
(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 6 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}
x_m = (fabs.f64 x)
(FPCore (x_m)
:precision binary64
(let* ((t_0 (+ (- (exp x_m) 2.0) (exp (- x_m)))))
(if (<= t_0 0.005)
(*
(pow x_m 2.0)
(+
1.0
(*
(pow x_m 2.0)
(+
0.08333333333333333
(*
(pow x_m 2.0)
(+ 0.002777777777777778 (* (pow x_m 2.0) 4.96031746031746e-5)))))))
t_0)))x_m = fabs(x);
double code(double x_m) {
double t_0 = (exp(x_m) - 2.0) + exp(-x_m);
double tmp;
if (t_0 <= 0.005) {
tmp = pow(x_m, 2.0) * (1.0 + (pow(x_m, 2.0) * (0.08333333333333333 + (pow(x_m, 2.0) * (0.002777777777777778 + (pow(x_m, 2.0) * 4.96031746031746e-5))))));
} else {
tmp = t_0;
}
return tmp;
}
x_m = abs(x)
real(8) function code(x_m)
real(8), intent (in) :: x_m
real(8) :: t_0
real(8) :: tmp
t_0 = (exp(x_m) - 2.0d0) + exp(-x_m)
if (t_0 <= 0.005d0) then
tmp = (x_m ** 2.0d0) * (1.0d0 + ((x_m ** 2.0d0) * (0.08333333333333333d0 + ((x_m ** 2.0d0) * (0.002777777777777778d0 + ((x_m ** 2.0d0) * 4.96031746031746d-5))))))
else
tmp = t_0
end if
code = tmp
end function
x_m = Math.abs(x);
public static double code(double x_m) {
double t_0 = (Math.exp(x_m) - 2.0) + Math.exp(-x_m);
double tmp;
if (t_0 <= 0.005) {
tmp = Math.pow(x_m, 2.0) * (1.0 + (Math.pow(x_m, 2.0) * (0.08333333333333333 + (Math.pow(x_m, 2.0) * (0.002777777777777778 + (Math.pow(x_m, 2.0) * 4.96031746031746e-5))))));
} else {
tmp = t_0;
}
return tmp;
}
x_m = math.fabs(x) def code(x_m): t_0 = (math.exp(x_m) - 2.0) + math.exp(-x_m) tmp = 0 if t_0 <= 0.005: tmp = math.pow(x_m, 2.0) * (1.0 + (math.pow(x_m, 2.0) * (0.08333333333333333 + (math.pow(x_m, 2.0) * (0.002777777777777778 + (math.pow(x_m, 2.0) * 4.96031746031746e-5)))))) else: tmp = t_0 return tmp
x_m = abs(x) function code(x_m) t_0 = Float64(Float64(exp(x_m) - 2.0) + exp(Float64(-x_m))) tmp = 0.0 if (t_0 <= 0.005) tmp = Float64((x_m ^ 2.0) * Float64(1.0 + Float64((x_m ^ 2.0) * Float64(0.08333333333333333 + Float64((x_m ^ 2.0) * Float64(0.002777777777777778 + Float64((x_m ^ 2.0) * 4.96031746031746e-5))))))); else tmp = t_0; end return tmp end
x_m = abs(x); function tmp_2 = code(x_m) t_0 = (exp(x_m) - 2.0) + exp(-x_m); tmp = 0.0; if (t_0 <= 0.005) tmp = (x_m ^ 2.0) * (1.0 + ((x_m ^ 2.0) * (0.08333333333333333 + ((x_m ^ 2.0) * (0.002777777777777778 + ((x_m ^ 2.0) * 4.96031746031746e-5)))))); else tmp = t_0; end tmp_2 = tmp; end
x_m = N[Abs[x], $MachinePrecision]
code[x$95$m_] := Block[{t$95$0 = N[(N[(N[Exp[x$95$m], $MachinePrecision] - 2.0), $MachinePrecision] + N[Exp[(-x$95$m)], $MachinePrecision]), $MachinePrecision]}, If[LessEqual[t$95$0, 0.005], N[(N[Power[x$95$m, 2.0], $MachinePrecision] * N[(1.0 + N[(N[Power[x$95$m, 2.0], $MachinePrecision] * N[(0.08333333333333333 + N[(N[Power[x$95$m, 2.0], $MachinePrecision] * N[(0.002777777777777778 + N[(N[Power[x$95$m, 2.0], $MachinePrecision] * 4.96031746031746e-5), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision], t$95$0]]
\begin{array}{l}
x_m = \left|x\right|
\\
\begin{array}{l}
t_0 := \left(e^{x\_m} - 2\right) + e^{-x\_m}\\
\mathbf{if}\;t\_0 \leq 0.005:\\
\;\;\;\;{x\_m}^{2} \cdot \left(1 + {x\_m}^{2} \cdot \left(0.08333333333333333 + {x\_m}^{2} \cdot \left(0.002777777777777778 + {x\_m}^{2} \cdot 4.96031746031746 \cdot 10^{-5}\right)\right)\right)\\
\mathbf{else}:\\
\;\;\;\;t\_0\\
\end{array}
\end{array}
if (+.f64 (-.f64 (exp.f64 x) #s(literal 2 binary64)) (exp.f64 (neg.f64 x))) < 0.0050000000000000001Initial program 56.5%
associate-+l-56.4%
sub-neg56.4%
sub-neg56.4%
distribute-neg-in56.4%
remove-double-neg56.4%
+-commutative56.4%
metadata-eval56.4%
Simplified56.4%
Taylor expanded in x around 0 100.0%
*-commutative100.0%
Simplified100.0%
if 0.0050000000000000001 < (+.f64 (-.f64 (exp.f64 x) #s(literal 2 binary64)) (exp.f64 (neg.f64 x))) Initial program 99.1%
Final simplification100.0%
x_m = (fabs.f64 x) (FPCore (x_m) :precision binary64 (let* ((t_0 (+ (- (exp x_m) 2.0) (exp (- x_m))))) (if (<= t_0 1e-9) (* x_m x_m) t_0)))
x_m = fabs(x);
double code(double x_m) {
double t_0 = (exp(x_m) - 2.0) + exp(-x_m);
double tmp;
if (t_0 <= 1e-9) {
tmp = x_m * x_m;
} else {
tmp = t_0;
}
return tmp;
}
x_m = abs(x)
real(8) function code(x_m)
real(8), intent (in) :: x_m
real(8) :: t_0
real(8) :: tmp
t_0 = (exp(x_m) - 2.0d0) + exp(-x_m)
if (t_0 <= 1d-9) then
tmp = x_m * x_m
else
tmp = t_0
end if
code = tmp
end function
x_m = Math.abs(x);
public static double code(double x_m) {
double t_0 = (Math.exp(x_m) - 2.0) + Math.exp(-x_m);
double tmp;
if (t_0 <= 1e-9) {
tmp = x_m * x_m;
} else {
tmp = t_0;
}
return tmp;
}
x_m = math.fabs(x) def code(x_m): t_0 = (math.exp(x_m) - 2.0) + math.exp(-x_m) tmp = 0 if t_0 <= 1e-9: tmp = x_m * x_m else: tmp = t_0 return tmp
x_m = abs(x) function code(x_m) t_0 = Float64(Float64(exp(x_m) - 2.0) + exp(Float64(-x_m))) tmp = 0.0 if (t_0 <= 1e-9) tmp = Float64(x_m * x_m); else tmp = t_0; end return tmp end
x_m = abs(x); function tmp_2 = code(x_m) t_0 = (exp(x_m) - 2.0) + exp(-x_m); tmp = 0.0; if (t_0 <= 1e-9) tmp = x_m * x_m; else tmp = t_0; end tmp_2 = tmp; end
x_m = N[Abs[x], $MachinePrecision]
code[x$95$m_] := Block[{t$95$0 = N[(N[(N[Exp[x$95$m], $MachinePrecision] - 2.0), $MachinePrecision] + N[Exp[(-x$95$m)], $MachinePrecision]), $MachinePrecision]}, If[LessEqual[t$95$0, 1e-9], N[(x$95$m * x$95$m), $MachinePrecision], t$95$0]]
\begin{array}{l}
x_m = \left|x\right|
\\
\begin{array}{l}
t_0 := \left(e^{x\_m} - 2\right) + e^{-x\_m}\\
\mathbf{if}\;t\_0 \leq 10^{-9}:\\
\;\;\;\;x\_m \cdot x\_m\\
\mathbf{else}:\\
\;\;\;\;t\_0\\
\end{array}
\end{array}
if (+.f64 (-.f64 (exp.f64 x) #s(literal 2 binary64)) (exp.f64 (neg.f64 x))) < 1.00000000000000006e-9Initial program 56.4%
associate-+l-56.3%
sub-neg56.3%
sub-neg56.3%
distribute-neg-in56.3%
remove-double-neg56.3%
+-commutative56.3%
metadata-eval56.3%
Simplified56.3%
add-cbrt-cube56.3%
pow1/356.3%
pow356.3%
associate-+r+56.2%
+-commutative56.2%
cosh-undef56.2%
Applied egg-rr56.2%
Taylor expanded in x around 0 69.6%
pow-pow99.7%
metadata-eval99.7%
unpow299.7%
Applied egg-rr99.7%
if 1.00000000000000006e-9 < (+.f64 (-.f64 (exp.f64 x) #s(literal 2 binary64)) (exp.f64 (neg.f64 x))) Initial program 97.5%
Final simplification99.7%
x_m = (fabs.f64 x) (FPCore (x_m) :precision binary64 (let* ((t_0 (+ (- (exp x_m) 2.0) (exp (- x_m))))) (if (<= t_0 1e-9) (fma x_m x_m (* 0.08333333333333333 (pow x_m 4.0))) t_0)))
x_m = fabs(x);
double code(double x_m) {
double t_0 = (exp(x_m) - 2.0) + exp(-x_m);
double tmp;
if (t_0 <= 1e-9) {
tmp = fma(x_m, x_m, (0.08333333333333333 * pow(x_m, 4.0)));
} else {
tmp = t_0;
}
return tmp;
}
x_m = abs(x) function code(x_m) t_0 = Float64(Float64(exp(x_m) - 2.0) + exp(Float64(-x_m))) tmp = 0.0 if (t_0 <= 1e-9) tmp = fma(x_m, x_m, Float64(0.08333333333333333 * (x_m ^ 4.0))); else tmp = t_0; end return tmp end
x_m = N[Abs[x], $MachinePrecision]
code[x$95$m_] := Block[{t$95$0 = N[(N[(N[Exp[x$95$m], $MachinePrecision] - 2.0), $MachinePrecision] + N[Exp[(-x$95$m)], $MachinePrecision]), $MachinePrecision]}, If[LessEqual[t$95$0, 1e-9], N[(x$95$m * x$95$m + N[(0.08333333333333333 * N[Power[x$95$m, 4.0], $MachinePrecision]), $MachinePrecision]), $MachinePrecision], t$95$0]]
\begin{array}{l}
x_m = \left|x\right|
\\
\begin{array}{l}
t_0 := \left(e^{x\_m} - 2\right) + e^{-x\_m}\\
\mathbf{if}\;t\_0 \leq 10^{-9}:\\
\;\;\;\;\mathsf{fma}\left(x\_m, x\_m, 0.08333333333333333 \cdot {x\_m}^{4}\right)\\
\mathbf{else}:\\
\;\;\;\;t\_0\\
\end{array}
\end{array}
if (+.f64 (-.f64 (exp.f64 x) #s(literal 2 binary64)) (exp.f64 (neg.f64 x))) < 1.00000000000000006e-9Initial program 56.4%
associate-+l-56.3%
sub-neg56.3%
sub-neg56.3%
distribute-neg-in56.3%
remove-double-neg56.3%
+-commutative56.3%
metadata-eval56.3%
Simplified56.3%
Taylor expanded in x around 0 100.0%
*-commutative100.0%
Simplified100.0%
Taylor expanded in x around 0 100.0%
distribute-rgt-in100.0%
*-lft-identity100.0%
associate-*l*100.0%
pow-sqr100.0%
metadata-eval100.0%
Simplified100.0%
unpow2100.0%
fma-define100.0%
Applied egg-rr100.0%
if 1.00000000000000006e-9 < (+.f64 (-.f64 (exp.f64 x) #s(literal 2 binary64)) (exp.f64 (neg.f64 x))) Initial program 97.5%
Final simplification99.9%
x_m = (fabs.f64 x) (FPCore (x_m) :precision binary64 (if (<= x_m 0.00021) (* x_m x_m) (+ (exp x_m) (+ (exp (- x_m)) -2.0))))
x_m = fabs(x);
double code(double x_m) {
double tmp;
if (x_m <= 0.00021) {
tmp = x_m * x_m;
} else {
tmp = exp(x_m) + (exp(-x_m) + -2.0);
}
return tmp;
}
x_m = abs(x)
real(8) function code(x_m)
real(8), intent (in) :: x_m
real(8) :: tmp
if (x_m <= 0.00021d0) then
tmp = x_m * x_m
else
tmp = exp(x_m) + (exp(-x_m) + (-2.0d0))
end if
code = tmp
end function
x_m = Math.abs(x);
public static double code(double x_m) {
double tmp;
if (x_m <= 0.00021) {
tmp = x_m * x_m;
} else {
tmp = Math.exp(x_m) + (Math.exp(-x_m) + -2.0);
}
return tmp;
}
x_m = math.fabs(x) def code(x_m): tmp = 0 if x_m <= 0.00021: tmp = x_m * x_m else: tmp = math.exp(x_m) + (math.exp(-x_m) + -2.0) return tmp
x_m = abs(x) function code(x_m) tmp = 0.0 if (x_m <= 0.00021) tmp = Float64(x_m * x_m); else tmp = Float64(exp(x_m) + Float64(exp(Float64(-x_m)) + -2.0)); end return tmp end
x_m = abs(x); function tmp_2 = code(x_m) tmp = 0.0; if (x_m <= 0.00021) tmp = x_m * x_m; else tmp = exp(x_m) + (exp(-x_m) + -2.0); end tmp_2 = tmp; end
x_m = N[Abs[x], $MachinePrecision] code[x$95$m_] := If[LessEqual[x$95$m, 0.00021], N[(x$95$m * x$95$m), $MachinePrecision], N[(N[Exp[x$95$m], $MachinePrecision] + N[(N[Exp[(-x$95$m)], $MachinePrecision] + -2.0), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}
x_m = \left|x\right|
\\
\begin{array}{l}
\mathbf{if}\;x\_m \leq 0.00021:\\
\;\;\;\;x\_m \cdot x\_m\\
\mathbf{else}:\\
\;\;\;\;e^{x\_m} + \left(e^{-x\_m} + -2\right)\\
\end{array}
\end{array}
if x < 2.1000000000000001e-4Initial program 57.0%
associate-+l-57.0%
sub-neg57.0%
sub-neg57.0%
distribute-neg-in57.0%
remove-double-neg57.0%
+-commutative57.0%
metadata-eval57.0%
Simplified57.0%
add-cbrt-cube56.2%
pow1/356.2%
pow356.2%
associate-+r+56.1%
+-commutative56.1%
cosh-undef56.1%
Applied egg-rr56.1%
Taylor expanded in x around 0 68.7%
pow-pow98.4%
metadata-eval98.4%
unpow298.4%
Applied egg-rr98.4%
if 2.1000000000000001e-4 < x Initial program 96.0%
associate-+l-96.0%
sub-neg96.0%
sub-neg96.0%
distribute-neg-in96.0%
remove-double-neg96.0%
+-commutative96.0%
metadata-eval96.0%
Simplified96.0%
Final simplification98.4%
x_m = (fabs.f64 x) (FPCore (x_m) :precision binary64 (if (<= x_m 0.000185) (* x_m x_m) (- (* 2.0 (cosh x_m)) 2.0)))
x_m = fabs(x);
double code(double x_m) {
double tmp;
if (x_m <= 0.000185) {
tmp = x_m * x_m;
} else {
tmp = (2.0 * cosh(x_m)) - 2.0;
}
return tmp;
}
x_m = abs(x)
real(8) function code(x_m)
real(8), intent (in) :: x_m
real(8) :: tmp
if (x_m <= 0.000185d0) then
tmp = x_m * x_m
else
tmp = (2.0d0 * cosh(x_m)) - 2.0d0
end if
code = tmp
end function
x_m = Math.abs(x);
public static double code(double x_m) {
double tmp;
if (x_m <= 0.000185) {
tmp = x_m * x_m;
} else {
tmp = (2.0 * Math.cosh(x_m)) - 2.0;
}
return tmp;
}
x_m = math.fabs(x) def code(x_m): tmp = 0 if x_m <= 0.000185: tmp = x_m * x_m else: tmp = (2.0 * math.cosh(x_m)) - 2.0 return tmp
x_m = abs(x) function code(x_m) tmp = 0.0 if (x_m <= 0.000185) tmp = Float64(x_m * x_m); else tmp = Float64(Float64(2.0 * cosh(x_m)) - 2.0); end return tmp end
x_m = abs(x); function tmp_2 = code(x_m) tmp = 0.0; if (x_m <= 0.000185) tmp = x_m * x_m; else tmp = (2.0 * cosh(x_m)) - 2.0; end tmp_2 = tmp; end
x_m = N[Abs[x], $MachinePrecision] code[x$95$m_] := If[LessEqual[x$95$m, 0.000185], N[(x$95$m * x$95$m), $MachinePrecision], N[(N[(2.0 * N[Cosh[x$95$m], $MachinePrecision]), $MachinePrecision] - 2.0), $MachinePrecision]]
\begin{array}{l}
x_m = \left|x\right|
\\
\begin{array}{l}
\mathbf{if}\;x\_m \leq 0.000185:\\
\;\;\;\;x\_m \cdot x\_m\\
\mathbf{else}:\\
\;\;\;\;2 \cdot \cosh x\_m - 2\\
\end{array}
\end{array}
if x < 1.85e-4Initial program 57.0%
associate-+l-57.0%
sub-neg57.0%
sub-neg57.0%
distribute-neg-in57.0%
remove-double-neg57.0%
+-commutative57.0%
metadata-eval57.0%
Simplified57.0%
add-cbrt-cube56.2%
pow1/356.2%
pow356.2%
associate-+r+56.1%
+-commutative56.1%
cosh-undef56.1%
Applied egg-rr56.1%
Taylor expanded in x around 0 68.7%
pow-pow98.4%
metadata-eval98.4%
unpow298.4%
Applied egg-rr98.4%
if 1.85e-4 < x Initial program 96.0%
associate-+l-96.0%
sub-neg96.0%
sub-neg96.0%
distribute-neg-in96.0%
remove-double-neg96.0%
+-commutative96.0%
metadata-eval96.0%
Simplified96.0%
+-commutative96.0%
associate-+r+96.0%
metadata-eval96.0%
sub-neg96.0%
+-commutative96.0%
associate-+r-95.2%
+-commutative95.2%
cosh-undef95.2%
Applied egg-rr95.2%
Final simplification98.3%
x_m = (fabs.f64 x) (FPCore (x_m) :precision binary64 (* x_m x_m))
x_m = fabs(x);
double code(double x_m) {
return x_m * x_m;
}
x_m = abs(x)
real(8) function code(x_m)
real(8), intent (in) :: x_m
code = x_m * x_m
end function
x_m = Math.abs(x);
public static double code(double x_m) {
return x_m * x_m;
}
x_m = math.fabs(x) def code(x_m): return x_m * x_m
x_m = abs(x) function code(x_m) return Float64(x_m * x_m) end
x_m = abs(x); function tmp = code(x_m) tmp = x_m * x_m; end
x_m = N[Abs[x], $MachinePrecision] code[x$95$m_] := N[(x$95$m * x$95$m), $MachinePrecision]
\begin{array}{l}
x_m = \left|x\right|
\\
x\_m \cdot x\_m
\end{array}
Initial program 57.5%
associate-+l-57.4%
sub-neg57.4%
sub-neg57.4%
distribute-neg-in57.4%
remove-double-neg57.4%
+-commutative57.4%
metadata-eval57.4%
Simplified57.4%
add-cbrt-cube56.7%
pow1/356.6%
pow356.6%
associate-+r+56.6%
+-commutative56.6%
cosh-undef56.6%
Applied egg-rr56.6%
Taylor expanded in x around 0 68.2%
pow-pow97.5%
metadata-eval97.5%
unpow297.5%
Applied egg-rr97.5%
Final simplification97.5%
(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 2024095
(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))))