 0 90.2%
Final simplification95.0%
(FPCore (x y z)
:precision binary64
(if (or (<= z -720.0)
(not
(or (<= z 8.3e+102) (and (not (<= z 3.6e+130)) (<= z 2.1e+153)))))
(exp (- z))
(* (pow y y) (exp x))))
double code(double x, double y, double z) {
double tmp;
if ((z <= -720.0) || !((z <= 8.3e+102) || (!(z <= 3.6e+130) && (z <= 2.1e+153)))) {
tmp = exp(-z);
} else {
tmp = pow(y, y) * exp(x);
}
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 <= (-720.0d0)) .or. (.not. (z <= 8.3d+102) .or. (.not. (z <= 3.6d+130)) .and. (z <= 2.1d+153))) then
tmp = exp(-z)
else
tmp = (y ** y) * exp(x)
end if
code = tmp
end function
public static double code(double x, double y, double z) {
double tmp;
if ((z <= -720.0) || !((z <= 8.3e+102) || (!(z <= 3.6e+130) && (z <= 2.1e+153)))) {
tmp = Math.exp(-z);
} else {
tmp = Math.pow(y, y) * Math.exp(x);
}
return tmp;
}
def code(x, y, z): tmp = 0 if (z <= -720.0) or not ((z <= 8.3e+102) or (not (z <= 3.6e+130) and (z <= 2.1e+153))): tmp = math.exp(-z) else: tmp = math.pow(y, y) * math.exp(x) return tmp
function code(x, y, z) tmp = 0.0 if ((z <= -720.0) || !((z <= 8.3e+102) || (!(z <= 3.6e+130) && (z <= 2.1e+153)))) tmp = exp(Float64(-z)); else tmp = Float64((y ^ y) * exp(x)); end return tmp end
function tmp_2 = code(x, y, z) tmp = 0.0; if ((z <= -720.0) || ~(((z <= 8.3e+102) || (~((z <= 3.6e+130)) && (z <= 2.1e+153))))) tmp = exp(-z); else tmp = (y ^ y) * exp(x); end tmp_2 = tmp; end
code[x_, y_, z_] := If[Or[LessEqual[z, -720.0], N[Not[Or[LessEqual[z, 8.3e+102], And[N[Not[LessEqual[z, 3.6e+130]], $MachinePrecision], LessEqual[z, 2.1e+153]]]], $MachinePrecision]], N[Exp[(-z)], $MachinePrecision], N[(N[Power[y, y], $MachinePrecision] * N[Exp[x], $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;z \leq -720 \lor \neg \left(z \leq 8.3 \cdot 10^{+102} \lor \neg \left(z \leq 3.6 \cdot 10^{+130}\right) \land z \leq 2.1 \cdot 10^{+153}\right):\\
\;\;\;\;e^{-z}\\
\mathbf{else}:\\
\;\;\;\;{y}^{y} \cdot e^{x}\\
\end{array}
\end{array}
if z < -720 or 8.3000000000000005e102 < z < 3.6000000000000001e130 or 2.10000000000000017e153 < z Initial program 100.0%
Taylor expanded in z around inf 87.5%
neg-mul-187.5%
Simplified87.5%
if -720 < z < 8.3000000000000005e102 or 3.6000000000000001e130 < z < 2.10000000000000017e153Initial program 100.0%
Taylor expanded in z around 0 98.1%
exp-sum87.1%
*-commutative87.1%
exp-to-pow87.1%
*-commutative87.1%
Simplified87.1%
Final simplification87.2%
(FPCore (x y z)
:precision binary64
(if (<= z -0.00036)
(/ (pow y y) (exp z))
(if (or (<= z 1.15e+103) (and (not (<= z 2.15e+131)) (<= z 5.2e+161)))
(* (pow y y) (exp x))
(exp (- z)))))
double code(double x, double y, double z) {
double tmp;
if (z <= -0.00036) {
tmp = pow(y, y) / exp(z);
} else if ((z <= 1.15e+103) || (!(z <= 2.15e+131) && (z <= 5.2e+161))) {
tmp = pow(y, y) * exp(x);
} else {
tmp = exp(-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 <= (-0.00036d0)) then
tmp = (y ** y) / exp(z)
else if ((z <= 1.15d+103) .or. (.not. (z <= 2.15d+131)) .and. (z <= 5.2d+161)) then
tmp = (y ** y) * exp(x)
else
tmp = exp(-z)
end if
code = tmp
end function
public static double code(double x, double y, double z) {
double tmp;
if (z <= -0.00036) {
tmp = Math.pow(y, y) / Math.exp(z);
} else if ((z <= 1.15e+103) || (!(z <= 2.15e+131) && (z <= 5.2e+161))) {
tmp = Math.pow(y, y) * Math.exp(x);
} else {
tmp = Math.exp(-z);
}
return tmp;
}
def code(x, y, z): tmp = 0 if z <= -0.00036: tmp = math.pow(y, y) / math.exp(z) elif (z <= 1.15e+103) or (not (z <= 2.15e+131) and (z <= 5.2e+161)): tmp = math.pow(y, y) * math.exp(x) else: tmp = math.exp(-z) return tmp
function code(x, y, z) tmp = 0.0 if (z <= -0.00036) tmp = Float64((y ^ y) / exp(z)); elseif ((z <= 1.15e+103) || (!(z <= 2.15e+131) && (z <= 5.2e+161))) tmp = Float64((y ^ y) * exp(x)); else tmp = exp(Float64(-z)); end return tmp end
function tmp_2 = code(x, y, z) tmp = 0.0; if (z <= -0.00036) tmp = (y ^ y) / exp(z); elseif ((z <= 1.15e+103) || (~((z <= 2.15e+131)) && (z <= 5.2e+161))) tmp = (y ^ y) * exp(x); else tmp = exp(-z); end tmp_2 = tmp; end
code[x_, y_, z_] := If[LessEqual[z, -0.00036], N[(N[Power[y, y], $MachinePrecision] / N[Exp[z], $MachinePrecision]), $MachinePrecision], If[Or[LessEqual[z, 1.15e+103], And[N[Not[LessEqual[z, 2.15e+131]], $MachinePrecision], LessEqual[z, 5.2e+161]]], N[(N[Power[y, y], $MachinePrecision] * N[Exp[x], $MachinePrecision]), $MachinePrecision], N[Exp[(-z)], $MachinePrecision]]]
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;z \leq -0.00036:\\
\;\;\;\;\frac{{y}^{y}}{e^{z}}\\
\mathbf{elif}\;z \leq 1.15 \cdot 10^{+103} \lor \neg \left(z \leq 2.15 \cdot 10^{+131}\right) \land z \leq 5.2 \cdot 10^{+161}:\\
\;\;\;\;{y}^{y} \cdot e^{x}\\
\mathbf{else}:\\
\;\;\;\;e^{-z}\\
\end{array}
\end{array}
if z < -3.60000000000000023e-4Initial program 100.0%
Taylor expanded in x around 0 90.2%
exp-diff90.2%
*-commutative90.2%
exp-to-pow90.2%
Simplified90.2%
if -3.60000000000000023e-4 < z < 1.15000000000000004e103 or 2.1500000000000001e131 < z < 5.1999999999999996e161Initial program 100.0%
Taylor expanded in z around 0 98.1%
exp-sum87.5%
*-commutative87.5%
exp-to-pow87.5%
*-commutative87.5%
Simplified87.5%
if 1.15000000000000004e103 < z < 2.1500000000000001e131 or 5.1999999999999996e161 < z Initial program 100.0%
Taylor expanded in z around inf 83.1%
neg-mul-183.1%
Simplified83.1%
Final simplification87.6%
(FPCore (x y z) :precision binary64 (if (or (<= x -3.4e+147) (not (<= x 8.5e+108))) (exp x) (exp (- (* y (log y)) z))))
double code(double x, double y, double z) {
double tmp;
if ((x <= -3.4e+147) || !(x <= 8.5e+108)) {
tmp = exp(x);
} else {
tmp = exp(((y * log(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 ((x <= (-3.4d+147)) .or. (.not. (x <= 8.5d+108))) then
tmp = exp(x)
else
tmp = exp(((y * log(y)) - z))
end if
code = tmp
end function
public static double code(double x, double y, double z) {
double tmp;
if ((x <= -3.4e+147) || !(x <= 8.5e+108)) {
tmp = Math.exp(x);
} else {
tmp = Math.exp(((y * Math.log(y)) - z));
}
return tmp;
}
def code(x, y, z): tmp = 0 if (x <= -3.4e+147) or not (x <= 8.5e+108): tmp = math.exp(x) else: tmp = math.exp(((y * math.log(y)) - z)) return tmp
function code(x, y, z) tmp = 0.0 if ((x <= -3.4e+147) || !(x <= 8.5e+108)) tmp = exp(x); else tmp = exp(Float64(Float64(y * log(y)) - z)); end return tmp end
function tmp_2 = code(x, y, z) tmp = 0.0; if ((x <= -3.4e+147) || ~((x <= 8.5e+108))) tmp = exp(x); else tmp = exp(((y * log(y)) - z)); end tmp_2 = tmp; end
code[x_, y_, z_] := If[Or[LessEqual[x, -3.4e+147], N[Not[LessEqual[x, 8.5e+108]], $MachinePrecision]], N[Exp[x], $MachinePrecision], N[Exp[N[(N[(y * N[Log[y], $MachinePrecision]), $MachinePrecision] - z), $MachinePrecision]], $MachinePrecision]]
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;x \leq -3.4 \cdot 10^{+147} \lor \neg \left(x \leq 8.5 \cdot 10^{+108}\right):\\
\;\;\;\;e^{x}\\
\mathbf{else}:\\
\;\;\;\;e^{y \cdot \log y - z}\\
\end{array}
\end{array}
if x < -3.4e147 or 8.50000000000000016e108 < x Initial program 100.0%
Taylor expanded in x around inf 89.2%
if -3.4e147 < x < 8.50000000000000016e108Initial program 100.0%
Taylor expanded in x around 0 92.3%
Final simplification91.3%
(FPCore (x y z)
:precision binary64
(let* ((t_0 (exp (- z))))
(if (<= y 1.26e-251)
(exp x)
(if (<= y 1e-195)
t_0
(if (<= y 2.25e-79) (exp x) (if (<= y 2.0) t_0 (pow y y)))))))
double code(double x, double y, double z) {
double t_0 = exp(-z);
double tmp;
if (y <= 1.26e-251) {
tmp = exp(x);
} else if (y <= 1e-195) {
tmp = t_0;
} else if (y <= 2.25e-79) {
tmp = exp(x);
} else if (y <= 2.0) {
tmp = t_0;
} else {
tmp = pow(y, y);
}
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) :: t_0
real(8) :: tmp
t_0 = exp(-z)
if (y <= 1.26d-251) then
tmp = exp(x)
else if (y <= 1d-195) then
tmp = t_0
else if (y <= 2.25d-79) then
tmp = exp(x)
else if (y <= 2.0d0) then
tmp = t_0
else
tmp = y ** y
end if
code = tmp
end function
public static double code(double x, double y, double z) {
double t_0 = Math.exp(-z);
double tmp;
if (y <= 1.26e-251) {
tmp = Math.exp(x);
} else if (y <= 1e-195) {
tmp = t_0;
} else if (y <= 2.25e-79) {
tmp = Math.exp(x);
} else if (y <= 2.0) {
tmp = t_0;
} else {
tmp = Math.pow(y, y);
}
return tmp;
}
def code(x, y, z): t_0 = math.exp(-z) tmp = 0 if y <= 1.26e-251: tmp = math.exp(x) elif y <= 1e-195: tmp = t_0 elif y <= 2.25e-79: tmp = math.exp(x) elif y <= 2.0: tmp = t_0 else: tmp = math.pow(y, y) return tmp
function code(x, y, z) t_0 = exp(Float64(-z)) tmp = 0.0 if (y <= 1.26e-251) tmp = exp(x); elseif (y <= 1e-195) tmp = t_0; elseif (y <= 2.25e-79) tmp = exp(x); elseif (y <= 2.0) tmp = t_0; else tmp = y ^ y; end return tmp end
function tmp_2 = code(x, y, z) t_0 = exp(-z); tmp = 0.0; if (y <= 1.26e-251) tmp = exp(x); elseif (y <= 1e-195) tmp = t_0; elseif (y <= 2.25e-79) tmp = exp(x); elseif (y <= 2.0) tmp = t_0; else tmp = y ^ y; end tmp_2 = tmp; end
code[x_, y_, z_] := Block[{t$95$0 = N[Exp[(-z)], $MachinePrecision]}, If[LessEqual[y, 1.26e-251], N[Exp[x], $MachinePrecision], If[LessEqual[y, 1e-195], t$95$0, If[LessEqual[y, 2.25e-79], N[Exp[x], $MachinePrecision], If[LessEqual[y, 2.0], t$95$0, N[Power[y, y], $MachinePrecision]]]]]]
\begin{array}{l}
\\
\begin{array}{l}
t_0 := e^{-z}\\
\mathbf{if}\;y \leq 1.26 \cdot 10^{-251}:\\
\;\;\;\;e^{x}\\
\mathbf{elif}\;y \leq 10^{-195}:\\
\;\;\;\;t\_0\\
\mathbf{elif}\;y \leq 2.25 \cdot 10^{-79}:\\
\;\;\;\;e^{x}\\
\mathbf{elif}\;y \leq 2:\\
\;\;\;\;t\_0\\
\mathbf{else}:\\
\;\;\;\;{y}^{y}\\
\end{array}
\end{array}
if y < 1.26000000000000001e-251 or 1.0000000000000001e-195 < y < 2.2500000000000001e-79Initial program 100.0%
Taylor expanded in x around inf 83.1%
if 1.26000000000000001e-251 < y < 1.0000000000000001e-195 or 2.2500000000000001e-79 < y < 2Initial program 100.0%
Taylor expanded in z around inf 75.8%
neg-mul-175.8%
Simplified75.8%
if 2 < y Initial program 100.0%
Taylor expanded in x around 0 90.3%
Taylor expanded in z around 0 80.6%
Final simplification80.4%
(FPCore (x y z) :precision binary64 (if (or (<= z -850.0) (not (<= z 8e+102))) (exp (- z)) (exp x)))
double code(double x, double y, double z) {
double tmp;
if ((z <= -850.0) || !(z <= 8e+102)) {
tmp = exp(-z);
} else {
tmp = exp(x);
}
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 <= (-850.0d0)) .or. (.not. (z <= 8d+102))) then
tmp = exp(-z)
else
tmp = exp(x)
end if
code = tmp
end function
public static double code(double x, double y, double z) {
double tmp;
if ((z <= -850.0) || !(z <= 8e+102)) {
tmp = Math.exp(-z);
} else {
tmp = Math.exp(x);
}
return tmp;
}
def code(x, y, z): tmp = 0 if (z <= -850.0) or not (z <= 8e+102): tmp = math.exp(-z) else: tmp = math.exp(x) return tmp
function code(x, y, z) tmp = 0.0 if ((z <= -850.0) || !(z <= 8e+102)) tmp = exp(Float64(-z)); else tmp = exp(x); end return tmp end
function tmp_2 = code(x, y, z) tmp = 0.0; if ((z <= -850.0) || ~((z <= 8e+102))) tmp = exp(-z); else tmp = exp(x); end tmp_2 = tmp; end
code[x_, y_, z_] := If[Or[LessEqual[z, -850.0], N[Not[LessEqual[z, 8e+102]], $MachinePrecision]], N[Exp[(-z)], $MachinePrecision], N[Exp[x], $MachinePrecision]]
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;z \leq -850 \lor \neg \left(z \leq 8 \cdot 10^{+102}\right):\\
\;\;\;\;e^{-z}\\
\mathbf{else}:\\
\;\;\;\;e^{x}\\
\end{array}
\end{array}
if z < -850 or 7.99999999999999982e102 < z Initial program 100.0%
Taylor expanded in z around inf 83.6%
neg-mul-183.6%
Simplified83.6%
if -850 < z < 7.99999999999999982e102Initial program 100.0%
Taylor expanded in x around inf 68.6%
Final simplification74.9%
(FPCore (x y z) :precision binary64 (exp x))
double code(double x, double y, double z) {
return exp(x);
}
real(8) function code(x, y, z)
real(8), intent (in) :: x
real(8), intent (in) :: y
real(8), intent (in) :: z
code = exp(x)
end function
public static double code(double x, double y, double z) {
return Math.exp(x);
}
def code(x, y, z): return math.exp(x)
function code(x, y, z) return exp(x) end
function tmp = code(x, y, z) tmp = exp(x); end
code[x_, y_, z_] := N[Exp[x], $MachinePrecision]
\begin{array}{l}
\\
e^{x}
\end{array}
Initial program 100.0%
Taylor expanded in x around inf 53.7%
Final simplification53.7%
(FPCore (x y z) :precision binary64 (exp (+ (- x z) (* (log y) y))))
double code(double x, double y, double z) {
return exp(((x - z) + (log(y) * y)));
}
real(8) function code(x, y, z)
real(8), intent (in) :: x
real(8), intent (in) :: y
real(8), intent (in) :: z
code = exp(((x - z) + (log(y) * y)))
end function
public static double code(double x, double y, double z) {
return Math.exp(((x - z) + (Math.log(y) * y)));
}
def code(x, y, z): return math.exp(((x - z) + (math.log(y) * y)))
function code(x, y, z) return exp(Float64(Float64(x - z) + Float64(log(y) * y))) end
function tmp = code(x, y, z) tmp = exp(((x - z) + (log(y) * y))); end
code[x_, y_, z_] := N[Exp[N[(N[(x - z), $MachinePrecision] + N[(N[Log[y], $MachinePrecision] * y), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]
\begin{array}{l}
\\
e^{\left(x - z\right) + \log y \cdot y}
\end{array}
herbie shell --seed 2024078
(FPCore (x y z)
:name "Statistics.Distribution.Poisson.Internal:probability from math-functions-0.1.5.2"
:precision binary64
:alt
(exp (+ (- x z) (* (log y) y)))
(exp (- (+ x (* y (log y))) z)))