
(FPCore (x) :precision binary64 (exp (- (- 1.0 (* x x)))))
double code(double x) {
return exp(-(1.0 - (x * x)));
}
real(8) function code(x)
real(8), intent (in) :: x
code = exp(-(1.0d0 - (x * x)))
end function
public static double code(double x) {
return Math.exp(-(1.0 - (x * x)));
}
def code(x): return math.exp(-(1.0 - (x * x)))
function code(x) return exp(Float64(-Float64(1.0 - Float64(x * x)))) end
function tmp = code(x) tmp = exp(-(1.0 - (x * x))); end
code[x_] := N[Exp[(-N[(1.0 - N[(x * x), $MachinePrecision]), $MachinePrecision])], $MachinePrecision]
\begin{array}{l}
\\
e^{-\left(1 - x \cdot x\right)}
\end{array}
Sampling outcomes in binary64 precision:
Herbie found 4 alternatives:
| Alternative | Accuracy | Speedup |
|---|
(FPCore (x) :precision binary64 (exp (- (- 1.0 (* x x)))))
double code(double x) {
return exp(-(1.0 - (x * x)));
}
real(8) function code(x)
real(8), intent (in) :: x
code = exp(-(1.0d0 - (x * x)))
end function
public static double code(double x) {
return Math.exp(-(1.0 - (x * x)));
}
def code(x): return math.exp(-(1.0 - (x * x)))
function code(x) return exp(Float64(-Float64(1.0 - Float64(x * x)))) end
function tmp = code(x) tmp = exp(-(1.0 - (x * x))); end
code[x_] := N[Exp[(-N[(1.0 - N[(x * x), $MachinePrecision]), $MachinePrecision])], $MachinePrecision]
\begin{array}{l}
\\
e^{-\left(1 - x \cdot x\right)}
\end{array}
(FPCore (x) :precision binary64 (exp (+ (* x x) -1.0)))
double code(double x) {
return exp(((x * x) + -1.0));
}
real(8) function code(x)
real(8), intent (in) :: x
code = exp(((x * x) + (-1.0d0)))
end function
public static double code(double x) {
return Math.exp(((x * x) + -1.0));
}
def code(x): return math.exp(((x * x) + -1.0))
function code(x) return exp(Float64(Float64(x * x) + -1.0)) end
function tmp = code(x) tmp = exp(((x * x) + -1.0)); end
code[x_] := N[Exp[N[(N[(x * x), $MachinePrecision] + -1.0), $MachinePrecision]], $MachinePrecision]
\begin{array}{l}
\\
e^{x \cdot x + -1}
\end{array}
Initial program 100.0%
neg-sub0100.0%
sqr-neg100.0%
associate--r-100.0%
metadata-eval100.0%
+-commutative100.0%
sqr-neg100.0%
Simplified100.0%
(FPCore (x) :precision binary64 (exp (+ x -1.0)))
double code(double x) {
return exp((x + -1.0));
}
real(8) function code(x)
real(8), intent (in) :: x
code = exp((x + (-1.0d0)))
end function
public static double code(double x) {
return Math.exp((x + -1.0));
}
def code(x): return math.exp((x + -1.0))
function code(x) return exp(Float64(x + -1.0)) end
function tmp = code(x) tmp = exp((x + -1.0)); end
code[x_] := N[Exp[N[(x + -1.0), $MachinePrecision]], $MachinePrecision]
\begin{array}{l}
\\
e^{x + -1}
\end{array}
Initial program 100.0%
neg-sub0100.0%
sqr-neg100.0%
associate--r-100.0%
metadata-eval100.0%
+-commutative100.0%
sqr-neg100.0%
Simplified100.0%
difference-of-sqr--1100.0%
exp-prod99.9%
sub-neg99.9%
metadata-eval99.9%
Applied egg-rr99.9%
Taylor expanded in x around 0 70.6%
exp-1-e70.6%
Simplified70.6%
Taylor expanded in x around inf 70.6%
log-E70.6%
sub-neg70.6%
metadata-eval70.6%
*-lft-identity70.6%
Simplified70.6%
(FPCore (x) :precision binary64 (/ (+ x 1.0) E))
double code(double x) {
return (x + 1.0) / ((double) M_E);
}
public static double code(double x) {
return (x + 1.0) / Math.E;
}
def code(x): return (x + 1.0) / math.e
function code(x) return Float64(Float64(x + 1.0) / exp(1)) end
function tmp = code(x) tmp = (x + 1.0) / 2.71828182845904523536; end
code[x_] := N[(N[(x + 1.0), $MachinePrecision] / E), $MachinePrecision]
\begin{array}{l}
\\
\frac{x + 1}{e}
\end{array}
Initial program 100.0%
neg-sub0100.0%
sqr-neg100.0%
associate--r-100.0%
metadata-eval100.0%
+-commutative100.0%
sqr-neg100.0%
Simplified100.0%
difference-of-sqr--1100.0%
exp-prod99.9%
sub-neg99.9%
metadata-eval99.9%
Applied egg-rr99.9%
Taylor expanded in x around 0 70.6%
exp-1-e70.6%
Simplified70.6%
Taylor expanded in x around 0 48.8%
exp-1-e48.8%
log-E48.8%
metadata-eval48.8%
log-E48.8%
associate-/l*48.8%
log-E48.8%
metadata-eval48.8%
exp-1-e48.8%
/-rgt-identity48.8%
associate-*r/48.8%
associate-*l/48.8%
/-rgt-identity48.8%
distribute-rgt1-in48.8%
exp-1-e48.8%
associate-*r/48.8%
*-rgt-identity48.8%
+-commutative48.8%
Simplified48.8%
Final simplification48.8%
(FPCore (x) :precision binary64 (/ 1.0 E))
double code(double x) {
return 1.0 / ((double) M_E);
}
public static double code(double x) {
return 1.0 / Math.E;
}
def code(x): return 1.0 / math.e
function code(x) return Float64(1.0 / exp(1)) end
function tmp = code(x) tmp = 1.0 / 2.71828182845904523536; end
code[x_] := N[(1.0 / E), $MachinePrecision]
\begin{array}{l}
\\
\frac{1}{e}
\end{array}
Initial program 100.0%
neg-sub0100.0%
sqr-neg100.0%
associate--r-100.0%
metadata-eval100.0%
+-commutative100.0%
sqr-neg100.0%
Simplified100.0%
difference-of-sqr--1100.0%
exp-prod99.9%
sub-neg99.9%
metadata-eval99.9%
Applied egg-rr99.9%
Taylor expanded in x around 0 70.6%
exp-1-e70.6%
Simplified70.6%
Taylor expanded in x around 0 49.9%
herbie shell --seed 2024103
(FPCore (x)
:name "exp neg sub"
:precision binary64
(exp (- (- 1.0 (* x x)))))