
(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%
(FPCore (x y)
:precision binary64
(let* ((t_0 (+ (* -2.0 (/ x y)) -1.0)) (t_1 (+ 1.0 (* 2.0 (/ y x)))))
(if (<= y -63.0)
t_0
(if (<= y 8.2e-70)
t_1
(if (<= y 5.6e-46) -1.0 (if (<= y 1.35e+25) t_1 t_0))))))
double code(double x, double y) {
double t_0 = (-2.0 * (x / y)) + -1.0;
double t_1 = 1.0 + (2.0 * (y / x));
double tmp;
if (y <= -63.0) {
tmp = t_0;
} else if (y <= 8.2e-70) {
tmp = t_1;
} else if (y <= 5.6e-46) {
tmp = -1.0;
} else if (y <= 1.35e+25) {
tmp = t_1;
} 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) :: t_1
real(8) :: tmp
t_0 = ((-2.0d0) * (x / y)) + (-1.0d0)
t_1 = 1.0d0 + (2.0d0 * (y / x))
if (y <= (-63.0d0)) then
tmp = t_0
else if (y <= 8.2d-70) then
tmp = t_1
else if (y <= 5.6d-46) then
tmp = -1.0d0
else if (y <= 1.35d+25) then
tmp = t_1
else
tmp = t_0
end if
code = tmp
end function
public static double code(double x, double y) {
double t_0 = (-2.0 * (x / y)) + -1.0;
double t_1 = 1.0 + (2.0 * (y / x));
double tmp;
if (y <= -63.0) {
tmp = t_0;
} else if (y <= 8.2e-70) {
tmp = t_1;
} else if (y <= 5.6e-46) {
tmp = -1.0;
} else if (y <= 1.35e+25) {
tmp = t_1;
} else {
tmp = t_0;
}
return tmp;
}
def code(x, y): t_0 = (-2.0 * (x / y)) + -1.0 t_1 = 1.0 + (2.0 * (y / x)) tmp = 0 if y <= -63.0: tmp = t_0 elif y <= 8.2e-70: tmp = t_1 elif y <= 5.6e-46: tmp = -1.0 elif y <= 1.35e+25: tmp = t_1 else: tmp = t_0 return tmp
function code(x, y) t_0 = Float64(Float64(-2.0 * Float64(x / y)) + -1.0) t_1 = Float64(1.0 + Float64(2.0 * Float64(y / x))) tmp = 0.0 if (y <= -63.0) tmp = t_0; elseif (y <= 8.2e-70) tmp = t_1; elseif (y <= 5.6e-46) tmp = -1.0; elseif (y <= 1.35e+25) tmp = t_1; else tmp = t_0; end return tmp end
function tmp_2 = code(x, y) t_0 = (-2.0 * (x / y)) + -1.0; t_1 = 1.0 + (2.0 * (y / x)); tmp = 0.0; if (y <= -63.0) tmp = t_0; elseif (y <= 8.2e-70) tmp = t_1; elseif (y <= 5.6e-46) tmp = -1.0; elseif (y <= 1.35e+25) tmp = t_1; else tmp = t_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]}, Block[{t$95$1 = N[(1.0 + N[(2.0 * N[(y / x), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]}, If[LessEqual[y, -63.0], t$95$0, If[LessEqual[y, 8.2e-70], t$95$1, If[LessEqual[y, 5.6e-46], -1.0, If[LessEqual[y, 1.35e+25], t$95$1, t$95$0]]]]]]
\begin{array}{l}
\\
\begin{array}{l}
t_0 := -2 \cdot \frac{x}{y} + -1\\
t_1 := 1 + 2 \cdot \frac{y}{x}\\
\mathbf{if}\;y \leq -63:\\
\;\;\;\;t\_0\\
\mathbf{elif}\;y \leq 8.2 \cdot 10^{-70}:\\
\;\;\;\;t\_1\\
\mathbf{elif}\;y \leq 5.6 \cdot 10^{-46}:\\
\;\;\;\;-1\\
\mathbf{elif}\;y \leq 1.35 \cdot 10^{+25}:\\
\;\;\;\;t\_1\\
\mathbf{else}:\\
\;\;\;\;t\_0\\
\end{array}
\end{array}
if y < -63 or 1.35e25 < y Initial program 100.0%
Taylor expanded in x around 0 78.0%
if -63 < y < 8.19999999999999955e-70 or 5.5999999999999997e-46 < y < 1.35e25Initial program 100.0%
Taylor expanded in y around 0 79.8%
if 8.19999999999999955e-70 < y < 5.5999999999999997e-46Initial program 100.0%
Taylor expanded in x around 0 100.0%
Final simplification79.4%
(FPCore (x y)
:precision binary64
(let* ((t_0 (+ 1.0 (* 2.0 (/ y x)))))
(if (<= x -1.15e-9)
t_0
(if (<= x -1.32e-154)
-1.0
(if (<= x -3.4e-166) 1.0 (if (<= x 38000.0) -1.0 t_0))))))
double code(double x, double y) {
double t_0 = 1.0 + (2.0 * (y / x));
double tmp;
if (x <= -1.15e-9) {
tmp = t_0;
} else if (x <= -1.32e-154) {
tmp = -1.0;
} else if (x <= -3.4e-166) {
tmp = 1.0;
} else if (x <= 38000.0) {
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 <= (-1.15d-9)) then
tmp = t_0
else if (x <= (-1.32d-154)) then
tmp = -1.0d0
else if (x <= (-3.4d-166)) then
tmp = 1.0d0
else if (x <= 38000.0d0) 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 <= -1.15e-9) {
tmp = t_0;
} else if (x <= -1.32e-154) {
tmp = -1.0;
} else if (x <= -3.4e-166) {
tmp = 1.0;
} else if (x <= 38000.0) {
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 <= -1.15e-9: tmp = t_0 elif x <= -1.32e-154: tmp = -1.0 elif x <= -3.4e-166: tmp = 1.0 elif x <= 38000.0: 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 <= -1.15e-9) tmp = t_0; elseif (x <= -1.32e-154) tmp = -1.0; elseif (x <= -3.4e-166) tmp = 1.0; elseif (x <= 38000.0) 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 <= -1.15e-9) tmp = t_0; elseif (x <= -1.32e-154) tmp = -1.0; elseif (x <= -3.4e-166) tmp = 1.0; elseif (x <= 38000.0) 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, -1.15e-9], t$95$0, If[LessEqual[x, -1.32e-154], -1.0, If[LessEqual[x, -3.4e-166], 1.0, If[LessEqual[x, 38000.0], -1.0, t$95$0]]]]]
\begin{array}{l}
\\
\begin{array}{l}
t_0 := 1 + 2 \cdot \frac{y}{x}\\
\mathbf{if}\;x \leq -1.15 \cdot 10^{-9}:\\
\;\;\;\;t\_0\\
\mathbf{elif}\;x \leq -1.32 \cdot 10^{-154}:\\
\;\;\;\;-1\\
\mathbf{elif}\;x \leq -3.4 \cdot 10^{-166}:\\
\;\;\;\;1\\
\mathbf{elif}\;x \leq 38000:\\
\;\;\;\;-1\\
\mathbf{else}:\\
\;\;\;\;t\_0\\
\end{array}
\end{array}
if x < -1.15e-9 or 38000 < x Initial program 100.0%
Taylor expanded in y around 0 80.9%
if -1.15e-9 < x < -1.31999999999999994e-154 or -3.3999999999999997e-166 < x < 38000Initial program 100.0%
Taylor expanded in x around 0 75.9%
if -1.31999999999999994e-154 < x < -3.3999999999999997e-166Initial program 100.0%
Taylor expanded in x around inf 100.0%
(FPCore (x y)
:precision binary64
(if (<= y -10000.0)
-1.0
(if (<= y 8.6e-70)
1.0
(if (<= y 5.2e-46) -1.0 (if (<= y 6.6e+24) 1.0 -1.0)))))
double code(double x, double y) {
double tmp;
if (y <= -10000.0) {
tmp = -1.0;
} else if (y <= 8.6e-70) {
tmp = 1.0;
} else if (y <= 5.2e-46) {
tmp = -1.0;
} else if (y <= 6.6e+24) {
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 <= (-10000.0d0)) then
tmp = -1.0d0
else if (y <= 8.6d-70) then
tmp = 1.0d0
else if (y <= 5.2d-46) then
tmp = -1.0d0
else if (y <= 6.6d+24) 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 <= -10000.0) {
tmp = -1.0;
} else if (y <= 8.6e-70) {
tmp = 1.0;
} else if (y <= 5.2e-46) {
tmp = -1.0;
} else if (y <= 6.6e+24) {
tmp = 1.0;
} else {
tmp = -1.0;
}
return tmp;
}
def code(x, y): tmp = 0 if y <= -10000.0: tmp = -1.0 elif y <= 8.6e-70: tmp = 1.0 elif y <= 5.2e-46: tmp = -1.0 elif y <= 6.6e+24: tmp = 1.0 else: tmp = -1.0 return tmp
function code(x, y) tmp = 0.0 if (y <= -10000.0) tmp = -1.0; elseif (y <= 8.6e-70) tmp = 1.0; elseif (y <= 5.2e-46) tmp = -1.0; elseif (y <= 6.6e+24) tmp = 1.0; else tmp = -1.0; end return tmp end
function tmp_2 = code(x, y) tmp = 0.0; if (y <= -10000.0) tmp = -1.0; elseif (y <= 8.6e-70) tmp = 1.0; elseif (y <= 5.2e-46) tmp = -1.0; elseif (y <= 6.6e+24) tmp = 1.0; else tmp = -1.0; end tmp_2 = tmp; end
code[x_, y_] := If[LessEqual[y, -10000.0], -1.0, If[LessEqual[y, 8.6e-70], 1.0, If[LessEqual[y, 5.2e-46], -1.0, If[LessEqual[y, 6.6e+24], 1.0, -1.0]]]]
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;y \leq -10000:\\
\;\;\;\;-1\\
\mathbf{elif}\;y \leq 8.6 \cdot 10^{-70}:\\
\;\;\;\;1\\
\mathbf{elif}\;y \leq 5.2 \cdot 10^{-46}:\\
\;\;\;\;-1\\
\mathbf{elif}\;y \leq 6.6 \cdot 10^{+24}:\\
\;\;\;\;1\\
\mathbf{else}:\\
\;\;\;\;-1\\
\end{array}
\end{array}
if y < -1e4 or 8.6e-70 < y < 5.2000000000000004e-46 or 6.5999999999999998e24 < y Initial program 100.0%
Taylor expanded in x around 0 77.6%
if -1e4 < y < 8.6e-70 or 5.2000000000000004e-46 < y < 6.5999999999999998e24Initial program 100.0%
Taylor expanded in x around inf 79.1%
(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 46.5%
(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 2024091
(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)))