
(FPCore (x)
:precision binary64
(let* ((t_0 (/ 1.0 (+ 1.0 (* 0.3275911 (fabs x))))))
(-
1.0
(*
(*
t_0
(+
0.254829592
(*
t_0
(+
-0.284496736
(*
t_0
(+ 1.421413741 (* t_0 (+ -1.453152027 (* t_0 1.061405429)))))))))
(exp (- (* (fabs x) (fabs x))))))))
double code(double x) {
double t_0 = 1.0 / (1.0 + (0.3275911 * fabs(x)));
return 1.0 - ((t_0 * (0.254829592 + (t_0 * (-0.284496736 + (t_0 * (1.421413741 + (t_0 * (-1.453152027 + (t_0 * 1.061405429))))))))) * exp(-(fabs(x) * fabs(x))));
}
real(8) function code(x)
real(8), intent (in) :: x
real(8) :: t_0
t_0 = 1.0d0 / (1.0d0 + (0.3275911d0 * abs(x)))
code = 1.0d0 - ((t_0 * (0.254829592d0 + (t_0 * ((-0.284496736d0) + (t_0 * (1.421413741d0 + (t_0 * ((-1.453152027d0) + (t_0 * 1.061405429d0))))))))) * exp(-(abs(x) * abs(x))))
end function
public static double code(double x) {
double t_0 = 1.0 / (1.0 + (0.3275911 * Math.abs(x)));
return 1.0 - ((t_0 * (0.254829592 + (t_0 * (-0.284496736 + (t_0 * (1.421413741 + (t_0 * (-1.453152027 + (t_0 * 1.061405429))))))))) * Math.exp(-(Math.abs(x) * Math.abs(x))));
}
def code(x): t_0 = 1.0 / (1.0 + (0.3275911 * math.fabs(x))) return 1.0 - ((t_0 * (0.254829592 + (t_0 * (-0.284496736 + (t_0 * (1.421413741 + (t_0 * (-1.453152027 + (t_0 * 1.061405429))))))))) * math.exp(-(math.fabs(x) * math.fabs(x))))
function code(x) t_0 = Float64(1.0 / Float64(1.0 + Float64(0.3275911 * abs(x)))) return Float64(1.0 - Float64(Float64(t_0 * Float64(0.254829592 + Float64(t_0 * Float64(-0.284496736 + Float64(t_0 * Float64(1.421413741 + Float64(t_0 * Float64(-1.453152027 + Float64(t_0 * 1.061405429))))))))) * exp(Float64(-Float64(abs(x) * abs(x)))))) end
function tmp = code(x) t_0 = 1.0 / (1.0 + (0.3275911 * abs(x))); tmp = 1.0 - ((t_0 * (0.254829592 + (t_0 * (-0.284496736 + (t_0 * (1.421413741 + (t_0 * (-1.453152027 + (t_0 * 1.061405429))))))))) * exp(-(abs(x) * abs(x)))); end
code[x_] := Block[{t$95$0 = N[(1.0 / N[(1.0 + N[(0.3275911 * N[Abs[x], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]}, N[(1.0 - N[(N[(t$95$0 * N[(0.254829592 + N[(t$95$0 * N[(-0.284496736 + N[(t$95$0 * N[(1.421413741 + N[(t$95$0 * N[(-1.453152027 + N[(t$95$0 * 1.061405429), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] * N[Exp[(-N[(N[Abs[x], $MachinePrecision] * N[Abs[x], $MachinePrecision]), $MachinePrecision])], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}
\\
\begin{array}{l}
t_0 := \frac{1}{1 + 0.3275911 \cdot \left|x\right|}\\
1 - \left(t\_0 \cdot \left(0.254829592 + t\_0 \cdot \left(-0.284496736 + t\_0 \cdot \left(1.421413741 + t\_0 \cdot \left(-1.453152027 + t\_0 \cdot 1.061405429\right)\right)\right)\right)\right) \cdot e^{-\left|x\right| \cdot \left|x\right|}
\end{array}
\end{array}
Sampling outcomes in binary64 precision:
Herbie found 4 alternatives:
| Alternative | Accuracy | Speedup |
|---|
(FPCore (x)
:precision binary64
(let* ((t_0 (/ 1.0 (+ 1.0 (* 0.3275911 (fabs x))))))
(-
1.0
(*
(*
t_0
(+
0.254829592
(*
t_0
(+
-0.284496736
(*
t_0
(+ 1.421413741 (* t_0 (+ -1.453152027 (* t_0 1.061405429)))))))))
(exp (- (* (fabs x) (fabs x))))))))
double code(double x) {
double t_0 = 1.0 / (1.0 + (0.3275911 * fabs(x)));
return 1.0 - ((t_0 * (0.254829592 + (t_0 * (-0.284496736 + (t_0 * (1.421413741 + (t_0 * (-1.453152027 + (t_0 * 1.061405429))))))))) * exp(-(fabs(x) * fabs(x))));
}
real(8) function code(x)
real(8), intent (in) :: x
real(8) :: t_0
t_0 = 1.0d0 / (1.0d0 + (0.3275911d0 * abs(x)))
code = 1.0d0 - ((t_0 * (0.254829592d0 + (t_0 * ((-0.284496736d0) + (t_0 * (1.421413741d0 + (t_0 * ((-1.453152027d0) + (t_0 * 1.061405429d0))))))))) * exp(-(abs(x) * abs(x))))
end function
public static double code(double x) {
double t_0 = 1.0 / (1.0 + (0.3275911 * Math.abs(x)));
return 1.0 - ((t_0 * (0.254829592 + (t_0 * (-0.284496736 + (t_0 * (1.421413741 + (t_0 * (-1.453152027 + (t_0 * 1.061405429))))))))) * Math.exp(-(Math.abs(x) * Math.abs(x))));
}
def code(x): t_0 = 1.0 / (1.0 + (0.3275911 * math.fabs(x))) return 1.0 - ((t_0 * (0.254829592 + (t_0 * (-0.284496736 + (t_0 * (1.421413741 + (t_0 * (-1.453152027 + (t_0 * 1.061405429))))))))) * math.exp(-(math.fabs(x) * math.fabs(x))))
function code(x) t_0 = Float64(1.0 / Float64(1.0 + Float64(0.3275911 * abs(x)))) return Float64(1.0 - Float64(Float64(t_0 * Float64(0.254829592 + Float64(t_0 * Float64(-0.284496736 + Float64(t_0 * Float64(1.421413741 + Float64(t_0 * Float64(-1.453152027 + Float64(t_0 * 1.061405429))))))))) * exp(Float64(-Float64(abs(x) * abs(x)))))) end
function tmp = code(x) t_0 = 1.0 / (1.0 + (0.3275911 * abs(x))); tmp = 1.0 - ((t_0 * (0.254829592 + (t_0 * (-0.284496736 + (t_0 * (1.421413741 + (t_0 * (-1.453152027 + (t_0 * 1.061405429))))))))) * exp(-(abs(x) * abs(x)))); end
code[x_] := Block[{t$95$0 = N[(1.0 / N[(1.0 + N[(0.3275911 * N[Abs[x], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]}, N[(1.0 - N[(N[(t$95$0 * N[(0.254829592 + N[(t$95$0 * N[(-0.284496736 + N[(t$95$0 * N[(1.421413741 + N[(t$95$0 * N[(-1.453152027 + N[(t$95$0 * 1.061405429), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] * N[Exp[(-N[(N[Abs[x], $MachinePrecision] * N[Abs[x], $MachinePrecision]), $MachinePrecision])], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}
\\
\begin{array}{l}
t_0 := \frac{1}{1 + 0.3275911 \cdot \left|x\right|}\\
1 - \left(t\_0 \cdot \left(0.254829592 + t\_0 \cdot \left(-0.284496736 + t\_0 \cdot \left(1.421413741 + t\_0 \cdot \left(-1.453152027 + t\_0 \cdot 1.061405429\right)\right)\right)\right)\right) \cdot e^{-\left|x\right| \cdot \left|x\right|}
\end{array}
\end{array}
x_m = (fabs.f64 x)
(FPCore (x_m)
:precision binary64
(let* ((t_0 (+ 1.0 (* (fabs x_m) 0.3275911))) (t_1 (/ 1.0 t_0)))
(if (<= (fabs x_m) 2e-7)
(+ 1e-9 (exp (log (* x_m 1.128386358070218))))
(+
1.0
(*
(exp (* x_m (- x_m)))
(*
t_1
(-
(*
t_1
(-
(*
t_1
(+
(* 1.453152027 (/ 1.0 (+ 1.0 (* x_m 0.3275911))))
(- (* 1.061405429 (/ -1.0 (pow t_0 2.0))) 1.421413741)))
-0.284496736))
0.254829592)))))))x_m = fabs(x);
double code(double x_m) {
double t_0 = 1.0 + (fabs(x_m) * 0.3275911);
double t_1 = 1.0 / t_0;
double tmp;
if (fabs(x_m) <= 2e-7) {
tmp = 1e-9 + exp(log((x_m * 1.128386358070218)));
} else {
tmp = 1.0 + (exp((x_m * -x_m)) * (t_1 * ((t_1 * ((t_1 * ((1.453152027 * (1.0 / (1.0 + (x_m * 0.3275911)))) + ((1.061405429 * (-1.0 / pow(t_0, 2.0))) - 1.421413741))) - -0.284496736)) - 0.254829592)));
}
return tmp;
}
x_m = abs(x)
real(8) function code(x_m)
real(8), intent (in) :: x_m
real(8) :: t_0
real(8) :: t_1
real(8) :: tmp
t_0 = 1.0d0 + (abs(x_m) * 0.3275911d0)
t_1 = 1.0d0 / t_0
if (abs(x_m) <= 2d-7) then
tmp = 1d-9 + exp(log((x_m * 1.128386358070218d0)))
else
tmp = 1.0d0 + (exp((x_m * -x_m)) * (t_1 * ((t_1 * ((t_1 * ((1.453152027d0 * (1.0d0 / (1.0d0 + (x_m * 0.3275911d0)))) + ((1.061405429d0 * ((-1.0d0) / (t_0 ** 2.0d0))) - 1.421413741d0))) - (-0.284496736d0))) - 0.254829592d0)))
end if
code = tmp
end function
x_m = Math.abs(x);
public static double code(double x_m) {
double t_0 = 1.0 + (Math.abs(x_m) * 0.3275911);
double t_1 = 1.0 / t_0;
double tmp;
if (Math.abs(x_m) <= 2e-7) {
tmp = 1e-9 + Math.exp(Math.log((x_m * 1.128386358070218)));
} else {
tmp = 1.0 + (Math.exp((x_m * -x_m)) * (t_1 * ((t_1 * ((t_1 * ((1.453152027 * (1.0 / (1.0 + (x_m * 0.3275911)))) + ((1.061405429 * (-1.0 / Math.pow(t_0, 2.0))) - 1.421413741))) - -0.284496736)) - 0.254829592)));
}
return tmp;
}
x_m = math.fabs(x) def code(x_m): t_0 = 1.0 + (math.fabs(x_m) * 0.3275911) t_1 = 1.0 / t_0 tmp = 0 if math.fabs(x_m) <= 2e-7: tmp = 1e-9 + math.exp(math.log((x_m * 1.128386358070218))) else: tmp = 1.0 + (math.exp((x_m * -x_m)) * (t_1 * ((t_1 * ((t_1 * ((1.453152027 * (1.0 / (1.0 + (x_m * 0.3275911)))) + ((1.061405429 * (-1.0 / math.pow(t_0, 2.0))) - 1.421413741))) - -0.284496736)) - 0.254829592))) return tmp
x_m = abs(x) function code(x_m) t_0 = Float64(1.0 + Float64(abs(x_m) * 0.3275911)) t_1 = Float64(1.0 / t_0) tmp = 0.0 if (abs(x_m) <= 2e-7) tmp = Float64(1e-9 + exp(log(Float64(x_m * 1.128386358070218)))); else tmp = Float64(1.0 + Float64(exp(Float64(x_m * Float64(-x_m))) * Float64(t_1 * Float64(Float64(t_1 * Float64(Float64(t_1 * Float64(Float64(1.453152027 * Float64(1.0 / Float64(1.0 + Float64(x_m * 0.3275911)))) + Float64(Float64(1.061405429 * Float64(-1.0 / (t_0 ^ 2.0))) - 1.421413741))) - -0.284496736)) - 0.254829592)))); end return tmp end
x_m = abs(x); function tmp_2 = code(x_m) t_0 = 1.0 + (abs(x_m) * 0.3275911); t_1 = 1.0 / t_0; tmp = 0.0; if (abs(x_m) <= 2e-7) tmp = 1e-9 + exp(log((x_m * 1.128386358070218))); else tmp = 1.0 + (exp((x_m * -x_m)) * (t_1 * ((t_1 * ((t_1 * ((1.453152027 * (1.0 / (1.0 + (x_m * 0.3275911)))) + ((1.061405429 * (-1.0 / (t_0 ^ 2.0))) - 1.421413741))) - -0.284496736)) - 0.254829592))); end tmp_2 = tmp; end
x_m = N[Abs[x], $MachinePrecision]
code[x$95$m_] := Block[{t$95$0 = N[(1.0 + N[(N[Abs[x$95$m], $MachinePrecision] * 0.3275911), $MachinePrecision]), $MachinePrecision]}, Block[{t$95$1 = N[(1.0 / t$95$0), $MachinePrecision]}, If[LessEqual[N[Abs[x$95$m], $MachinePrecision], 2e-7], N[(1e-9 + N[Exp[N[Log[N[(x$95$m * 1.128386358070218), $MachinePrecision]], $MachinePrecision]], $MachinePrecision]), $MachinePrecision], N[(1.0 + N[(N[Exp[N[(x$95$m * (-x$95$m)), $MachinePrecision]], $MachinePrecision] * N[(t$95$1 * N[(N[(t$95$1 * N[(N[(t$95$1 * N[(N[(1.453152027 * N[(1.0 / N[(1.0 + N[(x$95$m * 0.3275911), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] + N[(N[(1.061405429 * N[(-1.0 / N[Power[t$95$0, 2.0], $MachinePrecision]), $MachinePrecision]), $MachinePrecision] - 1.421413741), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] - -0.284496736), $MachinePrecision]), $MachinePrecision] - 0.254829592), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]]]
\begin{array}{l}
x_m = \left|x\right|
\\
\begin{array}{l}
t_0 := 1 + \left|x\_m\right| \cdot 0.3275911\\
t_1 := \frac{1}{t\_0}\\
\mathbf{if}\;\left|x\_m\right| \leq 2 \cdot 10^{-7}:\\
\;\;\;\;10^{-9} + e^{\log \left(x\_m \cdot 1.128386358070218\right)}\\
\mathbf{else}:\\
\;\;\;\;1 + e^{x\_m \cdot \left(-x\_m\right)} \cdot \left(t\_1 \cdot \left(t\_1 \cdot \left(t\_1 \cdot \left(1.453152027 \cdot \frac{1}{1 + x\_m \cdot 0.3275911} + \left(1.061405429 \cdot \frac{-1}{{t\_0}^{2}} - 1.421413741\right)\right) - -0.284496736\right) - 0.254829592\right)\right)\\
\end{array}
\end{array}
if (fabs.f64 x) < 1.9999999999999999e-7Initial program 57.8%
Simplified57.8%
Applied egg-rr57.2%
Taylor expanded in x around 0 98.5%
*-commutative98.5%
Simplified98.5%
add-exp-log45.9%
Applied egg-rr45.9%
if 1.9999999999999999e-7 < (fabs.f64 x) Initial program 99.8%
Simplified99.8%
Taylor expanded in x around 0 99.9%
expm1-log1p-u99.9%
expm1-udef99.9%
log1p-udef99.9%
add-exp-log99.9%
+-commutative99.9%
fma-udef99.9%
add-sqr-sqrt47.4%
fabs-sqr47.4%
add-sqr-sqrt99.4%
Applied egg-rr99.4%
fma-def99.4%
associate--l+99.4%
metadata-eval99.4%
+-rgt-identity99.4%
Simplified99.4%
Final simplification75.4%
x_m = (fabs.f64 x)
(FPCore (x_m)
:precision binary64
(let* ((t_0 (+ 1.0 (* x_m 0.3275911))))
(if (<= x_m 9e-7)
(+ 1e-9 (exp (log (* x_m 1.128386358070218))))
(+
1.0
(*
(exp (* x_m (- x_m)))
(*
(+
0.254829592
(*
(/ 1.0 t_0)
(-
-0.284496736
(*
(/ 1.0 (+ 1.0 (log (+ 1.0 (expm1 (* x_m 0.3275911))))))
(-
(* (+ -1.453152027 (/ 1.061405429 t_0)) (/ -1.0 t_0))
1.421413741)))))
(/ -1.0 (+ 1.0 (* (fabs x_m) 0.3275911)))))))))x_m = fabs(x);
double code(double x_m) {
double t_0 = 1.0 + (x_m * 0.3275911);
double tmp;
if (x_m <= 9e-7) {
tmp = 1e-9 + exp(log((x_m * 1.128386358070218)));
} else {
tmp = 1.0 + (exp((x_m * -x_m)) * ((0.254829592 + ((1.0 / t_0) * (-0.284496736 - ((1.0 / (1.0 + log((1.0 + expm1((x_m * 0.3275911)))))) * (((-1.453152027 + (1.061405429 / t_0)) * (-1.0 / t_0)) - 1.421413741))))) * (-1.0 / (1.0 + (fabs(x_m) * 0.3275911)))));
}
return tmp;
}
x_m = Math.abs(x);
public static double code(double x_m) {
double t_0 = 1.0 + (x_m * 0.3275911);
double tmp;
if (x_m <= 9e-7) {
tmp = 1e-9 + Math.exp(Math.log((x_m * 1.128386358070218)));
} else {
tmp = 1.0 + (Math.exp((x_m * -x_m)) * ((0.254829592 + ((1.0 / t_0) * (-0.284496736 - ((1.0 / (1.0 + Math.log((1.0 + Math.expm1((x_m * 0.3275911)))))) * (((-1.453152027 + (1.061405429 / t_0)) * (-1.0 / t_0)) - 1.421413741))))) * (-1.0 / (1.0 + (Math.abs(x_m) * 0.3275911)))));
}
return tmp;
}
x_m = math.fabs(x) def code(x_m): t_0 = 1.0 + (x_m * 0.3275911) tmp = 0 if x_m <= 9e-7: tmp = 1e-9 + math.exp(math.log((x_m * 1.128386358070218))) else: tmp = 1.0 + (math.exp((x_m * -x_m)) * ((0.254829592 + ((1.0 / t_0) * (-0.284496736 - ((1.0 / (1.0 + math.log((1.0 + math.expm1((x_m * 0.3275911)))))) * (((-1.453152027 + (1.061405429 / t_0)) * (-1.0 / t_0)) - 1.421413741))))) * (-1.0 / (1.0 + (math.fabs(x_m) * 0.3275911))))) return tmp
x_m = abs(x) function code(x_m) t_0 = Float64(1.0 + Float64(x_m * 0.3275911)) tmp = 0.0 if (x_m <= 9e-7) tmp = Float64(1e-9 + exp(log(Float64(x_m * 1.128386358070218)))); else tmp = Float64(1.0 + Float64(exp(Float64(x_m * Float64(-x_m))) * Float64(Float64(0.254829592 + Float64(Float64(1.0 / t_0) * Float64(-0.284496736 - Float64(Float64(1.0 / Float64(1.0 + log(Float64(1.0 + expm1(Float64(x_m * 0.3275911)))))) * Float64(Float64(Float64(-1.453152027 + Float64(1.061405429 / t_0)) * Float64(-1.0 / t_0)) - 1.421413741))))) * Float64(-1.0 / Float64(1.0 + Float64(abs(x_m) * 0.3275911)))))); end return tmp end
x_m = N[Abs[x], $MachinePrecision]
code[x$95$m_] := Block[{t$95$0 = N[(1.0 + N[(x$95$m * 0.3275911), $MachinePrecision]), $MachinePrecision]}, If[LessEqual[x$95$m, 9e-7], N[(1e-9 + N[Exp[N[Log[N[(x$95$m * 1.128386358070218), $MachinePrecision]], $MachinePrecision]], $MachinePrecision]), $MachinePrecision], N[(1.0 + N[(N[Exp[N[(x$95$m * (-x$95$m)), $MachinePrecision]], $MachinePrecision] * N[(N[(0.254829592 + N[(N[(1.0 / t$95$0), $MachinePrecision] * N[(-0.284496736 - N[(N[(1.0 / N[(1.0 + N[Log[N[(1.0 + N[(Exp[N[(x$95$m * 0.3275911), $MachinePrecision]] - 1), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]), $MachinePrecision] * N[(N[(N[(-1.453152027 + N[(1.061405429 / t$95$0), $MachinePrecision]), $MachinePrecision] * N[(-1.0 / t$95$0), $MachinePrecision]), $MachinePrecision] - 1.421413741), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] * N[(-1.0 / N[(1.0 + N[(N[Abs[x$95$m], $MachinePrecision] * 0.3275911), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]]
\begin{array}{l}
x_m = \left|x\right|
\\
\begin{array}{l}
t_0 := 1 + x\_m \cdot 0.3275911\\
\mathbf{if}\;x\_m \leq 9 \cdot 10^{-7}:\\
\;\;\;\;10^{-9} + e^{\log \left(x\_m \cdot 1.128386358070218\right)}\\
\mathbf{else}:\\
\;\;\;\;1 + e^{x\_m \cdot \left(-x\_m\right)} \cdot \left(\left(0.254829592 + \frac{1}{t\_0} \cdot \left(-0.284496736 - \frac{1}{1 + \log \left(1 + \mathsf{expm1}\left(x\_m \cdot 0.3275911\right)\right)} \cdot \left(\left(-1.453152027 + \frac{1.061405429}{t\_0}\right) \cdot \frac{-1}{t\_0} - 1.421413741\right)\right)\right) \cdot \frac{-1}{1 + \left|x\_m\right| \cdot 0.3275911}\right)\\
\end{array}
\end{array}
if x < 8.99999999999999959e-7Initial program 74.3%
Simplified74.3%
Applied egg-rr36.0%
Taylor expanded in x around 0 60.4%
*-commutative60.4%
Simplified60.4%
add-exp-log27.9%
Applied egg-rr27.9%
if 8.99999999999999959e-7 < x Initial program 99.9%
Simplified99.9%
expm1-log1p-u99.8%
expm1-udef99.8%
log1p-udef99.8%
add-exp-log99.8%
+-commutative99.8%
fma-udef99.8%
add-sqr-sqrt99.8%
fabs-sqr99.8%
add-sqr-sqrt99.8%
Applied egg-rr99.9%
fma-def99.8%
associate--l+99.8%
metadata-eval99.8%
+-rgt-identity99.8%
Simplified99.9%
expm1-log1p-u99.8%
expm1-udef99.8%
log1p-udef99.8%
add-exp-log99.8%
+-commutative99.8%
fma-udef99.8%
add-sqr-sqrt99.8%
fabs-sqr99.8%
add-sqr-sqrt99.8%
Applied egg-rr99.9%
fma-def99.8%
associate--l+99.8%
metadata-eval99.8%
+-rgt-identity99.8%
Simplified99.9%
log1p-expm1-u99.9%
log1p-udef99.9%
add-sqr-sqrt99.9%
fabs-sqr99.9%
add-sqr-sqrt99.9%
Applied egg-rr99.9%
expm1-log1p-u99.8%
expm1-udef99.8%
log1p-udef99.8%
add-exp-log99.8%
+-commutative99.8%
fma-udef99.8%
add-sqr-sqrt99.8%
fabs-sqr99.8%
add-sqr-sqrt99.8%
Applied egg-rr99.9%
fma-def99.8%
associate--l+99.8%
metadata-eval99.8%
+-rgt-identity99.8%
Simplified99.9%
Final simplification46.8%
x_m = (fabs.f64 x)
(FPCore (x_m)
:precision binary64
(let* ((t_0 (+ 1.0 (* (fabs x_m) 0.3275911))) (t_1 (+ 1.0 (* x_m 0.3275911))))
(if (<= x_m 9e-7)
(+ 1e-9 (exp (log (* x_m 1.128386358070218))))
(+
1.0
(*
(exp (* x_m (- x_m)))
(*
(/ 1.0 t_0)
(-
(*
(+
-0.284496736
(*
(/ 1.0 t_1)
(-
1.421413741
(* (+ -1.453152027 (/ 1.061405429 t_1)) (/ -1.0 t_1)))))
(/ -1.0 t_0))
0.254829592)))))))x_m = fabs(x);
double code(double x_m) {
double t_0 = 1.0 + (fabs(x_m) * 0.3275911);
double t_1 = 1.0 + (x_m * 0.3275911);
double tmp;
if (x_m <= 9e-7) {
tmp = 1e-9 + exp(log((x_m * 1.128386358070218)));
} else {
tmp = 1.0 + (exp((x_m * -x_m)) * ((1.0 / t_0) * (((-0.284496736 + ((1.0 / t_1) * (1.421413741 - ((-1.453152027 + (1.061405429 / t_1)) * (-1.0 / t_1))))) * (-1.0 / t_0)) - 0.254829592)));
}
return tmp;
}
x_m = abs(x)
real(8) function code(x_m)
real(8), intent (in) :: x_m
real(8) :: t_0
real(8) :: t_1
real(8) :: tmp
t_0 = 1.0d0 + (abs(x_m) * 0.3275911d0)
t_1 = 1.0d0 + (x_m * 0.3275911d0)
if (x_m <= 9d-7) then
tmp = 1d-9 + exp(log((x_m * 1.128386358070218d0)))
else
tmp = 1.0d0 + (exp((x_m * -x_m)) * ((1.0d0 / t_0) * ((((-0.284496736d0) + ((1.0d0 / t_1) * (1.421413741d0 - (((-1.453152027d0) + (1.061405429d0 / t_1)) * ((-1.0d0) / t_1))))) * ((-1.0d0) / t_0)) - 0.254829592d0)))
end if
code = tmp
end function
x_m = Math.abs(x);
public static double code(double x_m) {
double t_0 = 1.0 + (Math.abs(x_m) * 0.3275911);
double t_1 = 1.0 + (x_m * 0.3275911);
double tmp;
if (x_m <= 9e-7) {
tmp = 1e-9 + Math.exp(Math.log((x_m * 1.128386358070218)));
} else {
tmp = 1.0 + (Math.exp((x_m * -x_m)) * ((1.0 / t_0) * (((-0.284496736 + ((1.0 / t_1) * (1.421413741 - ((-1.453152027 + (1.061405429 / t_1)) * (-1.0 / t_1))))) * (-1.0 / t_0)) - 0.254829592)));
}
return tmp;
}
x_m = math.fabs(x) def code(x_m): t_0 = 1.0 + (math.fabs(x_m) * 0.3275911) t_1 = 1.0 + (x_m * 0.3275911) tmp = 0 if x_m <= 9e-7: tmp = 1e-9 + math.exp(math.log((x_m * 1.128386358070218))) else: tmp = 1.0 + (math.exp((x_m * -x_m)) * ((1.0 / t_0) * (((-0.284496736 + ((1.0 / t_1) * (1.421413741 - ((-1.453152027 + (1.061405429 / t_1)) * (-1.0 / t_1))))) * (-1.0 / t_0)) - 0.254829592))) return tmp
x_m = abs(x) function code(x_m) t_0 = Float64(1.0 + Float64(abs(x_m) * 0.3275911)) t_1 = Float64(1.0 + Float64(x_m * 0.3275911)) tmp = 0.0 if (x_m <= 9e-7) tmp = Float64(1e-9 + exp(log(Float64(x_m * 1.128386358070218)))); else tmp = Float64(1.0 + Float64(exp(Float64(x_m * Float64(-x_m))) * Float64(Float64(1.0 / t_0) * Float64(Float64(Float64(-0.284496736 + Float64(Float64(1.0 / t_1) * Float64(1.421413741 - Float64(Float64(-1.453152027 + Float64(1.061405429 / t_1)) * Float64(-1.0 / t_1))))) * Float64(-1.0 / t_0)) - 0.254829592)))); end return tmp end
x_m = abs(x); function tmp_2 = code(x_m) t_0 = 1.0 + (abs(x_m) * 0.3275911); t_1 = 1.0 + (x_m * 0.3275911); tmp = 0.0; if (x_m <= 9e-7) tmp = 1e-9 + exp(log((x_m * 1.128386358070218))); else tmp = 1.0 + (exp((x_m * -x_m)) * ((1.0 / t_0) * (((-0.284496736 + ((1.0 / t_1) * (1.421413741 - ((-1.453152027 + (1.061405429 / t_1)) * (-1.0 / t_1))))) * (-1.0 / t_0)) - 0.254829592))); end tmp_2 = tmp; end
x_m = N[Abs[x], $MachinePrecision]
code[x$95$m_] := Block[{t$95$0 = N[(1.0 + N[(N[Abs[x$95$m], $MachinePrecision] * 0.3275911), $MachinePrecision]), $MachinePrecision]}, Block[{t$95$1 = N[(1.0 + N[(x$95$m * 0.3275911), $MachinePrecision]), $MachinePrecision]}, If[LessEqual[x$95$m, 9e-7], N[(1e-9 + N[Exp[N[Log[N[(x$95$m * 1.128386358070218), $MachinePrecision]], $MachinePrecision]], $MachinePrecision]), $MachinePrecision], N[(1.0 + N[(N[Exp[N[(x$95$m * (-x$95$m)), $MachinePrecision]], $MachinePrecision] * N[(N[(1.0 / t$95$0), $MachinePrecision] * N[(N[(N[(-0.284496736 + N[(N[(1.0 / t$95$1), $MachinePrecision] * N[(1.421413741 - N[(N[(-1.453152027 + N[(1.061405429 / t$95$1), $MachinePrecision]), $MachinePrecision] * N[(-1.0 / t$95$1), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] * N[(-1.0 / t$95$0), $MachinePrecision]), $MachinePrecision] - 0.254829592), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]]]
\begin{array}{l}
x_m = \left|x\right|
\\
\begin{array}{l}
t_0 := 1 + \left|x\_m\right| \cdot 0.3275911\\
t_1 := 1 + x\_m \cdot 0.3275911\\
\mathbf{if}\;x\_m \leq 9 \cdot 10^{-7}:\\
\;\;\;\;10^{-9} + e^{\log \left(x\_m \cdot 1.128386358070218\right)}\\
\mathbf{else}:\\
\;\;\;\;1 + e^{x\_m \cdot \left(-x\_m\right)} \cdot \left(\frac{1}{t\_0} \cdot \left(\left(-0.284496736 + \frac{1}{t\_1} \cdot \left(1.421413741 - \left(-1.453152027 + \frac{1.061405429}{t\_1}\right) \cdot \frac{-1}{t\_1}\right)\right) \cdot \frac{-1}{t\_0} - 0.254829592\right)\right)\\
\end{array}
\end{array}
if x < 8.99999999999999959e-7Initial program 74.3%
Simplified74.3%
Applied egg-rr36.0%
Taylor expanded in x around 0 60.4%
*-commutative60.4%
Simplified60.4%
add-exp-log27.9%
Applied egg-rr27.9%
if 8.99999999999999959e-7 < x Initial program 99.9%
Simplified99.9%
expm1-log1p-u99.8%
expm1-udef99.8%
log1p-udef99.8%
add-exp-log99.8%
+-commutative99.8%
fma-udef99.8%
add-sqr-sqrt99.8%
fabs-sqr99.8%
add-sqr-sqrt99.8%
Applied egg-rr99.9%
fma-def99.8%
associate--l+99.8%
metadata-eval99.8%
+-rgt-identity99.8%
Simplified99.9%
expm1-log1p-u99.8%
expm1-udef99.8%
log1p-udef99.8%
add-exp-log99.8%
+-commutative99.8%
fma-udef99.8%
add-sqr-sqrt99.8%
fabs-sqr99.8%
add-sqr-sqrt99.8%
Applied egg-rr99.9%
fma-def99.8%
associate--l+99.8%
metadata-eval99.8%
+-rgt-identity99.8%
Simplified99.9%
expm1-log1p-u99.8%
expm1-udef99.8%
log1p-udef99.8%
add-exp-log99.8%
+-commutative99.8%
fma-udef99.8%
add-sqr-sqrt99.8%
fabs-sqr99.8%
add-sqr-sqrt99.8%
Applied egg-rr99.9%
fma-def99.8%
associate--l+99.8%
metadata-eval99.8%
+-rgt-identity99.8%
Simplified99.9%
Final simplification46.8%
x_m = (fabs.f64 x) (FPCore (x_m) :precision binary64 1e-9)
x_m = fabs(x);
double code(double x_m) {
return 1e-9;
}
x_m = abs(x)
real(8) function code(x_m)
real(8), intent (in) :: x_m
code = 1d-9
end function
x_m = Math.abs(x);
public static double code(double x_m) {
return 1e-9;
}
x_m = math.fabs(x) def code(x_m): return 1e-9
x_m = abs(x) function code(x_m) return 1e-9 end
x_m = abs(x); function tmp = code(x_m) tmp = 1e-9; end
x_m = N[Abs[x], $MachinePrecision] code[x$95$m_] := 1e-9
\begin{array}{l}
x_m = \left|x\right|
\\
10^{-9}
\end{array}
Initial program 81.0%
Simplified81.0%
Applied egg-rr26.8%
Taylor expanded in x around 0 50.1%
Final simplification50.1%
herbie shell --seed 2024041
(FPCore (x)
:name "Jmat.Real.erf"
:precision binary64
(- 1.0 (* (* (/ 1.0 (+ 1.0 (* 0.3275911 (fabs x)))) (+ 0.254829592 (* (/ 1.0 (+ 1.0 (* 0.3275911 (fabs x)))) (+ -0.284496736 (* (/ 1.0 (+ 1.0 (* 0.3275911 (fabs x)))) (+ 1.421413741 (* (/ 1.0 (+ 1.0 (* 0.3275911 (fabs x)))) (+ -1.453152027 (* (/ 1.0 (+ 1.0 (* 0.3275911 (fabs x)))) 1.061405429))))))))) (exp (- (* (fabs x) (fabs x)))))))