
(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 6 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 (/ 1.0 (/ (- x y) (+ x y))))
double code(double x, double y) {
return 1.0 / ((x - y) / (x + y));
}
real(8) function code(x, y)
real(8), intent (in) :: x
real(8), intent (in) :: y
code = 1.0d0 / ((x - y) / (x + y))
end function
public static double code(double x, double y) {
return 1.0 / ((x - y) / (x + y));
}
def code(x, y): return 1.0 / ((x - y) / (x + y))
function code(x, y) return Float64(1.0 / Float64(Float64(x - y) / Float64(x + y))) end
function tmp = code(x, y) tmp = 1.0 / ((x - y) / (x + y)); end
code[x_, y_] := N[(1.0 / N[(N[(x - y), $MachinePrecision] / N[(x + y), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\frac{1}{\frac{x - y}{x + y}}
\end{array}
Initial program 99.9%
clear-num99.9%
inv-pow99.9%
Applied egg-rr99.9%
unpow-199.9%
Applied egg-rr99.9%
Final simplification99.9%
(FPCore (x y) :precision binary64 (if (or (<= y -1.4e+27) (not (<= y 1.05e+64))) (+ (* -2.0 (/ x y)) -1.0) (+ 1.0 (* 2.0 (/ y x)))))
double code(double x, double y) {
double tmp;
if ((y <= -1.4e+27) || !(y <= 1.05e+64)) {
tmp = (-2.0 * (x / y)) + -1.0;
} else {
tmp = 1.0 + (2.0 * (y / x));
}
return tmp;
}
real(8) function code(x, y)
real(8), intent (in) :: x
real(8), intent (in) :: y
real(8) :: tmp
if ((y <= (-1.4d+27)) .or. (.not. (y <= 1.05d+64))) then
tmp = ((-2.0d0) * (x / y)) + (-1.0d0)
else
tmp = 1.0d0 + (2.0d0 * (y / x))
end if
code = tmp
end function
public static double code(double x, double y) {
double tmp;
if ((y <= -1.4e+27) || !(y <= 1.05e+64)) {
tmp = (-2.0 * (x / y)) + -1.0;
} else {
tmp = 1.0 + (2.0 * (y / x));
}
return tmp;
}
def code(x, y): tmp = 0 if (y <= -1.4e+27) or not (y <= 1.05e+64): tmp = (-2.0 * (x / y)) + -1.0 else: tmp = 1.0 + (2.0 * (y / x)) return tmp
function code(x, y) tmp = 0.0 if ((y <= -1.4e+27) || !(y <= 1.05e+64)) tmp = Float64(Float64(-2.0 * Float64(x / y)) + -1.0); else tmp = Float64(1.0 + Float64(2.0 * Float64(y / x))); end return tmp end
function tmp_2 = code(x, y) tmp = 0.0; if ((y <= -1.4e+27) || ~((y <= 1.05e+64))) tmp = (-2.0 * (x / y)) + -1.0; else tmp = 1.0 + (2.0 * (y / x)); end tmp_2 = tmp; end
code[x_, y_] := If[Or[LessEqual[y, -1.4e+27], N[Not[LessEqual[y, 1.05e+64]], $MachinePrecision]], N[(N[(-2.0 * N[(x / y), $MachinePrecision]), $MachinePrecision] + -1.0), $MachinePrecision], N[(1.0 + N[(2.0 * N[(y / x), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;y \leq -1.4 \cdot 10^{+27} \lor \neg \left(y \leq 1.05 \cdot 10^{+64}\right):\\
\;\;\;\;-2 \cdot \frac{x}{y} + -1\\
\mathbf{else}:\\
\;\;\;\;1 + 2 \cdot \frac{y}{x}\\
\end{array}
\end{array}
if y < -1.4e27 or 1.05e64 < y Initial program 99.8%
Taylor expanded in x around 0 79.2%
if -1.4e27 < y < 1.05e64Initial program 100.0%
Taylor expanded in y around 0 76.7%
Final simplification77.6%
(FPCore (x y) :precision binary64 (if (<= y -1.55e+29) -1.0 (if (<= y 1.25e+68) (+ 1.0 (* 2.0 (/ y x))) -1.0)))
double code(double x, double y) {
double tmp;
if (y <= -1.55e+29) {
tmp = -1.0;
} else if (y <= 1.25e+68) {
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 (y <= (-1.55d+29)) then
tmp = -1.0d0
else if (y <= 1.25d+68) 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 (y <= -1.55e+29) {
tmp = -1.0;
} else if (y <= 1.25e+68) {
tmp = 1.0 + (2.0 * (y / x));
} else {
tmp = -1.0;
}
return tmp;
}
def code(x, y): tmp = 0 if y <= -1.55e+29: tmp = -1.0 elif y <= 1.25e+68: tmp = 1.0 + (2.0 * (y / x)) else: tmp = -1.0 return tmp
function code(x, y) tmp = 0.0 if (y <= -1.55e+29) tmp = -1.0; elseif (y <= 1.25e+68) 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 (y <= -1.55e+29) tmp = -1.0; elseif (y <= 1.25e+68) tmp = 1.0 + (2.0 * (y / x)); else tmp = -1.0; end tmp_2 = tmp; end
code[x_, y_] := If[LessEqual[y, -1.55e+29], -1.0, If[LessEqual[y, 1.25e+68], N[(1.0 + N[(2.0 * N[(y / x), $MachinePrecision]), $MachinePrecision]), $MachinePrecision], -1.0]]
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;y \leq -1.55 \cdot 10^{+29}:\\
\;\;\;\;-1\\
\mathbf{elif}\;y \leq 1.25 \cdot 10^{+68}:\\
\;\;\;\;1 + 2 \cdot \frac{y}{x}\\
\mathbf{else}:\\
\;\;\;\;-1\\
\end{array}
\end{array}
if y < -1.5499999999999999e29 or 1.2500000000000001e68 < y Initial program 99.8%
Taylor expanded in x around 0 77.2%
if -1.5499999999999999e29 < y < 1.2500000000000001e68Initial program 100.0%
Taylor expanded in y around 0 76.7%
Final simplification76.9%
(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 99.9%
Final simplification99.9%
(FPCore (x y) :precision binary64 (if (<= y -5.6e+15) -1.0 (if (<= y 1.3e+64) 1.0 -1.0)))
double code(double x, double y) {
double tmp;
if (y <= -5.6e+15) {
tmp = -1.0;
} else if (y <= 1.3e+64) {
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 (y <= (-5.6d+15)) then
tmp = -1.0d0
else if (y <= 1.3d+64) 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 (y <= -5.6e+15) {
tmp = -1.0;
} else if (y <= 1.3e+64) {
tmp = 1.0;
} else {
tmp = -1.0;
}
return tmp;
}
def code(x, y): tmp = 0 if y <= -5.6e+15: tmp = -1.0 elif y <= 1.3e+64: tmp = 1.0 else: tmp = -1.0 return tmp
function code(x, y) tmp = 0.0 if (y <= -5.6e+15) tmp = -1.0; elseif (y <= 1.3e+64) tmp = 1.0; else tmp = -1.0; end return tmp end
function tmp_2 = code(x, y) tmp = 0.0; if (y <= -5.6e+15) tmp = -1.0; elseif (y <= 1.3e+64) tmp = 1.0; else tmp = -1.0; end tmp_2 = tmp; end
code[x_, y_] := If[LessEqual[y, -5.6e+15], -1.0, If[LessEqual[y, 1.3e+64], 1.0, -1.0]]
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;y \leq -5.6 \cdot 10^{+15}:\\
\;\;\;\;-1\\
\mathbf{elif}\;y \leq 1.3 \cdot 10^{+64}:\\
\;\;\;\;1\\
\mathbf{else}:\\
\;\;\;\;-1\\
\end{array}
\end{array}
if y < -5.6e15 or 1.29999999999999998e64 < y Initial program 99.8%
Taylor expanded in x around 0 75.6%
if -5.6e15 < y < 1.29999999999999998e64Initial program 100.0%
Taylor expanded in x around inf 75.5%
Final simplification75.6%
(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 99.9%
Taylor expanded in x around 0 43.5%
Final simplification43.5%
(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 2023322
(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)))