
(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 (log (+ (exp a) (exp b))))))
double code(double a, double b) {
return exp((a - log((exp(a) + exp(b)))));
}
real(8) function code(a, b)
real(8), intent (in) :: a
real(8), intent (in) :: b
code = exp((a - log((exp(a) + exp(b)))))
end function
public static double code(double a, double b) {
return Math.exp((a - Math.log((Math.exp(a) + Math.exp(b)))));
}
def code(a, b): return math.exp((a - math.log((math.exp(a) + math.exp(b)))))
function code(a, b) return exp(Float64(a - log(Float64(exp(a) + exp(b))))) end
function tmp = code(a, b) tmp = exp((a - log((exp(a) + exp(b))))); end
code[a_, b_] := N[Exp[N[(a - N[Log[N[(N[Exp[a], $MachinePrecision] + N[Exp[b], $MachinePrecision]), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]], $MachinePrecision]
\begin{array}{l}
\\
e^{a - \log \left(e^{a} + e^{b}\right)}
\end{array}
Initial program 98.4%
add-exp-log98.4%
div-exp99.2%
Applied egg-rr99.2%
Final simplification99.2%
(FPCore (a b) :precision binary64 (if (<= (exp a) 0.99998) (/ (exp a) (+ (exp a) 1.0)) (exp (- (log1p (exp b))))))
double code(double a, double b) {
double tmp;
if (exp(a) <= 0.99998) {
tmp = exp(a) / (exp(a) + 1.0);
} else {
tmp = exp(-log1p(exp(b)));
}
return tmp;
}
public static double code(double a, double b) {
double tmp;
if (Math.exp(a) <= 0.99998) {
tmp = Math.exp(a) / (Math.exp(a) + 1.0);
} else {
tmp = Math.exp(-Math.log1p(Math.exp(b)));
}
return tmp;
}
def code(a, b): tmp = 0 if math.exp(a) <= 0.99998: tmp = math.exp(a) / (math.exp(a) + 1.0) else: tmp = math.exp(-math.log1p(math.exp(b))) return tmp
function code(a, b) tmp = 0.0 if (exp(a) <= 0.99998) tmp = Float64(exp(a) / Float64(exp(a) + 1.0)); else tmp = exp(Float64(-log1p(exp(b)))); end return tmp end
code[a_, b_] := If[LessEqual[N[Exp[a], $MachinePrecision], 0.99998], N[(N[Exp[a], $MachinePrecision] / N[(N[Exp[a], $MachinePrecision] + 1.0), $MachinePrecision]), $MachinePrecision], N[Exp[(-N[Log[1 + N[Exp[b], $MachinePrecision]], $MachinePrecision])], $MachinePrecision]]
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;e^{a} \leq 0.99998:\\
\;\;\;\;\frac{e^{a}}{e^{a} + 1}\\
\mathbf{else}:\\
\;\;\;\;e^{-\mathsf{log1p}\left(e^{b}\right)}\\
\end{array}
\end{array}
if (exp.f64 a) < 0.99997999999999998Initial program 98.8%
Taylor expanded in b around 0 100.0%
if 0.99997999999999998 < (exp.f64 a) Initial program 98.3%
add-exp-log98.3%
div-exp99.4%
Applied egg-rr99.4%
Taylor expanded in a around 0 98.3%
log1p-def98.3%
neg-mul-198.3%
Simplified98.3%
Final simplification98.8%
(FPCore (a b) :precision binary64 (if (<= (exp a) 0.99998) (/ (exp a) (+ (exp a) 1.0)) (/ 1.0 (+ (exp b) 1.0))))
double code(double a, double b) {
double tmp;
if (exp(a) <= 0.99998) {
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) <= 0.99998d0) 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) <= 0.99998) {
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) <= 0.99998: 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) <= 0.99998) 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) <= 0.99998) 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], 0.99998], 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 0.99998:\\
\;\;\;\;\frac{e^{a}}{e^{a} + 1}\\
\mathbf{else}:\\
\;\;\;\;\frac{1}{e^{b} + 1}\\
\end{array}
\end{array}
if (exp.f64 a) < 0.99997999999999998Initial program 98.8%
Taylor expanded in b around 0 100.0%
if 0.99997999999999998 < (exp.f64 a) Initial program 98.3%
Taylor expanded in a around 0 98.3%
Final simplification98.8%
(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}
Initial program 98.4%
Final simplification98.4%
(FPCore (a b) :precision binary64 (if (<= (exp a) 0.0) (exp a) (/ 1.0 (+ (exp b) 1.0))))
double code(double a, double b) {
double tmp;
if (exp(a) <= 0.0) {
tmp = exp(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)
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);
} 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) else: tmp = 1.0 / (math.exp(b) + 1.0) return tmp
function code(a, b) tmp = 0.0 if (exp(a) <= 0.0) tmp = exp(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); 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[Exp[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:\\
\;\;\;\;e^{a}\\
\mathbf{else}:\\
\;\;\;\;\frac{1}{e^{b} + 1}\\
\end{array}
\end{array}
if (exp.f64 a) < 0.0Initial program 98.7%
add-exp-log98.7%
div-exp98.7%
Applied egg-rr98.7%
Taylor expanded in a around inf 100.0%
if 0.0 < (exp.f64 a) Initial program 98.3%
Taylor expanded in a around 0 97.6%
Final simplification98.3%
(FPCore (a b) :precision binary64 (if (<= (exp a) 0.0) (exp a) (+ 0.5 (* a 0.25))))
double code(double a, double b) {
double tmp;
if (exp(a) <= 0.0) {
tmp = exp(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 (exp(a) <= 0.0d0) then
tmp = exp(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 (Math.exp(a) <= 0.0) {
tmp = Math.exp(a);
} else {
tmp = 0.5 + (a * 0.25);
}
return tmp;
}
def code(a, b): tmp = 0 if math.exp(a) <= 0.0: tmp = math.exp(a) else: tmp = 0.5 + (a * 0.25) return tmp
function code(a, b) tmp = 0.0 if (exp(a) <= 0.0) tmp = exp(a); else tmp = Float64(0.5 + Float64(a * 0.25)); end return tmp end
function tmp_2 = code(a, b) tmp = 0.0; if (exp(a) <= 0.0) tmp = exp(a); else tmp = 0.5 + (a * 0.25); end tmp_2 = tmp; end
code[a_, b_] := If[LessEqual[N[Exp[a], $MachinePrecision], 0.0], N[Exp[a], $MachinePrecision], N[(0.5 + N[(a * 0.25), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;e^{a} \leq 0:\\
\;\;\;\;e^{a}\\
\mathbf{else}:\\
\;\;\;\;0.5 + a \cdot 0.25\\
\end{array}
\end{array}
if (exp.f64 a) < 0.0Initial program 98.7%
add-exp-log98.7%
div-exp98.7%
Applied egg-rr98.7%
Taylor expanded in a around inf 100.0%
if 0.0 < (exp.f64 a) Initial program 98.3%
Taylor expanded in b around 0 47.0%
Taylor expanded in a around 0 46.1%
*-commutative46.1%
Simplified46.1%
Final simplification62.5%
(FPCore (a b) :precision binary64 (if (<= b -5.4e-8) 1.0 (+ 0.5 (* a 0.25))))
double code(double a, double b) {
double tmp;
if (b <= -5.4e-8) {
tmp = 1.0;
} 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 (b <= (-5.4d-8)) then
tmp = 1.0d0
else
tmp = 0.5d0 + (a * 0.25d0)
end if
code = tmp
end function
public static double code(double a, double b) {
double tmp;
if (b <= -5.4e-8) {
tmp = 1.0;
} else {
tmp = 0.5 + (a * 0.25);
}
return tmp;
}
def code(a, b): tmp = 0 if b <= -5.4e-8: tmp = 1.0 else: tmp = 0.5 + (a * 0.25) return tmp
function code(a, b) tmp = 0.0 if (b <= -5.4e-8) tmp = 1.0; else tmp = Float64(0.5 + Float64(a * 0.25)); end return tmp end
function tmp_2 = code(a, b) tmp = 0.0; if (b <= -5.4e-8) tmp = 1.0; else tmp = 0.5 + (a * 0.25); end tmp_2 = tmp; end
code[a_, b_] := If[LessEqual[b, -5.4e-8], 1.0, N[(0.5 + N[(a * 0.25), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;b \leq -5.4 \cdot 10^{-8}:\\
\;\;\;\;1\\
\mathbf{else}:\\
\;\;\;\;0.5 + a \cdot 0.25\\
\end{array}
\end{array}
if b < -5.40000000000000005e-8Initial program 98.1%
add-exp-log98.1%
div-exp98.1%
Applied egg-rr98.1%
Taylor expanded in a around 0 96.3%
log1p-def96.3%
neg-mul-196.3%
Simplified96.3%
add-sqr-sqrt96.3%
pow1/296.3%
neg-mul-196.3%
*-commutative96.3%
add-sqr-sqrt96.3%
sqrt-unprod96.3%
sqr-neg96.3%
sqrt-unprod96.2%
add-sqr-sqrt96.3%
add-log-exp96.3%
pow-to-exp96.3%
pow-pow96.3%
metadata-eval96.3%
metadata-eval96.3%
pow-prod-up96.3%
Applied egg-rr96.3%
if -5.40000000000000005e-8 < b Initial program 98.5%
Taylor expanded in b around 0 73.7%
Taylor expanded in a around 0 36.5%
*-commutative36.5%
Simplified36.5%
Final simplification48.6%
(FPCore (a b) :precision binary64 (if (<= b -170000.0) 1.0 (/ 1.0 (+ b 2.0))))
double code(double a, double b) {
double tmp;
if (b <= -170000.0) {
tmp = 1.0;
} else {
tmp = 1.0 / (b + 2.0);
}
return tmp;
}
real(8) function code(a, b)
real(8), intent (in) :: a
real(8), intent (in) :: b
real(8) :: tmp
if (b <= (-170000.0d0)) then
tmp = 1.0d0
else
tmp = 1.0d0 / (b + 2.0d0)
end if
code = tmp
end function
public static double code(double a, double b) {
double tmp;
if (b <= -170000.0) {
tmp = 1.0;
} else {
tmp = 1.0 / (b + 2.0);
}
return tmp;
}
def code(a, b): tmp = 0 if b <= -170000.0: tmp = 1.0 else: tmp = 1.0 / (b + 2.0) return tmp
function code(a, b) tmp = 0.0 if (b <= -170000.0) tmp = 1.0; else tmp = Float64(1.0 / Float64(b + 2.0)); end return tmp end
function tmp_2 = code(a, b) tmp = 0.0; if (b <= -170000.0) tmp = 1.0; else tmp = 1.0 / (b + 2.0); end tmp_2 = tmp; end
code[a_, b_] := If[LessEqual[b, -170000.0], 1.0, N[(1.0 / N[(b + 2.0), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;b \leq -170000:\\
\;\;\;\;1\\
\mathbf{else}:\\
\;\;\;\;\frac{1}{b + 2}\\
\end{array}
\end{array}
if b < -1.7e5Initial program 100.0%
add-exp-log100.0%
div-exp100.0%
Applied egg-rr100.0%
Taylor expanded in a around 0 100.0%
log1p-def100.0%
neg-mul-1100.0%
Simplified100.0%
add-sqr-sqrt100.0%
pow1/2100.0%
neg-mul-1100.0%
*-commutative100.0%
add-sqr-sqrt100.0%
sqrt-unprod100.0%
sqr-neg100.0%
sqrt-unprod100.0%
add-sqr-sqrt100.0%
add-log-exp100.0%
pow-to-exp100.0%
pow-pow100.0%
metadata-eval100.0%
metadata-eval100.0%
pow-prod-up100.0%
Applied egg-rr100.0%
if -1.7e5 < b Initial program 98.0%
Taylor expanded in a around 0 73.9%
Taylor expanded in b around 0 37.1%
+-commutative37.1%
Simplified37.1%
Final simplification49.4%
(FPCore (a b) :precision binary64 (if (<= b -170000.0) 1.0 0.5))
double code(double a, double b) {
double tmp;
if (b <= -170000.0) {
tmp = 1.0;
} else {
tmp = 0.5;
}
return tmp;
}
real(8) function code(a, b)
real(8), intent (in) :: a
real(8), intent (in) :: b
real(8) :: tmp
if (b <= (-170000.0d0)) then
tmp = 1.0d0
else
tmp = 0.5d0
end if
code = tmp
end function
public static double code(double a, double b) {
double tmp;
if (b <= -170000.0) {
tmp = 1.0;
} else {
tmp = 0.5;
}
return tmp;
}
def code(a, b): tmp = 0 if b <= -170000.0: tmp = 1.0 else: tmp = 0.5 return tmp
function code(a, b) tmp = 0.0 if (b <= -170000.0) tmp = 1.0; else tmp = 0.5; end return tmp end
function tmp_2 = code(a, b) tmp = 0.0; if (b <= -170000.0) tmp = 1.0; else tmp = 0.5; end tmp_2 = tmp; end
code[a_, b_] := If[LessEqual[b, -170000.0], 1.0, 0.5]
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;b \leq -170000:\\
\;\;\;\;1\\
\mathbf{else}:\\
\;\;\;\;0.5\\
\end{array}
\end{array}
if b < -1.7e5Initial program 100.0%
add-exp-log100.0%
div-exp100.0%
Applied egg-rr100.0%
Taylor expanded in a around 0 100.0%
log1p-def100.0%
neg-mul-1100.0%
Simplified100.0%
add-sqr-sqrt100.0%
pow1/2100.0%
neg-mul-1100.0%
*-commutative100.0%
add-sqr-sqrt100.0%
sqrt-unprod100.0%
sqr-neg100.0%
sqrt-unprod100.0%
add-sqr-sqrt100.0%
add-log-exp100.0%
pow-to-exp100.0%
pow-pow100.0%
metadata-eval100.0%
metadata-eval100.0%
pow-prod-up100.0%
Applied egg-rr100.0%
if -1.7e5 < b Initial program 98.0%
Taylor expanded in a around 0 73.9%
Taylor expanded in b around 0 35.7%
Final simplification48.2%
(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}
Initial program 98.4%
Taylor expanded in a around 0 79.0%
Taylor expanded in b around 0 32.4%
Final simplification32.4%
(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 2024020
(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))))