
(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
(let* ((t_0 (+ (* -2.0 (/ x y)) -1.0)))
(if (<= y -6.5e-24)
t_0
(if (<= y 4.2e-20)
(+ 1.0 (* 2.0 (/ y x)))
(if (or (<= y 2.1e+18) (not (<= y 1.5e+49))) t_0 1.0)))))
double code(double x, double y) {
double t_0 = (-2.0 * (x / y)) + -1.0;
double tmp;
if (y <= -6.5e-24) {
tmp = t_0;
} else if (y <= 4.2e-20) {
tmp = 1.0 + (2.0 * (y / x));
} else if ((y <= 2.1e+18) || !(y <= 1.5e+49)) {
tmp = t_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) :: t_0
real(8) :: tmp
t_0 = ((-2.0d0) * (x / y)) + (-1.0d0)
if (y <= (-6.5d-24)) then
tmp = t_0
else if (y <= 4.2d-20) then
tmp = 1.0d0 + (2.0d0 * (y / x))
else if ((y <= 2.1d+18) .or. (.not. (y <= 1.5d+49))) then
tmp = t_0
else
tmp = 1.0d0
end if
code = tmp
end function
public static double code(double x, double y) {
double t_0 = (-2.0 * (x / y)) + -1.0;
double tmp;
if (y <= -6.5e-24) {
tmp = t_0;
} else if (y <= 4.2e-20) {
tmp = 1.0 + (2.0 * (y / x));
} else if ((y <= 2.1e+18) || !(y <= 1.5e+49)) {
tmp = t_0;
} else {
tmp = 1.0;
}
return tmp;
}
def code(x, y): t_0 = (-2.0 * (x / y)) + -1.0 tmp = 0 if y <= -6.5e-24: tmp = t_0 elif y <= 4.2e-20: tmp = 1.0 + (2.0 * (y / x)) elif (y <= 2.1e+18) or not (y <= 1.5e+49): tmp = t_0 else: tmp = 1.0 return tmp
function code(x, y) t_0 = Float64(Float64(-2.0 * Float64(x / y)) + -1.0) tmp = 0.0 if (y <= -6.5e-24) tmp = t_0; elseif (y <= 4.2e-20) tmp = Float64(1.0 + Float64(2.0 * Float64(y / x))); elseif ((y <= 2.1e+18) || !(y <= 1.5e+49)) tmp = t_0; else tmp = 1.0; end return tmp end
function tmp_2 = code(x, y) t_0 = (-2.0 * (x / y)) + -1.0; tmp = 0.0; if (y <= -6.5e-24) tmp = t_0; elseif (y <= 4.2e-20) tmp = 1.0 + (2.0 * (y / x)); elseif ((y <= 2.1e+18) || ~((y <= 1.5e+49))) tmp = t_0; else tmp = 1.0; end tmp_2 = tmp; end
code[x_, y_] := Block[{t$95$0 = N[(N[(-2.0 * N[(x / y), $MachinePrecision]), $MachinePrecision] + -1.0), $MachinePrecision]}, If[LessEqual[y, -6.5e-24], t$95$0, If[LessEqual[y, 4.2e-20], N[(1.0 + N[(2.0 * N[(y / x), $MachinePrecision]), $MachinePrecision]), $MachinePrecision], If[Or[LessEqual[y, 2.1e+18], N[Not[LessEqual[y, 1.5e+49]], $MachinePrecision]], t$95$0, 1.0]]]]
\begin{array}{l}
\\
\begin{array}{l}
t_0 := -2 \cdot \frac{x}{y} + -1\\
\mathbf{if}\;y \leq -6.5 \cdot 10^{-24}:\\
\;\;\;\;t_0\\
\mathbf{elif}\;y \leq 4.2 \cdot 10^{-20}:\\
\;\;\;\;1 + 2 \cdot \frac{y}{x}\\
\mathbf{elif}\;y \leq 2.1 \cdot 10^{+18} \lor \neg \left(y \leq 1.5 \cdot 10^{+49}\right):\\
\;\;\;\;t_0\\
\mathbf{else}:\\
\;\;\;\;1\\
\end{array}
\end{array}
if y < -6.5e-24 or 4.1999999999999998e-20 < y < 2.1e18 or 1.5000000000000001e49 < y Initial program 100.0%
Taylor expanded in x around 0 79.7%
if -6.5e-24 < y < 4.1999999999999998e-20Initial program 100.0%
Taylor expanded in y around 0 80.4%
if 2.1e18 < y < 1.5000000000000001e49Initial program 100.0%
Taylor expanded in x around inf 100.0%
Final simplification80.6%
(FPCore (x y)
:precision binary64
(if (<= y -2.5e-22)
-1.0
(if (<= y 1.9e-14)
(+ 1.0 (* 2.0 (/ y x)))
(if (<= y 5.2e+17) -1.0 (if (<= y 2e+50) 1.0 -1.0)))))
double code(double x, double y) {
double tmp;
if (y <= -2.5e-22) {
tmp = -1.0;
} else if (y <= 1.9e-14) {
tmp = 1.0 + (2.0 * (y / x));
} else if (y <= 5.2e+17) {
tmp = -1.0;
} else if (y <= 2e+50) {
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 <= (-2.5d-22)) then
tmp = -1.0d0
else if (y <= 1.9d-14) then
tmp = 1.0d0 + (2.0d0 * (y / x))
else if (y <= 5.2d+17) then
tmp = -1.0d0
else if (y <= 2d+50) 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 <= -2.5e-22) {
tmp = -1.0;
} else if (y <= 1.9e-14) {
tmp = 1.0 + (2.0 * (y / x));
} else if (y <= 5.2e+17) {
tmp = -1.0;
} else if (y <= 2e+50) {
tmp = 1.0;
} else {
tmp = -1.0;
}
return tmp;
}
def code(x, y): tmp = 0 if y <= -2.5e-22: tmp = -1.0 elif y <= 1.9e-14: tmp = 1.0 + (2.0 * (y / x)) elif y <= 5.2e+17: tmp = -1.0 elif y <= 2e+50: tmp = 1.0 else: tmp = -1.0 return tmp
function code(x, y) tmp = 0.0 if (y <= -2.5e-22) tmp = -1.0; elseif (y <= 1.9e-14) tmp = Float64(1.0 + Float64(2.0 * Float64(y / x))); elseif (y <= 5.2e+17) tmp = -1.0; elseif (y <= 2e+50) tmp = 1.0; else tmp = -1.0; end return tmp end
function tmp_2 = code(x, y) tmp = 0.0; if (y <= -2.5e-22) tmp = -1.0; elseif (y <= 1.9e-14) tmp = 1.0 + (2.0 * (y / x)); elseif (y <= 5.2e+17) tmp = -1.0; elseif (y <= 2e+50) tmp = 1.0; else tmp = -1.0; end tmp_2 = tmp; end
code[x_, y_] := If[LessEqual[y, -2.5e-22], -1.0, If[LessEqual[y, 1.9e-14], N[(1.0 + N[(2.0 * N[(y / x), $MachinePrecision]), $MachinePrecision]), $MachinePrecision], If[LessEqual[y, 5.2e+17], -1.0, If[LessEqual[y, 2e+50], 1.0, -1.0]]]]
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;y \leq -2.5 \cdot 10^{-22}:\\
\;\;\;\;-1\\
\mathbf{elif}\;y \leq 1.9 \cdot 10^{-14}:\\
\;\;\;\;1 + 2 \cdot \frac{y}{x}\\
\mathbf{elif}\;y \leq 5.2 \cdot 10^{+17}:\\
\;\;\;\;-1\\
\mathbf{elif}\;y \leq 2 \cdot 10^{+50}:\\
\;\;\;\;1\\
\mathbf{else}:\\
\;\;\;\;-1\\
\end{array}
\end{array}
if y < -2.49999999999999977e-22 or 1.9000000000000001e-14 < y < 5.2e17 or 2.0000000000000002e50 < y Initial program 100.0%
Taylor expanded in x around 0 78.6%
if -2.49999999999999977e-22 < y < 1.9000000000000001e-14Initial program 100.0%
Taylor expanded in y around 0 80.4%
if 5.2e17 < y < 2.0000000000000002e50Initial program 100.0%
Taylor expanded in x around inf 100.0%
Final simplification80.1%
(FPCore (x y)
:precision binary64
(if (<= y -3.2e-23)
-1.0
(if (<= y 3.4e-12)
1.0
(if (<= y 4e+18) -1.0 (if (<= y 3.4e+51) 1.0 -1.0)))))
double code(double x, double y) {
double tmp;
if (y <= -3.2e-23) {
tmp = -1.0;
} else if (y <= 3.4e-12) {
tmp = 1.0;
} else if (y <= 4e+18) {
tmp = -1.0;
} else if (y <= 3.4e+51) {
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 <= (-3.2d-23)) then
tmp = -1.0d0
else if (y <= 3.4d-12) then
tmp = 1.0d0
else if (y <= 4d+18) then
tmp = -1.0d0
else if (y <= 3.4d+51) 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 <= -3.2e-23) {
tmp = -1.0;
} else if (y <= 3.4e-12) {
tmp = 1.0;
} else if (y <= 4e+18) {
tmp = -1.0;
} else if (y <= 3.4e+51) {
tmp = 1.0;
} else {
tmp = -1.0;
}
return tmp;
}
def code(x, y): tmp = 0 if y <= -3.2e-23: tmp = -1.0 elif y <= 3.4e-12: tmp = 1.0 elif y <= 4e+18: tmp = -1.0 elif y <= 3.4e+51: tmp = 1.0 else: tmp = -1.0 return tmp
function code(x, y) tmp = 0.0 if (y <= -3.2e-23) tmp = -1.0; elseif (y <= 3.4e-12) tmp = 1.0; elseif (y <= 4e+18) tmp = -1.0; elseif (y <= 3.4e+51) tmp = 1.0; else tmp = -1.0; end return tmp end
function tmp_2 = code(x, y) tmp = 0.0; if (y <= -3.2e-23) tmp = -1.0; elseif (y <= 3.4e-12) tmp = 1.0; elseif (y <= 4e+18) tmp = -1.0; elseif (y <= 3.4e+51) tmp = 1.0; else tmp = -1.0; end tmp_2 = tmp; end
code[x_, y_] := If[LessEqual[y, -3.2e-23], -1.0, If[LessEqual[y, 3.4e-12], 1.0, If[LessEqual[y, 4e+18], -1.0, If[LessEqual[y, 3.4e+51], 1.0, -1.0]]]]
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;y \leq -3.2 \cdot 10^{-23}:\\
\;\;\;\;-1\\
\mathbf{elif}\;y \leq 3.4 \cdot 10^{-12}:\\
\;\;\;\;1\\
\mathbf{elif}\;y \leq 4 \cdot 10^{+18}:\\
\;\;\;\;-1\\
\mathbf{elif}\;y \leq 3.4 \cdot 10^{+51}:\\
\;\;\;\;1\\
\mathbf{else}:\\
\;\;\;\;-1\\
\end{array}
\end{array}
if y < -3.19999999999999976e-23 or 3.4000000000000001e-12 < y < 4e18 or 3.39999999999999984e51 < y Initial program 100.0%
Taylor expanded in x around 0 78.6%
if -3.19999999999999976e-23 < y < 3.4000000000000001e-12 or 4e18 < y < 3.39999999999999984e51Initial program 100.0%
Taylor expanded in x around inf 80.6%
Final simplification79.6%
(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 100.0%
Taylor expanded in x around 0 49.0%
Final simplification49.0%
(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 2023271
(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)))