
(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 72.8%
remove-double-neg72.8%
distribute-rgt-neg-out72.8%
distribute-frac-neg272.8%
neg-mul-172.8%
div-sub72.3%
distribute-lft-out--72.3%
neg-mul-172.3%
distribute-frac-neg272.3%
distribute-rgt-neg-out72.3%
remove-double-neg72.3%
cancel-sign-sub-inv72.3%
associate-/r*79.7%
associate-/r*79.7%
*-inverses79.7%
metadata-eval79.7%
metadata-eval79.7%
*-lft-identity79.7%
distribute-rgt-neg-out79.7%
Simplified100.0%
Final simplification100.0%
(FPCore (x y) :precision binary64 (if (or (<= x -5.5e-23) (not (<= x 1.4e+61))) (/ 0.5 y) (/ -0.5 x)))
double code(double x, double y) {
double tmp;
if ((x <= -5.5e-23) || !(x <= 1.4e+61)) {
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 <= (-5.5d-23)) .or. (.not. (x <= 1.4d+61))) 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 <= -5.5e-23) || !(x <= 1.4e+61)) {
tmp = 0.5 / y;
} else {
tmp = -0.5 / x;
}
return tmp;
}
def code(x, y): tmp = 0 if (x <= -5.5e-23) or not (x <= 1.4e+61): tmp = 0.5 / y else: tmp = -0.5 / x return tmp
function code(x, y) tmp = 0.0 if ((x <= -5.5e-23) || !(x <= 1.4e+61)) 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 <= -5.5e-23) || ~((x <= 1.4e+61))) tmp = 0.5 / y; else tmp = -0.5 / x; end tmp_2 = tmp; end
code[x_, y_] := If[Or[LessEqual[x, -5.5e-23], N[Not[LessEqual[x, 1.4e+61]], $MachinePrecision]], N[(0.5 / y), $MachinePrecision], N[(-0.5 / x), $MachinePrecision]]
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;x \leq -5.5 \cdot 10^{-23} \lor \neg \left(x \leq 1.4 \cdot 10^{+61}\right):\\
\;\;\;\;\frac{0.5}{y}\\
\mathbf{else}:\\
\;\;\;\;\frac{-0.5}{x}\\
\end{array}
\end{array}
if x < -5.5000000000000001e-23 or 1.4000000000000001e61 < x Initial program 71.3%
remove-double-neg71.3%
distribute-rgt-neg-out71.3%
distribute-frac-neg271.3%
neg-mul-171.3%
div-sub71.3%
distribute-lft-out--71.3%
neg-mul-171.3%
distribute-frac-neg271.3%
distribute-rgt-neg-out71.3%
remove-double-neg71.3%
cancel-sign-sub-inv71.3%
associate-/r*86.1%
associate-/r*86.1%
*-inverses86.1%
metadata-eval86.1%
metadata-eval86.1%
*-lft-identity86.1%
distribute-rgt-neg-out86.1%
Simplified100.0%
Taylor expanded in y around 0 77.9%
if -5.5000000000000001e-23 < x < 1.4000000000000001e61Initial program 74.2%
remove-double-neg74.2%
distribute-rgt-neg-out74.2%
distribute-frac-neg274.2%
neg-mul-174.2%
div-sub73.3%
distribute-lft-out--73.3%
neg-mul-173.3%
distribute-frac-neg273.3%
distribute-rgt-neg-out73.3%
remove-double-neg73.3%
cancel-sign-sub-inv73.3%
associate-/r*73.7%
associate-/r*73.7%
*-inverses73.7%
metadata-eval73.7%
metadata-eval73.7%
*-lft-identity73.7%
distribute-rgt-neg-out73.7%
Simplified100.0%
Taylor expanded in y around inf 78.2%
Final simplification78.1%
(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 72.8%
remove-double-neg72.8%
distribute-rgt-neg-out72.8%
distribute-frac-neg272.8%
neg-mul-172.8%
div-sub72.3%
distribute-lft-out--72.3%
neg-mul-172.3%
distribute-frac-neg272.3%
distribute-rgt-neg-out72.3%
remove-double-neg72.3%
cancel-sign-sub-inv72.3%
associate-/r*79.7%
associate-/r*79.7%
*-inverses79.7%
metadata-eval79.7%
metadata-eval79.7%
*-lft-identity79.7%
distribute-rgt-neg-out79.7%
Simplified100.0%
Taylor expanded in y around inf 51.8%
Final simplification51.8%
(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 2024072
(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)))