
(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 78.2%
remove-double-neg78.2%
distribute-rgt-neg-out78.2%
distribute-frac-neg278.2%
neg-mul-178.2%
div-sub77.7%
distribute-lft-out--77.7%
neg-mul-177.7%
distribute-frac-neg277.7%
distribute-rgt-neg-out77.7%
remove-double-neg77.7%
cancel-sign-sub-inv77.7%
associate-/r*84.1%
associate-/r*84.1%
*-inverses84.1%
metadata-eval84.1%
metadata-eval84.1%
metadata-eval84.1%
metadata-eval84.1%
Simplified100.0%
Final simplification100.0%
(FPCore (x y)
:precision binary64
(if (or (<= x -8.2e-110)
(not (or (<= x 1.45e-123) (and (not (<= x 1e-81)) (<= x 1e+18)))))
(/ 0.5 y)
(/ -0.5 x)))
double code(double x, double y) {
double tmp;
if ((x <= -8.2e-110) || !((x <= 1.45e-123) || (!(x <= 1e-81) && (x <= 1e+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 <= (-8.2d-110)) .or. (.not. (x <= 1.45d-123) .or. (.not. (x <= 1d-81)) .and. (x <= 1d+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 <= -8.2e-110) || !((x <= 1.45e-123) || (!(x <= 1e-81) && (x <= 1e+18)))) {
tmp = 0.5 / y;
} else {
tmp = -0.5 / x;
}
return tmp;
}
def code(x, y): tmp = 0 if (x <= -8.2e-110) or not ((x <= 1.45e-123) or (not (x <= 1e-81) and (x <= 1e+18))): tmp = 0.5 / y else: tmp = -0.5 / x return tmp
function code(x, y) tmp = 0.0 if ((x <= -8.2e-110) || !((x <= 1.45e-123) || (!(x <= 1e-81) && (x <= 1e+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 <= -8.2e-110) || ~(((x <= 1.45e-123) || (~((x <= 1e-81)) && (x <= 1e+18))))) tmp = 0.5 / y; else tmp = -0.5 / x; end tmp_2 = tmp; end
code[x_, y_] := If[Or[LessEqual[x, -8.2e-110], N[Not[Or[LessEqual[x, 1.45e-123], And[N[Not[LessEqual[x, 1e-81]], $MachinePrecision], LessEqual[x, 1e+18]]]], $MachinePrecision]], N[(0.5 / y), $MachinePrecision], N[(-0.5 / x), $MachinePrecision]]
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;x \leq -8.2 \cdot 10^{-110} \lor \neg \left(x \leq 1.45 \cdot 10^{-123} \lor \neg \left(x \leq 10^{-81}\right) \land x \leq 10^{+18}\right):\\
\;\;\;\;\frac{0.5}{y}\\
\mathbf{else}:\\
\;\;\;\;\frac{-0.5}{x}\\
\end{array}
\end{array}
if x < -8.19999999999999965e-110 or 1.45000000000000002e-123 < x < 9.9999999999999996e-82 or 1e18 < x Initial program 77.2%
remove-double-neg77.2%
distribute-rgt-neg-out77.2%
distribute-frac-neg277.2%
neg-mul-177.2%
div-sub76.9%
distribute-lft-out--76.9%
neg-mul-176.9%
distribute-frac-neg276.9%
distribute-rgt-neg-out76.9%
remove-double-neg76.9%
cancel-sign-sub-inv76.9%
associate-/r*87.0%
associate-/r*87.0%
*-inverses87.0%
metadata-eval87.0%
metadata-eval87.0%
metadata-eval87.0%
metadata-eval87.0%
Simplified100.0%
Taylor expanded in y around 0 76.4%
if -8.19999999999999965e-110 < x < 1.45000000000000002e-123 or 9.9999999999999996e-82 < x < 1e18Initial program 79.7%
remove-double-neg79.7%
distribute-rgt-neg-out79.7%
distribute-frac-neg279.7%
neg-mul-179.7%
div-sub78.9%
distribute-lft-out--78.9%
neg-mul-178.9%
distribute-frac-neg278.9%
distribute-rgt-neg-out78.9%
remove-double-neg78.9%
cancel-sign-sub-inv78.9%
associate-/r*80.0%
associate-/r*80.0%
*-inverses80.0%
metadata-eval80.0%
metadata-eval80.0%
metadata-eval80.0%
metadata-eval80.0%
Simplified100.0%
Taylor expanded in y around inf 87.2%
Final simplification80.8%
(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 78.2%
remove-double-neg78.2%
distribute-rgt-neg-out78.2%
distribute-frac-neg278.2%
neg-mul-178.2%
div-sub77.7%
distribute-lft-out--77.7%
neg-mul-177.7%
distribute-frac-neg277.7%
distribute-rgt-neg-out77.7%
remove-double-neg77.7%
cancel-sign-sub-inv77.7%
associate-/r*84.1%
associate-/r*84.1%
*-inverses84.1%
metadata-eval84.1%
metadata-eval84.1%
metadata-eval84.1%
metadata-eval84.1%
Simplified100.0%
Taylor expanded in y around inf 50.3%
Final simplification50.3%
(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 2024130
(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)))