
(FPCore (x y) :precision binary64 (- x (/ y (+ 1.0 (/ (* x y) 2.0)))))
double code(double x, double y) {
return x - (y / (1.0 + ((x * y) / 2.0)));
}
real(8) function code(x, y)
real(8), intent (in) :: x
real(8), intent (in) :: y
code = x - (y / (1.0d0 + ((x * y) / 2.0d0)))
end function
public static double code(double x, double y) {
return x - (y / (1.0 + ((x * y) / 2.0)));
}
def code(x, y): return x - (y / (1.0 + ((x * y) / 2.0)))
function code(x, y) return Float64(x - Float64(y / Float64(1.0 + Float64(Float64(x * y) / 2.0)))) end
function tmp = code(x, y) tmp = x - (y / (1.0 + ((x * y) / 2.0))); end
code[x_, y_] := N[(x - N[(y / N[(1.0 + N[(N[(x * y), $MachinePrecision] / 2.0), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
x - \frac{y}{1 + \frac{x \cdot y}{2}}
\end{array}
Sampling outcomes in binary64 precision:
Herbie found 6 alternatives:
| Alternative | Accuracy | Speedup |
|---|
(FPCore (x y) :precision binary64 (- x (/ y (+ 1.0 (/ (* x y) 2.0)))))
double code(double x, double y) {
return x - (y / (1.0 + ((x * y) / 2.0)));
}
real(8) function code(x, y)
real(8), intent (in) :: x
real(8), intent (in) :: y
code = x - (y / (1.0d0 + ((x * y) / 2.0d0)))
end function
public static double code(double x, double y) {
return x - (y / (1.0 + ((x * y) / 2.0)));
}
def code(x, y): return x - (y / (1.0 + ((x * y) / 2.0)))
function code(x, y) return Float64(x - Float64(y / Float64(1.0 + Float64(Float64(x * y) / 2.0)))) end
function tmp = code(x, y) tmp = x - (y / (1.0 + ((x * y) / 2.0))); end
code[x_, y_] := N[(x - N[(y / N[(1.0 + N[(N[(x * y), $MachinePrecision] / 2.0), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
x - \frac{y}{1 + \frac{x \cdot y}{2}}
\end{array}
(FPCore (x y) :precision binary64 (+ x (/ y (- -1.0 (/ (* x y) 2.0)))))
double code(double x, double y) {
return x + (y / (-1.0 - ((x * y) / 2.0)));
}
real(8) function code(x, y)
real(8), intent (in) :: x
real(8), intent (in) :: y
code = x + (y / ((-1.0d0) - ((x * y) / 2.0d0)))
end function
public static double code(double x, double y) {
return x + (y / (-1.0 - ((x * y) / 2.0)));
}
def code(x, y): return x + (y / (-1.0 - ((x * y) / 2.0)))
function code(x, y) return Float64(x + Float64(y / Float64(-1.0 - Float64(Float64(x * y) / 2.0)))) end
function tmp = code(x, y) tmp = x + (y / (-1.0 - ((x * y) / 2.0))); end
code[x_, y_] := N[(x + N[(y / N[(-1.0 - N[(N[(x * y), $MachinePrecision] / 2.0), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
x + \frac{y}{-1 - \frac{x \cdot y}{2}}
\end{array}
Initial program 99.9%
Final simplification99.9%
(FPCore (x y) :precision binary64 (if (<= x -1.3e-10) x (if (<= x 8e-28) (- x y) (if (<= x 9e-7) (/ -2.0 x) x))))
double code(double x, double y) {
double tmp;
if (x <= -1.3e-10) {
tmp = x;
} else if (x <= 8e-28) {
tmp = x - y;
} else if (x <= 9e-7) {
tmp = -2.0 / x;
} else {
tmp = x;
}
return tmp;
}
real(8) function code(x, y)
real(8), intent (in) :: x
real(8), intent (in) :: y
real(8) :: tmp
if (x <= (-1.3d-10)) then
tmp = x
else if (x <= 8d-28) then
tmp = x - y
else if (x <= 9d-7) then
tmp = (-2.0d0) / x
else
tmp = x
end if
code = tmp
end function
public static double code(double x, double y) {
double tmp;
if (x <= -1.3e-10) {
tmp = x;
} else if (x <= 8e-28) {
tmp = x - y;
} else if (x <= 9e-7) {
tmp = -2.0 / x;
} else {
tmp = x;
}
return tmp;
}
def code(x, y): tmp = 0 if x <= -1.3e-10: tmp = x elif x <= 8e-28: tmp = x - y elif x <= 9e-7: tmp = -2.0 / x else: tmp = x return tmp
function code(x, y) tmp = 0.0 if (x <= -1.3e-10) tmp = x; elseif (x <= 8e-28) tmp = Float64(x - y); elseif (x <= 9e-7) tmp = Float64(-2.0 / x); else tmp = x; end return tmp end
function tmp_2 = code(x, y) tmp = 0.0; if (x <= -1.3e-10) tmp = x; elseif (x <= 8e-28) tmp = x - y; elseif (x <= 9e-7) tmp = -2.0 / x; else tmp = x; end tmp_2 = tmp; end
code[x_, y_] := If[LessEqual[x, -1.3e-10], x, If[LessEqual[x, 8e-28], N[(x - y), $MachinePrecision], If[LessEqual[x, 9e-7], N[(-2.0 / x), $MachinePrecision], x]]]
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;x \leq -1.3 \cdot 10^{-10}:\\
\;\;\;\;x\\
\mathbf{elif}\;x \leq 8 \cdot 10^{-28}:\\
\;\;\;\;x - y\\
\mathbf{elif}\;x \leq 9 \cdot 10^{-7}:\\
\;\;\;\;\frac{-2}{x}\\
\mathbf{else}:\\
\;\;\;\;x\\
\end{array}
\end{array}
if x < -1.29999999999999991e-10 or 8.99999999999999959e-7 < x Initial program 100.0%
Taylor expanded in x around inf 97.9%
if -1.29999999999999991e-10 < x < 7.99999999999999977e-28Initial program 99.8%
Taylor expanded in y around 0 76.5%
neg-mul-176.5%
unsub-neg76.5%
Simplified76.5%
if 7.99999999999999977e-28 < x < 8.99999999999999959e-7Initial program 99.6%
Taylor expanded in y around inf 85.9%
associate-*r/85.9%
metadata-eval85.9%
Simplified85.9%
Taylor expanded in x around 0 84.0%
(FPCore (x y) :precision binary64 (if (or (<= y -1.85e+74) (not (<= y 2.45e+89))) (- x (/ 2.0 x)) (- x y)))
double code(double x, double y) {
double tmp;
if ((y <= -1.85e+74) || !(y <= 2.45e+89)) {
tmp = x - (2.0 / x);
} else {
tmp = x - y;
}
return tmp;
}
real(8) function code(x, y)
real(8), intent (in) :: x
real(8), intent (in) :: y
real(8) :: tmp
if ((y <= (-1.85d+74)) .or. (.not. (y <= 2.45d+89))) then
tmp = x - (2.0d0 / x)
else
tmp = x - y
end if
code = tmp
end function
public static double code(double x, double y) {
double tmp;
if ((y <= -1.85e+74) || !(y <= 2.45e+89)) {
tmp = x - (2.0 / x);
} else {
tmp = x - y;
}
return tmp;
}
def code(x, y): tmp = 0 if (y <= -1.85e+74) or not (y <= 2.45e+89): tmp = x - (2.0 / x) else: tmp = x - y return tmp
function code(x, y) tmp = 0.0 if ((y <= -1.85e+74) || !(y <= 2.45e+89)) tmp = Float64(x - Float64(2.0 / x)); else tmp = Float64(x - y); end return tmp end
function tmp_2 = code(x, y) tmp = 0.0; if ((y <= -1.85e+74) || ~((y <= 2.45e+89))) tmp = x - (2.0 / x); else tmp = x - y; end tmp_2 = tmp; end
code[x_, y_] := If[Or[LessEqual[y, -1.85e+74], N[Not[LessEqual[y, 2.45e+89]], $MachinePrecision]], N[(x - N[(2.0 / x), $MachinePrecision]), $MachinePrecision], N[(x - y), $MachinePrecision]]
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;y \leq -1.85 \cdot 10^{+74} \lor \neg \left(y \leq 2.45 \cdot 10^{+89}\right):\\
\;\;\;\;x - \frac{2}{x}\\
\mathbf{else}:\\
\;\;\;\;x - y\\
\end{array}
\end{array}
if y < -1.8500000000000001e74 or 2.44999999999999998e89 < y Initial program 99.8%
Taylor expanded in y around inf 87.6%
associate-*r/87.6%
metadata-eval87.6%
Simplified87.6%
if -1.8500000000000001e74 < y < 2.44999999999999998e89Initial program 100.0%
Taylor expanded in y around 0 97.9%
neg-mul-197.9%
unsub-neg97.9%
Simplified97.9%
Final simplification93.8%
(FPCore (x y) :precision binary64 (if (<= x -1.3e-10) x (if (<= x 1.45) (- x y) x)))
double code(double x, double y) {
double tmp;
if (x <= -1.3e-10) {
tmp = x;
} else if (x <= 1.45) {
tmp = x - y;
} else {
tmp = x;
}
return tmp;
}
real(8) function code(x, y)
real(8), intent (in) :: x
real(8), intent (in) :: y
real(8) :: tmp
if (x <= (-1.3d-10)) then
tmp = x
else if (x <= 1.45d0) then
tmp = x - y
else
tmp = x
end if
code = tmp
end function
public static double code(double x, double y) {
double tmp;
if (x <= -1.3e-10) {
tmp = x;
} else if (x <= 1.45) {
tmp = x - y;
} else {
tmp = x;
}
return tmp;
}
def code(x, y): tmp = 0 if x <= -1.3e-10: tmp = x elif x <= 1.45: tmp = x - y else: tmp = x return tmp
function code(x, y) tmp = 0.0 if (x <= -1.3e-10) tmp = x; elseif (x <= 1.45) tmp = Float64(x - y); else tmp = x; end return tmp end
function tmp_2 = code(x, y) tmp = 0.0; if (x <= -1.3e-10) tmp = x; elseif (x <= 1.45) tmp = x - y; else tmp = x; end tmp_2 = tmp; end
code[x_, y_] := If[LessEqual[x, -1.3e-10], x, If[LessEqual[x, 1.45], N[(x - y), $MachinePrecision], x]]
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;x \leq -1.3 \cdot 10^{-10}:\\
\;\;\;\;x\\
\mathbf{elif}\;x \leq 1.45:\\
\;\;\;\;x - y\\
\mathbf{else}:\\
\;\;\;\;x\\
\end{array}
\end{array}
if x < -1.29999999999999991e-10 or 1.44999999999999996 < x Initial program 100.0%
Taylor expanded in x around inf 97.9%
if -1.29999999999999991e-10 < x < 1.44999999999999996Initial program 99.8%
Taylor expanded in y around 0 73.3%
neg-mul-173.3%
unsub-neg73.3%
Simplified73.3%
(FPCore (x y) :precision binary64 (if (<= x -9.5e-69) x (if (<= x 4e-68) (- y) x)))
double code(double x, double y) {
double tmp;
if (x <= -9.5e-69) {
tmp = x;
} else if (x <= 4e-68) {
tmp = -y;
} else {
tmp = x;
}
return tmp;
}
real(8) function code(x, y)
real(8), intent (in) :: x
real(8), intent (in) :: y
real(8) :: tmp
if (x <= (-9.5d-69)) then
tmp = x
else if (x <= 4d-68) then
tmp = -y
else
tmp = x
end if
code = tmp
end function
public static double code(double x, double y) {
double tmp;
if (x <= -9.5e-69) {
tmp = x;
} else if (x <= 4e-68) {
tmp = -y;
} else {
tmp = x;
}
return tmp;
}
def code(x, y): tmp = 0 if x <= -9.5e-69: tmp = x elif x <= 4e-68: tmp = -y else: tmp = x return tmp
function code(x, y) tmp = 0.0 if (x <= -9.5e-69) tmp = x; elseif (x <= 4e-68) tmp = Float64(-y); else tmp = x; end return tmp end
function tmp_2 = code(x, y) tmp = 0.0; if (x <= -9.5e-69) tmp = x; elseif (x <= 4e-68) tmp = -y; else tmp = x; end tmp_2 = tmp; end
code[x_, y_] := If[LessEqual[x, -9.5e-69], x, If[LessEqual[x, 4e-68], (-y), x]]
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;x \leq -9.5 \cdot 10^{-69}:\\
\;\;\;\;x\\
\mathbf{elif}\;x \leq 4 \cdot 10^{-68}:\\
\;\;\;\;-y\\
\mathbf{else}:\\
\;\;\;\;x\\
\end{array}
\end{array}
if x < -9.50000000000000094e-69 or 4.00000000000000027e-68 < x Initial program 99.9%
Taylor expanded in x around inf 88.8%
if -9.50000000000000094e-69 < x < 4.00000000000000027e-68Initial program 99.9%
Taylor expanded in x around 0 62.7%
neg-mul-162.7%
Simplified62.7%
(FPCore (x y) :precision binary64 x)
double code(double x, double y) {
return x;
}
real(8) function code(x, y)
real(8), intent (in) :: x
real(8), intent (in) :: y
code = x
end function
public static double code(double x, double y) {
return x;
}
def code(x, y): return x
function code(x, y) return x end
function tmp = code(x, y) tmp = x; end
code[x_, y_] := x
\begin{array}{l}
\\
x
\end{array}
Initial program 99.9%
Taylor expanded in x around inf 59.4%
herbie shell --seed 2024145
(FPCore (x y)
:name "Data.Number.Erf:$cinvnormcdf from erf-2.0.0.0, B"
:precision binary64
(- x (/ y (+ 1.0 (/ (* x y) 2.0)))))