
(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 76.5%
div-sub75.8%
sub-neg75.8%
associate-/r*80.1%
associate-/r*80.1%
*-inverses80.1%
metadata-eval80.1%
neg-mul-180.1%
metadata-eval80.1%
metadata-eval80.1%
times-frac80.1%
distribute-lft-neg-in80.1%
distribute-rgt-neg-in80.1%
neg-mul-180.1%
distribute-rgt-neg-out80.1%
times-frac100.0%
*-inverses100.0%
metadata-eval100.0%
associate-*l/100.0%
metadata-eval100.0%
metadata-eval100.0%
*-commutative100.0%
associate-/r*100.0%
metadata-eval100.0%
Simplified100.0%
Final simplification100.0%
(FPCore (x y) :precision binary64 (if (<= y -1.65e-14) (/ -0.5 x) (if (<= y 5.5e-14) (/ 0.5 y) (/ -0.5 x))))
double code(double x, double y) {
double tmp;
if (y <= -1.65e-14) {
tmp = -0.5 / x;
} else if (y <= 5.5e-14) {
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 (y <= (-1.65d-14)) then
tmp = (-0.5d0) / x
else if (y <= 5.5d-14) 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 (y <= -1.65e-14) {
tmp = -0.5 / x;
} else if (y <= 5.5e-14) {
tmp = 0.5 / y;
} else {
tmp = -0.5 / x;
}
return tmp;
}
def code(x, y): tmp = 0 if y <= -1.65e-14: tmp = -0.5 / x elif y <= 5.5e-14: tmp = 0.5 / y else: tmp = -0.5 / x return tmp
function code(x, y) tmp = 0.0 if (y <= -1.65e-14) tmp = Float64(-0.5 / x); elseif (y <= 5.5e-14) 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 (y <= -1.65e-14) tmp = -0.5 / x; elseif (y <= 5.5e-14) tmp = 0.5 / y; else tmp = -0.5 / x; end tmp_2 = tmp; end
code[x_, y_] := If[LessEqual[y, -1.65e-14], N[(-0.5 / x), $MachinePrecision], If[LessEqual[y, 5.5e-14], N[(0.5 / y), $MachinePrecision], N[(-0.5 / x), $MachinePrecision]]]
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;y \leq -1.65 \cdot 10^{-14}:\\
\;\;\;\;\frac{-0.5}{x}\\
\mathbf{elif}\;y \leq 5.5 \cdot 10^{-14}:\\
\;\;\;\;\frac{0.5}{y}\\
\mathbf{else}:\\
\;\;\;\;\frac{-0.5}{x}\\
\end{array}
\end{array}
if y < -1.6499999999999999e-14 or 5.49999999999999991e-14 < y Initial program 83.9%
div-sub83.8%
sub-neg83.8%
associate-/r*90.4%
associate-/r*90.4%
*-inverses90.4%
metadata-eval90.4%
neg-mul-190.4%
metadata-eval90.4%
metadata-eval90.4%
times-frac90.4%
distribute-lft-neg-in90.4%
distribute-rgt-neg-in90.4%
neg-mul-190.4%
distribute-rgt-neg-out90.4%
times-frac100.0%
*-inverses100.0%
metadata-eval100.0%
associate-*l/100.0%
metadata-eval100.0%
metadata-eval100.0%
*-commutative100.0%
associate-/r*100.0%
metadata-eval100.0%
Simplified100.0%
Taylor expanded in y around inf 78.4%
if -1.6499999999999999e-14 < y < 5.49999999999999991e-14Initial program 67.9%
div-sub66.4%
sub-neg66.4%
associate-/r*67.9%
associate-/r*67.9%
*-inverses67.9%
metadata-eval67.9%
neg-mul-167.9%
metadata-eval67.9%
metadata-eval67.9%
times-frac67.9%
distribute-lft-neg-in67.9%
distribute-rgt-neg-in67.9%
neg-mul-167.9%
distribute-rgt-neg-out67.9%
times-frac100.0%
*-inverses100.0%
metadata-eval100.0%
associate-*l/100.0%
metadata-eval100.0%
metadata-eval100.0%
*-commutative100.0%
associate-/r*100.0%
metadata-eval100.0%
Simplified100.0%
Taylor expanded in y around 0 74.5%
Final simplification76.6%
(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 76.5%
div-sub75.8%
sub-neg75.8%
associate-/r*80.1%
associate-/r*80.1%
*-inverses80.1%
metadata-eval80.1%
neg-mul-180.1%
metadata-eval80.1%
metadata-eval80.1%
times-frac80.1%
distribute-lft-neg-in80.1%
distribute-rgt-neg-in80.1%
neg-mul-180.1%
distribute-rgt-neg-out80.1%
times-frac100.0%
*-inverses100.0%
metadata-eval100.0%
associate-*l/100.0%
metadata-eval100.0%
metadata-eval100.0%
*-commutative100.0%
associate-/r*100.0%
metadata-eval100.0%
Simplified100.0%
Taylor expanded in y around inf 54.2%
Final simplification54.2%
(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 2023268
(FPCore (x y)
:name "Linear.Projection:inversePerspective from linear-1.19.1.3, B"
:precision binary64
:herbie-target
(- (/ 0.5 y) (/ 0.5 x))
(/ (- x y) (* (* x 2.0) y)))