
(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 76.9%
remove-double-neg76.9%
distribute-rgt-neg-out76.9%
distribute-frac-neg276.9%
neg-mul-176.9%
div-sub76.4%
distribute-lft-out--76.4%
neg-mul-176.4%
distribute-frac-neg276.4%
distribute-rgt-neg-out76.4%
remove-double-neg76.4%
cancel-sign-sub-inv76.4%
associate-/r*82.3%
associate-/r*82.3%
*-inverses82.3%
metadata-eval82.3%
metadata-eval82.3%
*-lft-identity82.3%
distribute-rgt-neg-out82.3%
Simplified100.0%
Final simplification100.0%
(FPCore (x y)
:precision binary64
(if (or (<= y -6.2e-11)
(and (not (<= y 6e-67)) (or (<= y 1.7e-17) (not (<= y 3.4e+99)))))
(/ -0.5 x)
(/ 0.5 y)))
double code(double x, double y) {
double tmp;
if ((y <= -6.2e-11) || (!(y <= 6e-67) && ((y <= 1.7e-17) || !(y <= 3.4e+99)))) {
tmp = -0.5 / x;
} else {
tmp = 0.5 / y;
}
return tmp;
}
real(8) function code(x, y)
real(8), intent (in) :: x
real(8), intent (in) :: y
real(8) :: tmp
if ((y <= (-6.2d-11)) .or. (.not. (y <= 6d-67)) .and. (y <= 1.7d-17) .or. (.not. (y <= 3.4d+99))) then
tmp = (-0.5d0) / x
else
tmp = 0.5d0 / y
end if
code = tmp
end function
public static double code(double x, double y) {
double tmp;
if ((y <= -6.2e-11) || (!(y <= 6e-67) && ((y <= 1.7e-17) || !(y <= 3.4e+99)))) {
tmp = -0.5 / x;
} else {
tmp = 0.5 / y;
}
return tmp;
}
def code(x, y): tmp = 0 if (y <= -6.2e-11) or (not (y <= 6e-67) and ((y <= 1.7e-17) or not (y <= 3.4e+99))): tmp = -0.5 / x else: tmp = 0.5 / y return tmp
function code(x, y) tmp = 0.0 if ((y <= -6.2e-11) || (!(y <= 6e-67) && ((y <= 1.7e-17) || !(y <= 3.4e+99)))) tmp = Float64(-0.5 / x); else tmp = Float64(0.5 / y); end return tmp end
function tmp_2 = code(x, y) tmp = 0.0; if ((y <= -6.2e-11) || (~((y <= 6e-67)) && ((y <= 1.7e-17) || ~((y <= 3.4e+99))))) tmp = -0.5 / x; else tmp = 0.5 / y; end tmp_2 = tmp; end
code[x_, y_] := If[Or[LessEqual[y, -6.2e-11], And[N[Not[LessEqual[y, 6e-67]], $MachinePrecision], Or[LessEqual[y, 1.7e-17], N[Not[LessEqual[y, 3.4e+99]], $MachinePrecision]]]], N[(-0.5 / x), $MachinePrecision], N[(0.5 / y), $MachinePrecision]]
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;y \leq -6.2 \cdot 10^{-11} \lor \neg \left(y \leq 6 \cdot 10^{-67}\right) \land \left(y \leq 1.7 \cdot 10^{-17} \lor \neg \left(y \leq 3.4 \cdot 10^{+99}\right)\right):\\
\;\;\;\;\frac{-0.5}{x}\\
\mathbf{else}:\\
\;\;\;\;\frac{0.5}{y}\\
\end{array}
\end{array}
if y < -6.20000000000000056e-11 or 6.00000000000000065e-67 < y < 1.6999999999999999e-17 or 3.39999999999999984e99 < y Initial program 75.2%
remove-double-neg75.2%
distribute-rgt-neg-out75.2%
distribute-frac-neg275.2%
neg-mul-175.2%
div-sub75.2%
distribute-lft-out--75.2%
neg-mul-175.2%
distribute-frac-neg275.2%
distribute-rgt-neg-out75.2%
remove-double-neg75.2%
cancel-sign-sub-inv75.2%
associate-/r*84.9%
associate-/r*84.9%
*-inverses84.9%
metadata-eval84.9%
metadata-eval84.9%
*-lft-identity84.9%
distribute-rgt-neg-out84.9%
Simplified100.0%
Taylor expanded in y around inf 78.3%
if -6.20000000000000056e-11 < y < 6.00000000000000065e-67 or 1.6999999999999999e-17 < y < 3.39999999999999984e99Initial program 78.4%
remove-double-neg78.4%
distribute-rgt-neg-out78.4%
distribute-frac-neg278.4%
neg-mul-178.4%
div-sub77.4%
distribute-lft-out--77.4%
neg-mul-177.4%
distribute-frac-neg277.4%
distribute-rgt-neg-out77.4%
remove-double-neg77.4%
cancel-sign-sub-inv77.4%
associate-/r*80.1%
associate-/r*80.1%
*-inverses80.1%
metadata-eval80.1%
metadata-eval80.1%
*-lft-identity80.1%
distribute-rgt-neg-out80.1%
Simplified100.0%
Taylor expanded in y around 0 78.3%
Final simplification78.3%
(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 76.9%
remove-double-neg76.9%
distribute-rgt-neg-out76.9%
distribute-frac-neg276.9%
neg-mul-176.9%
div-sub76.4%
distribute-lft-out--76.4%
neg-mul-176.4%
distribute-frac-neg276.4%
distribute-rgt-neg-out76.4%
remove-double-neg76.4%
cancel-sign-sub-inv76.4%
associate-/r*82.3%
associate-/r*82.3%
*-inverses82.3%
metadata-eval82.3%
metadata-eval82.3%
*-lft-identity82.3%
distribute-rgt-neg-out82.3%
Simplified100.0%
Taylor expanded in y around inf 48.3%
Final simplification48.3%
(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 2024082
(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)))