
(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 (<= y -8.8e+47)
-1.0
(if (or (<= y 1.3e+29) (and (not (<= y 2.2e+65)) (<= y 3.3e+127)))
(+ 1.0 (* 2.0 (/ y x)))
-1.0)))
double code(double x, double y) {
double tmp;
if (y <= -8.8e+47) {
tmp = -1.0;
} else if ((y <= 1.3e+29) || (!(y <= 2.2e+65) && (y <= 3.3e+127))) {
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 <= (-8.8d+47)) then
tmp = -1.0d0
else if ((y <= 1.3d+29) .or. (.not. (y <= 2.2d+65)) .and. (y <= 3.3d+127)) 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 <= -8.8e+47) {
tmp = -1.0;
} else if ((y <= 1.3e+29) || (!(y <= 2.2e+65) && (y <= 3.3e+127))) {
tmp = 1.0 + (2.0 * (y / x));
} else {
tmp = -1.0;
}
return tmp;
}
def code(x, y): tmp = 0 if y <= -8.8e+47: tmp = -1.0 elif (y <= 1.3e+29) or (not (y <= 2.2e+65) and (y <= 3.3e+127)): tmp = 1.0 + (2.0 * (y / x)) else: tmp = -1.0 return tmp
function code(x, y) tmp = 0.0 if (y <= -8.8e+47) tmp = -1.0; elseif ((y <= 1.3e+29) || (!(y <= 2.2e+65) && (y <= 3.3e+127))) 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 <= -8.8e+47) tmp = -1.0; elseif ((y <= 1.3e+29) || (~((y <= 2.2e+65)) && (y <= 3.3e+127))) tmp = 1.0 + (2.0 * (y / x)); else tmp = -1.0; end tmp_2 = tmp; end
code[x_, y_] := If[LessEqual[y, -8.8e+47], -1.0, If[Or[LessEqual[y, 1.3e+29], And[N[Not[LessEqual[y, 2.2e+65]], $MachinePrecision], LessEqual[y, 3.3e+127]]], N[(1.0 + N[(2.0 * N[(y / x), $MachinePrecision]), $MachinePrecision]), $MachinePrecision], -1.0]]
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;y \leq -8.8 \cdot 10^{+47}:\\
\;\;\;\;-1\\
\mathbf{elif}\;y \leq 1.3 \cdot 10^{+29} \lor \neg \left(y \leq 2.2 \cdot 10^{+65}\right) \land y \leq 3.3 \cdot 10^{+127}:\\
\;\;\;\;1 + 2 \cdot \frac{y}{x}\\
\mathbf{else}:\\
\;\;\;\;-1\\
\end{array}
\end{array}
if y < -8.7999999999999997e47 or 1.3e29 < y < 2.1999999999999998e65 or 3.29999999999999977e127 < y Initial program 100.0%
Taylor expanded in x around 0 85.0%
if -8.7999999999999997e47 < y < 1.3e29 or 2.1999999999999998e65 < y < 3.29999999999999977e127Initial program 100.0%
Taylor expanded in y around 0 79.4%
Final simplification81.7%
(FPCore (x y) :precision binary64 (if (or (<= y -1.02e+48) (not (<= y 2.8e+32))) (+ (* -2.0 (/ x y)) -1.0) (+ 1.0 (* 2.0 (/ y x)))))
double code(double x, double y) {
double tmp;
if ((y <= -1.02e+48) || !(y <= 2.8e+32)) {
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 <= (-1.02d+48)) .or. (.not. (y <= 2.8d+32))) 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 <= -1.02e+48) || !(y <= 2.8e+32)) {
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 <= -1.02e+48) or not (y <= 2.8e+32): 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 <= -1.02e+48) || !(y <= 2.8e+32)) 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 <= -1.02e+48) || ~((y <= 2.8e+32))) 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, -1.02e+48], N[Not[LessEqual[y, 2.8e+32]], $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 -1.02 \cdot 10^{+48} \lor \neg \left(y \leq 2.8 \cdot 10^{+32}\right):\\
\;\;\;\;-2 \cdot \frac{x}{y} + -1\\
\mathbf{else}:\\
\;\;\;\;1 + 2 \cdot \frac{y}{x}\\
\end{array}
\end{array}
if y < -1.02e48 or 2.8e32 < y Initial program 100.0%
Taylor expanded in x around 0 80.4%
if -1.02e48 < y < 2.8e32Initial program 100.0%
Taylor expanded in y around 0 80.8%
Final simplification80.6%
(FPCore (x y) :precision binary64 (if (<= y -9e+47) -1.0 (if (<= y 5e+32) 1.0 -1.0)))
double code(double x, double y) {
double tmp;
if (y <= -9e+47) {
tmp = -1.0;
} else if (y <= 5e+32) {
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 <= (-9d+47)) then
tmp = -1.0d0
else if (y <= 5d+32) 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 <= -9e+47) {
tmp = -1.0;
} else if (y <= 5e+32) {
tmp = 1.0;
} else {
tmp = -1.0;
}
return tmp;
}
def code(x, y): tmp = 0 if y <= -9e+47: tmp = -1.0 elif y <= 5e+32: tmp = 1.0 else: tmp = -1.0 return tmp
function code(x, y) tmp = 0.0 if (y <= -9e+47) tmp = -1.0; elseif (y <= 5e+32) tmp = 1.0; else tmp = -1.0; end return tmp end
function tmp_2 = code(x, y) tmp = 0.0; if (y <= -9e+47) tmp = -1.0; elseif (y <= 5e+32) tmp = 1.0; else tmp = -1.0; end tmp_2 = tmp; end
code[x_, y_] := If[LessEqual[y, -9e+47], -1.0, If[LessEqual[y, 5e+32], 1.0, -1.0]]
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;y \leq -9 \cdot 10^{+47}:\\
\;\;\;\;-1\\
\mathbf{elif}\;y \leq 5 \cdot 10^{+32}:\\
\;\;\;\;1\\
\mathbf{else}:\\
\;\;\;\;-1\\
\end{array}
\end{array}
if y < -8.99999999999999958e47 or 4.9999999999999997e32 < y Initial program 100.0%
Taylor expanded in x around 0 79.2%
if -8.99999999999999958e47 < y < 4.9999999999999997e32Initial program 100.0%
Taylor expanded in x around inf 79.7%
Final simplification79.4%
(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 47.8%
Final simplification47.8%
(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 2024071
(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)))