
(FPCore (x) :precision binary64 (/ (exp x) (- (exp x) 1.0)))
double code(double x) {
return exp(x) / (exp(x) - 1.0);
}
real(8) function code(x)
real(8), intent (in) :: x
code = exp(x) / (exp(x) - 1.0d0)
end function
public static double code(double x) {
return Math.exp(x) / (Math.exp(x) - 1.0);
}
def code(x): return math.exp(x) / (math.exp(x) - 1.0)
function code(x) return Float64(exp(x) / Float64(exp(x) - 1.0)) end
function tmp = code(x) tmp = exp(x) / (exp(x) - 1.0); end
code[x_] := N[(N[Exp[x], $MachinePrecision] / N[(N[Exp[x], $MachinePrecision] - 1.0), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\frac{e^{x}}{e^{x} - 1}
\end{array}
Sampling outcomes in binary64 precision:
Herbie found 9 alternatives:
| Alternative | Accuracy | Speedup |
|---|
(FPCore (x) :precision binary64 (/ (exp x) (- (exp x) 1.0)))
double code(double x) {
return exp(x) / (exp(x) - 1.0);
}
real(8) function code(x)
real(8), intent (in) :: x
code = exp(x) / (exp(x) - 1.0d0)
end function
public static double code(double x) {
return Math.exp(x) / (Math.exp(x) - 1.0);
}
def code(x): return math.exp(x) / (math.exp(x) - 1.0)
function code(x) return Float64(exp(x) / Float64(exp(x) - 1.0)) end
function tmp = code(x) tmp = exp(x) / (exp(x) - 1.0); end
code[x_] := N[(N[Exp[x], $MachinePrecision] / N[(N[Exp[x], $MachinePrecision] - 1.0), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\frac{e^{x}}{e^{x} - 1}
\end{array}
(FPCore (x) :precision binary64 (/ -1.0 (expm1 (- x))))
double code(double x) {
return -1.0 / expm1(-x);
}
public static double code(double x) {
return -1.0 / Math.expm1(-x);
}
def code(x): return -1.0 / math.expm1(-x)
function code(x) return Float64(-1.0 / expm1(Float64(-x))) end
code[x_] := N[(-1.0 / N[(Exp[(-x)] - 1), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\frac{-1}{\mathsf{expm1}\left(-x\right)}
\end{array}
Initial program 33.9%
sub-neg33.9%
+-commutative33.9%
rgt-mult-inverse4.6%
exp-neg4.6%
distribute-rgt-neg-out4.6%
*-rgt-identity4.6%
distribute-lft-in4.6%
neg-sub04.6%
associate-+l-4.6%
neg-sub04.9%
associate-/r*4.9%
*-rgt-identity4.9%
associate-*r/4.9%
rgt-mult-inverse34.2%
distribute-frac-neg234.2%
distribute-neg-frac34.2%
metadata-eval34.2%
expm1-define100.0%
Simplified100.0%
(FPCore (x)
:precision binary64
(/
-1.0
(*
x
(+
-1.0
(* x (+ 0.5 (* x (- (* x 0.041666666666666664) 0.16666666666666666))))))))
double code(double x) {
return -1.0 / (x * (-1.0 + (x * (0.5 + (x * ((x * 0.041666666666666664) - 0.16666666666666666))))));
}
real(8) function code(x)
real(8), intent (in) :: x
code = (-1.0d0) / (x * ((-1.0d0) + (x * (0.5d0 + (x * ((x * 0.041666666666666664d0) - 0.16666666666666666d0))))))
end function
public static double code(double x) {
return -1.0 / (x * (-1.0 + (x * (0.5 + (x * ((x * 0.041666666666666664) - 0.16666666666666666))))));
}
def code(x): return -1.0 / (x * (-1.0 + (x * (0.5 + (x * ((x * 0.041666666666666664) - 0.16666666666666666))))))
function code(x) return Float64(-1.0 / Float64(x * Float64(-1.0 + Float64(x * Float64(0.5 + Float64(x * Float64(Float64(x * 0.041666666666666664) - 0.16666666666666666))))))) end
function tmp = code(x) tmp = -1.0 / (x * (-1.0 + (x * (0.5 + (x * ((x * 0.041666666666666664) - 0.16666666666666666)))))); end
code[x_] := N[(-1.0 / N[(x * N[(-1.0 + N[(x * N[(0.5 + N[(x * N[(N[(x * 0.041666666666666664), $MachinePrecision] - 0.16666666666666666), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\frac{-1}{x \cdot \left(-1 + x \cdot \left(0.5 + x \cdot \left(x \cdot 0.041666666666666664 - 0.16666666666666666\right)\right)\right)}
\end{array}
Initial program 33.9%
sub-neg33.9%
+-commutative33.9%
rgt-mult-inverse4.6%
exp-neg4.6%
distribute-rgt-neg-out4.6%
*-rgt-identity4.6%
distribute-lft-in4.6%
neg-sub04.6%
associate-+l-4.6%
neg-sub04.9%
associate-/r*4.9%
*-rgt-identity4.9%
associate-*r/4.9%
rgt-mult-inverse34.2%
distribute-frac-neg234.2%
distribute-neg-frac34.2%
metadata-eval34.2%
expm1-define100.0%
Simplified100.0%
Taylor expanded in x around 0 91.8%
Final simplification91.8%
(FPCore (x) :precision binary64 (/ -1.0 (* x (+ -1.0 (* x (+ 0.5 (* x (* x 0.041666666666666664))))))))
double code(double x) {
return -1.0 / (x * (-1.0 + (x * (0.5 + (x * (x * 0.041666666666666664))))));
}
real(8) function code(x)
real(8), intent (in) :: x
code = (-1.0d0) / (x * ((-1.0d0) + (x * (0.5d0 + (x * (x * 0.041666666666666664d0))))))
end function
public static double code(double x) {
return -1.0 / (x * (-1.0 + (x * (0.5 + (x * (x * 0.041666666666666664))))));
}
def code(x): return -1.0 / (x * (-1.0 + (x * (0.5 + (x * (x * 0.041666666666666664))))))
function code(x) return Float64(-1.0 / Float64(x * Float64(-1.0 + Float64(x * Float64(0.5 + Float64(x * Float64(x * 0.041666666666666664))))))) end
function tmp = code(x) tmp = -1.0 / (x * (-1.0 + (x * (0.5 + (x * (x * 0.041666666666666664)))))); end
code[x_] := N[(-1.0 / N[(x * N[(-1.0 + N[(x * N[(0.5 + N[(x * N[(x * 0.041666666666666664), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\frac{-1}{x \cdot \left(-1 + x \cdot \left(0.5 + x \cdot \left(x \cdot 0.041666666666666664\right)\right)\right)}
\end{array}
Initial program 33.9%
sub-neg33.9%
+-commutative33.9%
rgt-mult-inverse4.6%
exp-neg4.6%
distribute-rgt-neg-out4.6%
*-rgt-identity4.6%
distribute-lft-in4.6%
neg-sub04.6%
associate-+l-4.6%
neg-sub04.9%
associate-/r*4.9%
*-rgt-identity4.9%
associate-*r/4.9%
rgt-mult-inverse34.2%
distribute-frac-neg234.2%
distribute-neg-frac34.2%
metadata-eval34.2%
expm1-define100.0%
Simplified100.0%
Taylor expanded in x around 0 91.8%
Taylor expanded in x around inf 91.5%
*-commutative91.5%
Simplified91.5%
Final simplification91.5%
(FPCore (x) :precision binary64 (/ -1.0 (* x (+ -1.0 (* x (+ 0.5 (* x -0.16666666666666666)))))))
double code(double x) {
return -1.0 / (x * (-1.0 + (x * (0.5 + (x * -0.16666666666666666)))));
}
real(8) function code(x)
real(8), intent (in) :: x
code = (-1.0d0) / (x * ((-1.0d0) + (x * (0.5d0 + (x * (-0.16666666666666666d0))))))
end function
public static double code(double x) {
return -1.0 / (x * (-1.0 + (x * (0.5 + (x * -0.16666666666666666)))));
}
def code(x): return -1.0 / (x * (-1.0 + (x * (0.5 + (x * -0.16666666666666666)))))
function code(x) return Float64(-1.0 / Float64(x * Float64(-1.0 + Float64(x * Float64(0.5 + Float64(x * -0.16666666666666666)))))) end
function tmp = code(x) tmp = -1.0 / (x * (-1.0 + (x * (0.5 + (x * -0.16666666666666666))))); end
code[x_] := N[(-1.0 / N[(x * N[(-1.0 + N[(x * N[(0.5 + N[(x * -0.16666666666666666), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\frac{-1}{x \cdot \left(-1 + x \cdot \left(0.5 + x \cdot -0.16666666666666666\right)\right)}
\end{array}
Initial program 33.9%
sub-neg33.9%
+-commutative33.9%
rgt-mult-inverse4.6%
exp-neg4.6%
distribute-rgt-neg-out4.6%
*-rgt-identity4.6%
distribute-lft-in4.6%
neg-sub04.6%
associate-+l-4.6%
neg-sub04.9%
associate-/r*4.9%
*-rgt-identity4.9%
associate-*r/4.9%
rgt-mult-inverse34.2%
distribute-frac-neg234.2%
distribute-neg-frac34.2%
metadata-eval34.2%
expm1-define100.0%
Simplified100.0%
Taylor expanded in x around 0 89.6%
Final simplification89.6%
(FPCore (x) :precision binary64 (/ -1.0 (* x (+ -1.0 (* x (* x -0.16666666666666666))))))
double code(double x) {
return -1.0 / (x * (-1.0 + (x * (x * -0.16666666666666666))));
}
real(8) function code(x)
real(8), intent (in) :: x
code = (-1.0d0) / (x * ((-1.0d0) + (x * (x * (-0.16666666666666666d0)))))
end function
public static double code(double x) {
return -1.0 / (x * (-1.0 + (x * (x * -0.16666666666666666))));
}
def code(x): return -1.0 / (x * (-1.0 + (x * (x * -0.16666666666666666))))
function code(x) return Float64(-1.0 / Float64(x * Float64(-1.0 + Float64(x * Float64(x * -0.16666666666666666))))) end
function tmp = code(x) tmp = -1.0 / (x * (-1.0 + (x * (x * -0.16666666666666666)))); end
code[x_] := N[(-1.0 / N[(x * N[(-1.0 + N[(x * N[(x * -0.16666666666666666), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\frac{-1}{x \cdot \left(-1 + x \cdot \left(x \cdot -0.16666666666666666\right)\right)}
\end{array}
Initial program 33.9%
sub-neg33.9%
+-commutative33.9%
rgt-mult-inverse4.6%
exp-neg4.6%
distribute-rgt-neg-out4.6%
*-rgt-identity4.6%
distribute-lft-in4.6%
neg-sub04.6%
associate-+l-4.6%
neg-sub04.9%
associate-/r*4.9%
*-rgt-identity4.9%
associate-*r/4.9%
rgt-mult-inverse34.2%
distribute-frac-neg234.2%
distribute-neg-frac34.2%
metadata-eval34.2%
expm1-define100.0%
Simplified100.0%
Taylor expanded in x around 0 91.8%
Taylor expanded in x around 0 89.6%
+-commutative89.6%
Simplified89.6%
Taylor expanded in x around inf 88.8%
*-commutative88.8%
Simplified88.8%
Final simplification88.8%
(FPCore (x) :precision binary64 (/ -1.0 (* x (+ -1.0 (* x 0.5)))))
double code(double x) {
return -1.0 / (x * (-1.0 + (x * 0.5)));
}
real(8) function code(x)
real(8), intent (in) :: x
code = (-1.0d0) / (x * ((-1.0d0) + (x * 0.5d0)))
end function
public static double code(double x) {
return -1.0 / (x * (-1.0 + (x * 0.5)));
}
def code(x): return -1.0 / (x * (-1.0 + (x * 0.5)))
function code(x) return Float64(-1.0 / Float64(x * Float64(-1.0 + Float64(x * 0.5)))) end
function tmp = code(x) tmp = -1.0 / (x * (-1.0 + (x * 0.5))); end
code[x_] := N[(-1.0 / N[(x * N[(-1.0 + N[(x * 0.5), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\frac{-1}{x \cdot \left(-1 + x \cdot 0.5\right)}
\end{array}
Initial program 33.9%
sub-neg33.9%
+-commutative33.9%
rgt-mult-inverse4.6%
exp-neg4.6%
distribute-rgt-neg-out4.6%
*-rgt-identity4.6%
distribute-lft-in4.6%
neg-sub04.6%
associate-+l-4.6%
neg-sub04.9%
associate-/r*4.9%
*-rgt-identity4.9%
associate-*r/4.9%
rgt-mult-inverse34.2%
distribute-frac-neg234.2%
distribute-neg-frac34.2%
metadata-eval34.2%
expm1-define100.0%
Simplified100.0%
Taylor expanded in x around 0 85.5%
Final simplification85.5%
(FPCore (x) :precision binary64 (/ 1.0 x))
double code(double x) {
return 1.0 / x;
}
real(8) function code(x)
real(8), intent (in) :: x
code = 1.0d0 / x
end function
public static double code(double x) {
return 1.0 / x;
}
def code(x): return 1.0 / x
function code(x) return Float64(1.0 / x) end
function tmp = code(x) tmp = 1.0 / x; end
code[x_] := N[(1.0 / x), $MachinePrecision]
\begin{array}{l}
\\
\frac{1}{x}
\end{array}
Initial program 33.9%
sub-neg33.9%
+-commutative33.9%
rgt-mult-inverse4.6%
exp-neg4.6%
distribute-rgt-neg-out4.6%
*-rgt-identity4.6%
distribute-lft-in4.6%
neg-sub04.6%
associate-+l-4.6%
neg-sub04.9%
associate-/r*4.9%
*-rgt-identity4.9%
associate-*r/4.9%
rgt-mult-inverse34.2%
distribute-frac-neg234.2%
distribute-neg-frac34.2%
metadata-eval34.2%
expm1-define100.0%
Simplified100.0%
Taylor expanded in x around 0 70.2%
(FPCore (x) :precision binary64 1.0)
double code(double x) {
return 1.0;
}
real(8) function code(x)
real(8), intent (in) :: x
code = 1.0d0
end function
public static double code(double x) {
return 1.0;
}
def code(x): return 1.0
function code(x) return 1.0 end
function tmp = code(x) tmp = 1.0; end
code[x_] := 1.0
\begin{array}{l}
\\
1
\end{array}
Initial program 33.9%
sub-neg33.9%
+-commutative33.9%
rgt-mult-inverse4.6%
exp-neg4.6%
distribute-rgt-neg-out4.6%
*-rgt-identity4.6%
distribute-lft-in4.6%
neg-sub04.6%
associate-+l-4.6%
neg-sub04.9%
associate-/r*4.9%
*-rgt-identity4.9%
associate-*r/4.9%
rgt-mult-inverse34.2%
distribute-frac-neg234.2%
distribute-neg-frac34.2%
metadata-eval34.2%
expm1-define100.0%
Simplified100.0%
Applied egg-rr2.5%
unpow-12.5%
associate-*r/2.5%
*-rgt-identity2.5%
distribute-frac-neg22.5%
*-inverses3.8%
metadata-eval3.8%
Simplified3.8%
Final simplification3.8%
(FPCore (x) :precision binary64 0.5)
double code(double x) {
return 0.5;
}
real(8) function code(x)
real(8), intent (in) :: x
code = 0.5d0
end function
public static double code(double x) {
return 0.5;
}
def code(x): return 0.5
function code(x) return 0.5 end
function tmp = code(x) tmp = 0.5; end
code[x_] := 0.5
\begin{array}{l}
\\
0.5
\end{array}
Initial program 33.9%
sub-neg33.9%
+-commutative33.9%
rgt-mult-inverse4.6%
exp-neg4.6%
distribute-rgt-neg-out4.6%
*-rgt-identity4.6%
distribute-lft-in4.6%
neg-sub04.6%
associate-+l-4.6%
neg-sub04.9%
associate-/r*4.9%
*-rgt-identity4.9%
associate-*r/4.9%
rgt-mult-inverse34.2%
distribute-frac-neg234.2%
distribute-neg-frac34.2%
metadata-eval34.2%
expm1-define100.0%
Simplified100.0%
Taylor expanded in x around 0 70.2%
+-commutative70.2%
*-commutative70.2%
Simplified70.2%
Taylor expanded in x around inf 3.3%
(FPCore (x) :precision binary64 (/ (- 1.0) (expm1 (- x))))
double code(double x) {
return -1.0 / expm1(-x);
}
public static double code(double x) {
return -1.0 / Math.expm1(-x);
}
def code(x): return -1.0 / math.expm1(-x)
function code(x) return Float64(Float64(-1.0) / expm1(Float64(-x))) end
code[x_] := N[((-1.0) / N[(Exp[(-x)] - 1), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\frac{-1}{\mathsf{expm1}\left(-x\right)}
\end{array}
herbie shell --seed 2024110
(FPCore (x)
:name "expq2 (section 3.11)"
:precision binary64
:pre (> 710.0 x)
:alt
(/ (- 1.0) (expm1 (- x)))
(/ (exp x) (- (exp x) 1.0)))