
(FPCore (x) :precision binary64 (/ (- (exp x) (exp (- x))) 2.0))
double code(double x) {
return (exp(x) - exp(-x)) / 2.0;
}
real(8) function code(x)
real(8), intent (in) :: x
code = (exp(x) - exp(-x)) / 2.0d0
end function
public static double code(double x) {
return (Math.exp(x) - Math.exp(-x)) / 2.0;
}
def code(x): return (math.exp(x) - math.exp(-x)) / 2.0
function code(x) return Float64(Float64(exp(x) - exp(Float64(-x))) / 2.0) end
function tmp = code(x) tmp = (exp(x) - exp(-x)) / 2.0; end
code[x_] := N[(N[(N[Exp[x], $MachinePrecision] - N[Exp[(-x)], $MachinePrecision]), $MachinePrecision] / 2.0), $MachinePrecision]
\begin{array}{l}
\\
\frac{e^{x} - e^{-x}}{2}
\end{array}
Sampling outcomes in binary64 precision:
Herbie found 6 alternatives:
| Alternative | Accuracy | Speedup |
|---|
(FPCore (x) :precision binary64 (/ (- (exp x) (exp (- x))) 2.0))
double code(double x) {
return (exp(x) - exp(-x)) / 2.0;
}
real(8) function code(x)
real(8), intent (in) :: x
code = (exp(x) - exp(-x)) / 2.0d0
end function
public static double code(double x) {
return (Math.exp(x) - Math.exp(-x)) / 2.0;
}
def code(x): return (math.exp(x) - math.exp(-x)) / 2.0
function code(x) return Float64(Float64(exp(x) - exp(Float64(-x))) / 2.0) end
function tmp = code(x) tmp = (exp(x) - exp(-x)) / 2.0; end
code[x_] := N[(N[(N[Exp[x], $MachinePrecision] - N[Exp[(-x)], $MachinePrecision]), $MachinePrecision] / 2.0), $MachinePrecision]
\begin{array}{l}
\\
\frac{e^{x} - e^{-x}}{2}
\end{array}
x\_m = (fabs.f64 x)
x\_s = (copysign.f64 #s(literal 1 binary64) x)
(FPCore (x_s x_m)
:precision binary64
(*
x_s
(if (<= (- (exp x_m) (exp (- x_m))) 2e-7)
(+ x_m (* (pow x_m 3.0) 0.16666666666666666))
(/ (expm1 x_m) 2.0))))x\_m = fabs(x);
x\_s = copysign(1.0, x);
double code(double x_s, double x_m) {
double tmp;
if ((exp(x_m) - exp(-x_m)) <= 2e-7) {
tmp = x_m + (pow(x_m, 3.0) * 0.16666666666666666);
} else {
tmp = expm1(x_m) / 2.0;
}
return x_s * tmp;
}
x\_m = Math.abs(x);
x\_s = Math.copySign(1.0, x);
public static double code(double x_s, double x_m) {
double tmp;
if ((Math.exp(x_m) - Math.exp(-x_m)) <= 2e-7) {
tmp = x_m + (Math.pow(x_m, 3.0) * 0.16666666666666666);
} else {
tmp = Math.expm1(x_m) / 2.0;
}
return x_s * tmp;
}
x\_m = math.fabs(x) x\_s = math.copysign(1.0, x) def code(x_s, x_m): tmp = 0 if (math.exp(x_m) - math.exp(-x_m)) <= 2e-7: tmp = x_m + (math.pow(x_m, 3.0) * 0.16666666666666666) else: tmp = math.expm1(x_m) / 2.0 return x_s * tmp
x\_m = abs(x) x\_s = copysign(1.0, x) function code(x_s, x_m) tmp = 0.0 if (Float64(exp(x_m) - exp(Float64(-x_m))) <= 2e-7) tmp = Float64(x_m + Float64((x_m ^ 3.0) * 0.16666666666666666)); else tmp = Float64(expm1(x_m) / 2.0); end return Float64(x_s * tmp) end
x\_m = N[Abs[x], $MachinePrecision]
x\_s = N[With[{TMP1 = Abs[1.0], TMP2 = Sign[x]}, TMP1 * If[TMP2 == 0, 1, TMP2]], $MachinePrecision]
code[x$95$s_, x$95$m_] := N[(x$95$s * If[LessEqual[N[(N[Exp[x$95$m], $MachinePrecision] - N[Exp[(-x$95$m)], $MachinePrecision]), $MachinePrecision], 2e-7], N[(x$95$m + N[(N[Power[x$95$m, 3.0], $MachinePrecision] * 0.16666666666666666), $MachinePrecision]), $MachinePrecision], N[(N[(Exp[x$95$m] - 1), $MachinePrecision] / 2.0), $MachinePrecision]]), $MachinePrecision]
\begin{array}{l}
x\_m = \left|x\right|
\\
x\_s = \mathsf{copysign}\left(1, x\right)
\\
x\_s \cdot \begin{array}{l}
\mathbf{if}\;e^{x\_m} - e^{-x\_m} \leq 2 \cdot 10^{-7}:\\
\;\;\;\;x\_m + {x\_m}^{3} \cdot 0.16666666666666666\\
\mathbf{else}:\\
\;\;\;\;\frac{\mathsf{expm1}\left(x\_m\right)}{2}\\
\end{array}
\end{array}
if (-.f64 (exp.f64 x) (exp.f64 (neg.f64 x))) < 1.9999999999999999e-7Initial program 36.2%
Taylor expanded in x around 0 87.1%
+-commutative87.1%
distribute-rgt-in87.1%
associate-*l*87.1%
fma-define87.1%
pow-plus87.1%
metadata-eval87.1%
Simplified87.1%
Taylor expanded in x around 0 87.1%
distribute-rgt-in87.1%
*-lft-identity87.1%
associate-*r*87.1%
unpow287.1%
unpow387.1%
*-commutative87.1%
Simplified87.1%
if 1.9999999999999999e-7 < (-.f64 (exp.f64 x) (exp.f64 (neg.f64 x))) Initial program 100.0%
Taylor expanded in x around 0 100.0%
mul-1-neg100.0%
unsub-neg100.0%
Simplified100.0%
Taylor expanded in x around 0 100.0%
sub-neg100.0%
metadata-eval100.0%
Applied egg-rr100.0%
metadata-eval100.0%
sub-neg100.0%
expm1-define100.0%
Simplified100.0%
x\_m = (fabs.f64 x) x\_s = (copysign.f64 #s(literal 1 binary64) x) (FPCore (x_s x_m) :precision binary64 (* x_s (if (<= x_m 1.25) x_m (/ (expm1 x_m) 2.0))))
x\_m = fabs(x);
x\_s = copysign(1.0, x);
double code(double x_s, double x_m) {
double tmp;
if (x_m <= 1.25) {
tmp = x_m;
} else {
tmp = expm1(x_m) / 2.0;
}
return x_s * tmp;
}
x\_m = Math.abs(x);
x\_s = Math.copySign(1.0, x);
public static double code(double x_s, double x_m) {
double tmp;
if (x_m <= 1.25) {
tmp = x_m;
} else {
tmp = Math.expm1(x_m) / 2.0;
}
return x_s * tmp;
}
x\_m = math.fabs(x) x\_s = math.copysign(1.0, x) def code(x_s, x_m): tmp = 0 if x_m <= 1.25: tmp = x_m else: tmp = math.expm1(x_m) / 2.0 return x_s * tmp
x\_m = abs(x) x\_s = copysign(1.0, x) function code(x_s, x_m) tmp = 0.0 if (x_m <= 1.25) tmp = x_m; else tmp = Float64(expm1(x_m) / 2.0); end return Float64(x_s * tmp) end
x\_m = N[Abs[x], $MachinePrecision]
x\_s = N[With[{TMP1 = Abs[1.0], TMP2 = Sign[x]}, TMP1 * If[TMP2 == 0, 1, TMP2]], $MachinePrecision]
code[x$95$s_, x$95$m_] := N[(x$95$s * If[LessEqual[x$95$m, 1.25], x$95$m, N[(N[(Exp[x$95$m] - 1), $MachinePrecision] / 2.0), $MachinePrecision]]), $MachinePrecision]
\begin{array}{l}
x\_m = \left|x\right|
\\
x\_s = \mathsf{copysign}\left(1, x\right)
\\
x\_s \cdot \begin{array}{l}
\mathbf{if}\;x\_m \leq 1.25:\\
\;\;\;\;x\_m\\
\mathbf{else}:\\
\;\;\;\;\frac{\mathsf{expm1}\left(x\_m\right)}{2}\\
\end{array}
\end{array}
if x < 1.25Initial program 36.2%
Taylor expanded in x around 0 87.1%
+-commutative87.1%
distribute-rgt-in87.1%
associate-*l*87.1%
fma-define87.1%
pow-plus87.1%
metadata-eval87.1%
Simplified87.1%
Taylor expanded in x around 0 69.5%
if 1.25 < x Initial program 100.0%
Taylor expanded in x around 0 100.0%
mul-1-neg100.0%
unsub-neg100.0%
Simplified100.0%
Taylor expanded in x around 0 100.0%
sub-neg100.0%
metadata-eval100.0%
Applied egg-rr100.0%
metadata-eval100.0%
sub-neg100.0%
expm1-define100.0%
Simplified100.0%
x\_m = (fabs.f64 x)
x\_s = (copysign.f64 #s(literal 1 binary64) x)
(FPCore (x_s x_m)
:precision binary64
(*
x_s
(*
x_m
(+
1.0
(*
x_m
(+ 0.25 (* x_m (+ 0.08333333333333333 (* x_m 0.020833333333333332)))))))))x\_m = fabs(x);
x\_s = copysign(1.0, x);
double code(double x_s, double x_m) {
return x_s * (x_m * (1.0 + (x_m * (0.25 + (x_m * (0.08333333333333333 + (x_m * 0.020833333333333332)))))));
}
x\_m = abs(x)
x\_s = copysign(1.0d0, x)
real(8) function code(x_s, x_m)
real(8), intent (in) :: x_s
real(8), intent (in) :: x_m
code = x_s * (x_m * (1.0d0 + (x_m * (0.25d0 + (x_m * (0.08333333333333333d0 + (x_m * 0.020833333333333332d0)))))))
end function
x\_m = Math.abs(x);
x\_s = Math.copySign(1.0, x);
public static double code(double x_s, double x_m) {
return x_s * (x_m * (1.0 + (x_m * (0.25 + (x_m * (0.08333333333333333 + (x_m * 0.020833333333333332)))))));
}
x\_m = math.fabs(x) x\_s = math.copysign(1.0, x) def code(x_s, x_m): return x_s * (x_m * (1.0 + (x_m * (0.25 + (x_m * (0.08333333333333333 + (x_m * 0.020833333333333332)))))))
x\_m = abs(x) x\_s = copysign(1.0, x) function code(x_s, x_m) return Float64(x_s * Float64(x_m * Float64(1.0 + Float64(x_m * Float64(0.25 + Float64(x_m * Float64(0.08333333333333333 + Float64(x_m * 0.020833333333333332)))))))) end
x\_m = abs(x); x\_s = sign(x) * abs(1.0); function tmp = code(x_s, x_m) tmp = x_s * (x_m * (1.0 + (x_m * (0.25 + (x_m * (0.08333333333333333 + (x_m * 0.020833333333333332))))))); end
x\_m = N[Abs[x], $MachinePrecision]
x\_s = N[With[{TMP1 = Abs[1.0], TMP2 = Sign[x]}, TMP1 * If[TMP2 == 0, 1, TMP2]], $MachinePrecision]
code[x$95$s_, x$95$m_] := N[(x$95$s * N[(x$95$m * N[(1.0 + N[(x$95$m * N[(0.25 + N[(x$95$m * N[(0.08333333333333333 + N[(x$95$m * 0.020833333333333332), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
x\_m = \left|x\right|
\\
x\_s = \mathsf{copysign}\left(1, x\right)
\\
x\_s \cdot \left(x\_m \cdot \left(1 + x\_m \cdot \left(0.25 + x\_m \cdot \left(0.08333333333333333 + x\_m \cdot 0.020833333333333332\right)\right)\right)\right)
\end{array}
Initial program 51.1%
Taylor expanded in x around 0 27.8%
mul-1-neg27.8%
unsub-neg27.8%
Simplified27.8%
Taylor expanded in x around 0 72.0%
*-commutative72.0%
Simplified72.0%
x\_m = (fabs.f64 x) x\_s = (copysign.f64 #s(literal 1 binary64) x) (FPCore (x_s x_m) :precision binary64 (* x_s (* x_m (+ 1.0 (* x_m (+ 0.25 (* x_m 0.08333333333333333)))))))
x\_m = fabs(x);
x\_s = copysign(1.0, x);
double code(double x_s, double x_m) {
return x_s * (x_m * (1.0 + (x_m * (0.25 + (x_m * 0.08333333333333333)))));
}
x\_m = abs(x)
x\_s = copysign(1.0d0, x)
real(8) function code(x_s, x_m)
real(8), intent (in) :: x_s
real(8), intent (in) :: x_m
code = x_s * (x_m * (1.0d0 + (x_m * (0.25d0 + (x_m * 0.08333333333333333d0)))))
end function
x\_m = Math.abs(x);
x\_s = Math.copySign(1.0, x);
public static double code(double x_s, double x_m) {
return x_s * (x_m * (1.0 + (x_m * (0.25 + (x_m * 0.08333333333333333)))));
}
x\_m = math.fabs(x) x\_s = math.copysign(1.0, x) def code(x_s, x_m): return x_s * (x_m * (1.0 + (x_m * (0.25 + (x_m * 0.08333333333333333)))))
x\_m = abs(x) x\_s = copysign(1.0, x) function code(x_s, x_m) return Float64(x_s * Float64(x_m * Float64(1.0 + Float64(x_m * Float64(0.25 + Float64(x_m * 0.08333333333333333)))))) end
x\_m = abs(x); x\_s = sign(x) * abs(1.0); function tmp = code(x_s, x_m) tmp = x_s * (x_m * (1.0 + (x_m * (0.25 + (x_m * 0.08333333333333333))))); end
x\_m = N[Abs[x], $MachinePrecision]
x\_s = N[With[{TMP1 = Abs[1.0], TMP2 = Sign[x]}, TMP1 * If[TMP2 == 0, 1, TMP2]], $MachinePrecision]
code[x$95$s_, x$95$m_] := N[(x$95$s * N[(x$95$m * N[(1.0 + N[(x$95$m * N[(0.25 + N[(x$95$m * 0.08333333333333333), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
x\_m = \left|x\right|
\\
x\_s = \mathsf{copysign}\left(1, x\right)
\\
x\_s \cdot \left(x\_m \cdot \left(1 + x\_m \cdot \left(0.25 + x\_m \cdot 0.08333333333333333\right)\right)\right)
\end{array}
Initial program 51.1%
Taylor expanded in x around 0 27.8%
mul-1-neg27.8%
unsub-neg27.8%
Simplified27.8%
Taylor expanded in x around 0 85.1%
*-commutative85.1%
Simplified85.1%
x\_m = (fabs.f64 x) x\_s = (copysign.f64 #s(literal 1 binary64) x) (FPCore (x_s x_m) :precision binary64 (* x_s (* x_m (+ 1.0 (* x_m 0.25)))))
x\_m = fabs(x);
x\_s = copysign(1.0, x);
double code(double x_s, double x_m) {
return x_s * (x_m * (1.0 + (x_m * 0.25)));
}
x\_m = abs(x)
x\_s = copysign(1.0d0, x)
real(8) function code(x_s, x_m)
real(8), intent (in) :: x_s
real(8), intent (in) :: x_m
code = x_s * (x_m * (1.0d0 + (x_m * 0.25d0)))
end function
x\_m = Math.abs(x);
x\_s = Math.copySign(1.0, x);
public static double code(double x_s, double x_m) {
return x_s * (x_m * (1.0 + (x_m * 0.25)));
}
x\_m = math.fabs(x) x\_s = math.copysign(1.0, x) def code(x_s, x_m): return x_s * (x_m * (1.0 + (x_m * 0.25)))
x\_m = abs(x) x\_s = copysign(1.0, x) function code(x_s, x_m) return Float64(x_s * Float64(x_m * Float64(1.0 + Float64(x_m * 0.25)))) end
x\_m = abs(x); x\_s = sign(x) * abs(1.0); function tmp = code(x_s, x_m) tmp = x_s * (x_m * (1.0 + (x_m * 0.25))); end
x\_m = N[Abs[x], $MachinePrecision]
x\_s = N[With[{TMP1 = Abs[1.0], TMP2 = Sign[x]}, TMP1 * If[TMP2 == 0, 1, TMP2]], $MachinePrecision]
code[x$95$s_, x$95$m_] := N[(x$95$s * N[(x$95$m * N[(1.0 + N[(x$95$m * 0.25), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
x\_m = \left|x\right|
\\
x\_s = \mathsf{copysign}\left(1, x\right)
\\
x\_s \cdot \left(x\_m \cdot \left(1 + x\_m \cdot 0.25\right)\right)
\end{array}
Initial program 51.1%
Taylor expanded in x around 0 27.8%
mul-1-neg27.8%
unsub-neg27.8%
Simplified27.8%
Taylor expanded in x around 0 66.8%
*-commutative66.8%
Simplified66.8%
x\_m = (fabs.f64 x) x\_s = (copysign.f64 #s(literal 1 binary64) x) (FPCore (x_s x_m) :precision binary64 (* x_s x_m))
x\_m = fabs(x);
x\_s = copysign(1.0, x);
double code(double x_s, double x_m) {
return x_s * x_m;
}
x\_m = abs(x)
x\_s = copysign(1.0d0, x)
real(8) function code(x_s, x_m)
real(8), intent (in) :: x_s
real(8), intent (in) :: x_m
code = x_s * x_m
end function
x\_m = Math.abs(x);
x\_s = Math.copySign(1.0, x);
public static double code(double x_s, double x_m) {
return x_s * x_m;
}
x\_m = math.fabs(x) x\_s = math.copysign(1.0, x) def code(x_s, x_m): return x_s * x_m
x\_m = abs(x) x\_s = copysign(1.0, x) function code(x_s, x_m) return Float64(x_s * x_m) end
x\_m = abs(x); x\_s = sign(x) * abs(1.0); function tmp = code(x_s, x_m) tmp = x_s * x_m; end
x\_m = N[Abs[x], $MachinePrecision]
x\_s = N[With[{TMP1 = Abs[1.0], TMP2 = Sign[x]}, TMP1 * If[TMP2 == 0, 1, TMP2]], $MachinePrecision]
code[x$95$s_, x$95$m_] := N[(x$95$s * x$95$m), $MachinePrecision]
\begin{array}{l}
x\_m = \left|x\right|
\\
x\_s = \mathsf{copysign}\left(1, x\right)
\\
x\_s \cdot x\_m
\end{array}
Initial program 51.1%
Taylor expanded in x around 0 85.4%
+-commutative85.4%
distribute-rgt-in85.4%
associate-*l*85.4%
fma-define85.4%
pow-plus85.4%
metadata-eval85.4%
Simplified85.4%
Taylor expanded in x around 0 54.5%
herbie shell --seed 2024110
(FPCore (x)
:name "Hyperbolic sine"
:precision binary64
(/ (- (exp x) (exp (- x))) 2.0))