
(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 79.0%
remove-double-neg79.0%
distribute-rgt-neg-out79.0%
distribute-frac-neg279.0%
neg-mul-179.0%
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*85.6%
associate-/r*85.6%
*-inverses85.6%
metadata-eval85.6%
metadata-eval85.6%
metadata-eval85.6%
metadata-eval85.6%
Simplified100.0%
Final simplification100.0%
(FPCore (x y) :precision binary64 (if (or (<= y -4.8e+65) (not (<= y 1.2e-66))) (/ -0.5 x) (/ 0.5 y)))
double code(double x, double y) {
double tmp;
if ((y <= -4.8e+65) || !(y <= 1.2e-66)) {
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 <= (-4.8d+65)) .or. (.not. (y <= 1.2d-66))) 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 <= -4.8e+65) || !(y <= 1.2e-66)) {
tmp = -0.5 / x;
} else {
tmp = 0.5 / y;
}
return tmp;
}
def code(x, y): tmp = 0 if (y <= -4.8e+65) or not (y <= 1.2e-66): tmp = -0.5 / x else: tmp = 0.5 / y return tmp
function code(x, y) tmp = 0.0 if ((y <= -4.8e+65) || !(y <= 1.2e-66)) 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 <= -4.8e+65) || ~((y <= 1.2e-66))) tmp = -0.5 / x; else tmp = 0.5 / y; end tmp_2 = tmp; end
code[x_, y_] := If[Or[LessEqual[y, -4.8e+65], N[Not[LessEqual[y, 1.2e-66]], $MachinePrecision]], N[(-0.5 / x), $MachinePrecision], N[(0.5 / y), $MachinePrecision]]
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;y \leq -4.8 \cdot 10^{+65} \lor \neg \left(y \leq 1.2 \cdot 10^{-66}\right):\\
\;\;\;\;\frac{-0.5}{x}\\
\mathbf{else}:\\
\;\;\;\;\frac{0.5}{y}\\
\end{array}
\end{array}
if y < -4.8000000000000003e65 or 1.20000000000000013e-66 < y Initial program 77.0%
remove-double-neg77.0%
distribute-rgt-neg-out77.0%
distribute-frac-neg277.0%
neg-mul-177.0%
div-sub77.0%
distribute-lft-out--77.0%
neg-mul-177.0%
distribute-frac-neg277.0%
distribute-rgt-neg-out77.0%
remove-double-neg77.0%
cancel-sign-sub-inv77.0%
associate-/r*88.6%
associate-/r*88.6%
*-inverses88.6%
metadata-eval88.6%
metadata-eval88.6%
metadata-eval88.6%
metadata-eval88.6%
Simplified100.0%
Taylor expanded in y around inf 79.9%
if -4.8000000000000003e65 < y < 1.20000000000000013e-66Initial program 81.4%
remove-double-neg81.4%
distribute-rgt-neg-out81.4%
distribute-frac-neg281.4%
neg-mul-181.4%
div-sub81.0%
distribute-lft-out--81.0%
neg-mul-181.0%
distribute-frac-neg281.0%
distribute-rgt-neg-out81.0%
remove-double-neg81.0%
cancel-sign-sub-inv81.0%
associate-/r*82.2%
associate-/r*82.2%
*-inverses82.2%
metadata-eval82.2%
metadata-eval82.2%
metadata-eval82.2%
metadata-eval82.2%
Simplified99.9%
Taylor expanded in y around 0 77.3%
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 79.0%
remove-double-neg79.0%
distribute-rgt-neg-out79.0%
distribute-frac-neg279.0%
neg-mul-179.0%
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*85.6%
associate-/r*85.6%
*-inverses85.6%
metadata-eval85.6%
metadata-eval85.6%
metadata-eval85.6%
metadata-eval85.6%
Simplified100.0%
Taylor expanded in y around inf 54.0%
Final simplification54.0%
(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 2024095
(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)))