
(FPCore (x y) :precision binary64 (/ (+ x y) (- x y)))
double code(double x, double y) {
return (x + y) / (x - y);
}
real(8) function code(x, y)
real(8), intent (in) :: x
real(8), intent (in) :: y
code = (x + y) / (x - y)
end function
public static double code(double x, double y) {
return (x + y) / (x - y);
}
def code(x, y): return (x + y) / (x - y)
function code(x, y) return Float64(Float64(x + y) / Float64(x - y)) end
function tmp = code(x, y) tmp = (x + y) / (x - y); end
code[x_, y_] := N[(N[(x + y), $MachinePrecision] / N[(x - y), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\frac{x + y}{x - y}
\end{array}
Sampling outcomes in binary64 precision:
Herbie found 5 alternatives:
| Alternative | Accuracy | Speedup |
|---|
(FPCore (x y) :precision binary64 (/ (+ x y) (- x y)))
double code(double x, double y) {
return (x + y) / (x - y);
}
real(8) function code(x, y)
real(8), intent (in) :: x
real(8), intent (in) :: y
code = (x + y) / (x - y)
end function
public static double code(double x, double y) {
return (x + y) / (x - y);
}
def code(x, y): return (x + y) / (x - y)
function code(x, y) return Float64(Float64(x + y) / Float64(x - y)) end
function tmp = code(x, y) tmp = (x + y) / (x - y); end
code[x_, y_] := N[(N[(x + y), $MachinePrecision] / N[(x - y), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\frac{x + y}{x - y}
\end{array}
(FPCore (x y) :precision binary64 (/ (+ x y) (- x y)))
double code(double x, double y) {
return (x + y) / (x - y);
}
real(8) function code(x, y)
real(8), intent (in) :: x
real(8), intent (in) :: y
code = (x + y) / (x - y)
end function
public static double code(double x, double y) {
return (x + y) / (x - y);
}
def code(x, y): return (x + y) / (x - y)
function code(x, y) return Float64(Float64(x + y) / Float64(x - y)) end
function tmp = code(x, y) tmp = (x + y) / (x - y); end
code[x_, y_] := N[(N[(x + y), $MachinePrecision] / N[(x - y), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\frac{x + y}{x - y}
\end{array}
Initial program 100.0%
Final simplification100.0%
(FPCore (x y) :precision binary64 (if (or (<= x -3.2e-12) (not (<= x 2.3e-25))) (+ 1.0 (* 2.0 (/ y x))) -1.0))
double code(double x, double y) {
double tmp;
if ((x <= -3.2e-12) || !(x <= 2.3e-25)) {
tmp = 1.0 + (2.0 * (y / x));
} else {
tmp = -1.0;
}
return tmp;
}
real(8) function code(x, y)
real(8), intent (in) :: x
real(8), intent (in) :: y
real(8) :: tmp
if ((x <= (-3.2d-12)) .or. (.not. (x <= 2.3d-25))) then
tmp = 1.0d0 + (2.0d0 * (y / x))
else
tmp = -1.0d0
end if
code = tmp
end function
public static double code(double x, double y) {
double tmp;
if ((x <= -3.2e-12) || !(x <= 2.3e-25)) {
tmp = 1.0 + (2.0 * (y / x));
} else {
tmp = -1.0;
}
return tmp;
}
def code(x, y): tmp = 0 if (x <= -3.2e-12) or not (x <= 2.3e-25): tmp = 1.0 + (2.0 * (y / x)) else: tmp = -1.0 return tmp
function code(x, y) tmp = 0.0 if ((x <= -3.2e-12) || !(x <= 2.3e-25)) tmp = Float64(1.0 + Float64(2.0 * Float64(y / x))); else tmp = -1.0; end return tmp end
function tmp_2 = code(x, y) tmp = 0.0; if ((x <= -3.2e-12) || ~((x <= 2.3e-25))) tmp = 1.0 + (2.0 * (y / x)); else tmp = -1.0; end tmp_2 = tmp; end
code[x_, y_] := If[Or[LessEqual[x, -3.2e-12], N[Not[LessEqual[x, 2.3e-25]], $MachinePrecision]], N[(1.0 + N[(2.0 * N[(y / x), $MachinePrecision]), $MachinePrecision]), $MachinePrecision], -1.0]
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;x \leq -3.2 \cdot 10^{-12} \lor \neg \left(x \leq 2.3 \cdot 10^{-25}\right):\\
\;\;\;\;1 + 2 \cdot \frac{y}{x}\\
\mathbf{else}:\\
\;\;\;\;-1\\
\end{array}
\end{array}
if x < -3.2000000000000001e-12 or 2.2999999999999999e-25 < x Initial program 100.0%
Taylor expanded in y around 0 77.6%
if -3.2000000000000001e-12 < x < 2.2999999999999999e-25Initial program 100.0%
Taylor expanded in x around 0 78.3%
Final simplification77.9%
(FPCore (x y) :precision binary64 (if (or (<= x -1.2e+30) (not (<= x 1.3e-48))) (+ 1.0 (* 2.0 (/ y x))) (+ (* -2.0 (/ x y)) -1.0)))
double code(double x, double y) {
double tmp;
if ((x <= -1.2e+30) || !(x <= 1.3e-48)) {
tmp = 1.0 + (2.0 * (y / x));
} else {
tmp = (-2.0 * (x / y)) + -1.0;
}
return tmp;
}
real(8) function code(x, y)
real(8), intent (in) :: x
real(8), intent (in) :: y
real(8) :: tmp
if ((x <= (-1.2d+30)) .or. (.not. (x <= 1.3d-48))) then
tmp = 1.0d0 + (2.0d0 * (y / x))
else
tmp = ((-2.0d0) * (x / y)) + (-1.0d0)
end if
code = tmp
end function
public static double code(double x, double y) {
double tmp;
if ((x <= -1.2e+30) || !(x <= 1.3e-48)) {
tmp = 1.0 + (2.0 * (y / x));
} else {
tmp = (-2.0 * (x / y)) + -1.0;
}
return tmp;
}
def code(x, y): tmp = 0 if (x <= -1.2e+30) or not (x <= 1.3e-48): tmp = 1.0 + (2.0 * (y / x)) else: tmp = (-2.0 * (x / y)) + -1.0 return tmp
function code(x, y) tmp = 0.0 if ((x <= -1.2e+30) || !(x <= 1.3e-48)) tmp = Float64(1.0 + Float64(2.0 * Float64(y / x))); else tmp = Float64(Float64(-2.0 * Float64(x / y)) + -1.0); end return tmp end
function tmp_2 = code(x, y) tmp = 0.0; if ((x <= -1.2e+30) || ~((x <= 1.3e-48))) tmp = 1.0 + (2.0 * (y / x)); else tmp = (-2.0 * (x / y)) + -1.0; end tmp_2 = tmp; end
code[x_, y_] := If[Or[LessEqual[x, -1.2e+30], N[Not[LessEqual[x, 1.3e-48]], $MachinePrecision]], N[(1.0 + N[(2.0 * N[(y / x), $MachinePrecision]), $MachinePrecision]), $MachinePrecision], N[(N[(-2.0 * N[(x / y), $MachinePrecision]), $MachinePrecision] + -1.0), $MachinePrecision]]
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;x \leq -1.2 \cdot 10^{+30} \lor \neg \left(x \leq 1.3 \cdot 10^{-48}\right):\\
\;\;\;\;1 + 2 \cdot \frac{y}{x}\\
\mathbf{else}:\\
\;\;\;\;-2 \cdot \frac{x}{y} + -1\\
\end{array}
\end{array}
if x < -1.2e30 or 1.29999999999999994e-48 < x Initial program 100.0%
Taylor expanded in y around 0 78.4%
if -1.2e30 < x < 1.29999999999999994e-48Initial program 100.0%
Taylor expanded in x around 0 78.2%
Final simplification78.3%
(FPCore (x y) :precision binary64 (if (<= x -1.3e-9) 1.0 (if (<= x 2.4e-49) -1.0 1.0)))
double code(double x, double y) {
double tmp;
if (x <= -1.3e-9) {
tmp = 1.0;
} else if (x <= 2.4e-49) {
tmp = -1.0;
} else {
tmp = 1.0;
}
return tmp;
}
real(8) function code(x, y)
real(8), intent (in) :: x
real(8), intent (in) :: y
real(8) :: tmp
if (x <= (-1.3d-9)) then
tmp = 1.0d0
else if (x <= 2.4d-49) then
tmp = -1.0d0
else
tmp = 1.0d0
end if
code = tmp
end function
public static double code(double x, double y) {
double tmp;
if (x <= -1.3e-9) {
tmp = 1.0;
} else if (x <= 2.4e-49) {
tmp = -1.0;
} else {
tmp = 1.0;
}
return tmp;
}
def code(x, y): tmp = 0 if x <= -1.3e-9: tmp = 1.0 elif x <= 2.4e-49: tmp = -1.0 else: tmp = 1.0 return tmp
function code(x, y) tmp = 0.0 if (x <= -1.3e-9) tmp = 1.0; elseif (x <= 2.4e-49) tmp = -1.0; else tmp = 1.0; end return tmp end
function tmp_2 = code(x, y) tmp = 0.0; if (x <= -1.3e-9) tmp = 1.0; elseif (x <= 2.4e-49) tmp = -1.0; else tmp = 1.0; end tmp_2 = tmp; end
code[x_, y_] := If[LessEqual[x, -1.3e-9], 1.0, If[LessEqual[x, 2.4e-49], -1.0, 1.0]]
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;x \leq -1.3 \cdot 10^{-9}:\\
\;\;\;\;1\\
\mathbf{elif}\;x \leq 2.4 \cdot 10^{-49}:\\
\;\;\;\;-1\\
\mathbf{else}:\\
\;\;\;\;1\\
\end{array}
\end{array}
if x < -1.3000000000000001e-9 or 2.39999999999999992e-49 < x Initial program 100.0%
Taylor expanded in x around inf 76.3%
if -1.3000000000000001e-9 < x < 2.39999999999999992e-49Initial program 100.0%
Taylor expanded in x around 0 78.8%
Final simplification77.4%
(FPCore (x y) :precision binary64 -1.0)
double code(double x, double y) {
return -1.0;
}
real(8) function code(x, y)
real(8), intent (in) :: x
real(8), intent (in) :: y
code = -1.0d0
end function
public static double code(double x, double y) {
return -1.0;
}
def code(x, y): return -1.0
function code(x, y) return -1.0 end
function tmp = code(x, y) tmp = -1.0; end
code[x_, y_] := -1.0
\begin{array}{l}
\\
-1
\end{array}
Initial program 100.0%
Taylor expanded in x around 0 48.2%
Final simplification48.2%
(FPCore (x y) :precision binary64 (/ 1.0 (- (/ x (+ x y)) (/ y (+ x y)))))
double code(double x, double y) {
return 1.0 / ((x / (x + y)) - (y / (x + y)));
}
real(8) function code(x, y)
real(8), intent (in) :: x
real(8), intent (in) :: y
code = 1.0d0 / ((x / (x + y)) - (y / (x + y)))
end function
public static double code(double x, double y) {
return 1.0 / ((x / (x + y)) - (y / (x + y)));
}
def code(x, y): return 1.0 / ((x / (x + y)) - (y / (x + y)))
function code(x, y) return Float64(1.0 / Float64(Float64(x / Float64(x + y)) - Float64(y / Float64(x + y)))) end
function tmp = code(x, y) tmp = 1.0 / ((x / (x + y)) - (y / (x + y))); end
code[x_, y_] := N[(1.0 / N[(N[(x / N[(x + y), $MachinePrecision]), $MachinePrecision] - N[(y / N[(x + y), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\frac{1}{\frac{x}{x + y} - \frac{y}{x + y}}
\end{array}
herbie shell --seed 2023192
(FPCore (x y)
:name "Linear.Projection:perspective from linear-1.19.1.3, A"
:precision binary64
:herbie-target
(/ 1.0 (- (/ x (+ x y)) (/ y (+ x y))))
(/ (+ x y) (- x y)))