
(FPCore (x) :precision binary64 (/ 2.0 (+ (exp x) (exp (- x)))))
double code(double x) {
return 2.0 / (exp(x) + exp(-x));
}
real(8) function code(x)
real(8), intent (in) :: x
code = 2.0d0 / (exp(x) + exp(-x))
end function
public static double code(double x) {
return 2.0 / (Math.exp(x) + Math.exp(-x));
}
def code(x): return 2.0 / (math.exp(x) + math.exp(-x))
function code(x) return Float64(2.0 / Float64(exp(x) + exp(Float64(-x)))) end
function tmp = code(x) tmp = 2.0 / (exp(x) + exp(-x)); end
code[x_] := N[(2.0 / N[(N[Exp[x], $MachinePrecision] + N[Exp[(-x)], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\frac{2}{e^{x} + e^{-x}}
\end{array}
Sampling outcomes in binary64 precision:
Herbie found 7 alternatives:
| Alternative | Accuracy | Speedup |
|---|
(FPCore (x) :precision binary64 (/ 2.0 (+ (exp x) (exp (- x)))))
double code(double x) {
return 2.0 / (exp(x) + exp(-x));
}
real(8) function code(x)
real(8), intent (in) :: x
code = 2.0d0 / (exp(x) + exp(-x))
end function
public static double code(double x) {
return 2.0 / (Math.exp(x) + Math.exp(-x));
}
def code(x): return 2.0 / (math.exp(x) + math.exp(-x))
function code(x) return Float64(2.0 / Float64(exp(x) + exp(Float64(-x)))) end
function tmp = code(x) tmp = 2.0 / (exp(x) + exp(-x)); end
code[x_] := N[(2.0 / N[(N[Exp[x], $MachinePrecision] + N[Exp[(-x)], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\frac{2}{e^{x} + e^{-x}}
\end{array}
(FPCore (x) :precision binary64 (/ 2.0 (+ (exp x) (exp (- x)))))
double code(double x) {
return 2.0 / (exp(x) + exp(-x));
}
real(8) function code(x)
real(8), intent (in) :: x
code = 2.0d0 / (exp(x) + exp(-x))
end function
public static double code(double x) {
return 2.0 / (Math.exp(x) + Math.exp(-x));
}
def code(x): return 2.0 / (math.exp(x) + math.exp(-x))
function code(x) return Float64(2.0 / Float64(exp(x) + exp(Float64(-x)))) end
function tmp = code(x) tmp = 2.0 / (exp(x) + exp(-x)); end
code[x_] := N[(2.0 / N[(N[Exp[x], $MachinePrecision] + N[Exp[(-x)], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\frac{2}{e^{x} + e^{-x}}
\end{array}
Initial program 100.0%
(FPCore (x) :precision binary64 (if (<= x 360.0) (/ 2.0 (fma x x 2.0)) 0.0))
double code(double x) {
double tmp;
if (x <= 360.0) {
tmp = 2.0 / fma(x, x, 2.0);
} else {
tmp = 0.0;
}
return tmp;
}
function code(x) tmp = 0.0 if (x <= 360.0) tmp = Float64(2.0 / fma(x, x, 2.0)); else tmp = 0.0; end return tmp end
code[x_] := If[LessEqual[x, 360.0], N[(2.0 / N[(x * x + 2.0), $MachinePrecision]), $MachinePrecision], 0.0]
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;x \leq 360:\\
\;\;\;\;\frac{2}{\mathsf{fma}\left(x, x, 2\right)}\\
\mathbf{else}:\\
\;\;\;\;0\\
\end{array}
\end{array}
if x < 360Initial program 100.0%
Taylor expanded in x around 0 83.0%
+-commutative83.0%
unpow283.0%
fma-define83.0%
Simplified83.0%
if 360 < x Initial program 100.0%
Applied egg-rr100.0%
(FPCore (x) :precision binary64 (+ (+ 1.0 (/ 2.0 (fma x x 2.0))) -1.0))
double code(double x) {
return (1.0 + (2.0 / fma(x, x, 2.0))) + -1.0;
}
function code(x) return Float64(Float64(1.0 + Float64(2.0 / fma(x, x, 2.0))) + -1.0) end
code[x_] := N[(N[(1.0 + N[(2.0 / N[(x * x + 2.0), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] + -1.0), $MachinePrecision]
\begin{array}{l}
\\
\left(1 + \frac{2}{\mathsf{fma}\left(x, x, 2\right)}\right) + -1
\end{array}
Initial program 100.0%
Taylor expanded in x around 0 75.9%
+-commutative75.9%
unpow275.9%
fma-define75.9%
Simplified75.9%
expm1-log1p-u75.9%
expm1-undefine97.4%
log1p-undefine97.4%
rem-exp-log97.4%
Applied egg-rr97.4%
Final simplification97.4%
(FPCore (x) :precision binary64 (+ (+ 2.0 (/ 2.0 (fma x x 2.0))) -2.0))
double code(double x) {
return (2.0 + (2.0 / fma(x, x, 2.0))) + -2.0;
}
function code(x) return Float64(Float64(2.0 + Float64(2.0 / fma(x, x, 2.0))) + -2.0) end
code[x_] := N[(N[(2.0 + N[(2.0 / N[(x * x + 2.0), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] + -2.0), $MachinePrecision]
\begin{array}{l}
\\
\left(2 + \frac{2}{\mathsf{fma}\left(x, x, 2\right)}\right) + -2
\end{array}
Initial program 100.0%
Taylor expanded in x around 0 75.9%
+-commutative75.9%
unpow275.9%
fma-define75.9%
Simplified75.9%
expm1-log1p-u75.9%
expm1-undefine97.4%
log1p-undefine97.4%
rem-exp-log97.4%
Applied egg-rr97.4%
expm1-log1p-u95.8%
expm1-undefine95.8%
log1p-undefine96.3%
+-commutative96.3%
add-exp-log97.4%
+-commutative97.4%
associate-+l+97.4%
metadata-eval97.4%
Applied egg-rr97.4%
associate--l-97.4%
metadata-eval97.4%
sub-neg97.4%
+-commutative97.4%
metadata-eval97.4%
Applied egg-rr97.4%
(FPCore (x) :precision binary64 (if (<= x 360.0) 1.0 0.0))
double code(double x) {
double tmp;
if (x <= 360.0) {
tmp = 1.0;
} else {
tmp = 0.0;
}
return tmp;
}
real(8) function code(x)
real(8), intent (in) :: x
real(8) :: tmp
if (x <= 360.0d0) then
tmp = 1.0d0
else
tmp = 0.0d0
end if
code = tmp
end function
public static double code(double x) {
double tmp;
if (x <= 360.0) {
tmp = 1.0;
} else {
tmp = 0.0;
}
return tmp;
}
def code(x): tmp = 0 if x <= 360.0: tmp = 1.0 else: tmp = 0.0 return tmp
function code(x) tmp = 0.0 if (x <= 360.0) tmp = 1.0; else tmp = 0.0; end return tmp end
function tmp_2 = code(x) tmp = 0.0; if (x <= 360.0) tmp = 1.0; else tmp = 0.0; end tmp_2 = tmp; end
code[x_] := If[LessEqual[x, 360.0], 1.0, 0.0]
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;x \leq 360:\\
\;\;\;\;1\\
\mathbf{else}:\\
\;\;\;\;0\\
\end{array}
\end{array}
if x < 360Initial program 100.0%
Taylor expanded in x around 0 61.9%
if 360 < x Initial program 100.0%
Applied egg-rr100.0%
(FPCore (x) :precision binary64 (if (<= x 360.0) 0.5 0.0))
double code(double x) {
double tmp;
if (x <= 360.0) {
tmp = 0.5;
} else {
tmp = 0.0;
}
return tmp;
}
real(8) function code(x)
real(8), intent (in) :: x
real(8) :: tmp
if (x <= 360.0d0) then
tmp = 0.5d0
else
tmp = 0.0d0
end if
code = tmp
end function
public static double code(double x) {
double tmp;
if (x <= 360.0) {
tmp = 0.5;
} else {
tmp = 0.0;
}
return tmp;
}
def code(x): tmp = 0 if x <= 360.0: tmp = 0.5 else: tmp = 0.0 return tmp
function code(x) tmp = 0.0 if (x <= 360.0) tmp = 0.5; else tmp = 0.0; end return tmp end
function tmp_2 = code(x) tmp = 0.0; if (x <= 360.0) tmp = 0.5; else tmp = 0.0; end tmp_2 = tmp; end
code[x_] := If[LessEqual[x, 360.0], 0.5, 0.0]
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;x \leq 360:\\
\;\;\;\;0.5\\
\mathbf{else}:\\
\;\;\;\;0\\
\end{array}
\end{array}
if x < 360Initial program 100.0%
Applied egg-rr12.9%
if 360 < x Initial program 100.0%
Applied egg-rr100.0%
(FPCore (x) :precision binary64 0.0)
double code(double x) {
return 0.0;
}
real(8) function code(x)
real(8), intent (in) :: x
code = 0.0d0
end function
public static double code(double x) {
return 0.0;
}
def code(x): return 0.0
function code(x) return 0.0 end
function tmp = code(x) tmp = 0.0; end
code[x_] := 0.0
\begin{array}{l}
\\
0
\end{array}
Initial program 100.0%
Applied egg-rr53.8%
herbie shell --seed 2024086
(FPCore (x)
:name "Hyperbolic secant"
:precision binary64
(/ 2.0 (+ (exp x) (exp (- x)))))