
(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 (+ 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}
Initial program 99.9%
add-cbrt-cube99.9%
pow399.9%
Applied egg-rr99.9%
rem-cbrt-cube99.9%
clear-num99.9%
Applied egg-rr99.9%
div-sub100.0%
Applied egg-rr100.0%
Final simplification100.0%
(FPCore (x y) :precision binary64 (if (or (<= x -1.85e+24) (not (<= x 3.5e-23))) (+ 1.0 (* 2.0 (/ y x))) -1.0))
double code(double x, double y) {
double tmp;
if ((x <= -1.85e+24) || !(x <= 3.5e-23)) {
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 <= (-1.85d+24)) .or. (.not. (x <= 3.5d-23))) 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 <= -1.85e+24) || !(x <= 3.5e-23)) {
tmp = 1.0 + (2.0 * (y / x));
} else {
tmp = -1.0;
}
return tmp;
}
def code(x, y): tmp = 0 if (x <= -1.85e+24) or not (x <= 3.5e-23): tmp = 1.0 + (2.0 * (y / x)) else: tmp = -1.0 return tmp
function code(x, y) tmp = 0.0 if ((x <= -1.85e+24) || !(x <= 3.5e-23)) 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 <= -1.85e+24) || ~((x <= 3.5e-23))) tmp = 1.0 + (2.0 * (y / x)); else tmp = -1.0; end tmp_2 = tmp; end
code[x_, y_] := If[Or[LessEqual[x, -1.85e+24], N[Not[LessEqual[x, 3.5e-23]], $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 -1.85 \cdot 10^{+24} \lor \neg \left(x \leq 3.5 \cdot 10^{-23}\right):\\
\;\;\;\;1 + 2 \cdot \frac{y}{x}\\
\mathbf{else}:\\
\;\;\;\;-1\\
\end{array}
\end{array}
if x < -1.85e24 or 3.49999999999999993e-23 < x Initial program 100.0%
Taylor expanded in y around 0 75.8%
if -1.85e24 < x < 3.49999999999999993e-23Initial program 99.9%
Taylor expanded in x around 0 78.4%
Final simplification77.2%
(FPCore (x y) :precision binary64 (if (or (<= x -3e+35) (not (<= x 4.1e-22))) (+ 1.0 (* 2.0 (/ y x))) (+ (* -2.0 (/ x y)) -1.0)))
double code(double x, double y) {
double tmp;
if ((x <= -3e+35) || !(x <= 4.1e-22)) {
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 <= (-3d+35)) .or. (.not. (x <= 4.1d-22))) 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 <= -3e+35) || !(x <= 4.1e-22)) {
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 <= -3e+35) or not (x <= 4.1e-22): 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 <= -3e+35) || !(x <= 4.1e-22)) 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 <= -3e+35) || ~((x <= 4.1e-22))) 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, -3e+35], N[Not[LessEqual[x, 4.1e-22]], $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 \cdot 10^{+35} \lor \neg \left(x \leq 4.1 \cdot 10^{-22}\right):\\
\;\;\;\;1 + 2 \cdot \frac{y}{x}\\
\mathbf{else}:\\
\;\;\;\;-2 \cdot \frac{x}{y} + -1\\
\end{array}
\end{array}
if x < -2.99999999999999991e35 or 4.0999999999999999e-22 < x Initial program 100.0%
Taylor expanded in y around 0 76.2%
if -2.99999999999999991e35 < x < 4.0999999999999999e-22Initial program 99.9%
Taylor expanded in x around 0 79.6%
Final simplification78.0%
(FPCore (x y) :precision binary64 (if (<= x -4e+42) 1.0 (if (<= x 4e-26) -1.0 1.0)))
double code(double x, double y) {
double tmp;
if (x <= -4e+42) {
tmp = 1.0;
} else if (x <= 4e-26) {
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 <= (-4d+42)) then
tmp = 1.0d0
else if (x <= 4d-26) 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 <= -4e+42) {
tmp = 1.0;
} else if (x <= 4e-26) {
tmp = -1.0;
} else {
tmp = 1.0;
}
return tmp;
}
def code(x, y): tmp = 0 if x <= -4e+42: tmp = 1.0 elif x <= 4e-26: tmp = -1.0 else: tmp = 1.0 return tmp
function code(x, y) tmp = 0.0 if (x <= -4e+42) tmp = 1.0; elseif (x <= 4e-26) tmp = -1.0; else tmp = 1.0; end return tmp end
function tmp_2 = code(x, y) tmp = 0.0; if (x <= -4e+42) tmp = 1.0; elseif (x <= 4e-26) tmp = -1.0; else tmp = 1.0; end tmp_2 = tmp; end
code[x_, y_] := If[LessEqual[x, -4e+42], 1.0, If[LessEqual[x, 4e-26], -1.0, 1.0]]
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;x \leq -4 \cdot 10^{+42}:\\
\;\;\;\;1\\
\mathbf{elif}\;x \leq 4 \cdot 10^{-26}:\\
\;\;\;\;-1\\
\mathbf{else}:\\
\;\;\;\;1\\
\end{array}
\end{array}
if x < -4.00000000000000018e42 or 4.0000000000000002e-26 < x Initial program 100.0%
Taylor expanded in x around inf 75.5%
if -4.00000000000000018e42 < x < 4.0000000000000002e-26Initial program 99.9%
Taylor expanded in x around 0 78.0%
Final simplification76.8%
(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 99.9%
Final simplification99.9%
(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 52.6%
Final simplification52.6%
(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 2024130
(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)))