
(FPCore (x) :precision binary64 (+ (- (exp x) 2.0) (exp (- x))))
double code(double x) {
return (exp(x) - 2.0) + exp(-x);
}
real(8) function code(x)
real(8), intent (in) :: x
code = (exp(x) - 2.0d0) + exp(-x)
end function
public static double code(double x) {
return (Math.exp(x) - 2.0) + Math.exp(-x);
}
def code(x): return (math.exp(x) - 2.0) + math.exp(-x)
function code(x) return Float64(Float64(exp(x) - 2.0) + exp(Float64(-x))) end
function tmp = code(x) tmp = (exp(x) - 2.0) + exp(-x); end
code[x_] := N[(N[(N[Exp[x], $MachinePrecision] - 2.0), $MachinePrecision] + N[Exp[(-x)], $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\left(e^{x} - 2\right) + e^{-x}
\end{array}
Sampling outcomes in binary64 precision:
Herbie found 5 alternatives:
| Alternative | Accuracy | Speedup |
|---|
(FPCore (x) :precision binary64 (+ (- (exp x) 2.0) (exp (- x))))
double code(double x) {
return (exp(x) - 2.0) + exp(-x);
}
real(8) function code(x)
real(8), intent (in) :: x
code = (exp(x) - 2.0d0) + exp(-x)
end function
public static double code(double x) {
return (Math.exp(x) - 2.0) + Math.exp(-x);
}
def code(x): return (math.exp(x) - 2.0) + math.exp(-x)
function code(x) return Float64(Float64(exp(x) - 2.0) + exp(Float64(-x))) end
function tmp = code(x) tmp = (exp(x) - 2.0) + exp(-x); end
code[x_] := N[(N[(N[Exp[x], $MachinePrecision] - 2.0), $MachinePrecision] + N[Exp[(-x)], $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\left(e^{x} - 2\right) + e^{-x}
\end{array}
(FPCore (x)
:precision binary64
(pow
(*
x
(+
1.0
(*
(pow x 2.0)
(+
0.041666666666666664
(*
(pow x 2.0)
(+ 0.0005208333333333333 (* (pow x 2.0) 3.1001984126984127e-6)))))))
2.0))
double code(double x) {
return pow((x * (1.0 + (pow(x, 2.0) * (0.041666666666666664 + (pow(x, 2.0) * (0.0005208333333333333 + (pow(x, 2.0) * 3.1001984126984127e-6))))))), 2.0);
}
real(8) function code(x)
real(8), intent (in) :: x
code = (x * (1.0d0 + ((x ** 2.0d0) * (0.041666666666666664d0 + ((x ** 2.0d0) * (0.0005208333333333333d0 + ((x ** 2.0d0) * 3.1001984126984127d-6))))))) ** 2.0d0
end function
public static double code(double x) {
return Math.pow((x * (1.0 + (Math.pow(x, 2.0) * (0.041666666666666664 + (Math.pow(x, 2.0) * (0.0005208333333333333 + (Math.pow(x, 2.0) * 3.1001984126984127e-6))))))), 2.0);
}
def code(x): return math.pow((x * (1.0 + (math.pow(x, 2.0) * (0.041666666666666664 + (math.pow(x, 2.0) * (0.0005208333333333333 + (math.pow(x, 2.0) * 3.1001984126984127e-6))))))), 2.0)
function code(x) return Float64(x * Float64(1.0 + Float64((x ^ 2.0) * Float64(0.041666666666666664 + Float64((x ^ 2.0) * Float64(0.0005208333333333333 + Float64((x ^ 2.0) * 3.1001984126984127e-6))))))) ^ 2.0 end
function tmp = code(x) tmp = (x * (1.0 + ((x ^ 2.0) * (0.041666666666666664 + ((x ^ 2.0) * (0.0005208333333333333 + ((x ^ 2.0) * 3.1001984126984127e-6))))))) ^ 2.0; end
code[x_] := N[Power[N[(x * N[(1.0 + N[(N[Power[x, 2.0], $MachinePrecision] * N[(0.041666666666666664 + N[(N[Power[x, 2.0], $MachinePrecision] * N[(0.0005208333333333333 + N[(N[Power[x, 2.0], $MachinePrecision] * 3.1001984126984127e-6), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision], 2.0], $MachinePrecision]
\begin{array}{l}
\\
{\left(x \cdot \left(1 + {x}^{2} \cdot \left(0.041666666666666664 + {x}^{2} \cdot \left(0.0005208333333333333 + {x}^{2} \cdot 3.1001984126984127 \cdot 10^{-6}\right)\right)\right)\right)}^{2}
\end{array}
Initial program 57.3%
associate-+l-57.3%
sub-neg57.3%
sub-neg57.3%
distribute-neg-in57.3%
remove-double-neg57.3%
+-commutative57.3%
metadata-eval57.3%
Simplified57.3%
Taylor expanded in x around 0 99.2%
*-commutative99.2%
Simplified99.2%
add-sqr-sqrt99.2%
pow299.2%
Applied egg-rr99.2%
Taylor expanded in x around 0 99.3%
*-commutative99.3%
Simplified99.3%
Final simplification99.3%
(FPCore (x)
:precision binary64
(*
(pow x 2.0)
(+
1.0
(*
(pow x 2.0)
(+
0.08333333333333333
(*
(pow x 2.0)
(+ 0.002777777777777778 (* (pow x 2.0) 4.96031746031746e-5))))))))
double code(double x) {
return pow(x, 2.0) * (1.0 + (pow(x, 2.0) * (0.08333333333333333 + (pow(x, 2.0) * (0.002777777777777778 + (pow(x, 2.0) * 4.96031746031746e-5))))));
}
real(8) function code(x)
real(8), intent (in) :: x
code = (x ** 2.0d0) * (1.0d0 + ((x ** 2.0d0) * (0.08333333333333333d0 + ((x ** 2.0d0) * (0.002777777777777778d0 + ((x ** 2.0d0) * 4.96031746031746d-5))))))
end function
public static double code(double x) {
return Math.pow(x, 2.0) * (1.0 + (Math.pow(x, 2.0) * (0.08333333333333333 + (Math.pow(x, 2.0) * (0.002777777777777778 + (Math.pow(x, 2.0) * 4.96031746031746e-5))))));
}
def code(x): return math.pow(x, 2.0) * (1.0 + (math.pow(x, 2.0) * (0.08333333333333333 + (math.pow(x, 2.0) * (0.002777777777777778 + (math.pow(x, 2.0) * 4.96031746031746e-5))))))
function code(x) return Float64((x ^ 2.0) * Float64(1.0 + Float64((x ^ 2.0) * Float64(0.08333333333333333 + Float64((x ^ 2.0) * Float64(0.002777777777777778 + Float64((x ^ 2.0) * 4.96031746031746e-5))))))) end
function tmp = code(x) tmp = (x ^ 2.0) * (1.0 + ((x ^ 2.0) * (0.08333333333333333 + ((x ^ 2.0) * (0.002777777777777778 + ((x ^ 2.0) * 4.96031746031746e-5)))))); end
code[x_] := N[(N[Power[x, 2.0], $MachinePrecision] * N[(1.0 + N[(N[Power[x, 2.0], $MachinePrecision] * N[(0.08333333333333333 + N[(N[Power[x, 2.0], $MachinePrecision] * N[(0.002777777777777778 + N[(N[Power[x, 2.0], $MachinePrecision] * 4.96031746031746e-5), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
{x}^{2} \cdot \left(1 + {x}^{2} \cdot \left(0.08333333333333333 + {x}^{2} \cdot \left(0.002777777777777778 + {x}^{2} \cdot 4.96031746031746 \cdot 10^{-5}\right)\right)\right)
\end{array}
Initial program 57.3%
associate-+l-57.3%
sub-neg57.3%
sub-neg57.3%
distribute-neg-in57.3%
remove-double-neg57.3%
+-commutative57.3%
metadata-eval57.3%
Simplified57.3%
Taylor expanded in x around 0 99.2%
*-commutative99.2%
Simplified99.2%
Final simplification99.2%
(FPCore (x) :precision binary64 (* (* x x) (+ 1.0 (* 0.08333333333333333 (* x x)))))
double code(double x) {
return (x * x) * (1.0 + (0.08333333333333333 * (x * x)));
}
real(8) function code(x)
real(8), intent (in) :: x
code = (x * x) * (1.0d0 + (0.08333333333333333d0 * (x * x)))
end function
public static double code(double x) {
return (x * x) * (1.0 + (0.08333333333333333 * (x * x)));
}
def code(x): return (x * x) * (1.0 + (0.08333333333333333 * (x * x)))
function code(x) return Float64(Float64(x * x) * Float64(1.0 + Float64(0.08333333333333333 * Float64(x * x)))) end
function tmp = code(x) tmp = (x * x) * (1.0 + (0.08333333333333333 * (x * x))); end
code[x_] := N[(N[(x * x), $MachinePrecision] * N[(1.0 + N[(0.08333333333333333 * N[(x * x), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\left(x \cdot x\right) \cdot \left(1 + 0.08333333333333333 \cdot \left(x \cdot x\right)\right)
\end{array}
Initial program 57.3%
associate-+l-57.3%
sub-neg57.3%
sub-neg57.3%
distribute-neg-in57.3%
remove-double-neg57.3%
+-commutative57.3%
metadata-eval57.3%
Simplified57.3%
Taylor expanded in x around 0 99.1%
*-commutative99.1%
Simplified99.1%
unpow298.8%
Applied egg-rr99.1%
unpow298.8%
Applied egg-rr99.1%
Final simplification99.1%
(FPCore (x) :precision binary64 (* x x))
double code(double x) {
return x * x;
}
real(8) function code(x)
real(8), intent (in) :: x
code = x * x
end function
public static double code(double x) {
return x * x;
}
def code(x): return x * x
function code(x) return Float64(x * x) end
function tmp = code(x) tmp = x * x; end
code[x_] := N[(x * x), $MachinePrecision]
\begin{array}{l}
\\
x \cdot x
\end{array}
Initial program 57.3%
associate-+l-57.3%
sub-neg57.3%
sub-neg57.3%
distribute-neg-in57.3%
remove-double-neg57.3%
+-commutative57.3%
metadata-eval57.3%
Simplified57.3%
Taylor expanded in x around 0 98.8%
unpow298.8%
Applied egg-rr98.8%
Final simplification98.8%
(FPCore (x) :precision binary64 x)
double code(double x) {
return x;
}
real(8) function code(x)
real(8), intent (in) :: x
code = x
end function
public static double code(double x) {
return x;
}
def code(x): return x
function code(x) return x end
function tmp = code(x) tmp = x; end
code[x_] := x
\begin{array}{l}
\\
x
\end{array}
Initial program 57.3%
associate-+l-57.3%
sub-neg57.3%
sub-neg57.3%
distribute-neg-in57.3%
remove-double-neg57.3%
+-commutative57.3%
metadata-eval57.3%
Simplified57.3%
Taylor expanded in x around 0 56.4%
Taylor expanded in x around 0 6.2%
Final simplification6.2%
(FPCore (x) :precision binary64 (let* ((t_0 (sinh (/ x 2.0)))) (* 4.0 (* t_0 t_0))))
double code(double x) {
double t_0 = sinh((x / 2.0));
return 4.0 * (t_0 * t_0);
}
real(8) function code(x)
real(8), intent (in) :: x
real(8) :: t_0
t_0 = sinh((x / 2.0d0))
code = 4.0d0 * (t_0 * t_0)
end function
public static double code(double x) {
double t_0 = Math.sinh((x / 2.0));
return 4.0 * (t_0 * t_0);
}
def code(x): t_0 = math.sinh((x / 2.0)) return 4.0 * (t_0 * t_0)
function code(x) t_0 = sinh(Float64(x / 2.0)) return Float64(4.0 * Float64(t_0 * t_0)) end
function tmp = code(x) t_0 = sinh((x / 2.0)); tmp = 4.0 * (t_0 * t_0); end
code[x_] := Block[{t$95$0 = N[Sinh[N[(x / 2.0), $MachinePrecision]], $MachinePrecision]}, N[(4.0 * N[(t$95$0 * t$95$0), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}
\\
\begin{array}{l}
t_0 := \sinh \left(\frac{x}{2}\right)\\
4 \cdot \left(t\_0 \cdot t\_0\right)
\end{array}
\end{array}
herbie shell --seed 2024054
(FPCore (x)
:name "exp2 (problem 3.3.7)"
:precision binary64
:pre (<= (fabs x) 710.0)
:alt
(* 4.0 (* (sinh (/ x 2.0)) (sinh (/ x 2.0))))
(+ (- (exp x) 2.0) (exp (- x))))