
(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 (pow (/ (- x y) (+ x y)) -1.0))
double code(double x, double y) {
return pow(((x - y) / (x + y)), -1.0);
}
real(8) function code(x, y)
real(8), intent (in) :: x
real(8), intent (in) :: y
code = ((x - y) / (x + y)) ** (-1.0d0)
end function
public static double code(double x, double y) {
return Math.pow(((x - y) / (x + y)), -1.0);
}
def code(x, y): return math.pow(((x - y) / (x + y)), -1.0)
function code(x, y) return Float64(Float64(x - y) / Float64(x + y)) ^ -1.0 end
function tmp = code(x, y) tmp = ((x - y) / (x + y)) ^ -1.0; end
code[x_, y_] := N[Power[N[(N[(x - y), $MachinePrecision] / N[(x + y), $MachinePrecision]), $MachinePrecision], -1.0], $MachinePrecision]
\begin{array}{l}
\\
{\left(\frac{x - y}{x + y}\right)}^{-1}
\end{array}
Initial program 100.0%
clear-num100.0%
inv-pow100.0%
Applied egg-rr100.0%
(FPCore (x y) :precision binary64 (if (or (<= y -4.75e+24) (not (<= y 1.1e-56))) (+ -1.0 (* -2.0 (/ x y))) (+ 1.0 (* 2.0 (/ y x)))))
double code(double x, double y) {
double tmp;
if ((y <= -4.75e+24) || !(y <= 1.1e-56)) {
tmp = -1.0 + (-2.0 * (x / y));
} 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 <= (-4.75d+24)) .or. (.not. (y <= 1.1d-56))) then
tmp = (-1.0d0) + ((-2.0d0) * (x / y))
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 <= -4.75e+24) || !(y <= 1.1e-56)) {
tmp = -1.0 + (-2.0 * (x / y));
} else {
tmp = 1.0 + (2.0 * (y / x));
}
return tmp;
}
def code(x, y): tmp = 0 if (y <= -4.75e+24) or not (y <= 1.1e-56): tmp = -1.0 + (-2.0 * (x / y)) else: tmp = 1.0 + (2.0 * (y / x)) return tmp
function code(x, y) tmp = 0.0 if ((y <= -4.75e+24) || !(y <= 1.1e-56)) tmp = Float64(-1.0 + Float64(-2.0 * Float64(x / y))); 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 <= -4.75e+24) || ~((y <= 1.1e-56))) tmp = -1.0 + (-2.0 * (x / y)); else tmp = 1.0 + (2.0 * (y / x)); end tmp_2 = tmp; end
code[x_, y_] := If[Or[LessEqual[y, -4.75e+24], N[Not[LessEqual[y, 1.1e-56]], $MachinePrecision]], N[(-1.0 + N[(-2.0 * N[(x / y), $MachinePrecision]), $MachinePrecision]), $MachinePrecision], N[(1.0 + N[(2.0 * N[(y / x), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;y \leq -4.75 \cdot 10^{+24} \lor \neg \left(y \leq 1.1 \cdot 10^{-56}\right):\\
\;\;\;\;-1 + -2 \cdot \frac{x}{y}\\
\mathbf{else}:\\
\;\;\;\;1 + 2 \cdot \frac{y}{x}\\
\end{array}
\end{array}
if y < -4.7500000000000001e24 or 1.10000000000000002e-56 < y Initial program 100.0%
Taylor expanded in x around 0 78.7%
if -4.7500000000000001e24 < y < 1.10000000000000002e-56Initial program 100.0%
Taylor expanded in y around 0 81.9%
Final simplification80.2%
(FPCore (x y) :precision binary64 (if (<= y -9e+54) -1.0 (if (<= y 2.8e-56) (+ 1.0 (* 2.0 (/ y x))) -1.0)))
double code(double x, double y) {
double tmp;
if (y <= -9e+54) {
tmp = -1.0;
} else if (y <= 2.8e-56) {
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 <= (-9d+54)) then
tmp = -1.0d0
else if (y <= 2.8d-56) 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 <= -9e+54) {
tmp = -1.0;
} else if (y <= 2.8e-56) {
tmp = 1.0 + (2.0 * (y / x));
} else {
tmp = -1.0;
}
return tmp;
}
def code(x, y): tmp = 0 if y <= -9e+54: tmp = -1.0 elif y <= 2.8e-56: tmp = 1.0 + (2.0 * (y / x)) else: tmp = -1.0 return tmp
function code(x, y) tmp = 0.0 if (y <= -9e+54) tmp = -1.0; elseif (y <= 2.8e-56) 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 <= -9e+54) tmp = -1.0; elseif (y <= 2.8e-56) tmp = 1.0 + (2.0 * (y / x)); else tmp = -1.0; end tmp_2 = tmp; end
code[x_, y_] := If[LessEqual[y, -9e+54], -1.0, If[LessEqual[y, 2.8e-56], N[(1.0 + N[(2.0 * N[(y / x), $MachinePrecision]), $MachinePrecision]), $MachinePrecision], -1.0]]
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;y \leq -9 \cdot 10^{+54}:\\
\;\;\;\;-1\\
\mathbf{elif}\;y \leq 2.8 \cdot 10^{-56}:\\
\;\;\;\;1 + 2 \cdot \frac{y}{x}\\
\mathbf{else}:\\
\;\;\;\;-1\\
\end{array}
\end{array}
if y < -8.99999999999999968e54 or 2.79999999999999993e-56 < y Initial program 100.0%
Taylor expanded in x around 0 79.1%
if -8.99999999999999968e54 < y < 2.79999999999999993e-56Initial program 100.0%
Taylor expanded in y around 0 80.5%
(FPCore (x y) :precision binary64 (if (<= y -5e-22) -1.0 (if (<= y 1.4e-58) 1.0 -1.0)))
double code(double x, double y) {
double tmp;
if (y <= -5e-22) {
tmp = -1.0;
} else if (y <= 1.4e-58) {
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 <= (-5d-22)) then
tmp = -1.0d0
else if (y <= 1.4d-58) 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 <= -5e-22) {
tmp = -1.0;
} else if (y <= 1.4e-58) {
tmp = 1.0;
} else {
tmp = -1.0;
}
return tmp;
}
def code(x, y): tmp = 0 if y <= -5e-22: tmp = -1.0 elif y <= 1.4e-58: tmp = 1.0 else: tmp = -1.0 return tmp
function code(x, y) tmp = 0.0 if (y <= -5e-22) tmp = -1.0; elseif (y <= 1.4e-58) tmp = 1.0; else tmp = -1.0; end return tmp end
function tmp_2 = code(x, y) tmp = 0.0; if (y <= -5e-22) tmp = -1.0; elseif (y <= 1.4e-58) tmp = 1.0; else tmp = -1.0; end tmp_2 = tmp; end
code[x_, y_] := If[LessEqual[y, -5e-22], -1.0, If[LessEqual[y, 1.4e-58], 1.0, -1.0]]
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;y \leq -5 \cdot 10^{-22}:\\
\;\;\;\;-1\\
\mathbf{elif}\;y \leq 1.4 \cdot 10^{-58}:\\
\;\;\;\;1\\
\mathbf{else}:\\
\;\;\;\;-1\\
\end{array}
\end{array}
if y < -4.99999999999999954e-22 or 1.4e-58 < y Initial program 100.0%
Taylor expanded in x around 0 76.6%
if -4.99999999999999954e-22 < y < 1.4e-58Initial program 100.0%
Taylor expanded in x around inf 82.8%
(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%
(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 48.8%
(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 2024085
(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)))