
(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 (/ (exp x) (expm1 x)))
double code(double x) {
return exp(x) / expm1(x);
}
public static double code(double x) {
return Math.exp(x) / Math.expm1(x);
}
def code(x): return math.exp(x) / math.expm1(x)
function code(x) return Float64(exp(x) / expm1(x)) end
code[x_] := N[(N[Exp[x], $MachinePrecision] / N[(Exp[x] - 1), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\frac{e^{x}}{\mathsf{expm1}\left(x\right)}
\end{array}
Initial program 39.2%
expm1-define100.0%
Simplified100.0%
(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 39.2%
sub-neg39.2%
+-commutative39.2%
rgt-mult-inverse4.8%
exp-neg4.8%
distribute-rgt-neg-out4.8%
*-rgt-identity4.8%
distribute-lft-in4.7%
neg-sub04.7%
associate-+l-4.7%
neg-sub04.7%
associate-/r*4.7%
*-rgt-identity4.7%
associate-*r/4.7%
rgt-mult-inverse39.0%
distribute-frac-neg239.0%
distribute-neg-frac39.0%
metadata-eval39.0%
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 39.2%
expm1-define100.0%
Simplified100.0%
Taylor expanded in x around 0 98.0%
(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 39.2%
sub-neg39.2%
+-commutative39.2%
rgt-mult-inverse4.8%
exp-neg4.8%
distribute-rgt-neg-out4.8%
*-rgt-identity4.8%
distribute-lft-in4.7%
neg-sub04.7%
associate-+l-4.7%
neg-sub04.7%
associate-/r*4.7%
*-rgt-identity4.7%
associate-*r/4.7%
rgt-mult-inverse39.0%
distribute-frac-neg239.0%
distribute-neg-frac39.0%
metadata-eval39.0%
expm1-define100.0%
Simplified100.0%
Taylor expanded in x around 0 90.7%
Final simplification90.7%
(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 39.2%
sub-neg39.2%
+-commutative39.2%
rgt-mult-inverse4.8%
exp-neg4.8%
distribute-rgt-neg-out4.8%
*-rgt-identity4.8%
distribute-lft-in4.7%
neg-sub04.7%
associate-+l-4.7%
neg-sub04.7%
associate-/r*4.7%
*-rgt-identity4.7%
associate-*r/4.7%
rgt-mult-inverse39.0%
distribute-frac-neg239.0%
distribute-neg-frac39.0%
metadata-eval39.0%
expm1-define100.0%
Simplified100.0%
Taylor expanded in x around 0 90.7%
Taylor expanded in x around inf 90.2%
*-commutative90.2%
Simplified90.2%
Final simplification90.2%
(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 39.2%
sub-neg39.2%
+-commutative39.2%
rgt-mult-inverse4.8%
exp-neg4.8%
distribute-rgt-neg-out4.8%
*-rgt-identity4.8%
distribute-lft-in4.7%
neg-sub04.7%
associate-+l-4.7%
neg-sub04.7%
associate-/r*4.7%
*-rgt-identity4.7%
associate-*r/4.7%
rgt-mult-inverse39.0%
distribute-frac-neg239.0%
distribute-neg-frac39.0%
metadata-eval39.0%
expm1-define100.0%
Simplified100.0%
Taylor expanded in x around 0 89.0%
Final simplification89.0%
(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 39.2%
sub-neg39.2%
+-commutative39.2%
rgt-mult-inverse4.8%
exp-neg4.8%
distribute-rgt-neg-out4.8%
*-rgt-identity4.8%
distribute-lft-in4.7%
neg-sub04.7%
associate-+l-4.7%
neg-sub04.7%
associate-/r*4.7%
*-rgt-identity4.7%
associate-*r/4.7%
rgt-mult-inverse39.0%
distribute-frac-neg239.0%
distribute-neg-frac39.0%
metadata-eval39.0%
expm1-define100.0%
Simplified100.0%
Taylor expanded in x around 0 82.4%
sub-neg82.4%
metadata-eval82.4%
distribute-rgt-in82.4%
*-commutative82.4%
neg-mul-182.4%
Applied egg-rr82.4%
Final simplification82.4%
(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 39.2%
sub-neg39.2%
+-commutative39.2%
rgt-mult-inverse4.8%
exp-neg4.8%
distribute-rgt-neg-out4.8%
*-rgt-identity4.8%
distribute-lft-in4.7%
neg-sub04.7%
associate-+l-4.7%
neg-sub04.7%
associate-/r*4.7%
*-rgt-identity4.7%
associate-*r/4.7%
rgt-mult-inverse39.0%
distribute-frac-neg239.0%
distribute-neg-frac39.0%
metadata-eval39.0%
expm1-define100.0%
Simplified100.0%
Taylor expanded in x around 0 82.4%
Final simplification82.4%
(FPCore (x) :precision binary64 (+ (+ 0.5 (/ 1.0 x)) (* x 0.08333333333333333)))
double code(double x) {
return (0.5 + (1.0 / x)) + (x * 0.08333333333333333);
}
real(8) function code(x)
real(8), intent (in) :: x
code = (0.5d0 + (1.0d0 / x)) + (x * 0.08333333333333333d0)
end function
public static double code(double x) {
return (0.5 + (1.0 / x)) + (x * 0.08333333333333333);
}
def code(x): return (0.5 + (1.0 / x)) + (x * 0.08333333333333333)
function code(x) return Float64(Float64(0.5 + Float64(1.0 / x)) + Float64(x * 0.08333333333333333)) end
function tmp = code(x) tmp = (0.5 + (1.0 / x)) + (x * 0.08333333333333333); end
code[x_] := N[(N[(0.5 + N[(1.0 / x), $MachinePrecision]), $MachinePrecision] + N[(x * 0.08333333333333333), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\left(0.5 + \frac{1}{x}\right) + x \cdot 0.08333333333333333
\end{array}
Initial program 39.2%
sub-neg39.2%
+-commutative39.2%
rgt-mult-inverse4.8%
exp-neg4.8%
distribute-rgt-neg-out4.8%
*-rgt-identity4.8%
distribute-lft-in4.7%
neg-sub04.7%
associate-+l-4.7%
neg-sub04.7%
associate-/r*4.7%
*-rgt-identity4.7%
associate-*r/4.7%
rgt-mult-inverse39.0%
distribute-frac-neg239.0%
distribute-neg-frac39.0%
metadata-eval39.0%
expm1-define100.0%
Simplified100.0%
Taylor expanded in x around 0 65.6%
*-commutative65.6%
Simplified65.6%
Taylor expanded in x around -inf 35.5%
mul-1-neg35.5%
distribute-rgt-neg-in35.5%
sub-neg35.5%
associate-*r/35.5%
distribute-lft-in35.5%
metadata-eval35.5%
associate-*r/35.5%
metadata-eval35.5%
metadata-eval35.5%
Simplified35.5%
distribute-neg-in35.5%
distribute-neg-frac235.5%
add-sqr-sqrt19.0%
sqrt-unprod19.3%
sqr-neg19.3%
sqrt-unprod0.2%
add-sqr-sqrt1.2%
sub-neg1.2%
frac-2neg1.2%
distribute-neg-in1.2%
metadata-eval1.2%
distribute-frac-neg21.2%
metadata-eval1.2%
frac-2neg1.2%
add-sqr-sqrt1.0%
sqrt-unprod17.4%
sqr-neg17.4%
sqrt-unprod16.3%
add-sqr-sqrt35.5%
Applied egg-rr35.5%
pow135.5%
sub-neg35.5%
metadata-eval35.5%
Applied egg-rr35.5%
unpow135.5%
distribute-lft-in35.5%
*-commutative35.5%
associate-*l/65.7%
associate-/l*65.7%
*-inverses65.7%
*-rgt-identity65.7%
+-commutative65.7%
Simplified65.7%
Final simplification65.7%
(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 39.2%
sub-neg39.2%
+-commutative39.2%
rgt-mult-inverse4.8%
exp-neg4.8%
distribute-rgt-neg-out4.8%
*-rgt-identity4.8%
distribute-lft-in4.7%
neg-sub04.7%
associate-+l-4.7%
neg-sub04.7%
associate-/r*4.7%
*-rgt-identity4.7%
associate-*r/4.7%
rgt-mult-inverse39.0%
distribute-frac-neg239.0%
distribute-neg-frac39.0%
metadata-eval39.0%
expm1-define100.0%
Simplified100.0%
Taylor expanded in x around 0 65.4%
*-commutative65.4%
Simplified65.4%
Taylor expanded in x around 0 65.4%
+-commutative65.4%
*-commutative65.4%
fma-undefine65.4%
*-lft-identity65.4%
associate-*l/65.4%
fma-undefine65.4%
distribute-rgt-in65.4%
associate-*r*65.4%
*-commutative65.4%
associate-*r*65.4%
rgt-mult-inverse65.4%
metadata-eval65.4%
*-lft-identity65.4%
+-commutative65.4%
Simplified65.4%
Final simplification65.4%
(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 39.2%
sub-neg39.2%
+-commutative39.2%
rgt-mult-inverse4.8%
exp-neg4.8%
distribute-rgt-neg-out4.8%
*-rgt-identity4.8%
distribute-lft-in4.7%
neg-sub04.7%
associate-+l-4.7%
neg-sub04.7%
associate-/r*4.7%
*-rgt-identity4.7%
associate-*r/4.7%
rgt-mult-inverse39.0%
distribute-frac-neg239.0%
distribute-neg-frac39.0%
metadata-eval39.0%
expm1-define100.0%
Simplified100.0%
Taylor expanded in x around 0 65.4%
(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 39.2%
sub-neg39.2%
+-commutative39.2%
rgt-mult-inverse4.8%
exp-neg4.8%
distribute-rgt-neg-out4.8%
*-rgt-identity4.8%
distribute-lft-in4.7%
neg-sub04.7%
associate-+l-4.7%
neg-sub04.7%
associate-/r*4.7%
*-rgt-identity4.7%
associate-*r/4.7%
rgt-mult-inverse39.0%
distribute-frac-neg239.0%
distribute-neg-frac39.0%
metadata-eval39.0%
expm1-define100.0%
Simplified100.0%
Taylor expanded in x around 0 65.4%
*-commutative65.4%
Simplified65.4%
Taylor expanded in x around inf 3.2%
(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 2024169
(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)))