
(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 (+ (/ y (- x y)) (/ x (- x y))))
double code(double x, double y) {
return (y / (x - y)) + (x / (x - y));
}
real(8) function code(x, y)
real(8), intent (in) :: x
real(8), intent (in) :: y
code = (y / (x - y)) + (x / (x - y))
end function
public static double code(double x, double y) {
return (y / (x - y)) + (x / (x - y));
}
def code(x, y): return (y / (x - y)) + (x / (x - y))
function code(x, y) return Float64(Float64(y / Float64(x - y)) + Float64(x / Float64(x - y))) end
function tmp = code(x, y) tmp = (y / (x - y)) + (x / (x - y)); end
code[x_, y_] := N[(N[(y / N[(x - y), $MachinePrecision]), $MachinePrecision] + N[(x / N[(x - y), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\frac{y}{x - y} + \frac{x}{x - y}
\end{array}
Initial program 99.9%
log1p-expm1-u99.9%
Applied egg-rr99.9%
log1p-expm199.9%
div-inv99.7%
*-commutative99.7%
distribute-lft-in99.7%
+-commutative99.7%
associate-*l/99.8%
*-un-lft-identity99.8%
associate-*l/100.0%
*-un-lft-identity100.0%
Applied egg-rr100.0%
Final simplification100.0%
(FPCore (x y) :precision binary64 (if (or (<= y -3.4e+76) (not (<= y 8e-35))) (+ (* -2.0 (/ x y)) -1.0) (+ 1.0 (/ (* y 2.0) x))))
double code(double x, double y) {
double tmp;
if ((y <= -3.4e+76) || !(y <= 8e-35)) {
tmp = (-2.0 * (x / y)) + -1.0;
} else {
tmp = 1.0 + ((y * 2.0) / x);
}
return tmp;
}
real(8) function code(x, y)
real(8), intent (in) :: x
real(8), intent (in) :: y
real(8) :: tmp
if ((y <= (-3.4d+76)) .or. (.not. (y <= 8d-35))) then
tmp = ((-2.0d0) * (x / y)) + (-1.0d0)
else
tmp = 1.0d0 + ((y * 2.0d0) / x)
end if
code = tmp
end function
public static double code(double x, double y) {
double tmp;
if ((y <= -3.4e+76) || !(y <= 8e-35)) {
tmp = (-2.0 * (x / y)) + -1.0;
} else {
tmp = 1.0 + ((y * 2.0) / x);
}
return tmp;
}
def code(x, y): tmp = 0 if (y <= -3.4e+76) or not (y <= 8e-35): tmp = (-2.0 * (x / y)) + -1.0 else: tmp = 1.0 + ((y * 2.0) / x) return tmp
function code(x, y) tmp = 0.0 if ((y <= -3.4e+76) || !(y <= 8e-35)) tmp = Float64(Float64(-2.0 * Float64(x / y)) + -1.0); else tmp = Float64(1.0 + Float64(Float64(y * 2.0) / x)); end return tmp end
function tmp_2 = code(x, y) tmp = 0.0; if ((y <= -3.4e+76) || ~((y <= 8e-35))) tmp = (-2.0 * (x / y)) + -1.0; else tmp = 1.0 + ((y * 2.0) / x); end tmp_2 = tmp; end
code[x_, y_] := If[Or[LessEqual[y, -3.4e+76], N[Not[LessEqual[y, 8e-35]], $MachinePrecision]], N[(N[(-2.0 * N[(x / y), $MachinePrecision]), $MachinePrecision] + -1.0), $MachinePrecision], N[(1.0 + N[(N[(y * 2.0), $MachinePrecision] / x), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;y \leq -3.4 \cdot 10^{+76} \lor \neg \left(y \leq 8 \cdot 10^{-35}\right):\\
\;\;\;\;-2 \cdot \frac{x}{y} + -1\\
\mathbf{else}:\\
\;\;\;\;1 + \frac{y \cdot 2}{x}\\
\end{array}
\end{array}
if y < -3.3999999999999997e76 or 8.00000000000000006e-35 < y Initial program 99.9%
Taylor expanded in x around 0 82.8%
if -3.3999999999999997e76 < y < 8.00000000000000006e-35Initial program 99.9%
Taylor expanded in y around 0 82.7%
associate-*r/82.7%
Simplified82.7%
Final simplification82.8%
(FPCore (x y) :precision binary64 (if (<= y -6.5e+76) -1.0 (if (<= y 1.55e-36) (+ 1.0 (/ (* y 2.0) x)) -1.0)))
double code(double x, double y) {
double tmp;
if (y <= -6.5e+76) {
tmp = -1.0;
} else if (y <= 1.55e-36) {
tmp = 1.0 + ((y * 2.0) / 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 <= (-6.5d+76)) then
tmp = -1.0d0
else if (y <= 1.55d-36) then
tmp = 1.0d0 + ((y * 2.0d0) / x)
else
tmp = -1.0d0
end if
code = tmp
end function
public static double code(double x, double y) {
double tmp;
if (y <= -6.5e+76) {
tmp = -1.0;
} else if (y <= 1.55e-36) {
tmp = 1.0 + ((y * 2.0) / x);
} else {
tmp = -1.0;
}
return tmp;
}
def code(x, y): tmp = 0 if y <= -6.5e+76: tmp = -1.0 elif y <= 1.55e-36: tmp = 1.0 + ((y * 2.0) / x) else: tmp = -1.0 return tmp
function code(x, y) tmp = 0.0 if (y <= -6.5e+76) tmp = -1.0; elseif (y <= 1.55e-36) tmp = Float64(1.0 + Float64(Float64(y * 2.0) / x)); else tmp = -1.0; end return tmp end
function tmp_2 = code(x, y) tmp = 0.0; if (y <= -6.5e+76) tmp = -1.0; elseif (y <= 1.55e-36) tmp = 1.0 + ((y * 2.0) / x); else tmp = -1.0; end tmp_2 = tmp; end
code[x_, y_] := If[LessEqual[y, -6.5e+76], -1.0, If[LessEqual[y, 1.55e-36], N[(1.0 + N[(N[(y * 2.0), $MachinePrecision] / x), $MachinePrecision]), $MachinePrecision], -1.0]]
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;y \leq -6.5 \cdot 10^{+76}:\\
\;\;\;\;-1\\
\mathbf{elif}\;y \leq 1.55 \cdot 10^{-36}:\\
\;\;\;\;1 + \frac{y \cdot 2}{x}\\
\mathbf{else}:\\
\;\;\;\;-1\\
\end{array}
\end{array}
if y < -6.5000000000000005e76 or 1.5499999999999999e-36 < y Initial program 99.9%
Taylor expanded in x around 0 81.6%
if -6.5000000000000005e76 < y < 1.5499999999999999e-36Initial program 99.9%
Taylor expanded in y around 0 82.7%
associate-*r/82.7%
Simplified82.7%
Final simplification82.2%
(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 99.9%
Final simplification99.9%
(FPCore (x y) :precision binary64 (if (<= y -1.5e+76) -1.0 (if (<= y 4.7e-35) 1.0 -1.0)))
double code(double x, double y) {
double tmp;
if (y <= -1.5e+76) {
tmp = -1.0;
} else if (y <= 4.7e-35) {
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 <= (-1.5d+76)) then
tmp = -1.0d0
else if (y <= 4.7d-35) 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 <= -1.5e+76) {
tmp = -1.0;
} else if (y <= 4.7e-35) {
tmp = 1.0;
} else {
tmp = -1.0;
}
return tmp;
}
def code(x, y): tmp = 0 if y <= -1.5e+76: tmp = -1.0 elif y <= 4.7e-35: tmp = 1.0 else: tmp = -1.0 return tmp
function code(x, y) tmp = 0.0 if (y <= -1.5e+76) tmp = -1.0; elseif (y <= 4.7e-35) tmp = 1.0; else tmp = -1.0; end return tmp end
function tmp_2 = code(x, y) tmp = 0.0; if (y <= -1.5e+76) tmp = -1.0; elseif (y <= 4.7e-35) tmp = 1.0; else tmp = -1.0; end tmp_2 = tmp; end
code[x_, y_] := If[LessEqual[y, -1.5e+76], -1.0, If[LessEqual[y, 4.7e-35], 1.0, -1.0]]
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;y \leq -1.5 \cdot 10^{+76}:\\
\;\;\;\;-1\\
\mathbf{elif}\;y \leq 4.7 \cdot 10^{-35}:\\
\;\;\;\;1\\
\mathbf{else}:\\
\;\;\;\;-1\\
\end{array}
\end{array}
if y < -1.4999999999999999e76 or 4.7e-35 < y Initial program 99.9%
Taylor expanded in x around 0 81.6%
if -1.4999999999999999e76 < y < 4.7e-35Initial program 99.9%
Taylor expanded in x around inf 81.2%
Final simplification81.4%
(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 47.0%
Final simplification47.0%
(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 2023301
(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)))