
(FPCore (x y) :precision binary64 (/ (* (* x 2.0) y) (- x y)))
double code(double x, double y) {
return ((x * 2.0) * y) / (x - y);
}
real(8) function code(x, y)
real(8), intent (in) :: x
real(8), intent (in) :: y
code = ((x * 2.0d0) * y) / (x - y)
end function
public static double code(double x, double y) {
return ((x * 2.0) * y) / (x - y);
}
def code(x, y): return ((x * 2.0) * y) / (x - y)
function code(x, y) return Float64(Float64(Float64(x * 2.0) * y) / Float64(x - y)) end
function tmp = code(x, y) tmp = ((x * 2.0) * y) / (x - y); end
code[x_, y_] := N[(N[(N[(x * 2.0), $MachinePrecision] * y), $MachinePrecision] / N[(x - y), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\frac{\left(x \cdot 2\right) \cdot y}{x - y}
\end{array}
Sampling outcomes in binary64 precision:
Herbie found 4 alternatives:
| Alternative | Accuracy | Speedup |
|---|
(FPCore (x y) :precision binary64 (/ (* (* x 2.0) y) (- x y)))
double code(double x, double y) {
return ((x * 2.0) * y) / (x - y);
}
real(8) function code(x, y)
real(8), intent (in) :: x
real(8), intent (in) :: y
code = ((x * 2.0d0) * y) / (x - y)
end function
public static double code(double x, double y) {
return ((x * 2.0) * y) / (x - y);
}
def code(x, y): return ((x * 2.0) * y) / (x - y)
function code(x, y) return Float64(Float64(Float64(x * 2.0) * y) / Float64(x - y)) end
function tmp = code(x, y) tmp = ((x * 2.0) * y) / (x - y); end
code[x_, y_] := N[(N[(N[(x * 2.0), $MachinePrecision] * y), $MachinePrecision] / N[(x - y), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\frac{\left(x \cdot 2\right) \cdot y}{x - y}
\end{array}
(FPCore (x y) :precision binary64 (if (<= x -1.04e+155) (* (fma (/ 2.0 x) y 2.0) y) (if (<= x 1.05e+137) (* (* 2.0 x) (/ y (- x y))) (* y 2.0))))
double code(double x, double y) {
double tmp;
if (x <= -1.04e+155) {
tmp = fma((2.0 / x), y, 2.0) * y;
} else if (x <= 1.05e+137) {
tmp = (2.0 * x) * (y / (x - y));
} else {
tmp = y * 2.0;
}
return tmp;
}
function code(x, y) tmp = 0.0 if (x <= -1.04e+155) tmp = Float64(fma(Float64(2.0 / x), y, 2.0) * y); elseif (x <= 1.05e+137) tmp = Float64(Float64(2.0 * x) * Float64(y / Float64(x - y))); else tmp = Float64(y * 2.0); end return tmp end
code[x_, y_] := If[LessEqual[x, -1.04e+155], N[(N[(N[(2.0 / x), $MachinePrecision] * y + 2.0), $MachinePrecision] * y), $MachinePrecision], If[LessEqual[x, 1.05e+137], N[(N[(2.0 * x), $MachinePrecision] * N[(y / N[(x - y), $MachinePrecision]), $MachinePrecision]), $MachinePrecision], N[(y * 2.0), $MachinePrecision]]]
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;x \leq -1.04 \cdot 10^{+155}:\\
\;\;\;\;\mathsf{fma}\left(\frac{2}{x}, y, 2\right) \cdot y\\
\mathbf{elif}\;x \leq 1.05 \cdot 10^{+137}:\\
\;\;\;\;\left(2 \cdot x\right) \cdot \frac{y}{x - y}\\
\mathbf{else}:\\
\;\;\;\;y \cdot 2\\
\end{array}
\end{array}
if x < -1.03999999999999996e155Initial program 58.0%
Taylor expanded in y around 0
*-commutativeN/A
+-commutativeN/A
*-lft-identityN/A
associate-*l/N/A
associate-*l*N/A
*-commutativeN/A
lower-*.f64N/A
*-commutativeN/A
lower-fma.f64N/A
associate-*r/N/A
metadata-evalN/A
lower-/.f6494.1
Applied rewrites94.1%
if -1.03999999999999996e155 < x < 1.05e137Initial program 79.8%
lift-/.f64N/A
lift-*.f64N/A
associate-/l*N/A
*-commutativeN/A
lower-*.f64N/A
lower-/.f6498.1
lift-*.f64N/A
*-commutativeN/A
lower-*.f6498.1
Applied rewrites98.1%
if 1.05e137 < x Initial program 69.3%
Taylor expanded in y around 0
*-commutativeN/A
lower-*.f6490.6
Applied rewrites90.6%
Final simplification96.7%
(FPCore (x y) :precision binary64 (if (<= x -1.3e-9) (* y 2.0) (if (<= x 4e+80) (* (fma (/ x y) -2.0 -2.0) x) (* y 2.0))))
double code(double x, double y) {
double tmp;
if (x <= -1.3e-9) {
tmp = y * 2.0;
} else if (x <= 4e+80) {
tmp = fma((x / y), -2.0, -2.0) * x;
} else {
tmp = y * 2.0;
}
return tmp;
}
function code(x, y) tmp = 0.0 if (x <= -1.3e-9) tmp = Float64(y * 2.0); elseif (x <= 4e+80) tmp = Float64(fma(Float64(x / y), -2.0, -2.0) * x); else tmp = Float64(y * 2.0); end return tmp end
code[x_, y_] := If[LessEqual[x, -1.3e-9], N[(y * 2.0), $MachinePrecision], If[LessEqual[x, 4e+80], N[(N[(N[(x / y), $MachinePrecision] * -2.0 + -2.0), $MachinePrecision] * x), $MachinePrecision], N[(y * 2.0), $MachinePrecision]]]
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;x \leq -1.3 \cdot 10^{-9}:\\
\;\;\;\;y \cdot 2\\
\mathbf{elif}\;x \leq 4 \cdot 10^{+80}:\\
\;\;\;\;\mathsf{fma}\left(\frac{x}{y}, -2, -2\right) \cdot x\\
\mathbf{else}:\\
\;\;\;\;y \cdot 2\\
\end{array}
\end{array}
if x < -1.3000000000000001e-9 or 4e80 < x Initial program 72.6%
Taylor expanded in y around 0
*-commutativeN/A
lower-*.f6480.6
Applied rewrites80.6%
if -1.3000000000000001e-9 < x < 4e80Initial program 78.1%
Taylor expanded in y around inf
lower-*.f6475.4
Applied rewrites75.4%
Taylor expanded in y around inf
associate-*r/N/A
unpow2N/A
associate-*r*N/A
associate-*l/N/A
associate-*r/N/A
distribute-rgt-inN/A
+-commutativeN/A
metadata-evalN/A
sub-negN/A
*-commutativeN/A
lower-*.f64N/A
sub-negN/A
*-commutativeN/A
metadata-evalN/A
lower-fma.f64N/A
lower-/.f6475.7
Applied rewrites75.7%
(FPCore (x y) :precision binary64 (if (<= x -7.8e-8) (* y 2.0) (if (<= x 4e+80) (* -2.0 x) (* y 2.0))))
double code(double x, double y) {
double tmp;
if (x <= -7.8e-8) {
tmp = y * 2.0;
} else if (x <= 4e+80) {
tmp = -2.0 * x;
} else {
tmp = y * 2.0;
}
return tmp;
}
real(8) function code(x, y)
real(8), intent (in) :: x
real(8), intent (in) :: y
real(8) :: tmp
if (x <= (-7.8d-8)) then
tmp = y * 2.0d0
else if (x <= 4d+80) then
tmp = (-2.0d0) * x
else
tmp = y * 2.0d0
end if
code = tmp
end function
public static double code(double x, double y) {
double tmp;
if (x <= -7.8e-8) {
tmp = y * 2.0;
} else if (x <= 4e+80) {
tmp = -2.0 * x;
} else {
tmp = y * 2.0;
}
return tmp;
}
def code(x, y): tmp = 0 if x <= -7.8e-8: tmp = y * 2.0 elif x <= 4e+80: tmp = -2.0 * x else: tmp = y * 2.0 return tmp
function code(x, y) tmp = 0.0 if (x <= -7.8e-8) tmp = Float64(y * 2.0); elseif (x <= 4e+80) tmp = Float64(-2.0 * x); else tmp = Float64(y * 2.0); end return tmp end
function tmp_2 = code(x, y) tmp = 0.0; if (x <= -7.8e-8) tmp = y * 2.0; elseif (x <= 4e+80) tmp = -2.0 * x; else tmp = y * 2.0; end tmp_2 = tmp; end
code[x_, y_] := If[LessEqual[x, -7.8e-8], N[(y * 2.0), $MachinePrecision], If[LessEqual[x, 4e+80], N[(-2.0 * x), $MachinePrecision], N[(y * 2.0), $MachinePrecision]]]
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;x \leq -7.8 \cdot 10^{-8}:\\
\;\;\;\;y \cdot 2\\
\mathbf{elif}\;x \leq 4 \cdot 10^{+80}:\\
\;\;\;\;-2 \cdot x\\
\mathbf{else}:\\
\;\;\;\;y \cdot 2\\
\end{array}
\end{array}
if x < -7.7999999999999997e-8 or 4e80 < x Initial program 72.6%
Taylor expanded in y around 0
*-commutativeN/A
lower-*.f6480.6
Applied rewrites80.6%
if -7.7999999999999997e-8 < x < 4e80Initial program 78.1%
Taylor expanded in y around inf
lower-*.f6475.4
Applied rewrites75.4%
(FPCore (x y) :precision binary64 (* -2.0 x))
double code(double x, double y) {
return -2.0 * x;
}
real(8) function code(x, y)
real(8), intent (in) :: x
real(8), intent (in) :: y
code = (-2.0d0) * x
end function
public static double code(double x, double y) {
return -2.0 * x;
}
def code(x, y): return -2.0 * x
function code(x, y) return Float64(-2.0 * x) end
function tmp = code(x, y) tmp = -2.0 * x; end
code[x_, y_] := N[(-2.0 * x), $MachinePrecision]
\begin{array}{l}
\\
-2 \cdot x
\end{array}
Initial program 75.6%
Taylor expanded in y around inf
lower-*.f6451.3
Applied rewrites51.3%
(FPCore (x y)
:precision binary64
(let* ((t_0 (* (/ (* 2.0 x) (- x y)) y)))
(if (< x -1.7210442634149447e+81)
t_0
(if (< x 83645045635564430.0) (/ (* x 2.0) (/ (- x y) y)) t_0))))
double code(double x, double y) {
double t_0 = ((2.0 * x) / (x - y)) * y;
double tmp;
if (x < -1.7210442634149447e+81) {
tmp = t_0;
} else if (x < 83645045635564430.0) {
tmp = (x * 2.0) / ((x - y) / y);
} 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 = ((2.0d0 * x) / (x - y)) * y
if (x < (-1.7210442634149447d+81)) then
tmp = t_0
else if (x < 83645045635564430.0d0) then
tmp = (x * 2.0d0) / ((x - y) / y)
else
tmp = t_0
end if
code = tmp
end function
public static double code(double x, double y) {
double t_0 = ((2.0 * x) / (x - y)) * y;
double tmp;
if (x < -1.7210442634149447e+81) {
tmp = t_0;
} else if (x < 83645045635564430.0) {
tmp = (x * 2.0) / ((x - y) / y);
} else {
tmp = t_0;
}
return tmp;
}
def code(x, y): t_0 = ((2.0 * x) / (x - y)) * y tmp = 0 if x < -1.7210442634149447e+81: tmp = t_0 elif x < 83645045635564430.0: tmp = (x * 2.0) / ((x - y) / y) else: tmp = t_0 return tmp
function code(x, y) t_0 = Float64(Float64(Float64(2.0 * x) / Float64(x - y)) * y) tmp = 0.0 if (x < -1.7210442634149447e+81) tmp = t_0; elseif (x < 83645045635564430.0) tmp = Float64(Float64(x * 2.0) / Float64(Float64(x - y) / y)); else tmp = t_0; end return tmp end
function tmp_2 = code(x, y) t_0 = ((2.0 * x) / (x - y)) * y; tmp = 0.0; if (x < -1.7210442634149447e+81) tmp = t_0; elseif (x < 83645045635564430.0) tmp = (x * 2.0) / ((x - y) / y); else tmp = t_0; end tmp_2 = tmp; end
code[x_, y_] := Block[{t$95$0 = N[(N[(N[(2.0 * x), $MachinePrecision] / N[(x - y), $MachinePrecision]), $MachinePrecision] * y), $MachinePrecision]}, If[Less[x, -1.7210442634149447e+81], t$95$0, If[Less[x, 83645045635564430.0], N[(N[(x * 2.0), $MachinePrecision] / N[(N[(x - y), $MachinePrecision] / y), $MachinePrecision]), $MachinePrecision], t$95$0]]]
\begin{array}{l}
\\
\begin{array}{l}
t_0 := \frac{2 \cdot x}{x - y} \cdot y\\
\mathbf{if}\;x < -1.7210442634149447 \cdot 10^{+81}:\\
\;\;\;\;t\_0\\
\mathbf{elif}\;x < 83645045635564430:\\
\;\;\;\;\frac{x \cdot 2}{\frac{x - y}{y}}\\
\mathbf{else}:\\
\;\;\;\;t\_0\\
\end{array}
\end{array}
herbie shell --seed 2024270
(FPCore (x y)
:name "Linear.Projection:perspective from linear-1.19.1.3, B"
:precision binary64
:alt
(! :herbie-platform default (if (< x -1721044263414944700000000000000000000000000000000000000000000000000000000000000000) (* (/ (* 2 x) (- x y)) y) (if (< x 83645045635564430) (/ (* x 2) (/ (- x y) y)) (* (/ (* 2 x) (- x y)) y))))
(/ (* (* x 2.0) y) (- x y)))