
(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 80.0%
remove-double-neg80.0%
distribute-rgt-neg-out80.0%
distribute-frac-neg280.0%
neg-mul-180.0%
div-sub79.4%
distribute-lft-out--79.4%
neg-mul-179.4%
distribute-frac-neg279.4%
distribute-rgt-neg-out79.4%
remove-double-neg79.4%
cancel-sign-sub-inv79.4%
associate-/r*83.7%
associate-/r*83.7%
*-inverses83.7%
metadata-eval83.7%
metadata-eval83.7%
*-lft-identity83.7%
distribute-rgt-neg-out83.7%
Simplified100.0%
(FPCore (x y) :precision binary64 (if (or (<= x -4.4e-38) (not (<= x 6.8e-62))) (/ 0.5 y) (/ -0.5 x)))
double code(double x, double y) {
double tmp;
if ((x <= -4.4e-38) || !(x <= 6.8e-62)) {
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 <= (-4.4d-38)) .or. (.not. (x <= 6.8d-62))) 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 <= -4.4e-38) || !(x <= 6.8e-62)) {
tmp = 0.5 / y;
} else {
tmp = -0.5 / x;
}
return tmp;
}
def code(x, y): tmp = 0 if (x <= -4.4e-38) or not (x <= 6.8e-62): tmp = 0.5 / y else: tmp = -0.5 / x return tmp
function code(x, y) tmp = 0.0 if ((x <= -4.4e-38) || !(x <= 6.8e-62)) 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 <= -4.4e-38) || ~((x <= 6.8e-62))) tmp = 0.5 / y; else tmp = -0.5 / x; end tmp_2 = tmp; end
code[x_, y_] := If[Or[LessEqual[x, -4.4e-38], N[Not[LessEqual[x, 6.8e-62]], $MachinePrecision]], N[(0.5 / y), $MachinePrecision], N[(-0.5 / x), $MachinePrecision]]
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;x \leq -4.4 \cdot 10^{-38} \lor \neg \left(x \leq 6.8 \cdot 10^{-62}\right):\\
\;\;\;\;\frac{0.5}{y}\\
\mathbf{else}:\\
\;\;\;\;\frac{-0.5}{x}\\
\end{array}
\end{array}
if x < -4.40000000000000015e-38 or 6.79999999999999975e-62 < x Initial program 82.2%
remove-double-neg82.2%
distribute-rgt-neg-out82.2%
distribute-frac-neg282.2%
neg-mul-182.2%
div-sub82.1%
distribute-lft-out--82.1%
neg-mul-182.1%
distribute-frac-neg282.1%
distribute-rgt-neg-out82.1%
remove-double-neg82.1%
cancel-sign-sub-inv82.1%
associate-/r*89.9%
associate-/r*89.9%
*-inverses89.9%
metadata-eval89.9%
metadata-eval89.9%
*-lft-identity89.9%
distribute-rgt-neg-out89.9%
Simplified100.0%
Taylor expanded in y around 0 74.5%
if -4.40000000000000015e-38 < x < 6.79999999999999975e-62Initial program 77.6%
remove-double-neg77.6%
distribute-rgt-neg-out77.6%
distribute-frac-neg277.6%
neg-mul-177.6%
div-sub76.5%
distribute-lft-out--76.5%
neg-mul-176.5%
distribute-frac-neg276.5%
distribute-rgt-neg-out76.5%
remove-double-neg76.5%
cancel-sign-sub-inv76.5%
associate-/r*77.1%
associate-/r*77.1%
*-inverses77.1%
metadata-eval77.1%
metadata-eval77.1%
*-lft-identity77.1%
distribute-rgt-neg-out77.1%
Simplified100.0%
Taylor expanded in y around inf 83.1%
Final simplification78.7%
(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 80.0%
remove-double-neg80.0%
distribute-rgt-neg-out80.0%
distribute-frac-neg280.0%
neg-mul-180.0%
div-sub79.4%
distribute-lft-out--79.4%
neg-mul-179.4%
distribute-frac-neg279.4%
distribute-rgt-neg-out79.4%
remove-double-neg79.4%
cancel-sign-sub-inv79.4%
associate-/r*83.7%
associate-/r*83.7%
*-inverses83.7%
metadata-eval83.7%
metadata-eval83.7%
*-lft-identity83.7%
distribute-rgt-neg-out83.7%
Simplified100.0%
Taylor expanded in y around inf 54.7%
(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 2024101
(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)))