
(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 76.3%
remove-double-neg76.3%
distribute-rgt-neg-out76.3%
distribute-frac-neg276.3%
neg-mul-176.3%
div-sub75.8%
distribute-lft-out--75.8%
neg-mul-175.8%
distribute-frac-neg275.8%
distribute-rgt-neg-out75.8%
remove-double-neg75.8%
cancel-sign-sub-inv75.8%
associate-/r*82.0%
associate-/r*82.0%
*-inverses82.0%
metadata-eval82.0%
metadata-eval82.0%
*-lft-identity82.0%
distribute-rgt-neg-out82.0%
Simplified100.0%
(FPCore (x y) :precision binary64 (if (or (<= y -1.2e-52) (not (<= y 1.8e-22))) (/ -0.5 x) (/ 0.5 y)))
double code(double x, double y) {
double tmp;
if ((y <= -1.2e-52) || !(y <= 1.8e-22)) {
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 <= (-1.2d-52)) .or. (.not. (y <= 1.8d-22))) 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 <= -1.2e-52) || !(y <= 1.8e-22)) {
tmp = -0.5 / x;
} else {
tmp = 0.5 / y;
}
return tmp;
}
def code(x, y): tmp = 0 if (y <= -1.2e-52) or not (y <= 1.8e-22): tmp = -0.5 / x else: tmp = 0.5 / y return tmp
function code(x, y) tmp = 0.0 if ((y <= -1.2e-52) || !(y <= 1.8e-22)) 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 <= -1.2e-52) || ~((y <= 1.8e-22))) tmp = -0.5 / x; else tmp = 0.5 / y; end tmp_2 = tmp; end
code[x_, y_] := If[Or[LessEqual[y, -1.2e-52], N[Not[LessEqual[y, 1.8e-22]], $MachinePrecision]], N[(-0.5 / x), $MachinePrecision], N[(0.5 / y), $MachinePrecision]]
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;y \leq -1.2 \cdot 10^{-52} \lor \neg \left(y \leq 1.8 \cdot 10^{-22}\right):\\
\;\;\;\;\frac{-0.5}{x}\\
\mathbf{else}:\\
\;\;\;\;\frac{0.5}{y}\\
\end{array}
\end{array}
if y < -1.2000000000000001e-52 or 1.7999999999999999e-22 < y Initial program 79.0%
remove-double-neg79.0%
distribute-rgt-neg-out79.0%
distribute-frac-neg279.0%
neg-mul-179.0%
div-sub79.0%
distribute-lft-out--79.0%
neg-mul-179.0%
distribute-frac-neg279.0%
distribute-rgt-neg-out79.0%
remove-double-neg79.0%
cancel-sign-sub-inv79.0%
associate-/r*89.2%
associate-/r*89.2%
*-inverses89.2%
metadata-eval89.2%
metadata-eval89.2%
*-lft-identity89.2%
distribute-rgt-neg-out89.2%
Simplified100.0%
Taylor expanded in y around inf 76.6%
if -1.2000000000000001e-52 < y < 1.7999999999999999e-22Initial program 72.8%
remove-double-neg72.8%
distribute-rgt-neg-out72.8%
distribute-frac-neg272.8%
neg-mul-172.8%
div-sub71.7%
distribute-lft-out--71.7%
neg-mul-171.7%
distribute-frac-neg271.7%
distribute-rgt-neg-out71.7%
remove-double-neg71.7%
cancel-sign-sub-inv71.7%
associate-/r*72.5%
associate-/r*72.5%
*-inverses72.5%
metadata-eval72.5%
metadata-eval72.5%
*-lft-identity72.5%
distribute-rgt-neg-out72.5%
Simplified100.0%
Taylor expanded in y around 0 80.6%
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 76.3%
remove-double-neg76.3%
distribute-rgt-neg-out76.3%
distribute-frac-neg276.3%
neg-mul-176.3%
div-sub75.8%
distribute-lft-out--75.8%
neg-mul-175.8%
distribute-frac-neg275.8%
distribute-rgt-neg-out75.8%
remove-double-neg75.8%
cancel-sign-sub-inv75.8%
associate-/r*82.0%
associate-/r*82.0%
*-inverses82.0%
metadata-eval82.0%
metadata-eval82.0%
*-lft-identity82.0%
distribute-rgt-neg-out82.0%
Simplified100.0%
Taylor expanded in y around inf 52.4%
(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 2024116
(FPCore (x y)
:name "Linear.Projection:inversePerspective from linear-1.19.1.3, B"
:precision binary64
:alt
(! :herbie-platform default (- (/ 1/2 y) (/ 1/2 x)))
(/ (- x y) (* (* x 2.0) y)))