
(FPCore (v) :precision binary64 (* (* (/ (sqrt 2.0) 4.0) (sqrt (- 1.0 (* 3.0 (* v v))))) (- 1.0 (* v v))))
double code(double v) {
return ((sqrt(2.0) / 4.0) * sqrt((1.0 - (3.0 * (v * v))))) * (1.0 - (v * v));
}
real(8) function code(v)
real(8), intent (in) :: v
code = ((sqrt(2.0d0) / 4.0d0) * sqrt((1.0d0 - (3.0d0 * (v * v))))) * (1.0d0 - (v * v))
end function
public static double code(double v) {
return ((Math.sqrt(2.0) / 4.0) * Math.sqrt((1.0 - (3.0 * (v * v))))) * (1.0 - (v * v));
}
def code(v): return ((math.sqrt(2.0) / 4.0) * math.sqrt((1.0 - (3.0 * (v * v))))) * (1.0 - (v * v))
function code(v) return Float64(Float64(Float64(sqrt(2.0) / 4.0) * sqrt(Float64(1.0 - Float64(3.0 * Float64(v * v))))) * Float64(1.0 - Float64(v * v))) end
function tmp = code(v) tmp = ((sqrt(2.0) / 4.0) * sqrt((1.0 - (3.0 * (v * v))))) * (1.0 - (v * v)); end
code[v_] := N[(N[(N[(N[Sqrt[2.0], $MachinePrecision] / 4.0), $MachinePrecision] * N[Sqrt[N[(1.0 - N[(3.0 * N[(v * v), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]), $MachinePrecision] * N[(1.0 - N[(v * v), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\left(\frac{\sqrt{2}}{4} \cdot \sqrt{1 - 3 \cdot \left(v \cdot v\right)}\right) \cdot \left(1 - v \cdot v\right)
\end{array}
Sampling outcomes in binary64 precision:
Herbie found 6 alternatives:
| Alternative | Accuracy | Speedup |
|---|
(FPCore (v) :precision binary64 (* (* (/ (sqrt 2.0) 4.0) (sqrt (- 1.0 (* 3.0 (* v v))))) (- 1.0 (* v v))))
double code(double v) {
return ((sqrt(2.0) / 4.0) * sqrt((1.0 - (3.0 * (v * v))))) * (1.0 - (v * v));
}
real(8) function code(v)
real(8), intent (in) :: v
code = ((sqrt(2.0d0) / 4.0d0) * sqrt((1.0d0 - (3.0d0 * (v * v))))) * (1.0d0 - (v * v))
end function
public static double code(double v) {
return ((Math.sqrt(2.0) / 4.0) * Math.sqrt((1.0 - (3.0 * (v * v))))) * (1.0 - (v * v));
}
def code(v): return ((math.sqrt(2.0) / 4.0) * math.sqrt((1.0 - (3.0 * (v * v))))) * (1.0 - (v * v))
function code(v) return Float64(Float64(Float64(sqrt(2.0) / 4.0) * sqrt(Float64(1.0 - Float64(3.0 * Float64(v * v))))) * Float64(1.0 - Float64(v * v))) end
function tmp = code(v) tmp = ((sqrt(2.0) / 4.0) * sqrt((1.0 - (3.0 * (v * v))))) * (1.0 - (v * v)); end
code[v_] := N[(N[(N[(N[Sqrt[2.0], $MachinePrecision] / 4.0), $MachinePrecision] * N[Sqrt[N[(1.0 - N[(3.0 * N[(v * v), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]), $MachinePrecision] * N[(1.0 - N[(v * v), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\left(\frac{\sqrt{2}}{4} \cdot \sqrt{1 - 3 \cdot \left(v \cdot v\right)}\right) \cdot \left(1 - v \cdot v\right)
\end{array}
(FPCore (v) :precision binary64 (* (/ (pow (pow (* 2.0 (- 2.0 (fma 3.0 (pow v 2.0) 1.0))) 1.5) 0.3333333333333333) 4.0) (- 1.0 (* v v))))
double code(double v) {
return (pow(pow((2.0 * (2.0 - fma(3.0, pow(v, 2.0), 1.0))), 1.5), 0.3333333333333333) / 4.0) * (1.0 - (v * v));
}
function code(v) return Float64(Float64(((Float64(2.0 * Float64(2.0 - fma(3.0, (v ^ 2.0), 1.0))) ^ 1.5) ^ 0.3333333333333333) / 4.0) * Float64(1.0 - Float64(v * v))) end
code[v_] := N[(N[(N[Power[N[Power[N[(2.0 * N[(2.0 - N[(3.0 * N[Power[v, 2.0], $MachinePrecision] + 1.0), $MachinePrecision]), $MachinePrecision]), $MachinePrecision], 1.5], $MachinePrecision], 0.3333333333333333], $MachinePrecision] / 4.0), $MachinePrecision] * N[(1.0 - N[(v * v), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\frac{{\left({\left(2 \cdot \left(2 - \mathsf{fma}\left(3, {v}^{2}, 1\right)\right)\right)}^{1.5}\right)}^{0.3333333333333333}}{4} \cdot \left(1 - v \cdot v\right)
\end{array}
Initial program 99.9%
expm1-log1p-u99.9%
expm1-undefine99.9%
log1p-undefine99.9%
add-exp-log99.9%
+-commutative99.9%
fma-define99.9%
pow299.9%
Applied egg-rr99.9%
associate-*l/99.9%
sqrt-unprod100.0%
associate--r-100.0%
Applied egg-rr100.0%
+-commutative100.0%
associate-+r-100.0%
metadata-eval100.0%
Simplified100.0%
add-cbrt-cube98.4%
pow1/3100.0%
add-sqr-sqrt100.0%
pow1100.0%
pow1/2100.0%
pow-prod-up100.0%
metadata-eval100.0%
Applied egg-rr100.0%
(FPCore (v) :precision binary64 (* (- 1.0 (* v v)) (/ (sqrt (* 2.0 (- 2.0 (fma 3.0 (pow v 2.0) 1.0)))) 4.0)))
double code(double v) {
return (1.0 - (v * v)) * (sqrt((2.0 * (2.0 - fma(3.0, pow(v, 2.0), 1.0)))) / 4.0);
}
function code(v) return Float64(Float64(1.0 - Float64(v * v)) * Float64(sqrt(Float64(2.0 * Float64(2.0 - fma(3.0, (v ^ 2.0), 1.0)))) / 4.0)) end
code[v_] := N[(N[(1.0 - N[(v * v), $MachinePrecision]), $MachinePrecision] * N[(N[Sqrt[N[(2.0 * N[(2.0 - N[(3.0 * N[Power[v, 2.0], $MachinePrecision] + 1.0), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]], $MachinePrecision] / 4.0), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\left(1 - v \cdot v\right) \cdot \frac{\sqrt{2 \cdot \left(2 - \mathsf{fma}\left(3, {v}^{2}, 1\right)\right)}}{4}
\end{array}
Initial program 99.9%
expm1-log1p-u99.9%
expm1-undefine99.9%
log1p-undefine99.9%
add-exp-log99.9%
+-commutative99.9%
fma-define99.9%
pow299.9%
Applied egg-rr99.9%
associate-*l/99.9%
sqrt-unprod100.0%
associate--r-100.0%
Applied egg-rr100.0%
+-commutative100.0%
associate-+r-100.0%
metadata-eval100.0%
Simplified100.0%
Final simplification100.0%
(FPCore (v) :precision binary64 (* (- 1.0 (* v v)) (/ (sqrt (+ 2.0 (* (pow v 2.0) -6.0))) 4.0)))
double code(double v) {
return (1.0 - (v * v)) * (sqrt((2.0 + (pow(v, 2.0) * -6.0))) / 4.0);
}
real(8) function code(v)
real(8), intent (in) :: v
code = (1.0d0 - (v * v)) * (sqrt((2.0d0 + ((v ** 2.0d0) * (-6.0d0)))) / 4.0d0)
end function
public static double code(double v) {
return (1.0 - (v * v)) * (Math.sqrt((2.0 + (Math.pow(v, 2.0) * -6.0))) / 4.0);
}
def code(v): return (1.0 - (v * v)) * (math.sqrt((2.0 + (math.pow(v, 2.0) * -6.0))) / 4.0)
function code(v) return Float64(Float64(1.0 - Float64(v * v)) * Float64(sqrt(Float64(2.0 + Float64((v ^ 2.0) * -6.0))) / 4.0)) end
function tmp = code(v) tmp = (1.0 - (v * v)) * (sqrt((2.0 + ((v ^ 2.0) * -6.0))) / 4.0); end
code[v_] := N[(N[(1.0 - N[(v * v), $MachinePrecision]), $MachinePrecision] * N[(N[Sqrt[N[(2.0 + N[(N[Power[v, 2.0], $MachinePrecision] * -6.0), $MachinePrecision]), $MachinePrecision]], $MachinePrecision] / 4.0), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\left(1 - v \cdot v\right) \cdot \frac{\sqrt{2 + {v}^{2} \cdot -6}}{4}
\end{array}
Initial program 99.9%
expm1-log1p-u99.9%
expm1-undefine99.9%
log1p-undefine99.9%
add-exp-log99.9%
+-commutative99.9%
fma-define99.9%
pow299.9%
Applied egg-rr99.9%
associate-*l/99.9%
sqrt-unprod100.0%
associate--r-100.0%
Applied egg-rr100.0%
+-commutative100.0%
associate-+r-100.0%
metadata-eval100.0%
Simplified100.0%
Taylor expanded in v around 0 100.0%
*-un-lft-identity100.0%
distribute-lft-in100.0%
metadata-eval100.0%
associate-*r*100.0%
metadata-eval100.0%
Applied egg-rr100.0%
*-lft-identity100.0%
*-commutative100.0%
Simplified100.0%
Final simplification100.0%
(FPCore (v) :precision binary64 (* (sqrt 2.0) (+ 0.25 (* (pow v 2.0) -0.625))))
double code(double v) {
return sqrt(2.0) * (0.25 + (pow(v, 2.0) * -0.625));
}
real(8) function code(v)
real(8), intent (in) :: v
code = sqrt(2.0d0) * (0.25d0 + ((v ** 2.0d0) * (-0.625d0)))
end function
public static double code(double v) {
return Math.sqrt(2.0) * (0.25 + (Math.pow(v, 2.0) * -0.625));
}
def code(v): return math.sqrt(2.0) * (0.25 + (math.pow(v, 2.0) * -0.625))
function code(v) return Float64(sqrt(2.0) * Float64(0.25 + Float64((v ^ 2.0) * -0.625))) end
function tmp = code(v) tmp = sqrt(2.0) * (0.25 + ((v ^ 2.0) * -0.625)); end
code[v_] := N[(N[Sqrt[2.0], $MachinePrecision] * N[(0.25 + N[(N[Power[v, 2.0], $MachinePrecision] * -0.625), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\sqrt{2} \cdot \left(0.25 + {v}^{2} \cdot -0.625\right)
\end{array}
Initial program 99.9%
Taylor expanded in v around 0 98.9%
+-commutative98.9%
associate-*r*98.9%
distribute-rgt-out98.9%
*-commutative98.9%
Simplified98.9%
Taylor expanded in v around 0 99.0%
+-commutative99.0%
associate-*r*99.0%
distribute-rgt-out99.0%
Simplified99.0%
Final simplification99.0%
(FPCore (v) :precision binary64 (* (- 1.0 (* v v)) (* (sqrt 2.0) 0.25)))
double code(double v) {
return (1.0 - (v * v)) * (sqrt(2.0) * 0.25);
}
real(8) function code(v)
real(8), intent (in) :: v
code = (1.0d0 - (v * v)) * (sqrt(2.0d0) * 0.25d0)
end function
public static double code(double v) {
return (1.0 - (v * v)) * (Math.sqrt(2.0) * 0.25);
}
def code(v): return (1.0 - (v * v)) * (math.sqrt(2.0) * 0.25)
function code(v) return Float64(Float64(1.0 - Float64(v * v)) * Float64(sqrt(2.0) * 0.25)) end
function tmp = code(v) tmp = (1.0 - (v * v)) * (sqrt(2.0) * 0.25); end
code[v_] := N[(N[(1.0 - N[(v * v), $MachinePrecision]), $MachinePrecision] * N[(N[Sqrt[2.0], $MachinePrecision] * 0.25), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\left(1 - v \cdot v\right) \cdot \left(\sqrt{2} \cdot 0.25\right)
\end{array}
Initial program 99.9%
Taylor expanded in v around 0 97.9%
Final simplification97.9%
(FPCore (v) :precision binary64 (sqrt 0.125))
double code(double v) {
return sqrt(0.125);
}
real(8) function code(v)
real(8), intent (in) :: v
code = sqrt(0.125d0)
end function
public static double code(double v) {
return Math.sqrt(0.125);
}
def code(v): return math.sqrt(0.125)
function code(v) return sqrt(0.125) end
function tmp = code(v) tmp = sqrt(0.125); end
code[v_] := N[Sqrt[0.125], $MachinePrecision]
\begin{array}{l}
\\
\sqrt{0.125}
\end{array}
Initial program 99.9%
Taylor expanded in v around 0 97.9%
add-sqr-sqrt96.4%
pow296.4%
*-commutative96.4%
metadata-eval96.4%
div-inv96.4%
add-sqr-sqrt96.4%
sqrt-unprod96.4%
frac-times96.4%
rem-square-sqrt96.4%
metadata-eval96.4%
metadata-eval96.4%
pow296.4%
Applied egg-rr96.4%
Taylor expanded in v around 0 97.8%
herbie shell --seed 2024090
(FPCore (v)
:name "Falkner and Boettcher, Appendix B, 2"
:precision binary64
(* (* (/ (sqrt 2.0) 4.0) (sqrt (- 1.0 (* 3.0 (* v v))))) (- 1.0 (* v v))))