
(FPCore (x) :precision binary64 (sqrt (/ (- (exp (* 2.0 x)) 1.0) (- (exp x) 1.0))))
double code(double x) {
return sqrt(((exp((2.0 * x)) - 1.0) / (exp(x) - 1.0)));
}
real(8) function code(x)
real(8), intent (in) :: x
code = sqrt(((exp((2.0d0 * x)) - 1.0d0) / (exp(x) - 1.0d0)))
end function
public static double code(double x) {
return Math.sqrt(((Math.exp((2.0 * x)) - 1.0) / (Math.exp(x) - 1.0)));
}
def code(x): return math.sqrt(((math.exp((2.0 * x)) - 1.0) / (math.exp(x) - 1.0)))
function code(x) return sqrt(Float64(Float64(exp(Float64(2.0 * x)) - 1.0) / Float64(exp(x) - 1.0))) end
function tmp = code(x) tmp = sqrt(((exp((2.0 * x)) - 1.0) / (exp(x) - 1.0))); end
code[x_] := N[Sqrt[N[(N[(N[Exp[N[(2.0 * x), $MachinePrecision]], $MachinePrecision] - 1.0), $MachinePrecision] / N[(N[Exp[x], $MachinePrecision] - 1.0), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]
\begin{array}{l}
\\
\sqrt{\frac{e^{2 \cdot x} - 1}{e^{x} - 1}}
\end{array}
Sampling outcomes in binary64 precision:
Herbie found 5 alternatives:
| Alternative | Accuracy | Speedup |
|---|
(FPCore (x) :precision binary64 (sqrt (/ (- (exp (* 2.0 x)) 1.0) (- (exp x) 1.0))))
double code(double x) {
return sqrt(((exp((2.0 * x)) - 1.0) / (exp(x) - 1.0)));
}
real(8) function code(x)
real(8), intent (in) :: x
code = sqrt(((exp((2.0d0 * x)) - 1.0d0) / (exp(x) - 1.0d0)))
end function
public static double code(double x) {
return Math.sqrt(((Math.exp((2.0 * x)) - 1.0) / (Math.exp(x) - 1.0)));
}
def code(x): return math.sqrt(((math.exp((2.0 * x)) - 1.0) / (math.exp(x) - 1.0)))
function code(x) return sqrt(Float64(Float64(exp(Float64(2.0 * x)) - 1.0) / Float64(exp(x) - 1.0))) end
function tmp = code(x) tmp = sqrt(((exp((2.0 * x)) - 1.0) / (exp(x) - 1.0))); end
code[x_] := N[Sqrt[N[(N[(N[Exp[N[(2.0 * x), $MachinePrecision]], $MachinePrecision] - 1.0), $MachinePrecision] / N[(N[Exp[x], $MachinePrecision] - 1.0), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]
\begin{array}{l}
\\
\sqrt{\frac{e^{2 \cdot x} - 1}{e^{x} - 1}}
\end{array}
(FPCore (x) :precision binary64 (sqrt (- (exp x) -1.0)))
double code(double x) {
return sqrt((exp(x) - -1.0));
}
real(8) function code(x)
real(8), intent (in) :: x
code = sqrt((exp(x) - (-1.0d0)))
end function
public static double code(double x) {
return Math.sqrt((Math.exp(x) - -1.0));
}
def code(x): return math.sqrt((math.exp(x) - -1.0))
function code(x) return sqrt(Float64(exp(x) - -1.0)) end
function tmp = code(x) tmp = sqrt((exp(x) - -1.0)); end
code[x_] := N[Sqrt[N[(N[Exp[x], $MachinePrecision] - -1.0), $MachinePrecision]], $MachinePrecision]
\begin{array}{l}
\\
\sqrt{e^{x} - -1}
\end{array}
Initial program 40.3%
lift-/.f64N/A
lift--.f64N/A
lift-exp.f64N/A
lift-*.f64N/A
*-commutativeN/A
exp-prodN/A
lift-exp.f64N/A
pow2N/A
metadata-evalN/A
lift--.f64N/A
flip-+N/A
metadata-evalN/A
metadata-evalN/A
sub-negN/A
lower--.f64N/A
metadata-eval100.0
Applied rewrites100.0%
(FPCore (x)
:precision binary64
(if (<= (/ (- (exp (* 2.0 x)) 1.0) (- (exp x) 1.0)) 1.5)
(sqrt 2.0)
(fma
(fma (fma 0.036458333333333336 x 0.1875) x 0.5)
(/ x (sqrt 2.0))
(sqrt 2.0))))
double code(double x) {
double tmp;
if (((exp((2.0 * x)) - 1.0) / (exp(x) - 1.0)) <= 1.5) {
tmp = sqrt(2.0);
} else {
tmp = fma(fma(fma(0.036458333333333336, x, 0.1875), x, 0.5), (x / sqrt(2.0)), sqrt(2.0));
}
return tmp;
}
function code(x) tmp = 0.0 if (Float64(Float64(exp(Float64(2.0 * x)) - 1.0) / Float64(exp(x) - 1.0)) <= 1.5) tmp = sqrt(2.0); else tmp = fma(fma(fma(0.036458333333333336, x, 0.1875), x, 0.5), Float64(x / sqrt(2.0)), sqrt(2.0)); end return tmp end
code[x_] := If[LessEqual[N[(N[(N[Exp[N[(2.0 * x), $MachinePrecision]], $MachinePrecision] - 1.0), $MachinePrecision] / N[(N[Exp[x], $MachinePrecision] - 1.0), $MachinePrecision]), $MachinePrecision], 1.5], N[Sqrt[2.0], $MachinePrecision], N[(N[(N[(0.036458333333333336 * x + 0.1875), $MachinePrecision] * x + 0.5), $MachinePrecision] * N[(x / N[Sqrt[2.0], $MachinePrecision]), $MachinePrecision] + N[Sqrt[2.0], $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;\frac{e^{2 \cdot x} - 1}{e^{x} - 1} \leq 1.5:\\
\;\;\;\;\sqrt{2}\\
\mathbf{else}:\\
\;\;\;\;\mathsf{fma}\left(\mathsf{fma}\left(\mathsf{fma}\left(0.036458333333333336, x, 0.1875\right), x, 0.5\right), \frac{x}{\sqrt{2}}, \sqrt{2}\right)\\
\end{array}
\end{array}
if (/.f64 (-.f64 (exp.f64 (*.f64 #s(literal 2 binary64) x)) #s(literal 1 binary64)) (-.f64 (exp.f64 x) #s(literal 1 binary64))) < 1.5Initial program 100.0%
Taylor expanded in x around 0
Applied rewrites20.7%
if 1.5 < (/.f64 (-.f64 (exp.f64 (*.f64 #s(literal 2 binary64) x)) #s(literal 1 binary64)) (-.f64 (exp.f64 x) #s(literal 1 binary64))) Initial program 6.3%
Taylor expanded in x around 0
Applied rewrites96.1%
Taylor expanded in x around 0
+-commutativeN/A
Applied rewrites98.6%
Taylor expanded in x around 0
Applied rewrites98.9%
Applied rewrites98.9%
(FPCore (x) :precision binary64 (if (<= (/ (- (exp (* 2.0 x)) 1.0) (- (exp x) 1.0)) 1.5) (sqrt 2.0) (sqrt (fma (fma (fma 0.16666666666666666 x 0.5) x 1.0) x 2.0))))
double code(double x) {
double tmp;
if (((exp((2.0 * x)) - 1.0) / (exp(x) - 1.0)) <= 1.5) {
tmp = sqrt(2.0);
} else {
tmp = sqrt(fma(fma(fma(0.16666666666666666, x, 0.5), x, 1.0), x, 2.0));
}
return tmp;
}
function code(x) tmp = 0.0 if (Float64(Float64(exp(Float64(2.0 * x)) - 1.0) / Float64(exp(x) - 1.0)) <= 1.5) tmp = sqrt(2.0); else tmp = sqrt(fma(fma(fma(0.16666666666666666, x, 0.5), x, 1.0), x, 2.0)); end return tmp end
code[x_] := If[LessEqual[N[(N[(N[Exp[N[(2.0 * x), $MachinePrecision]], $MachinePrecision] - 1.0), $MachinePrecision] / N[(N[Exp[x], $MachinePrecision] - 1.0), $MachinePrecision]), $MachinePrecision], 1.5], N[Sqrt[2.0], $MachinePrecision], N[Sqrt[N[(N[(N[(0.16666666666666666 * x + 0.5), $MachinePrecision] * x + 1.0), $MachinePrecision] * x + 2.0), $MachinePrecision]], $MachinePrecision]]
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;\frac{e^{2 \cdot x} - 1}{e^{x} - 1} \leq 1.5:\\
\;\;\;\;\sqrt{2}\\
\mathbf{else}:\\
\;\;\;\;\sqrt{\mathsf{fma}\left(\mathsf{fma}\left(\mathsf{fma}\left(0.16666666666666666, x, 0.5\right), x, 1\right), x, 2\right)}\\
\end{array}
\end{array}
if (/.f64 (-.f64 (exp.f64 (*.f64 #s(literal 2 binary64) x)) #s(literal 1 binary64)) (-.f64 (exp.f64 x) #s(literal 1 binary64))) < 1.5Initial program 100.0%
Taylor expanded in x around 0
Applied rewrites20.7%
if 1.5 < (/.f64 (-.f64 (exp.f64 (*.f64 #s(literal 2 binary64) x)) #s(literal 1 binary64)) (-.f64 (exp.f64 x) #s(literal 1 binary64))) Initial program 6.3%
Taylor expanded in x around 0
+-commutativeN/A
*-commutativeN/A
lower-fma.f64N/A
+-commutativeN/A
*-commutativeN/A
lower-fma.f64N/A
+-commutativeN/A
lower-fma.f6498.9
Applied rewrites98.9%
(FPCore (x) :precision binary64 (if (<= (/ (- (exp (* 2.0 x)) 1.0) (- (exp x) 1.0)) 1.5) (sqrt 2.0) (sqrt (fma (fma 0.5 x 1.0) x 2.0))))
double code(double x) {
double tmp;
if (((exp((2.0 * x)) - 1.0) / (exp(x) - 1.0)) <= 1.5) {
tmp = sqrt(2.0);
} else {
tmp = sqrt(fma(fma(0.5, x, 1.0), x, 2.0));
}
return tmp;
}
function code(x) tmp = 0.0 if (Float64(Float64(exp(Float64(2.0 * x)) - 1.0) / Float64(exp(x) - 1.0)) <= 1.5) tmp = sqrt(2.0); else tmp = sqrt(fma(fma(0.5, x, 1.0), x, 2.0)); end return tmp end
code[x_] := If[LessEqual[N[(N[(N[Exp[N[(2.0 * x), $MachinePrecision]], $MachinePrecision] - 1.0), $MachinePrecision] / N[(N[Exp[x], $MachinePrecision] - 1.0), $MachinePrecision]), $MachinePrecision], 1.5], N[Sqrt[2.0], $MachinePrecision], N[Sqrt[N[(N[(0.5 * x + 1.0), $MachinePrecision] * x + 2.0), $MachinePrecision]], $MachinePrecision]]
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;\frac{e^{2 \cdot x} - 1}{e^{x} - 1} \leq 1.5:\\
\;\;\;\;\sqrt{2}\\
\mathbf{else}:\\
\;\;\;\;\sqrt{\mathsf{fma}\left(\mathsf{fma}\left(0.5, x, 1\right), x, 2\right)}\\
\end{array}
\end{array}
if (/.f64 (-.f64 (exp.f64 (*.f64 #s(literal 2 binary64) x)) #s(literal 1 binary64)) (-.f64 (exp.f64 x) #s(literal 1 binary64))) < 1.5Initial program 100.0%
Taylor expanded in x around 0
Applied rewrites20.7%
if 1.5 < (/.f64 (-.f64 (exp.f64 (*.f64 #s(literal 2 binary64) x)) #s(literal 1 binary64)) (-.f64 (exp.f64 x) #s(literal 1 binary64))) Initial program 6.3%
Taylor expanded in x around 0
+-commutativeN/A
*-commutativeN/A
lower-fma.f64N/A
+-commutativeN/A
lower-fma.f6498.6
Applied rewrites98.6%
(FPCore (x) :precision binary64 (sqrt 2.0))
double code(double x) {
return sqrt(2.0);
}
real(8) function code(x)
real(8), intent (in) :: x
code = sqrt(2.0d0)
end function
public static double code(double x) {
return Math.sqrt(2.0);
}
def code(x): return math.sqrt(2.0)
function code(x) return sqrt(2.0) end
function tmp = code(x) tmp = sqrt(2.0); end
code[x_] := N[Sqrt[2.0], $MachinePrecision]
\begin{array}{l}
\\
\sqrt{2}
\end{array}
Initial program 40.3%
Taylor expanded in x around 0
Applied rewrites68.7%
herbie shell --seed 2024235
(FPCore (x)
:name "sqrtexp (problem 3.4.4)"
:precision binary64
(sqrt (/ (- (exp (* 2.0 x)) 1.0) (- (exp x) 1.0))))