
(FPCore (x y) :precision binary64 (/ (- x y) (* (* x 2.0) y)))
double code(double x, double y) {
return (x - y) / ((x * 2.0) * y);
}
real(8) function code(x, y)
real(8), intent (in) :: x
real(8), intent (in) :: y
code = (x - y) / ((x * 2.0d0) * y)
end function
public static double code(double x, double y) {
return (x - y) / ((x * 2.0) * y);
}
def code(x, y): return (x - y) / ((x * 2.0) * y)
function code(x, y) return Float64(Float64(x - y) / Float64(Float64(x * 2.0) * y)) end
function tmp = code(x, y) tmp = (x - y) / ((x * 2.0) * y); end
code[x_, y_] := N[(N[(x - y), $MachinePrecision] / N[(N[(x * 2.0), $MachinePrecision] * y), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\frac{x - y}{\left(x \cdot 2\right) \cdot y}
\end{array}
Sampling outcomes in binary64 precision:
Herbie found 3 alternatives:
| Alternative | Accuracy | Speedup |
|---|
(FPCore (x y) :precision binary64 (/ (- x y) (* (* x 2.0) y)))
double code(double x, double y) {
return (x - y) / ((x * 2.0) * y);
}
real(8) function code(x, y)
real(8), intent (in) :: x
real(8), intent (in) :: y
code = (x - y) / ((x * 2.0d0) * y)
end function
public static double code(double x, double y) {
return (x - y) / ((x * 2.0) * y);
}
def code(x, y): return (x - y) / ((x * 2.0) * y)
function code(x, y) return Float64(Float64(x - y) / Float64(Float64(x * 2.0) * y)) end
function tmp = code(x, y) tmp = (x - y) / ((x * 2.0) * y); end
code[x_, y_] := N[(N[(x - y), $MachinePrecision] / N[(N[(x * 2.0), $MachinePrecision] * y), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\frac{x - y}{\left(x \cdot 2\right) \cdot y}
\end{array}
(FPCore (x y) :precision binary64 (+ (/ 0.5 y) (/ -0.5 x)))
double code(double x, double y) {
return (0.5 / y) + (-0.5 / x);
}
real(8) function code(x, y)
real(8), intent (in) :: x
real(8), intent (in) :: y
code = (0.5d0 / y) + ((-0.5d0) / x)
end function
public static double code(double x, double y) {
return (0.5 / y) + (-0.5 / x);
}
def code(x, y): return (0.5 / y) + (-0.5 / x)
function code(x, y) return Float64(Float64(0.5 / y) + Float64(-0.5 / x)) end
function tmp = code(x, y) tmp = (0.5 / y) + (-0.5 / x); end
code[x_, y_] := N[(N[(0.5 / y), $MachinePrecision] + N[(-0.5 / x), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\frac{0.5}{y} + \frac{-0.5}{x}
\end{array}
Initial program 75.7%
remove-double-neg75.7%
distribute-rgt-neg-out75.7%
distribute-frac-neg275.7%
neg-mul-175.7%
div-sub75.3%
distribute-lft-out--75.3%
neg-mul-175.3%
distribute-frac-neg275.3%
distribute-rgt-neg-out75.3%
remove-double-neg75.3%
cancel-sign-sub-inv75.3%
associate-/r*82.8%
associate-/r*83.2%
*-inverses83.2%
metadata-eval83.2%
metadata-eval83.2%
*-lft-identity83.2%
distribute-rgt-neg-out83.2%
Simplified100.0%
(FPCore (x y)
:precision binary64
(if (or (<= x -1.3e+122)
(not
(or (<= x -2.1e+43) (and (not (<= x -5600000.0)) (<= x 2.6e-18)))))
(/ 0.5 y)
(/ -0.5 x)))
double code(double x, double y) {
double tmp;
if ((x <= -1.3e+122) || !((x <= -2.1e+43) || (!(x <= -5600000.0) && (x <= 2.6e-18)))) {
tmp = 0.5 / y;
} else {
tmp = -0.5 / 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+122)) .or. (.not. (x <= (-2.1d+43)) .or. (.not. (x <= (-5600000.0d0))) .and. (x <= 2.6d-18))) then
tmp = 0.5d0 / y
else
tmp = (-0.5d0) / x
end if
code = tmp
end function
public static double code(double x, double y) {
double tmp;
if ((x <= -1.3e+122) || !((x <= -2.1e+43) || (!(x <= -5600000.0) && (x <= 2.6e-18)))) {
tmp = 0.5 / y;
} else {
tmp = -0.5 / x;
}
return tmp;
}
def code(x, y): tmp = 0 if (x <= -1.3e+122) or not ((x <= -2.1e+43) or (not (x <= -5600000.0) and (x <= 2.6e-18))): tmp = 0.5 / y else: tmp = -0.5 / x return tmp
function code(x, y) tmp = 0.0 if ((x <= -1.3e+122) || !((x <= -2.1e+43) || (!(x <= -5600000.0) && (x <= 2.6e-18)))) tmp = Float64(0.5 / y); else tmp = Float64(-0.5 / x); end return tmp end
function tmp_2 = code(x, y) tmp = 0.0; if ((x <= -1.3e+122) || ~(((x <= -2.1e+43) || (~((x <= -5600000.0)) && (x <= 2.6e-18))))) tmp = 0.5 / y; else tmp = -0.5 / x; end tmp_2 = tmp; end
code[x_, y_] := If[Or[LessEqual[x, -1.3e+122], N[Not[Or[LessEqual[x, -2.1e+43], And[N[Not[LessEqual[x, -5600000.0]], $MachinePrecision], LessEqual[x, 2.6e-18]]]], $MachinePrecision]], N[(0.5 / y), $MachinePrecision], N[(-0.5 / x), $MachinePrecision]]
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;x \leq -1.3 \cdot 10^{+122} \lor \neg \left(x \leq -2.1 \cdot 10^{+43} \lor \neg \left(x \leq -5600000\right) \land x \leq 2.6 \cdot 10^{-18}\right):\\
\;\;\;\;\frac{0.5}{y}\\
\mathbf{else}:\\
\;\;\;\;\frac{-0.5}{x}\\
\end{array}
\end{array}
if x < -1.30000000000000004e122 or -2.10000000000000002e43 < x < -5.6e6 or 2.6e-18 < x Initial program 72.4%
remove-double-neg72.4%
distribute-rgt-neg-out72.4%
distribute-frac-neg272.4%
neg-mul-172.4%
div-sub72.4%
distribute-lft-out--72.4%
neg-mul-172.4%
distribute-frac-neg272.4%
distribute-rgt-neg-out72.4%
remove-double-neg72.4%
cancel-sign-sub-inv72.4%
associate-/r*88.9%
associate-/r*89.8%
*-inverses89.8%
metadata-eval89.8%
metadata-eval89.8%
*-lft-identity89.8%
distribute-rgt-neg-out89.8%
Simplified100.0%
Taylor expanded in y around 0 83.6%
if -1.30000000000000004e122 < x < -2.10000000000000002e43 or -5.6e6 < x < 2.6e-18Initial program 78.2%
remove-double-neg78.2%
distribute-rgt-neg-out78.2%
distribute-frac-neg278.2%
neg-mul-178.2%
div-sub77.6%
distribute-lft-out--77.6%
neg-mul-177.6%
distribute-frac-neg277.6%
distribute-rgt-neg-out77.6%
remove-double-neg77.6%
cancel-sign-sub-inv77.6%
associate-/r*78.1%
associate-/r*78.1%
*-inverses78.1%
metadata-eval78.1%
metadata-eval78.1%
*-lft-identity78.1%
distribute-rgt-neg-out78.1%
Simplified100.0%
Taylor expanded in y around inf 80.7%
Final simplification82.0%
(FPCore (x y) :precision binary64 (/ -0.5 x))
double code(double x, double y) {
return -0.5 / x;
}
real(8) function code(x, y)
real(8), intent (in) :: x
real(8), intent (in) :: y
code = (-0.5d0) / x
end function
public static double code(double x, double y) {
return -0.5 / x;
}
def code(x, y): return -0.5 / x
function code(x, y) return Float64(-0.5 / x) end
function tmp = code(x, y) tmp = -0.5 / x; end
code[x_, y_] := N[(-0.5 / x), $MachinePrecision]
\begin{array}{l}
\\
\frac{-0.5}{x}
\end{array}
Initial program 75.7%
remove-double-neg75.7%
distribute-rgt-neg-out75.7%
distribute-frac-neg275.7%
neg-mul-175.7%
div-sub75.3%
distribute-lft-out--75.3%
neg-mul-175.3%
distribute-frac-neg275.3%
distribute-rgt-neg-out75.3%
remove-double-neg75.3%
cancel-sign-sub-inv75.3%
associate-/r*82.8%
associate-/r*83.2%
*-inverses83.2%
metadata-eval83.2%
metadata-eval83.2%
*-lft-identity83.2%
distribute-rgt-neg-out83.2%
Simplified100.0%
Taylor expanded in y around inf 53.8%
(FPCore (x y) :precision binary64 (- (/ 0.5 y) (/ 0.5 x)))
double code(double x, double y) {
return (0.5 / y) - (0.5 / x);
}
real(8) function code(x, y)
real(8), intent (in) :: x
real(8), intent (in) :: y
code = (0.5d0 / y) - (0.5d0 / x)
end function
public static double code(double x, double y) {
return (0.5 / y) - (0.5 / x);
}
def code(x, y): return (0.5 / y) - (0.5 / x)
function code(x, y) return Float64(Float64(0.5 / y) - Float64(0.5 / x)) end
function tmp = code(x, y) tmp = (0.5 / y) - (0.5 / x); end
code[x_, y_] := N[(N[(0.5 / y), $MachinePrecision] - N[(0.5 / x), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\frac{0.5}{y} - \frac{0.5}{x}
\end{array}
herbie shell --seed 2024108
(FPCore (x y)
:name "Linear.Projection:inversePerspective from linear-1.19.1.3, B"
:precision binary64
:alt
(- (/ 0.5 y) (/ 0.5 x))
(/ (- x y) (* (* x 2.0) y)))