
(FPCore (x y) :precision binary64 (let* ((t_0 (* (* y 4.0) y))) (/ (- (* x x) t_0) (+ (* x x) t_0))))
double code(double x, double y) {
double t_0 = (y * 4.0) * y;
return ((x * x) - t_0) / ((x * x) + t_0);
}
real(8) function code(x, y)
real(8), intent (in) :: x
real(8), intent (in) :: y
real(8) :: t_0
t_0 = (y * 4.0d0) * y
code = ((x * x) - t_0) / ((x * x) + t_0)
end function
public static double code(double x, double y) {
double t_0 = (y * 4.0) * y;
return ((x * x) - t_0) / ((x * x) + t_0);
}
def code(x, y): t_0 = (y * 4.0) * y return ((x * x) - t_0) / ((x * x) + t_0)
function code(x, y) t_0 = Float64(Float64(y * 4.0) * y) return Float64(Float64(Float64(x * x) - t_0) / Float64(Float64(x * x) + t_0)) end
function tmp = code(x, y) t_0 = (y * 4.0) * y; tmp = ((x * x) - t_0) / ((x * x) + t_0); end
code[x_, y_] := Block[{t$95$0 = N[(N[(y * 4.0), $MachinePrecision] * y), $MachinePrecision]}, N[(N[(N[(x * x), $MachinePrecision] - t$95$0), $MachinePrecision] / N[(N[(x * x), $MachinePrecision] + t$95$0), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}
\\
\begin{array}{l}
t_0 := \left(y \cdot 4\right) \cdot y\\
\frac{x \cdot x - t\_0}{x \cdot x + t\_0}
\end{array}
\end{array}
Sampling outcomes in binary64 precision:
Herbie found 4 alternatives:
| Alternative | Accuracy | Speedup |
|---|
(FPCore (x y) :precision binary64 (let* ((t_0 (* (* y 4.0) y))) (/ (- (* x x) t_0) (+ (* x x) t_0))))
double code(double x, double y) {
double t_0 = (y * 4.0) * y;
return ((x * x) - t_0) / ((x * x) + t_0);
}
real(8) function code(x, y)
real(8), intent (in) :: x
real(8), intent (in) :: y
real(8) :: t_0
t_0 = (y * 4.0d0) * y
code = ((x * x) - t_0) / ((x * x) + t_0)
end function
public static double code(double x, double y) {
double t_0 = (y * 4.0) * y;
return ((x * x) - t_0) / ((x * x) + t_0);
}
def code(x, y): t_0 = (y * 4.0) * y return ((x * x) - t_0) / ((x * x) + t_0)
function code(x, y) t_0 = Float64(Float64(y * 4.0) * y) return Float64(Float64(Float64(x * x) - t_0) / Float64(Float64(x * x) + t_0)) end
function tmp = code(x, y) t_0 = (y * 4.0) * y; tmp = ((x * x) - t_0) / ((x * x) + t_0); end
code[x_, y_] := Block[{t$95$0 = N[(N[(y * 4.0), $MachinePrecision] * y), $MachinePrecision]}, N[(N[(N[(x * x), $MachinePrecision] - t$95$0), $MachinePrecision] / N[(N[(x * x), $MachinePrecision] + t$95$0), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}
\\
\begin{array}{l}
t_0 := \left(y \cdot 4\right) \cdot y\\
\frac{x \cdot x - t\_0}{x \cdot x + t\_0}
\end{array}
\end{array}
(FPCore (x y)
:precision binary64
(if (<= (* x x) 1e-249)
-1.0
(if (<= (* x x) 4e+161)
(/ (fma -4.0 (* y y) (* x x)) (fma (* 4.0 y) y (* x x)))
(fma (* (/ y x) -8.0) (/ y x) 1.0))))
double code(double x, double y) {
double tmp;
if ((x * x) <= 1e-249) {
tmp = -1.0;
} else if ((x * x) <= 4e+161) {
tmp = fma(-4.0, (y * y), (x * x)) / fma((4.0 * y), y, (x * x));
} else {
tmp = fma(((y / x) * -8.0), (y / x), 1.0);
}
return tmp;
}
function code(x, y) tmp = 0.0 if (Float64(x * x) <= 1e-249) tmp = -1.0; elseif (Float64(x * x) <= 4e+161) tmp = Float64(fma(-4.0, Float64(y * y), Float64(x * x)) / fma(Float64(4.0 * y), y, Float64(x * x))); else tmp = fma(Float64(Float64(y / x) * -8.0), Float64(y / x), 1.0); end return tmp end
code[x_, y_] := If[LessEqual[N[(x * x), $MachinePrecision], 1e-249], -1.0, If[LessEqual[N[(x * x), $MachinePrecision], 4e+161], N[(N[(-4.0 * N[(y * y), $MachinePrecision] + N[(x * x), $MachinePrecision]), $MachinePrecision] / N[(N[(4.0 * y), $MachinePrecision] * y + N[(x * x), $MachinePrecision]), $MachinePrecision]), $MachinePrecision], N[(N[(N[(y / x), $MachinePrecision] * -8.0), $MachinePrecision] * N[(y / x), $MachinePrecision] + 1.0), $MachinePrecision]]]
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;x \cdot x \leq 10^{-249}:\\
\;\;\;\;-1\\
\mathbf{elif}\;x \cdot x \leq 4 \cdot 10^{+161}:\\
\;\;\;\;\frac{\mathsf{fma}\left(-4, y \cdot y, x \cdot x\right)}{\mathsf{fma}\left(4 \cdot y, y, x \cdot x\right)}\\
\mathbf{else}:\\
\;\;\;\;\mathsf{fma}\left(\frac{y}{x} \cdot -8, \frac{y}{x}, 1\right)\\
\end{array}
\end{array}
if (*.f64 x x) < 1.00000000000000005e-249Initial program 48.6%
Taylor expanded in y around inf
Applied rewrites90.4%
if 1.00000000000000005e-249 < (*.f64 x x) < 4.0000000000000002e161Initial program 79.8%
lift--.f64N/A
sub-negN/A
+-commutativeN/A
lift-*.f64N/A
lift-*.f64N/A
*-commutativeN/A
associate-*l*N/A
distribute-lft-neg-inN/A
lower-fma.f64N/A
metadata-evalN/A
lower-*.f6479.8
lift-+.f64N/A
+-commutativeN/A
lift-*.f64N/A
lower-fma.f6479.8
lift-*.f64N/A
*-commutativeN/A
lower-*.f6479.8
Applied rewrites79.8%
if 4.0000000000000002e161 < (*.f64 x x) Initial program 21.1%
Taylor expanded in y around 0
+-commutativeN/A
unpow2N/A
unpow2N/A
times-fracN/A
associate-*r*N/A
lower-fma.f64N/A
lower-*.f64N/A
lower-/.f64N/A
lower-/.f6481.1
Applied rewrites81.1%
Final simplification83.2%
(FPCore (x y) :precision binary64 (if (<= (* x x) 2e-94) -1.0 (fma (* (/ y x) -8.0) (/ y x) 1.0)))
double code(double x, double y) {
double tmp;
if ((x * x) <= 2e-94) {
tmp = -1.0;
} else {
tmp = fma(((y / x) * -8.0), (y / x), 1.0);
}
return tmp;
}
function code(x, y) tmp = 0.0 if (Float64(x * x) <= 2e-94) tmp = -1.0; else tmp = fma(Float64(Float64(y / x) * -8.0), Float64(y / x), 1.0); end return tmp end
code[x_, y_] := If[LessEqual[N[(x * x), $MachinePrecision], 2e-94], -1.0, N[(N[(N[(y / x), $MachinePrecision] * -8.0), $MachinePrecision] * N[(y / x), $MachinePrecision] + 1.0), $MachinePrecision]]
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;x \cdot x \leq 2 \cdot 10^{-94}:\\
\;\;\;\;-1\\
\mathbf{else}:\\
\;\;\;\;\mathsf{fma}\left(\frac{y}{x} \cdot -8, \frac{y}{x}, 1\right)\\
\end{array}
\end{array}
if (*.f64 x x) < 1.9999999999999999e-94Initial program 62.0%
Taylor expanded in y around inf
Applied rewrites84.5%
if 1.9999999999999999e-94 < (*.f64 x x) Initial program 39.9%
Taylor expanded in y around 0
+-commutativeN/A
unpow2N/A
unpow2N/A
times-fracN/A
associate-*r*N/A
lower-fma.f64N/A
lower-*.f64N/A
lower-/.f64N/A
lower-/.f6472.9
Applied rewrites72.9%
Final simplification77.8%
(FPCore (x y) :precision binary64 (if (<= (* x x) 1.26e-67) -1.0 1.0))
double code(double x, double y) {
double tmp;
if ((x * x) <= 1.26e-67) {
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 ((x * x) <= 1.26d-67) 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 ((x * x) <= 1.26e-67) {
tmp = -1.0;
} else {
tmp = 1.0;
}
return tmp;
}
def code(x, y): tmp = 0 if (x * x) <= 1.26e-67: tmp = -1.0 else: tmp = 1.0 return tmp
function code(x, y) tmp = 0.0 if (Float64(x * x) <= 1.26e-67) tmp = -1.0; else tmp = 1.0; end return tmp end
function tmp_2 = code(x, y) tmp = 0.0; if ((x * x) <= 1.26e-67) tmp = -1.0; else tmp = 1.0; end tmp_2 = tmp; end
code[x_, y_] := If[LessEqual[N[(x * x), $MachinePrecision], 1.26e-67], -1.0, 1.0]
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;x \cdot x \leq 1.26 \cdot 10^{-67}:\\
\;\;\;\;-1\\
\mathbf{else}:\\
\;\;\;\;1\\
\end{array}
\end{array}
if (*.f64 x x) < 1.26e-67Initial program 61.8%
Taylor expanded in y around inf
Applied rewrites83.9%
if 1.26e-67 < (*.f64 x x) Initial program 39.7%
Taylor expanded in y around 0
Applied rewrites72.4%
(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 49.2%
Taylor expanded in y around inf
Applied rewrites52.3%
(FPCore (x y)
:precision binary64
(let* ((t_0 (* (* y y) 4.0))
(t_1 (+ (* x x) t_0))
(t_2 (/ t_0 t_1))
(t_3 (* (* y 4.0) y)))
(if (< (/ (- (* x x) t_3) (+ (* x x) t_3)) 0.9743233849626781)
(- (/ (* x x) t_1) t_2)
(- (pow (/ x (sqrt t_1)) 2.0) t_2))))
double code(double x, double y) {
double t_0 = (y * y) * 4.0;
double t_1 = (x * x) + t_0;
double t_2 = t_0 / t_1;
double t_3 = (y * 4.0) * y;
double tmp;
if ((((x * x) - t_3) / ((x * x) + t_3)) < 0.9743233849626781) {
tmp = ((x * x) / t_1) - t_2;
} else {
tmp = pow((x / sqrt(t_1)), 2.0) - t_2;
}
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) :: t_2
real(8) :: t_3
real(8) :: tmp
t_0 = (y * y) * 4.0d0
t_1 = (x * x) + t_0
t_2 = t_0 / t_1
t_3 = (y * 4.0d0) * y
if ((((x * x) - t_3) / ((x * x) + t_3)) < 0.9743233849626781d0) then
tmp = ((x * x) / t_1) - t_2
else
tmp = ((x / sqrt(t_1)) ** 2.0d0) - t_2
end if
code = tmp
end function
public static double code(double x, double y) {
double t_0 = (y * y) * 4.0;
double t_1 = (x * x) + t_0;
double t_2 = t_0 / t_1;
double t_3 = (y * 4.0) * y;
double tmp;
if ((((x * x) - t_3) / ((x * x) + t_3)) < 0.9743233849626781) {
tmp = ((x * x) / t_1) - t_2;
} else {
tmp = Math.pow((x / Math.sqrt(t_1)), 2.0) - t_2;
}
return tmp;
}
def code(x, y): t_0 = (y * y) * 4.0 t_1 = (x * x) + t_0 t_2 = t_0 / t_1 t_3 = (y * 4.0) * y tmp = 0 if (((x * x) - t_3) / ((x * x) + t_3)) < 0.9743233849626781: tmp = ((x * x) / t_1) - t_2 else: tmp = math.pow((x / math.sqrt(t_1)), 2.0) - t_2 return tmp
function code(x, y) t_0 = Float64(Float64(y * y) * 4.0) t_1 = Float64(Float64(x * x) + t_0) t_2 = Float64(t_0 / t_1) t_3 = Float64(Float64(y * 4.0) * y) tmp = 0.0 if (Float64(Float64(Float64(x * x) - t_3) / Float64(Float64(x * x) + t_3)) < 0.9743233849626781) tmp = Float64(Float64(Float64(x * x) / t_1) - t_2); else tmp = Float64((Float64(x / sqrt(t_1)) ^ 2.0) - t_2); end return tmp end
function tmp_2 = code(x, y) t_0 = (y * y) * 4.0; t_1 = (x * x) + t_0; t_2 = t_0 / t_1; t_3 = (y * 4.0) * y; tmp = 0.0; if ((((x * x) - t_3) / ((x * x) + t_3)) < 0.9743233849626781) tmp = ((x * x) / t_1) - t_2; else tmp = ((x / sqrt(t_1)) ^ 2.0) - t_2; end tmp_2 = tmp; end
code[x_, y_] := Block[{t$95$0 = N[(N[(y * y), $MachinePrecision] * 4.0), $MachinePrecision]}, Block[{t$95$1 = N[(N[(x * x), $MachinePrecision] + t$95$0), $MachinePrecision]}, Block[{t$95$2 = N[(t$95$0 / t$95$1), $MachinePrecision]}, Block[{t$95$3 = N[(N[(y * 4.0), $MachinePrecision] * y), $MachinePrecision]}, If[Less[N[(N[(N[(x * x), $MachinePrecision] - t$95$3), $MachinePrecision] / N[(N[(x * x), $MachinePrecision] + t$95$3), $MachinePrecision]), $MachinePrecision], 0.9743233849626781], N[(N[(N[(x * x), $MachinePrecision] / t$95$1), $MachinePrecision] - t$95$2), $MachinePrecision], N[(N[Power[N[(x / N[Sqrt[t$95$1], $MachinePrecision]), $MachinePrecision], 2.0], $MachinePrecision] - t$95$2), $MachinePrecision]]]]]]
\begin{array}{l}
\\
\begin{array}{l}
t_0 := \left(y \cdot y\right) \cdot 4\\
t_1 := x \cdot x + t\_0\\
t_2 := \frac{t\_0}{t\_1}\\
t_3 := \left(y \cdot 4\right) \cdot y\\
\mathbf{if}\;\frac{x \cdot x - t\_3}{x \cdot x + t\_3} < 0.9743233849626781:\\
\;\;\;\;\frac{x \cdot x}{t\_1} - t\_2\\
\mathbf{else}:\\
\;\;\;\;{\left(\frac{x}{\sqrt{t\_1}}\right)}^{2} - t\_2\\
\end{array}
\end{array}
herbie shell --seed 2024276
(FPCore (x y)
:name "Diagrams.TwoD.Arc:arcBetween from diagrams-lib-1.3.0.3"
:precision binary64
:alt
(! :herbie-platform default (if (< (/ (- (* x x) (* (* y 4) y)) (+ (* x x) (* (* y 4) y))) 9743233849626781/10000000000000000) (- (/ (* x x) (+ (* x x) (* (* y y) 4))) (/ (* (* y y) 4) (+ (* x x) (* (* y y) 4)))) (- (pow (/ x (sqrt (+ (* x x) (* (* y y) 4)))) 2) (/ (* (* y y) 4) (+ (* x x) (* (* y y) 4))))))
(/ (- (* x x) (* (* y 4.0) y)) (+ (* x x) (* (* y 4.0) y))))