
(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 79.1%
remove-double-neg79.1%
distribute-rgt-neg-out79.1%
distribute-frac-neg279.1%
neg-mul-179.1%
div-sub78.8%
distribute-lft-out--78.8%
neg-mul-178.8%
distribute-frac-neg278.8%
distribute-rgt-neg-out78.8%
remove-double-neg78.8%
cancel-sign-sub-inv78.8%
associate-/r*83.8%
associate-/r*84.2%
*-inverses84.2%
metadata-eval84.2%
metadata-eval84.2%
*-lft-identity84.2%
distribute-rgt-neg-out84.2%
Simplified100.0%
Final simplification100.0%
(FPCore (x y) :precision binary64 (if (or (<= x -1.56e+43) (not (<= x 3.1e-31))) (/ 0.5 y) (/ -0.5 x)))
double code(double x, double y) {
double tmp;
if ((x <= -1.56e+43) || !(x <= 3.1e-31)) {
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 <= (-1.56d+43)) .or. (.not. (x <= 3.1d-31))) 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 <= -1.56e+43) || !(x <= 3.1e-31)) {
tmp = 0.5 / y;
} else {
tmp = -0.5 / x;
}
return tmp;
}
def code(x, y): tmp = 0 if (x <= -1.56e+43) or not (x <= 3.1e-31): tmp = 0.5 / y else: tmp = -0.5 / x return tmp
function code(x, y) tmp = 0.0 if ((x <= -1.56e+43) || !(x <= 3.1e-31)) 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 <= -1.56e+43) || ~((x <= 3.1e-31))) tmp = 0.5 / y; else tmp = -0.5 / x; end tmp_2 = tmp; end
code[x_, y_] := If[Or[LessEqual[x, -1.56e+43], N[Not[LessEqual[x, 3.1e-31]], $MachinePrecision]], N[(0.5 / y), $MachinePrecision], N[(-0.5 / x), $MachinePrecision]]
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;x \leq -1.56 \cdot 10^{+43} \lor \neg \left(x \leq 3.1 \cdot 10^{-31}\right):\\
\;\;\;\;\frac{0.5}{y}\\
\mathbf{else}:\\
\;\;\;\;\frac{-0.5}{x}\\
\end{array}
\end{array}
if x < -1.55999999999999988e43 or 3.1e-31 < x Initial program 78.0%
remove-double-neg78.0%
distribute-rgt-neg-out78.0%
distribute-frac-neg278.0%
neg-mul-178.0%
div-sub78.0%
distribute-lft-out--78.0%
neg-mul-178.0%
distribute-frac-neg278.0%
distribute-rgt-neg-out78.0%
remove-double-neg78.0%
cancel-sign-sub-inv78.0%
associate-/r*87.8%
associate-/r*88.6%
*-inverses88.6%
metadata-eval88.6%
metadata-eval88.6%
*-lft-identity88.6%
distribute-rgt-neg-out88.6%
Simplified100.0%
Taylor expanded in y around 0 80.5%
if -1.55999999999999988e43 < x < 3.1e-31Initial program 80.1%
remove-double-neg80.1%
distribute-rgt-neg-out80.1%
distribute-frac-neg280.1%
neg-mul-180.1%
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*80.4%
associate-/r*80.4%
*-inverses80.4%
metadata-eval80.4%
metadata-eval80.4%
*-lft-identity80.4%
distribute-rgt-neg-out80.4%
Simplified100.0%
Taylor expanded in y around inf 80.2%
Final simplification80.3%
(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 79.1%
remove-double-neg79.1%
distribute-rgt-neg-out79.1%
distribute-frac-neg279.1%
neg-mul-179.1%
div-sub78.8%
distribute-lft-out--78.8%
neg-mul-178.8%
distribute-frac-neg278.8%
distribute-rgt-neg-out78.8%
remove-double-neg78.8%
cancel-sign-sub-inv78.8%
associate-/r*83.8%
associate-/r*84.2%
*-inverses84.2%
metadata-eval84.2%
metadata-eval84.2%
*-lft-identity84.2%
distribute-rgt-neg-out84.2%
Simplified100.0%
Taylor expanded in y around inf 53.7%
Final simplification53.7%
(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 2024067
(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)))