
(FPCore (a b) :precision binary64 (/ (exp a) (+ (exp a) (exp b))))
double code(double a, double b) {
return exp(a) / (exp(a) + exp(b));
}
real(8) function code(a, b)
real(8), intent (in) :: a
real(8), intent (in) :: b
code = exp(a) / (exp(a) + exp(b))
end function
public static double code(double a, double b) {
return Math.exp(a) / (Math.exp(a) + Math.exp(b));
}
def code(a, b): return math.exp(a) / (math.exp(a) + math.exp(b))
function code(a, b) return Float64(exp(a) / Float64(exp(a) + exp(b))) end
function tmp = code(a, b) tmp = exp(a) / (exp(a) + exp(b)); end
code[a_, b_] := N[(N[Exp[a], $MachinePrecision] / N[(N[Exp[a], $MachinePrecision] + N[Exp[b], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\frac{e^{a}}{e^{a} + e^{b}}
\end{array}
Sampling outcomes in binary64 precision:
Herbie found 10 alternatives:
| Alternative | Accuracy | Speedup |
|---|
(FPCore (a b) :precision binary64 (/ (exp a) (+ (exp a) (exp b))))
double code(double a, double b) {
return exp(a) / (exp(a) + exp(b));
}
real(8) function code(a, b)
real(8), intent (in) :: a
real(8), intent (in) :: b
code = exp(a) / (exp(a) + exp(b))
end function
public static double code(double a, double b) {
return Math.exp(a) / (Math.exp(a) + Math.exp(b));
}
def code(a, b): return math.exp(a) / (math.exp(a) + math.exp(b))
function code(a, b) return Float64(exp(a) / Float64(exp(a) + exp(b))) end
function tmp = code(a, b) tmp = exp(a) / (exp(a) + exp(b)); end
code[a_, b_] := N[(N[Exp[a], $MachinePrecision] / N[(N[Exp[a], $MachinePrecision] + N[Exp[b], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\frac{e^{a}}{e^{a} + e^{b}}
\end{array}
(FPCore (a b) :precision binary64 (/ (exp a) (+ (exp a) (exp b))))
double code(double a, double b) {
return exp(a) / (exp(a) + exp(b));
}
real(8) function code(a, b)
real(8), intent (in) :: a
real(8), intent (in) :: b
code = exp(a) / (exp(a) + exp(b))
end function
public static double code(double a, double b) {
return Math.exp(a) / (Math.exp(a) + Math.exp(b));
}
def code(a, b): return math.exp(a) / (math.exp(a) + math.exp(b))
function code(a, b) return Float64(exp(a) / Float64(exp(a) + exp(b))) end
function tmp = code(a, b) tmp = exp(a) / (exp(a) + exp(b)); end
code[a_, b_] := N[(N[Exp[a], $MachinePrecision] / N[(N[Exp[a], $MachinePrecision] + N[Exp[b], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\frac{e^{a}}{e^{a} + e^{b}}
\end{array}
(FPCore (a b) :precision binary64 (if (<= (exp a) 0.999999994) (/ (exp a) (+ (exp a) 1.0)) (/ 1.0 (+ (exp b) 1.0))))
double code(double a, double b) {
double tmp;
if (exp(a) <= 0.999999994) {
tmp = exp(a) / (exp(a) + 1.0);
} else {
tmp = 1.0 / (exp(b) + 1.0);
}
return tmp;
}
real(8) function code(a, b)
real(8), intent (in) :: a
real(8), intent (in) :: b
real(8) :: tmp
if (exp(a) <= 0.999999994d0) then
tmp = exp(a) / (exp(a) + 1.0d0)
else
tmp = 1.0d0 / (exp(b) + 1.0d0)
end if
code = tmp
end function
public static double code(double a, double b) {
double tmp;
if (Math.exp(a) <= 0.999999994) {
tmp = Math.exp(a) / (Math.exp(a) + 1.0);
} else {
tmp = 1.0 / (Math.exp(b) + 1.0);
}
return tmp;
}
def code(a, b): tmp = 0 if math.exp(a) <= 0.999999994: tmp = math.exp(a) / (math.exp(a) + 1.0) else: tmp = 1.0 / (math.exp(b) + 1.0) return tmp
function code(a, b) tmp = 0.0 if (exp(a) <= 0.999999994) tmp = Float64(exp(a) / Float64(exp(a) + 1.0)); else tmp = Float64(1.0 / Float64(exp(b) + 1.0)); end return tmp end
function tmp_2 = code(a, b) tmp = 0.0; if (exp(a) <= 0.999999994) tmp = exp(a) / (exp(a) + 1.0); else tmp = 1.0 / (exp(b) + 1.0); end tmp_2 = tmp; end
code[a_, b_] := If[LessEqual[N[Exp[a], $MachinePrecision], 0.999999994], N[(N[Exp[a], $MachinePrecision] / N[(N[Exp[a], $MachinePrecision] + 1.0), $MachinePrecision]), $MachinePrecision], N[(1.0 / N[(N[Exp[b], $MachinePrecision] + 1.0), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;e^{a} \leq 0.999999994:\\
\;\;\;\;\frac{e^{a}}{e^{a} + 1}\\
\mathbf{else}:\\
\;\;\;\;\frac{1}{e^{b} + 1}\\
\end{array}
\end{array}
(FPCore (a b) :precision binary64 (if (<= (exp a) 0.999999994) (* (exp a) (/ -1.0 (- (- -2.0 a) b))) (/ 1.0 (+ (exp b) 1.0))))
double code(double a, double b) {
double tmp;
if (exp(a) <= 0.999999994) {
tmp = exp(a) * (-1.0 / ((-2.0 - a) - b));
} else {
tmp = 1.0 / (exp(b) + 1.0);
}
return tmp;
}
real(8) function code(a, b)
real(8), intent (in) :: a
real(8), intent (in) :: b
real(8) :: tmp
if (exp(a) <= 0.999999994d0) then
tmp = exp(a) * ((-1.0d0) / (((-2.0d0) - a) - b))
else
tmp = 1.0d0 / (exp(b) + 1.0d0)
end if
code = tmp
end function
public static double code(double a, double b) {
double tmp;
if (Math.exp(a) <= 0.999999994) {
tmp = Math.exp(a) * (-1.0 / ((-2.0 - a) - b));
} else {
tmp = 1.0 / (Math.exp(b) + 1.0);
}
return tmp;
}
def code(a, b): tmp = 0 if math.exp(a) <= 0.999999994: tmp = math.exp(a) * (-1.0 / ((-2.0 - a) - b)) else: tmp = 1.0 / (math.exp(b) + 1.0) return tmp
function code(a, b) tmp = 0.0 if (exp(a) <= 0.999999994) tmp = Float64(exp(a) * Float64(-1.0 / Float64(Float64(-2.0 - a) - b))); else tmp = Float64(1.0 / Float64(exp(b) + 1.0)); end return tmp end
function tmp_2 = code(a, b) tmp = 0.0; if (exp(a) <= 0.999999994) tmp = exp(a) * (-1.0 / ((-2.0 - a) - b)); else tmp = 1.0 / (exp(b) + 1.0); end tmp_2 = tmp; end
code[a_, b_] := If[LessEqual[N[Exp[a], $MachinePrecision], 0.999999994], N[(N[Exp[a], $MachinePrecision] * N[(-1.0 / N[(N[(-2.0 - a), $MachinePrecision] - b), $MachinePrecision]), $MachinePrecision]), $MachinePrecision], N[(1.0 / N[(N[Exp[b], $MachinePrecision] + 1.0), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;e^{a} \leq 0.999999994:\\
\;\;\;\;e^{a} \cdot \frac{-1}{\left(-2 - a\right) - b}\\
\mathbf{else}:\\
\;\;\;\;\frac{1}{e^{b} + 1}\\
\end{array}
\end{array}
(FPCore (a b) :precision binary64 (if (<= (exp a) 0.999999994) (/ (exp a) (+ b (+ a 2.0))) (/ 1.0 (+ (exp b) 1.0))))
double code(double a, double b) {
double tmp;
if (exp(a) <= 0.999999994) {
tmp = exp(a) / (b + (a + 2.0));
} else {
tmp = 1.0 / (exp(b) + 1.0);
}
return tmp;
}
real(8) function code(a, b)
real(8), intent (in) :: a
real(8), intent (in) :: b
real(8) :: tmp
if (exp(a) <= 0.999999994d0) then
tmp = exp(a) / (b + (a + 2.0d0))
else
tmp = 1.0d0 / (exp(b) + 1.0d0)
end if
code = tmp
end function
public static double code(double a, double b) {
double tmp;
if (Math.exp(a) <= 0.999999994) {
tmp = Math.exp(a) / (b + (a + 2.0));
} else {
tmp = 1.0 / (Math.exp(b) + 1.0);
}
return tmp;
}
def code(a, b): tmp = 0 if math.exp(a) <= 0.999999994: tmp = math.exp(a) / (b + (a + 2.0)) else: tmp = 1.0 / (math.exp(b) + 1.0) return tmp
function code(a, b) tmp = 0.0 if (exp(a) <= 0.999999994) tmp = Float64(exp(a) / Float64(b + Float64(a + 2.0))); else tmp = Float64(1.0 / Float64(exp(b) + 1.0)); end return tmp end
function tmp_2 = code(a, b) tmp = 0.0; if (exp(a) <= 0.999999994) tmp = exp(a) / (b + (a + 2.0)); else tmp = 1.0 / (exp(b) + 1.0); end tmp_2 = tmp; end
code[a_, b_] := If[LessEqual[N[Exp[a], $MachinePrecision], 0.999999994], N[(N[Exp[a], $MachinePrecision] / N[(b + N[(a + 2.0), $MachinePrecision]), $MachinePrecision]), $MachinePrecision], N[(1.0 / N[(N[Exp[b], $MachinePrecision] + 1.0), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;e^{a} \leq 0.999999994:\\
\;\;\;\;\frac{e^{a}}{b + \left(a + 2\right)}\\
\mathbf{else}:\\
\;\;\;\;\frac{1}{e^{b} + 1}\\
\end{array}
\end{array}
(FPCore (a b) :precision binary64 (if (<= (exp a) 0.0) (/ (exp a) a) (/ 1.0 (+ (exp b) 1.0))))
double code(double a, double b) {
double tmp;
if (exp(a) <= 0.0) {
tmp = exp(a) / a;
} else {
tmp = 1.0 / (exp(b) + 1.0);
}
return tmp;
}
real(8) function code(a, b)
real(8), intent (in) :: a
real(8), intent (in) :: b
real(8) :: tmp
if (exp(a) <= 0.0d0) then
tmp = exp(a) / a
else
tmp = 1.0d0 / (exp(b) + 1.0d0)
end if
code = tmp
end function
public static double code(double a, double b) {
double tmp;
if (Math.exp(a) <= 0.0) {
tmp = Math.exp(a) / a;
} else {
tmp = 1.0 / (Math.exp(b) + 1.0);
}
return tmp;
}
def code(a, b): tmp = 0 if math.exp(a) <= 0.0: tmp = math.exp(a) / a else: tmp = 1.0 / (math.exp(b) + 1.0) return tmp
function code(a, b) tmp = 0.0 if (exp(a) <= 0.0) tmp = Float64(exp(a) / a); else tmp = Float64(1.0 / Float64(exp(b) + 1.0)); end return tmp end
function tmp_2 = code(a, b) tmp = 0.0; if (exp(a) <= 0.0) tmp = exp(a) / a; else tmp = 1.0 / (exp(b) + 1.0); end tmp_2 = tmp; end
code[a_, b_] := If[LessEqual[N[Exp[a], $MachinePrecision], 0.0], N[(N[Exp[a], $MachinePrecision] / a), $MachinePrecision], N[(1.0 / N[(N[Exp[b], $MachinePrecision] + 1.0), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;e^{a} \leq 0:\\
\;\;\;\;\frac{e^{a}}{a}\\
\mathbf{else}:\\
\;\;\;\;\frac{1}{e^{b} + 1}\\
\end{array}
\end{array}
(FPCore (a b) :precision binary64 (if (<= (exp a) 0.999999994) (/ (exp a) (+ a 2.0)) (/ 1.0 (+ (exp b) 1.0))))
double code(double a, double b) {
double tmp;
if (exp(a) <= 0.999999994) {
tmp = exp(a) / (a + 2.0);
} else {
tmp = 1.0 / (exp(b) + 1.0);
}
return tmp;
}
real(8) function code(a, b)
real(8), intent (in) :: a
real(8), intent (in) :: b
real(8) :: tmp
if (exp(a) <= 0.999999994d0) then
tmp = exp(a) / (a + 2.0d0)
else
tmp = 1.0d0 / (exp(b) + 1.0d0)
end if
code = tmp
end function
public static double code(double a, double b) {
double tmp;
if (Math.exp(a) <= 0.999999994) {
tmp = Math.exp(a) / (a + 2.0);
} else {
tmp = 1.0 / (Math.exp(b) + 1.0);
}
return tmp;
}
def code(a, b): tmp = 0 if math.exp(a) <= 0.999999994: tmp = math.exp(a) / (a + 2.0) else: tmp = 1.0 / (math.exp(b) + 1.0) return tmp
function code(a, b) tmp = 0.0 if (exp(a) <= 0.999999994) tmp = Float64(exp(a) / Float64(a + 2.0)); else tmp = Float64(1.0 / Float64(exp(b) + 1.0)); end return tmp end
function tmp_2 = code(a, b) tmp = 0.0; if (exp(a) <= 0.999999994) tmp = exp(a) / (a + 2.0); else tmp = 1.0 / (exp(b) + 1.0); end tmp_2 = tmp; end
code[a_, b_] := If[LessEqual[N[Exp[a], $MachinePrecision], 0.999999994], N[(N[Exp[a], $MachinePrecision] / N[(a + 2.0), $MachinePrecision]), $MachinePrecision], N[(1.0 / N[(N[Exp[b], $MachinePrecision] + 1.0), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;e^{a} \leq 0.999999994:\\
\;\;\;\;\frac{e^{a}}{a + 2}\\
\mathbf{else}:\\
\;\;\;\;\frac{1}{e^{b} + 1}\\
\end{array}
\end{array}
(FPCore (a b) :precision binary64 (/ (exp a) (+ (exp b) (+ a 1.0))))
double code(double a, double b) {
return exp(a) / (exp(b) + (a + 1.0));
}
real(8) function code(a, b)
real(8), intent (in) :: a
real(8), intent (in) :: b
code = exp(a) / (exp(b) + (a + 1.0d0))
end function
public static double code(double a, double b) {
return Math.exp(a) / (Math.exp(b) + (a + 1.0));
}
def code(a, b): return math.exp(a) / (math.exp(b) + (a + 1.0))
function code(a, b) return Float64(exp(a) / Float64(exp(b) + Float64(a + 1.0))) end
function tmp = code(a, b) tmp = exp(a) / (exp(b) + (a + 1.0)); end
code[a_, b_] := N[(N[Exp[a], $MachinePrecision] / N[(N[Exp[b], $MachinePrecision] + N[(a + 1.0), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\frac{e^{a}}{e^{b} + \left(a + 1\right)}
\end{array}
(FPCore (a b) :precision binary64 (if (<= a -2.2) (/ (exp a) a) (+ 0.5 (* a 0.25))))
double code(double a, double b) {
double tmp;
if (a <= -2.2) {
tmp = exp(a) / a;
} else {
tmp = 0.5 + (a * 0.25);
}
return tmp;
}
real(8) function code(a, b)
real(8), intent (in) :: a
real(8), intent (in) :: b
real(8) :: tmp
if (a <= (-2.2d0)) then
tmp = exp(a) / a
else
tmp = 0.5d0 + (a * 0.25d0)
end if
code = tmp
end function
public static double code(double a, double b) {
double tmp;
if (a <= -2.2) {
tmp = Math.exp(a) / a;
} else {
tmp = 0.5 + (a * 0.25);
}
return tmp;
}
def code(a, b): tmp = 0 if a <= -2.2: tmp = math.exp(a) / a else: tmp = 0.5 + (a * 0.25) return tmp
function code(a, b) tmp = 0.0 if (a <= -2.2) tmp = Float64(exp(a) / a); else tmp = Float64(0.5 + Float64(a * 0.25)); end return tmp end
function tmp_2 = code(a, b) tmp = 0.0; if (a <= -2.2) tmp = exp(a) / a; else tmp = 0.5 + (a * 0.25); end tmp_2 = tmp; end
code[a_, b_] := If[LessEqual[a, -2.2], N[(N[Exp[a], $MachinePrecision] / a), $MachinePrecision], N[(0.5 + N[(a * 0.25), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;a \leq -2.2:\\
\;\;\;\;\frac{e^{a}}{a}\\
\mathbf{else}:\\
\;\;\;\;0.5 + a \cdot 0.25\\
\end{array}
\end{array}
(FPCore (a b) :precision binary64 (+ 0.5 (* a 0.25)))
double code(double a, double b) {
return 0.5 + (a * 0.25);
}
real(8) function code(a, b)
real(8), intent (in) :: a
real(8), intent (in) :: b
code = 0.5d0 + (a * 0.25d0)
end function
public static double code(double a, double b) {
return 0.5 + (a * 0.25);
}
def code(a, b): return 0.5 + (a * 0.25)
function code(a, b) return Float64(0.5 + Float64(a * 0.25)) end
function tmp = code(a, b) tmp = 0.5 + (a * 0.25); end
code[a_, b_] := N[(0.5 + N[(a * 0.25), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
0.5 + a \cdot 0.25
\end{array}
(FPCore (a b) :precision binary64 0.5)
double code(double a, double b) {
return 0.5;
}
real(8) function code(a, b)
real(8), intent (in) :: a
real(8), intent (in) :: b
code = 0.5d0
end function
public static double code(double a, double b) {
return 0.5;
}
def code(a, b): return 0.5
function code(a, b) return 0.5 end
function tmp = code(a, b) tmp = 0.5; end
code[a_, b_] := 0.5
\begin{array}{l}
\\
0.5
\end{array}
(FPCore (a b) :precision binary64 (/ 1.0 (+ 1.0 (exp (- b a)))))
double code(double a, double b) {
return 1.0 / (1.0 + exp((b - a)));
}
real(8) function code(a, b)
real(8), intent (in) :: a
real(8), intent (in) :: b
code = 1.0d0 / (1.0d0 + exp((b - a)))
end function
public static double code(double a, double b) {
return 1.0 / (1.0 + Math.exp((b - a)));
}
def code(a, b): return 1.0 / (1.0 + math.exp((b - a)))
function code(a, b) return Float64(1.0 / Float64(1.0 + exp(Float64(b - a)))) end
function tmp = code(a, b) tmp = 1.0 / (1.0 + exp((b - a))); end
code[a_, b_] := N[(1.0 / N[(1.0 + N[Exp[N[(b - a), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\frac{1}{1 + e^{b - a}}
\end{array}
herbie shell --seed 2024006
(FPCore (a b)
:name "Quotient of sum of exps"
:precision binary64
:herbie-target
(/ 1.0 (+ 1.0 (exp (- b a))))
(/ (exp a) (+ (exp a) (exp b))))