
(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 12 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 37.2%
sub-neg37.2%
+-commutative37.2%
rgt-mult-inverse7.1%
exp-neg7.1%
distribute-rgt-neg-out7.1%
*-rgt-identity7.1%
distribute-lft-in7.0%
neg-sub07.0%
associate-+l-7.0%
neg-sub06.9%
associate-/r*6.9%
*-rgt-identity6.9%
associate-*r/6.9%
rgt-mult-inverse36.9%
distribute-frac-neg236.9%
distribute-neg-frac36.9%
metadata-eval36.9%
expm1-define100.0%
Simplified100.0%
(FPCore (x) :precision binary64 (/ (exp x) x))
double code(double x) {
return exp(x) / x;
}
real(8) function code(x)
real(8), intent (in) :: x
code = exp(x) / x
end function
public static double code(double x) {
return Math.exp(x) / x;
}
def code(x): return math.exp(x) / x
function code(x) return Float64(exp(x) / x) end
function tmp = code(x) tmp = exp(x) / x; end
code[x_] := N[(N[Exp[x], $MachinePrecision] / x), $MachinePrecision]
\begin{array}{l}
\\
\frac{e^{x}}{x}
\end{array}
Initial program 37.2%
expm1-define100.0%
Simplified100.0%
Taylor expanded in x around 0 96.3%
(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 37.2%
sub-neg37.2%
+-commutative37.2%
rgt-mult-inverse7.1%
exp-neg7.1%
distribute-rgt-neg-out7.1%
*-rgt-identity7.1%
distribute-lft-in7.0%
neg-sub07.0%
associate-+l-7.0%
neg-sub06.9%
associate-/r*6.9%
*-rgt-identity6.9%
associate-*r/6.9%
rgt-mult-inverse36.9%
distribute-frac-neg236.9%
distribute-neg-frac36.9%
metadata-eval36.9%
expm1-define100.0%
Simplified100.0%
Taylor expanded in x around 0 89.0%
Final simplification89.0%
(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 37.2%
sub-neg37.2%
+-commutative37.2%
rgt-mult-inverse7.1%
exp-neg7.1%
distribute-rgt-neg-out7.1%
*-rgt-identity7.1%
distribute-lft-in7.0%
neg-sub07.0%
associate-+l-7.0%
neg-sub06.9%
associate-/r*6.9%
*-rgt-identity6.9%
associate-*r/6.9%
rgt-mult-inverse36.9%
distribute-frac-neg236.9%
distribute-neg-frac36.9%
metadata-eval36.9%
expm1-define100.0%
Simplified100.0%
Taylor expanded in x around 0 89.0%
Taylor expanded in x around inf 88.5%
*-commutative88.5%
Simplified88.5%
Final simplification88.5%
(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 37.2%
sub-neg37.2%
+-commutative37.2%
rgt-mult-inverse7.1%
exp-neg7.1%
distribute-rgt-neg-out7.1%
*-rgt-identity7.1%
distribute-lft-in7.0%
neg-sub07.0%
associate-+l-7.0%
neg-sub06.9%
associate-/r*6.9%
*-rgt-identity6.9%
associate-*r/6.9%
rgt-mult-inverse36.9%
distribute-frac-neg236.9%
distribute-neg-frac36.9%
metadata-eval36.9%
expm1-define100.0%
Simplified100.0%
Taylor expanded in x around 0 87.8%
Final simplification87.8%
(FPCore (x) :precision binary64 (if (<= x -1.75) (/ -1.0 (* x (* x 0.5))) (+ 0.5 (/ 1.0 x))))
double code(double x) {
double tmp;
if (x <= -1.75) {
tmp = -1.0 / (x * (x * 0.5));
} else {
tmp = 0.5 + (1.0 / x);
}
return tmp;
}
real(8) function code(x)
real(8), intent (in) :: x
real(8) :: tmp
if (x <= (-1.75d0)) then
tmp = (-1.0d0) / (x * (x * 0.5d0))
else
tmp = 0.5d0 + (1.0d0 / x)
end if
code = tmp
end function
public static double code(double x) {
double tmp;
if (x <= -1.75) {
tmp = -1.0 / (x * (x * 0.5));
} else {
tmp = 0.5 + (1.0 / x);
}
return tmp;
}
def code(x): tmp = 0 if x <= -1.75: tmp = -1.0 / (x * (x * 0.5)) else: tmp = 0.5 + (1.0 / x) return tmp
function code(x) tmp = 0.0 if (x <= -1.75) tmp = Float64(-1.0 / Float64(x * Float64(x * 0.5))); else tmp = Float64(0.5 + Float64(1.0 / x)); end return tmp end
function tmp_2 = code(x) tmp = 0.0; if (x <= -1.75) tmp = -1.0 / (x * (x * 0.5)); else tmp = 0.5 + (1.0 / x); end tmp_2 = tmp; end
code[x_] := If[LessEqual[x, -1.75], N[(-1.0 / N[(x * N[(x * 0.5), $MachinePrecision]), $MachinePrecision]), $MachinePrecision], N[(0.5 + N[(1.0 / x), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;x \leq -1.75:\\
\;\;\;\;\frac{-1}{x \cdot \left(x \cdot 0.5\right)}\\
\mathbf{else}:\\
\;\;\;\;0.5 + \frac{1}{x}\\
\end{array}
\end{array}
if x < -1.75Initial program 100.0%
sub-neg100.0%
+-commutative100.0%
rgt-mult-inverse3.8%
exp-neg3.8%
distribute-rgt-neg-out3.8%
*-rgt-identity3.8%
distribute-lft-in3.7%
neg-sub03.7%
associate-+l-3.7%
neg-sub03.7%
associate-/r*3.8%
*-rgt-identity3.8%
associate-*r/3.8%
rgt-mult-inverse100.0%
distribute-frac-neg2100.0%
distribute-neg-frac100.0%
metadata-eval100.0%
expm1-define100.0%
Simplified100.0%
Taylor expanded in x around 0 53.9%
Taylor expanded in x around inf 53.9%
Taylor expanded in x around inf 53.9%
if -1.75 < x Initial program 8.6%
sub-neg8.6%
+-commutative8.6%
rgt-mult-inverse8.6%
exp-neg8.6%
distribute-rgt-neg-out8.6%
*-rgt-identity8.6%
distribute-lft-in8.5%
neg-sub08.5%
associate-+l-8.5%
neg-sub08.3%
associate-/r*8.3%
*-rgt-identity8.3%
associate-*r/8.3%
rgt-mult-inverse8.3%
distribute-frac-neg28.3%
distribute-neg-frac8.3%
metadata-eval8.3%
expm1-define100.0%
Simplified100.0%
Taylor expanded in x around 0 97.4%
*-commutative97.4%
Simplified97.4%
Taylor expanded in x around 0 97.4%
+-commutative97.4%
*-commutative97.4%
fma-undefine97.4%
*-lft-identity97.4%
associate-*l/97.4%
fma-undefine97.4%
distribute-rgt-in97.4%
associate-*r*97.4%
*-commutative97.4%
associate-*r*97.4%
rgt-mult-inverse97.4%
metadata-eval97.4%
*-lft-identity97.4%
+-commutative97.4%
Simplified97.4%
Final simplification83.8%
(FPCore (x) :precision binary64 (/ -1.0 (- (* x (* x 0.5)) x)))
double code(double x) {
return -1.0 / ((x * (x * 0.5)) - x);
}
real(8) function code(x)
real(8), intent (in) :: x
code = (-1.0d0) / ((x * (x * 0.5d0)) - x)
end function
public static double code(double x) {
return -1.0 / ((x * (x * 0.5)) - x);
}
def code(x): return -1.0 / ((x * (x * 0.5)) - x)
function code(x) return Float64(-1.0 / Float64(Float64(x * Float64(x * 0.5)) - x)) end
function tmp = code(x) tmp = -1.0 / ((x * (x * 0.5)) - x); end
code[x_] := N[(-1.0 / N[(N[(x * N[(x * 0.5), $MachinePrecision]), $MachinePrecision] - x), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\frac{-1}{x \cdot \left(x \cdot 0.5\right) - x}
\end{array}
Initial program 37.2%
sub-neg37.2%
+-commutative37.2%
rgt-mult-inverse7.1%
exp-neg7.1%
distribute-rgt-neg-out7.1%
*-rgt-identity7.1%
distribute-lft-in7.0%
neg-sub07.0%
associate-+l-7.0%
neg-sub06.9%
associate-/r*6.9%
*-rgt-identity6.9%
associate-*r/6.9%
rgt-mult-inverse36.9%
distribute-frac-neg236.9%
distribute-neg-frac36.9%
metadata-eval36.9%
expm1-define100.0%
Simplified100.0%
Taylor expanded in x around 0 83.7%
sub-neg83.7%
metadata-eval83.7%
distribute-rgt-in83.7%
*-commutative83.7%
neg-mul-183.7%
Applied egg-rr83.7%
Final simplification83.7%
(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 37.2%
sub-neg37.2%
+-commutative37.2%
rgt-mult-inverse7.1%
exp-neg7.1%
distribute-rgt-neg-out7.1%
*-rgt-identity7.1%
distribute-lft-in7.0%
neg-sub07.0%
associate-+l-7.0%
neg-sub06.9%
associate-/r*6.9%
*-rgt-identity6.9%
associate-*r/6.9%
rgt-mult-inverse36.9%
distribute-frac-neg236.9%
distribute-neg-frac36.9%
metadata-eval36.9%
expm1-define100.0%
Simplified100.0%
Taylor expanded in x around 0 83.7%
Final simplification83.7%
(FPCore (x) :precision binary64 (+ 0.5 (/ 1.0 x)))
double code(double x) {
return 0.5 + (1.0 / x);
}
real(8) function code(x)
real(8), intent (in) :: x
code = 0.5d0 + (1.0d0 / x)
end function
public static double code(double x) {
return 0.5 + (1.0 / x);
}
def code(x): return 0.5 + (1.0 / x)
function code(x) return Float64(0.5 + Float64(1.0 / x)) end
function tmp = code(x) tmp = 0.5 + (1.0 / x); end
code[x_] := N[(0.5 + N[(1.0 / x), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
0.5 + \frac{1}{x}
\end{array}
Initial program 37.2%
sub-neg37.2%
+-commutative37.2%
rgt-mult-inverse7.1%
exp-neg7.1%
distribute-rgt-neg-out7.1%
*-rgt-identity7.1%
distribute-lft-in7.0%
neg-sub07.0%
associate-+l-7.0%
neg-sub06.9%
associate-/r*6.9%
*-rgt-identity6.9%
associate-*r/6.9%
rgt-mult-inverse36.9%
distribute-frac-neg236.9%
distribute-neg-frac36.9%
metadata-eval36.9%
expm1-define100.0%
Simplified100.0%
Taylor expanded in x around 0 67.9%
*-commutative67.9%
Simplified67.9%
Taylor expanded in x around 0 67.9%
+-commutative67.9%
*-commutative67.9%
fma-undefine67.9%
*-lft-identity67.9%
associate-*l/68.0%
fma-undefine68.0%
distribute-rgt-in68.0%
associate-*r*68.0%
*-commutative68.0%
associate-*r*68.0%
rgt-mult-inverse68.0%
metadata-eval68.0%
*-lft-identity68.0%
+-commutative68.0%
Simplified68.0%
Final simplification68.0%
(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 37.2%
sub-neg37.2%
+-commutative37.2%
rgt-mult-inverse7.1%
exp-neg7.1%
distribute-rgt-neg-out7.1%
*-rgt-identity7.1%
distribute-lft-in7.0%
neg-sub07.0%
associate-+l-7.0%
neg-sub06.9%
associate-/r*6.9%
*-rgt-identity6.9%
associate-*r/6.9%
rgt-mult-inverse36.9%
distribute-frac-neg236.9%
distribute-neg-frac36.9%
metadata-eval36.9%
expm1-define100.0%
Simplified100.0%
Taylor expanded in x around 0 67.7%
(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 37.2%
expm1-define100.0%
Simplified100.0%
Taylor expanded in x around 0 96.3%
Taylor expanded in x around 0 67.1%
Taylor expanded in x around inf 3.7%
(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 37.2%
sub-neg37.2%
+-commutative37.2%
rgt-mult-inverse7.1%
exp-neg7.1%
distribute-rgt-neg-out7.1%
*-rgt-identity7.1%
distribute-lft-in7.0%
neg-sub07.0%
associate-+l-7.0%
neg-sub06.9%
associate-/r*6.9%
*-rgt-identity6.9%
associate-*r/6.9%
rgt-mult-inverse36.9%
distribute-frac-neg236.9%
distribute-neg-frac36.9%
metadata-eval36.9%
expm1-define100.0%
Simplified100.0%
Taylor expanded in x around 0 67.9%
*-commutative67.9%
Simplified67.9%
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 2024161
(FPCore (x)
:name "expq2 (section 3.11)"
:precision binary64
:pre (> 710.0 x)
:alt
(! :herbie-platform default (/ (- 1) (expm1 (- x))))
(/ (exp x) (- (exp x) 1.0)))