
(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 (- (log (exp (/ (- y) (- y x)))) (/ x (- y x))))
double code(double x, double y) {
return log(exp((-y / (y - x)))) - (x / (y - x));
}
real(8) function code(x, y)
real(8), intent (in) :: x
real(8), intent (in) :: y
code = log(exp((-y / (y - x)))) - (x / (y - x))
end function
public static double code(double x, double y) {
return Math.log(Math.exp((-y / (y - x)))) - (x / (y - x));
}
def code(x, y): return math.log(math.exp((-y / (y - x)))) - (x / (y - x))
function code(x, y) return Float64(log(exp(Float64(Float64(-y) / Float64(y - x)))) - Float64(x / Float64(y - x))) end
function tmp = code(x, y) tmp = log(exp((-y / (y - x)))) - (x / (y - x)); end
code[x_, y_] := N[(N[Log[N[Exp[N[((-y) / N[(y - x), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]], $MachinePrecision] - N[(x / N[(y - x), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\log \left(e^{\frac{-y}{y - x}}\right) - \frac{x}{y - x}
\end{array}
Initial program 100.0%
frac-2neg100.0%
neg-sub0100.0%
+-commutative100.0%
associate--r+100.0%
neg-sub0100.0%
div-sub100.0%
sub-neg100.0%
distribute-neg-in100.0%
+-commutative100.0%
remove-double-neg100.0%
sub-neg100.0%
sub-neg100.0%
distribute-neg-in100.0%
+-commutative100.0%
remove-double-neg100.0%
sub-neg100.0%
Applied egg-rr100.0%
add-log-exp_binary64100.0%
Applied rewrite-once100.0%
Final simplification100.0%
(FPCore (x y) :precision binary64 (if (<= y -1.06e-29) -1.0 (if (<= y 2.4e+82) (+ 1.0 (* 2.0 (/ y x))) -1.0)))
double code(double x, double y) {
double tmp;
if (y <= -1.06e-29) {
tmp = -1.0;
} else if (y <= 2.4e+82) {
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 <= (-1.06d-29)) then
tmp = -1.0d0
else if (y <= 2.4d+82) 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 <= -1.06e-29) {
tmp = -1.0;
} else if (y <= 2.4e+82) {
tmp = 1.0 + (2.0 * (y / x));
} else {
tmp = -1.0;
}
return tmp;
}
def code(x, y): tmp = 0 if y <= -1.06e-29: tmp = -1.0 elif y <= 2.4e+82: tmp = 1.0 + (2.0 * (y / x)) else: tmp = -1.0 return tmp
function code(x, y) tmp = 0.0 if (y <= -1.06e-29) tmp = -1.0; elseif (y <= 2.4e+82) 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 <= -1.06e-29) tmp = -1.0; elseif (y <= 2.4e+82) tmp = 1.0 + (2.0 * (y / x)); else tmp = -1.0; end tmp_2 = tmp; end
code[x_, y_] := If[LessEqual[y, -1.06e-29], -1.0, If[LessEqual[y, 2.4e+82], N[(1.0 + N[(2.0 * N[(y / x), $MachinePrecision]), $MachinePrecision]), $MachinePrecision], -1.0]]
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;y \leq -1.06 \cdot 10^{-29}:\\
\;\;\;\;-1\\
\mathbf{elif}\;y \leq 2.4 \cdot 10^{+82}:\\
\;\;\;\;1 + 2 \cdot \frac{y}{x}\\
\mathbf{else}:\\
\;\;\;\;-1\\
\end{array}
\end{array}
if y < -1.05999999999999995e-29 or 2.39999999999999998e82 < y Initial program 100.0%
Taylor expanded in x around 0 80.5%
if -1.05999999999999995e-29 < y < 2.39999999999999998e82Initial program 100.0%
Taylor expanded in y around 0 81.3%
Final simplification80.9%
(FPCore (x y) :precision binary64 (- (/ y (- x y)) (/ x (- y x))))
double code(double x, double y) {
return (y / (x - y)) - (x / (y - x));
}
real(8) function code(x, y)
real(8), intent (in) :: x
real(8), intent (in) :: y
code = (y / (x - y)) - (x / (y - x))
end function
public static double code(double x, double y) {
return (y / (x - y)) - (x / (y - x));
}
def code(x, y): return (y / (x - y)) - (x / (y - x))
function code(x, y) return Float64(Float64(y / Float64(x - y)) - Float64(x / Float64(y - x))) end
function tmp = code(x, y) tmp = (y / (x - y)) - (x / (y - x)); end
code[x_, y_] := N[(N[(y / N[(x - y), $MachinePrecision]), $MachinePrecision] - N[(x / N[(y - x), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\frac{y}{x - y} - \frac{x}{y - x}
\end{array}
Initial program 100.0%
frac-2neg100.0%
neg-sub0100.0%
+-commutative100.0%
associate--r+100.0%
neg-sub0100.0%
div-sub100.0%
sub-neg100.0%
distribute-neg-in100.0%
+-commutative100.0%
remove-double-neg100.0%
sub-neg100.0%
sub-neg100.0%
distribute-neg-in100.0%
+-commutative100.0%
remove-double-neg100.0%
sub-neg100.0%
Applied egg-rr100.0%
add-log-exp_binary64100.0%
Applied rewrite-once100.0%
rem-log-exp100.0%
distribute-frac-neg100.0%
neg-sub0100.0%
div-inv99.9%
cancel-sign-sub-inv99.9%
div-inv100.0%
frac-2neg100.0%
remove-double-neg100.0%
Applied egg-rr100.0%
+-lft-identity100.0%
neg-sub0100.0%
associate-+l-100.0%
neg-sub0100.0%
+-commutative100.0%
sub-neg100.0%
Simplified100.0%
Final simplification100.0%
(FPCore (x y) :precision binary64 (/ (+ y x) (- x y)))
double code(double x, double y) {
return (y + x) / (x - y);
}
real(8) function code(x, y)
real(8), intent (in) :: x
real(8), intent (in) :: y
code = (y + x) / (x - y)
end function
public static double code(double x, double y) {
return (y + x) / (x - y);
}
def code(x, y): return (y + x) / (x - y)
function code(x, y) return Float64(Float64(y + x) / Float64(x - y)) end
function tmp = code(x, y) tmp = (y + x) / (x - y); end
code[x_, y_] := N[(N[(y + x), $MachinePrecision] / N[(x - y), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\frac{y + x}{x - y}
\end{array}
Initial program 100.0%
Final simplification100.0%
(FPCore (x y) :precision binary64 (if (<= y -4.6e-28) -1.0 (if (<= y 2.1e+77) 1.0 -1.0)))
double code(double x, double y) {
double tmp;
if (y <= -4.6e-28) {
tmp = -1.0;
} else if (y <= 2.1e+77) {
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 <= (-4.6d-28)) then
tmp = -1.0d0
else if (y <= 2.1d+77) 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 <= -4.6e-28) {
tmp = -1.0;
} else if (y <= 2.1e+77) {
tmp = 1.0;
} else {
tmp = -1.0;
}
return tmp;
}
def code(x, y): tmp = 0 if y <= -4.6e-28: tmp = -1.0 elif y <= 2.1e+77: tmp = 1.0 else: tmp = -1.0 return tmp
function code(x, y) tmp = 0.0 if (y <= -4.6e-28) tmp = -1.0; elseif (y <= 2.1e+77) tmp = 1.0; else tmp = -1.0; end return tmp end
function tmp_2 = code(x, y) tmp = 0.0; if (y <= -4.6e-28) tmp = -1.0; elseif (y <= 2.1e+77) tmp = 1.0; else tmp = -1.0; end tmp_2 = tmp; end
code[x_, y_] := If[LessEqual[y, -4.6e-28], -1.0, If[LessEqual[y, 2.1e+77], 1.0, -1.0]]
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;y \leq -4.6 \cdot 10^{-28}:\\
\;\;\;\;-1\\
\mathbf{elif}\;y \leq 2.1 \cdot 10^{+77}:\\
\;\;\;\;1\\
\mathbf{else}:\\
\;\;\;\;-1\\
\end{array}
\end{array}
if y < -4.59999999999999971e-28 or 2.0999999999999999e77 < y Initial program 100.0%
Taylor expanded in x around 0 79.5%
if -4.59999999999999971e-28 < y < 2.0999999999999999e77Initial program 100.0%
Taylor expanded in x around inf 81.3%
Final simplification80.5%
(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 48.0%
Final simplification48.0%
(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 2023297
(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)))