
(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%
(FPCore (x y)
:precision binary64
(if (<= y -4.5e+45)
-1.0
(if (<= y 2.7e-12)
(+ 1.0 (* 2.0 (/ y x)))
(if (<= y 62000.0) -1.0 (if (<= y 200000000.0) 1.0 -1.0)))))
double code(double x, double y) {
double tmp;
if (y <= -4.5e+45) {
tmp = -1.0;
} else if (y <= 2.7e-12) {
tmp = 1.0 + (2.0 * (y / x));
} else if (y <= 62000.0) {
tmp = -1.0;
} else if (y <= 200000000.0) {
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 <= (-4.5d+45)) then
tmp = -1.0d0
else if (y <= 2.7d-12) then
tmp = 1.0d0 + (2.0d0 * (y / x))
else if (y <= 62000.0d0) then
tmp = -1.0d0
else if (y <= 200000000.0d0) 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 <= -4.5e+45) {
tmp = -1.0;
} else if (y <= 2.7e-12) {
tmp = 1.0 + (2.0 * (y / x));
} else if (y <= 62000.0) {
tmp = -1.0;
} else if (y <= 200000000.0) {
tmp = 1.0;
} else {
tmp = -1.0;
}
return tmp;
}
def code(x, y): tmp = 0 if y <= -4.5e+45: tmp = -1.0 elif y <= 2.7e-12: tmp = 1.0 + (2.0 * (y / x)) elif y <= 62000.0: tmp = -1.0 elif y <= 200000000.0: tmp = 1.0 else: tmp = -1.0 return tmp
function code(x, y) tmp = 0.0 if (y <= -4.5e+45) tmp = -1.0; elseif (y <= 2.7e-12) tmp = Float64(1.0 + Float64(2.0 * Float64(y / x))); elseif (y <= 62000.0) tmp = -1.0; elseif (y <= 200000000.0) tmp = 1.0; else tmp = -1.0; end return tmp end
function tmp_2 = code(x, y) tmp = 0.0; if (y <= -4.5e+45) tmp = -1.0; elseif (y <= 2.7e-12) tmp = 1.0 + (2.0 * (y / x)); elseif (y <= 62000.0) tmp = -1.0; elseif (y <= 200000000.0) tmp = 1.0; else tmp = -1.0; end tmp_2 = tmp; end
code[x_, y_] := If[LessEqual[y, -4.5e+45], -1.0, If[LessEqual[y, 2.7e-12], N[(1.0 + N[(2.0 * N[(y / x), $MachinePrecision]), $MachinePrecision]), $MachinePrecision], If[LessEqual[y, 62000.0], -1.0, If[LessEqual[y, 200000000.0], 1.0, -1.0]]]]
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;y \leq -4.5 \cdot 10^{+45}:\\
\;\;\;\;-1\\
\mathbf{elif}\;y \leq 2.7 \cdot 10^{-12}:\\
\;\;\;\;1 + 2 \cdot \frac{y}{x}\\
\mathbf{elif}\;y \leq 62000:\\
\;\;\;\;-1\\
\mathbf{elif}\;y \leq 200000000:\\
\;\;\;\;1\\
\mathbf{else}:\\
\;\;\;\;-1\\
\end{array}
\end{array}
if y < -4.4999999999999998e45 or 2.6999999999999998e-12 < y < 62000 or 2e8 < y Initial program 100.0%
Taylor expanded in x around 0 83.9%
if -4.4999999999999998e45 < y < 2.6999999999999998e-12Initial program 99.9%
Taylor expanded in y around 0 80.7%
if 62000 < y < 2e8Initial program 100.0%
Taylor expanded in x around inf 100.0%
(FPCore (x y)
:precision binary64
(if (<= y -2e+43)
-1.0
(if (<= y 8e-13)
1.0
(if (<= y 59000.0) -1.0 (if (<= y 64000000.0) 1.0 -1.0)))))
double code(double x, double y) {
double tmp;
if (y <= -2e+43) {
tmp = -1.0;
} else if (y <= 8e-13) {
tmp = 1.0;
} else if (y <= 59000.0) {
tmp = -1.0;
} else if (y <= 64000000.0) {
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 <= (-2d+43)) then
tmp = -1.0d0
else if (y <= 8d-13) then
tmp = 1.0d0
else if (y <= 59000.0d0) then
tmp = -1.0d0
else if (y <= 64000000.0d0) 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 <= -2e+43) {
tmp = -1.0;
} else if (y <= 8e-13) {
tmp = 1.0;
} else if (y <= 59000.0) {
tmp = -1.0;
} else if (y <= 64000000.0) {
tmp = 1.0;
} else {
tmp = -1.0;
}
return tmp;
}
def code(x, y): tmp = 0 if y <= -2e+43: tmp = -1.0 elif y <= 8e-13: tmp = 1.0 elif y <= 59000.0: tmp = -1.0 elif y <= 64000000.0: tmp = 1.0 else: tmp = -1.0 return tmp
function code(x, y) tmp = 0.0 if (y <= -2e+43) tmp = -1.0; elseif (y <= 8e-13) tmp = 1.0; elseif (y <= 59000.0) tmp = -1.0; elseif (y <= 64000000.0) tmp = 1.0; else tmp = -1.0; end return tmp end
function tmp_2 = code(x, y) tmp = 0.0; if (y <= -2e+43) tmp = -1.0; elseif (y <= 8e-13) tmp = 1.0; elseif (y <= 59000.0) tmp = -1.0; elseif (y <= 64000000.0) tmp = 1.0; else tmp = -1.0; end tmp_2 = tmp; end
code[x_, y_] := If[LessEqual[y, -2e+43], -1.0, If[LessEqual[y, 8e-13], 1.0, If[LessEqual[y, 59000.0], -1.0, If[LessEqual[y, 64000000.0], 1.0, -1.0]]]]
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;y \leq -2 \cdot 10^{+43}:\\
\;\;\;\;-1\\
\mathbf{elif}\;y \leq 8 \cdot 10^{-13}:\\
\;\;\;\;1\\
\mathbf{elif}\;y \leq 59000:\\
\;\;\;\;-1\\
\mathbf{elif}\;y \leq 64000000:\\
\;\;\;\;1\\
\mathbf{else}:\\
\;\;\;\;-1\\
\end{array}
\end{array}
if y < -2.00000000000000003e43 or 8.0000000000000002e-13 < y < 59000 or 6.4e7 < y Initial program 100.0%
Taylor expanded in x around 0 83.3%
if -2.00000000000000003e43 < y < 8.0000000000000002e-13 or 59000 < y < 6.4e7Initial program 99.9%
Taylor expanded in x around inf 80.0%
(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 53.2%
(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 2024107
(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)))