
(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 -1.75e+18)
(not (or (<= x -1.6e-51) (and (not (<= x -3.55e-90)) (<= x 3e-67)))))
(+ 1.0 (* 2.0 (/ y x)))
-1.0))
double code(double x, double y) {
double tmp;
if ((x <= -1.75e+18) || !((x <= -1.6e-51) || (!(x <= -3.55e-90) && (x <= 3e-67)))) {
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 <= (-1.75d+18)) .or. (.not. (x <= (-1.6d-51)) .or. (.not. (x <= (-3.55d-90))) .and. (x <= 3d-67))) 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 <= -1.75e+18) || !((x <= -1.6e-51) || (!(x <= -3.55e-90) && (x <= 3e-67)))) {
tmp = 1.0 + (2.0 * (y / x));
} else {
tmp = -1.0;
}
return tmp;
}
def code(x, y): tmp = 0 if (x <= -1.75e+18) or not ((x <= -1.6e-51) or (not (x <= -3.55e-90) and (x <= 3e-67))): tmp = 1.0 + (2.0 * (y / x)) else: tmp = -1.0 return tmp
function code(x, y) tmp = 0.0 if ((x <= -1.75e+18) || !((x <= -1.6e-51) || (!(x <= -3.55e-90) && (x <= 3e-67)))) 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 <= -1.75e+18) || ~(((x <= -1.6e-51) || (~((x <= -3.55e-90)) && (x <= 3e-67))))) tmp = 1.0 + (2.0 * (y / x)); else tmp = -1.0; end tmp_2 = tmp; end
code[x_, y_] := If[Or[LessEqual[x, -1.75e+18], N[Not[Or[LessEqual[x, -1.6e-51], And[N[Not[LessEqual[x, -3.55e-90]], $MachinePrecision], LessEqual[x, 3e-67]]]], $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 -1.75 \cdot 10^{+18} \lor \neg \left(x \leq -1.6 \cdot 10^{-51} \lor \neg \left(x \leq -3.55 \cdot 10^{-90}\right) \land x \leq 3 \cdot 10^{-67}\right):\\
\;\;\;\;1 + 2 \cdot \frac{y}{x}\\
\mathbf{else}:\\
\;\;\;\;-1\\
\end{array}
\end{array}
if x < -1.75e18 or -1.6e-51 < x < -3.5500000000000001e-90 or 3.00000000000000032e-67 < x Initial program 100.0%
Taylor expanded in y around 0 78.1%
if -1.75e18 < x < -1.6e-51 or -3.5500000000000001e-90 < x < 3.00000000000000032e-67Initial program 100.0%
Taylor expanded in x around 0 85.9%
Final simplification81.3%
(FPCore (x y)
:precision binary64
(if (or (<= x -3.7e+17)
(not (or (<= x -3.1e-53) (and (not (<= x -5.7e-92)) (<= x 3.2e-65)))))
(+ 1.0 (* 2.0 (/ y x)))
(+ (* -2.0 (/ x y)) -1.0)))
double code(double x, double y) {
double tmp;
if ((x <= -3.7e+17) || !((x <= -3.1e-53) || (!(x <= -5.7e-92) && (x <= 3.2e-65)))) {
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 <= (-3.7d+17)) .or. (.not. (x <= (-3.1d-53)) .or. (.not. (x <= (-5.7d-92))) .and. (x <= 3.2d-65))) 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 <= -3.7e+17) || !((x <= -3.1e-53) || (!(x <= -5.7e-92) && (x <= 3.2e-65)))) {
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 <= -3.7e+17) or not ((x <= -3.1e-53) or (not (x <= -5.7e-92) and (x <= 3.2e-65))): 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 <= -3.7e+17) || !((x <= -3.1e-53) || (!(x <= -5.7e-92) && (x <= 3.2e-65)))) 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 <= -3.7e+17) || ~(((x <= -3.1e-53) || (~((x <= -5.7e-92)) && (x <= 3.2e-65))))) 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, -3.7e+17], N[Not[Or[LessEqual[x, -3.1e-53], And[N[Not[LessEqual[x, -5.7e-92]], $MachinePrecision], LessEqual[x, 3.2e-65]]]], $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 -3.7 \cdot 10^{+17} \lor \neg \left(x \leq -3.1 \cdot 10^{-53} \lor \neg \left(x \leq -5.7 \cdot 10^{-92}\right) \land x \leq 3.2 \cdot 10^{-65}\right):\\
\;\;\;\;1 + 2 \cdot \frac{y}{x}\\
\mathbf{else}:\\
\;\;\;\;-2 \cdot \frac{x}{y} + -1\\
\end{array}
\end{array}
if x < -3.7e17 or -3.10000000000000015e-53 < x < -5.70000000000000009e-92 or 3.1999999999999999e-65 < x Initial program 100.0%
Taylor expanded in y around 0 78.1%
if -3.7e17 < x < -3.10000000000000015e-53 or -5.70000000000000009e-92 < x < 3.1999999999999999e-65Initial program 100.0%
Taylor expanded in x around 0 86.2%
Final simplification81.4%
(FPCore (x y) :precision binary64 (if (<= x -1e+18) 1.0 (if (<= x -4e-51) -1.0 (if (<= x -4e-90) 1.0 (if (<= x 5e-71) -1.0 1.0)))))
double code(double x, double y) {
double tmp;
if (x <= -1e+18) {
tmp = 1.0;
} else if (x <= -4e-51) {
tmp = -1.0;
} else if (x <= -4e-90) {
tmp = 1.0;
} else if (x <= 5e-71) {
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 <= (-1d+18)) then
tmp = 1.0d0
else if (x <= (-4d-51)) then
tmp = -1.0d0
else if (x <= (-4d-90)) then
tmp = 1.0d0
else if (x <= 5d-71) 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 <= -1e+18) {
tmp = 1.0;
} else if (x <= -4e-51) {
tmp = -1.0;
} else if (x <= -4e-90) {
tmp = 1.0;
} else if (x <= 5e-71) {
tmp = -1.0;
} else {
tmp = 1.0;
}
return tmp;
}
def code(x, y): tmp = 0 if x <= -1e+18: tmp = 1.0 elif x <= -4e-51: tmp = -1.0 elif x <= -4e-90: tmp = 1.0 elif x <= 5e-71: tmp = -1.0 else: tmp = 1.0 return tmp
function code(x, y) tmp = 0.0 if (x <= -1e+18) tmp = 1.0; elseif (x <= -4e-51) tmp = -1.0; elseif (x <= -4e-90) tmp = 1.0; elseif (x <= 5e-71) tmp = -1.0; else tmp = 1.0; end return tmp end
function tmp_2 = code(x, y) tmp = 0.0; if (x <= -1e+18) tmp = 1.0; elseif (x <= -4e-51) tmp = -1.0; elseif (x <= -4e-90) tmp = 1.0; elseif (x <= 5e-71) tmp = -1.0; else tmp = 1.0; end tmp_2 = tmp; end
code[x_, y_] := If[LessEqual[x, -1e+18], 1.0, If[LessEqual[x, -4e-51], -1.0, If[LessEqual[x, -4e-90], 1.0, If[LessEqual[x, 5e-71], -1.0, 1.0]]]]
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;x \leq -1 \cdot 10^{+18}:\\
\;\;\;\;1\\
\mathbf{elif}\;x \leq -4 \cdot 10^{-51}:\\
\;\;\;\;-1\\
\mathbf{elif}\;x \leq -4 \cdot 10^{-90}:\\
\;\;\;\;1\\
\mathbf{elif}\;x \leq 5 \cdot 10^{-71}:\\
\;\;\;\;-1\\
\mathbf{else}:\\
\;\;\;\;1\\
\end{array}
\end{array}
if x < -1e18 or -4e-51 < x < -3.99999999999999998e-90 or 4.99999999999999998e-71 < x Initial program 100.0%
Taylor expanded in x around inf 77.3%
if -1e18 < x < -4e-51 or -3.99999999999999998e-90 < x < 4.99999999999999998e-71Initial program 100.0%
Taylor expanded in x around 0 85.9%
Final simplification80.8%
(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 48.7%
Final simplification48.7%
(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 2024059
(FPCore (x y)
:name "Linear.Projection:perspective from linear-1.19.1.3, A"
:precision binary64
:alt
(/ 1.0 (- (/ x (+ x y)) (/ y (+ x y))))
(/ (+ x y) (- x y)))