
(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 10 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 35.7%
sub-neg35.7%
+-commutative35.7%
rgt-mult-inverse4.5%
exp-neg4.5%
distribute-rgt-neg-out4.5%
*-rgt-identity4.5%
distribute-lft-in4.5%
neg-sub04.5%
associate-+l-4.5%
neg-sub04.1%
associate-/r*4.1%
*-rgt-identity4.1%
associate-*r/4.1%
rgt-mult-inverse35.3%
distribute-frac-neg235.3%
distribute-neg-frac35.3%
metadata-eval35.3%
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 35.7%
expm1-define100.0%
Simplified100.0%
Taylor expanded in x around 0 98.3%
(FPCore (x)
:precision binary64
(/
-1.0
(*
x
(+
(* x (+ 0.5 (* x (- (* x 0.041666666666666664) 0.16666666666666666))))
-1.0))))
double code(double x) {
return -1.0 / (x * ((x * (0.5 + (x * ((x * 0.041666666666666664) - 0.16666666666666666)))) + -1.0));
}
real(8) function code(x)
real(8), intent (in) :: x
code = (-1.0d0) / (x * ((x * (0.5d0 + (x * ((x * 0.041666666666666664d0) - 0.16666666666666666d0)))) + (-1.0d0)))
end function
public static double code(double x) {
return -1.0 / (x * ((x * (0.5 + (x * ((x * 0.041666666666666664) - 0.16666666666666666)))) + -1.0));
}
def code(x): return -1.0 / (x * ((x * (0.5 + (x * ((x * 0.041666666666666664) - 0.16666666666666666)))) + -1.0))
function code(x) return Float64(-1.0 / Float64(x * Float64(Float64(x * Float64(0.5 + Float64(x * Float64(Float64(x * 0.041666666666666664) - 0.16666666666666666)))) + -1.0))) end
function tmp = code(x) tmp = -1.0 / (x * ((x * (0.5 + (x * ((x * 0.041666666666666664) - 0.16666666666666666)))) + -1.0)); end
code[x_] := N[(-1.0 / N[(x * N[(N[(x * N[(0.5 + N[(x * N[(N[(x * 0.041666666666666664), $MachinePrecision] - 0.16666666666666666), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] + -1.0), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\frac{-1}{x \cdot \left(x \cdot \left(0.5 + x \cdot \left(x \cdot 0.041666666666666664 - 0.16666666666666666\right)\right) + -1\right)}
\end{array}
Initial program 35.7%
sub-neg35.7%
+-commutative35.7%
rgt-mult-inverse4.5%
exp-neg4.5%
distribute-rgt-neg-out4.5%
*-rgt-identity4.5%
distribute-lft-in4.5%
neg-sub04.5%
associate-+l-4.5%
neg-sub04.1%
associate-/r*4.1%
*-rgt-identity4.1%
associate-*r/4.1%
rgt-mult-inverse35.3%
distribute-frac-neg235.3%
distribute-neg-frac35.3%
metadata-eval35.3%
expm1-define100.0%
Simplified100.0%
Taylor expanded in x around 0 90.6%
Final simplification90.6%
(FPCore (x) :precision binary64 (/ -1.0 (* x (+ (* x (+ 0.5 (* x (* x 0.041666666666666664)))) -1.0))))
double code(double x) {
return -1.0 / (x * ((x * (0.5 + (x * (x * 0.041666666666666664)))) + -1.0));
}
real(8) function code(x)
real(8), intent (in) :: x
code = (-1.0d0) / (x * ((x * (0.5d0 + (x * (x * 0.041666666666666664d0)))) + (-1.0d0)))
end function
public static double code(double x) {
return -1.0 / (x * ((x * (0.5 + (x * (x * 0.041666666666666664)))) + -1.0));
}
def code(x): return -1.0 / (x * ((x * (0.5 + (x * (x * 0.041666666666666664)))) + -1.0))
function code(x) return Float64(-1.0 / Float64(x * Float64(Float64(x * Float64(0.5 + Float64(x * Float64(x * 0.041666666666666664)))) + -1.0))) end
function tmp = code(x) tmp = -1.0 / (x * ((x * (0.5 + (x * (x * 0.041666666666666664)))) + -1.0)); end
code[x_] := N[(-1.0 / N[(x * N[(N[(x * N[(0.5 + N[(x * N[(x * 0.041666666666666664), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] + -1.0), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\frac{-1}{x \cdot \left(x \cdot \left(0.5 + x \cdot \left(x \cdot 0.041666666666666664\right)\right) + -1\right)}
\end{array}
Initial program 35.7%
sub-neg35.7%
+-commutative35.7%
rgt-mult-inverse4.5%
exp-neg4.5%
distribute-rgt-neg-out4.5%
*-rgt-identity4.5%
distribute-lft-in4.5%
neg-sub04.5%
associate-+l-4.5%
neg-sub04.1%
associate-/r*4.1%
*-rgt-identity4.1%
associate-*r/4.1%
rgt-mult-inverse35.3%
distribute-frac-neg235.3%
distribute-neg-frac35.3%
metadata-eval35.3%
expm1-define100.0%
Simplified100.0%
Taylor expanded in x around 0 90.6%
Taylor expanded in x around inf 90.4%
*-commutative90.4%
Simplified90.4%
Final simplification90.4%
(FPCore (x) :precision binary64 (/ -1.0 (* x (+ (* x (+ 0.5 (* x -0.16666666666666666))) -1.0))))
double code(double x) {
return -1.0 / (x * ((x * (0.5 + (x * -0.16666666666666666))) + -1.0));
}
real(8) function code(x)
real(8), intent (in) :: x
code = (-1.0d0) / (x * ((x * (0.5d0 + (x * (-0.16666666666666666d0)))) + (-1.0d0)))
end function
public static double code(double x) {
return -1.0 / (x * ((x * (0.5 + (x * -0.16666666666666666))) + -1.0));
}
def code(x): return -1.0 / (x * ((x * (0.5 + (x * -0.16666666666666666))) + -1.0))
function code(x) return Float64(-1.0 / Float64(x * Float64(Float64(x * Float64(0.5 + Float64(x * -0.16666666666666666))) + -1.0))) end
function tmp = code(x) tmp = -1.0 / (x * ((x * (0.5 + (x * -0.16666666666666666))) + -1.0)); end
code[x_] := N[(-1.0 / N[(x * N[(N[(x * N[(0.5 + N[(x * -0.16666666666666666), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] + -1.0), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\frac{-1}{x \cdot \left(x \cdot \left(0.5 + x \cdot -0.16666666666666666\right) + -1\right)}
\end{array}
Initial program 35.7%
sub-neg35.7%
+-commutative35.7%
rgt-mult-inverse4.5%
exp-neg4.5%
distribute-rgt-neg-out4.5%
*-rgt-identity4.5%
distribute-lft-in4.5%
neg-sub04.5%
associate-+l-4.5%
neg-sub04.1%
associate-/r*4.1%
*-rgt-identity4.1%
associate-*r/4.1%
rgt-mult-inverse35.3%
distribute-frac-neg235.3%
distribute-neg-frac35.3%
metadata-eval35.3%
expm1-define100.0%
Simplified100.0%
Taylor expanded in x around 0 88.3%
Final simplification88.3%
(FPCore (x) :precision binary64 (/ -1.0 (* x (+ (* x 0.5) -1.0))))
double code(double x) {
return -1.0 / (x * ((x * 0.5) + -1.0));
}
real(8) function code(x)
real(8), intent (in) :: x
code = (-1.0d0) / (x * ((x * 0.5d0) + (-1.0d0)))
end function
public static double code(double x) {
return -1.0 / (x * ((x * 0.5) + -1.0));
}
def code(x): return -1.0 / (x * ((x * 0.5) + -1.0))
function code(x) return Float64(-1.0 / Float64(x * Float64(Float64(x * 0.5) + -1.0))) end
function tmp = code(x) tmp = -1.0 / (x * ((x * 0.5) + -1.0)); end
code[x_] := N[(-1.0 / N[(x * N[(N[(x * 0.5), $MachinePrecision] + -1.0), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\frac{-1}{x \cdot \left(x \cdot 0.5 + -1\right)}
\end{array}
Initial program 35.7%
sub-neg35.7%
+-commutative35.7%
rgt-mult-inverse4.5%
exp-neg4.5%
distribute-rgt-neg-out4.5%
*-rgt-identity4.5%
distribute-lft-in4.5%
neg-sub04.5%
associate-+l-4.5%
neg-sub04.1%
associate-/r*4.1%
*-rgt-identity4.1%
associate-*r/4.1%
rgt-mult-inverse35.3%
distribute-frac-neg235.3%
distribute-neg-frac35.3%
metadata-eval35.3%
expm1-define100.0%
Simplified100.0%
Taylor expanded in x around 0 82.2%
Final simplification82.2%
(FPCore (x) :precision binary64 (+ (* x 0.08333333333333333) (+ 0.5 (/ 1.0 x))))
double code(double x) {
return (x * 0.08333333333333333) + (0.5 + (1.0 / x));
}
real(8) function code(x)
real(8), intent (in) :: x
code = (x * 0.08333333333333333d0) + (0.5d0 + (1.0d0 / x))
end function
public static double code(double x) {
return (x * 0.08333333333333333) + (0.5 + (1.0 / x));
}
def code(x): return (x * 0.08333333333333333) + (0.5 + (1.0 / x))
function code(x) return Float64(Float64(x * 0.08333333333333333) + Float64(0.5 + Float64(1.0 / x))) end
function tmp = code(x) tmp = (x * 0.08333333333333333) + (0.5 + (1.0 / x)); end
code[x_] := N[(N[(x * 0.08333333333333333), $MachinePrecision] + N[(0.5 + N[(1.0 / x), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
x \cdot 0.08333333333333333 + \left(0.5 + \frac{1}{x}\right)
\end{array}
Initial program 35.7%
sub-neg35.7%
+-commutative35.7%
rgt-mult-inverse4.5%
exp-neg4.5%
distribute-rgt-neg-out4.5%
*-rgt-identity4.5%
distribute-lft-in4.5%
neg-sub04.5%
associate-+l-4.5%
neg-sub04.1%
associate-/r*4.1%
*-rgt-identity4.1%
associate-*r/4.1%
rgt-mult-inverse35.3%
distribute-frac-neg235.3%
distribute-neg-frac35.3%
metadata-eval35.3%
expm1-define100.0%
Simplified100.0%
Taylor expanded in x around 0 68.6%
*-commutative68.6%
Simplified68.6%
Taylor expanded in x around -inf 37.2%
mul-1-neg37.2%
distribute-rgt-neg-in37.2%
sub-neg37.2%
associate-*r/37.2%
distribute-lft-in37.2%
metadata-eval37.2%
associate-*r/37.2%
metadata-eval37.2%
metadata-eval37.2%
Simplified37.2%
distribute-neg-in37.2%
div-inv37.1%
distribute-rgt-neg-in37.1%
mul-1-neg37.1%
div-inv37.1%
add-sqr-sqrt16.5%
sqrt-unprod16.8%
frac-times16.7%
metadata-eval16.7%
metadata-eval16.7%
frac-times16.8%
sqrt-unprod0.2%
add-sqr-sqrt1.2%
div-inv1.2%
sub-neg1.2%
Applied egg-rr37.2%
pow137.2%
sub-neg37.2%
metadata-eval37.2%
Applied egg-rr37.2%
unpow137.2%
+-commutative37.2%
distribute-lft-in37.2%
*-lft-identity37.2%
associate-*l/37.1%
associate-*r*68.4%
rgt-mult-inverse68.6%
*-lft-identity68.6%
Simplified68.6%
(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 35.7%
sub-neg35.7%
+-commutative35.7%
rgt-mult-inverse4.5%
exp-neg4.5%
distribute-rgt-neg-out4.5%
*-rgt-identity4.5%
distribute-lft-in4.5%
neg-sub04.5%
associate-+l-4.5%
neg-sub04.1%
associate-/r*4.1%
*-rgt-identity4.1%
associate-*r/4.1%
rgt-mult-inverse35.3%
distribute-frac-neg235.3%
distribute-neg-frac35.3%
metadata-eval35.3%
expm1-define100.0%
Simplified100.0%
Taylor expanded in x around 0 68.6%
*-commutative68.6%
Simplified68.6%
Taylor expanded in x around 0 68.6%
+-commutative68.6%
*-commutative68.6%
fma-undefine68.6%
*-lft-identity68.6%
associate-*l/68.6%
fma-undefine68.6%
distribute-rgt-in68.6%
associate-*r*68.6%
*-commutative68.6%
associate-*r*68.6%
rgt-mult-inverse68.6%
metadata-eval68.6%
*-lft-identity68.6%
+-commutative68.6%
Simplified68.6%
Final simplification68.6%
(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 35.7%
sub-neg35.7%
+-commutative35.7%
rgt-mult-inverse4.5%
exp-neg4.5%
distribute-rgt-neg-out4.5%
*-rgt-identity4.5%
distribute-lft-in4.5%
neg-sub04.5%
associate-+l-4.5%
neg-sub04.1%
associate-/r*4.1%
*-rgt-identity4.1%
associate-*r/4.1%
rgt-mult-inverse35.3%
distribute-frac-neg235.3%
distribute-neg-frac35.3%
metadata-eval35.3%
expm1-define100.0%
Simplified100.0%
Taylor expanded in x around 0 68.6%
(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 35.7%
sub-neg35.7%
+-commutative35.7%
rgt-mult-inverse4.5%
exp-neg4.5%
distribute-rgt-neg-out4.5%
*-rgt-identity4.5%
distribute-lft-in4.5%
neg-sub04.5%
associate-+l-4.5%
neg-sub04.1%
associate-/r*4.1%
*-rgt-identity4.1%
associate-*r/4.1%
rgt-mult-inverse35.3%
distribute-frac-neg235.3%
distribute-neg-frac35.3%
metadata-eval35.3%
expm1-define100.0%
Simplified100.0%
Taylor expanded in x around 0 68.6%
*-commutative68.6%
Simplified68.6%
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 2024136
(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)))