
(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 4 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 (+ 1.0 (* 2.0 (/ y x)))))
(if (<= x -1.12e+14)
t_0
(if (<= x -2e-8)
-1.0
(if (<= x -2e-45) 1.0 (if (<= x 1.85e-51) -1.0 t_0))))))
double code(double x, double y) {
double t_0 = 1.0 + (2.0 * (y / x));
double tmp;
if (x <= -1.12e+14) {
tmp = t_0;
} else if (x <= -2e-8) {
tmp = -1.0;
} else if (x <= -2e-45) {
tmp = 1.0;
} else if (x <= 1.85e-51) {
tmp = -1.0;
} else {
tmp = t_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 = 1.0d0 + (2.0d0 * (y / x))
if (x <= (-1.12d+14)) then
tmp = t_0
else if (x <= (-2d-8)) then
tmp = -1.0d0
else if (x <= (-2d-45)) then
tmp = 1.0d0
else if (x <= 1.85d-51) then
tmp = -1.0d0
else
tmp = t_0
end if
code = tmp
end function
public static double code(double x, double y) {
double t_0 = 1.0 + (2.0 * (y / x));
double tmp;
if (x <= -1.12e+14) {
tmp = t_0;
} else if (x <= -2e-8) {
tmp = -1.0;
} else if (x <= -2e-45) {
tmp = 1.0;
} else if (x <= 1.85e-51) {
tmp = -1.0;
} else {
tmp = t_0;
}
return tmp;
}
def code(x, y): t_0 = 1.0 + (2.0 * (y / x)) tmp = 0 if x <= -1.12e+14: tmp = t_0 elif x <= -2e-8: tmp = -1.0 elif x <= -2e-45: tmp = 1.0 elif x <= 1.85e-51: tmp = -1.0 else: tmp = t_0 return tmp
function code(x, y) t_0 = Float64(1.0 + Float64(2.0 * Float64(y / x))) tmp = 0.0 if (x <= -1.12e+14) tmp = t_0; elseif (x <= -2e-8) tmp = -1.0; elseif (x <= -2e-45) tmp = 1.0; elseif (x <= 1.85e-51) tmp = -1.0; else tmp = t_0; end return tmp end
function tmp_2 = code(x, y) t_0 = 1.0 + (2.0 * (y / x)); tmp = 0.0; if (x <= -1.12e+14) tmp = t_0; elseif (x <= -2e-8) tmp = -1.0; elseif (x <= -2e-45) tmp = 1.0; elseif (x <= 1.85e-51) tmp = -1.0; else tmp = t_0; end tmp_2 = tmp; end
code[x_, y_] := Block[{t$95$0 = N[(1.0 + N[(2.0 * N[(y / x), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]}, If[LessEqual[x, -1.12e+14], t$95$0, If[LessEqual[x, -2e-8], -1.0, If[LessEqual[x, -2e-45], 1.0, If[LessEqual[x, 1.85e-51], -1.0, t$95$0]]]]]
\begin{array}{l}
\\
\begin{array}{l}
t_0 := 1 + 2 \cdot \frac{y}{x}\\
\mathbf{if}\;x \leq -1.12 \cdot 10^{+14}:\\
\;\;\;\;t_0\\
\mathbf{elif}\;x \leq -2 \cdot 10^{-8}:\\
\;\;\;\;-1\\
\mathbf{elif}\;x \leq -2 \cdot 10^{-45}:\\
\;\;\;\;1\\
\mathbf{elif}\;x \leq 1.85 \cdot 10^{-51}:\\
\;\;\;\;-1\\
\mathbf{else}:\\
\;\;\;\;t_0\\
\end{array}
\end{array}
if x < -1.12e14 or 1.84999999999999987e-51 < x Initial program 100.0%
Taylor expanded in y around 0 79.1%
if -1.12e14 < x < -2e-8 or -1.99999999999999997e-45 < x < 1.84999999999999987e-51Initial program 100.0%
Taylor expanded in x around 0 82.2%
if -2e-8 < x < -1.99999999999999997e-45Initial program 100.0%
Taylor expanded in x around inf 100.0%
Final simplification80.9%
(FPCore (x y) :precision binary64 (if (<= y -3.5e+52) -1.0 (if (<= y 2e-10) 1.0 -1.0)))
double code(double x, double y) {
double tmp;
if (y <= -3.5e+52) {
tmp = -1.0;
} else if (y <= 2e-10) {
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 <= (-3.5d+52)) then
tmp = -1.0d0
else if (y <= 2d-10) 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 <= -3.5e+52) {
tmp = -1.0;
} else if (y <= 2e-10) {
tmp = 1.0;
} else {
tmp = -1.0;
}
return tmp;
}
def code(x, y): tmp = 0 if y <= -3.5e+52: tmp = -1.0 elif y <= 2e-10: tmp = 1.0 else: tmp = -1.0 return tmp
function code(x, y) tmp = 0.0 if (y <= -3.5e+52) tmp = -1.0; elseif (y <= 2e-10) tmp = 1.0; else tmp = -1.0; end return tmp end
function tmp_2 = code(x, y) tmp = 0.0; if (y <= -3.5e+52) tmp = -1.0; elseif (y <= 2e-10) tmp = 1.0; else tmp = -1.0; end tmp_2 = tmp; end
code[x_, y_] := If[LessEqual[y, -3.5e+52], -1.0, If[LessEqual[y, 2e-10], 1.0, -1.0]]
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;y \leq -3.5 \cdot 10^{+52}:\\
\;\;\;\;-1\\
\mathbf{elif}\;y \leq 2 \cdot 10^{-10}:\\
\;\;\;\;1\\
\mathbf{else}:\\
\;\;\;\;-1\\
\end{array}
\end{array}
if y < -3.5e52 or 2.00000000000000007e-10 < y Initial program 100.0%
Taylor expanded in x around 0 74.6%
if -3.5e52 < y < 2.00000000000000007e-10Initial program 100.0%
Taylor expanded in x around inf 79.9%
Final simplification77.3%
(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 46.8%
Final simplification46.8%
(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 2023228
(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)))