
(FPCore (x) :precision binary64 (sqrt (* 2.0 (* x x))))
double code(double x) {
return sqrt((2.0 * (x * x)));
}
real(8) function code(x)
real(8), intent (in) :: x
code = sqrt((2.0d0 * (x * x)))
end function
public static double code(double x) {
return Math.sqrt((2.0 * (x * x)));
}
def code(x): return math.sqrt((2.0 * (x * x)))
function code(x) return sqrt(Float64(2.0 * Float64(x * x))) end
function tmp = code(x) tmp = sqrt((2.0 * (x * x))); end
code[x_] := N[Sqrt[N[(2.0 * N[(x * x), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]
\begin{array}{l}
\\
\sqrt{2 \cdot \left(x \cdot x\right)}
\end{array}
Sampling outcomes in binary64 precision:
Herbie found 4 alternatives:
| Alternative | Accuracy | Speedup |
|---|
(FPCore (x) :precision binary64 (sqrt (* 2.0 (* x x))))
double code(double x) {
return sqrt((2.0 * (x * x)));
}
real(8) function code(x)
real(8), intent (in) :: x
code = sqrt((2.0d0 * (x * x)))
end function
public static double code(double x) {
return Math.sqrt((2.0 * (x * x)));
}
def code(x): return math.sqrt((2.0 * (x * x)))
function code(x) return sqrt(Float64(2.0 * Float64(x * x))) end
function tmp = code(x) tmp = sqrt((2.0 * (x * x))); end
code[x_] := N[Sqrt[N[(2.0 * N[(x * x), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]
\begin{array}{l}
\\
\sqrt{2 \cdot \left(x \cdot x\right)}
\end{array}
x_m = (fabs.f64 x) (FPCore (x_m) :precision binary64 (* (sqrt (* 2.0 x_m)) (sqrt x_m)))
x_m = fabs(x);
double code(double x_m) {
return sqrt((2.0 * x_m)) * sqrt(x_m);
}
x_m = abs(x)
real(8) function code(x_m)
real(8), intent (in) :: x_m
code = sqrt((2.0d0 * x_m)) * sqrt(x_m)
end function
x_m = Math.abs(x);
public static double code(double x_m) {
return Math.sqrt((2.0 * x_m)) * Math.sqrt(x_m);
}
x_m = math.fabs(x) def code(x_m): return math.sqrt((2.0 * x_m)) * math.sqrt(x_m)
x_m = abs(x) function code(x_m) return Float64(sqrt(Float64(2.0 * x_m)) * sqrt(x_m)) end
x_m = abs(x); function tmp = code(x_m) tmp = sqrt((2.0 * x_m)) * sqrt(x_m); end
x_m = N[Abs[x], $MachinePrecision] code[x$95$m_] := N[(N[Sqrt[N[(2.0 * x$95$m), $MachinePrecision]], $MachinePrecision] * N[Sqrt[x$95$m], $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
x_m = \left|x\right|
\\
\sqrt{2 \cdot x\_m} \cdot \sqrt{x\_m}
\end{array}
Initial program 53.5%
pow1/2N/A
associate-*r*N/A
unpow-prod-downN/A
*-lowering-*.f64N/A
pow-lowering-pow.f64N/A
*-lowering-*.f64N/A
pow1/2N/A
sqrt-lowering-sqrt.f6451.3%
Applied egg-rr51.3%
unpow1/2N/A
sqrt-lowering-sqrt.f64N/A
*-lowering-*.f6451.3%
Applied egg-rr51.3%
x_m = (fabs.f64 x) (FPCore (x_m) :precision binary64 (/ (sqrt 2.0) (/ 1.0 x_m)))
x_m = fabs(x);
double code(double x_m) {
return sqrt(2.0) / (1.0 / x_m);
}
x_m = abs(x)
real(8) function code(x_m)
real(8), intent (in) :: x_m
code = sqrt(2.0d0) / (1.0d0 / x_m)
end function
x_m = Math.abs(x);
public static double code(double x_m) {
return Math.sqrt(2.0) / (1.0 / x_m);
}
x_m = math.fabs(x) def code(x_m): return math.sqrt(2.0) / (1.0 / x_m)
x_m = abs(x) function code(x_m) return Float64(sqrt(2.0) / Float64(1.0 / x_m)) end
x_m = abs(x); function tmp = code(x_m) tmp = sqrt(2.0) / (1.0 / x_m); end
x_m = N[Abs[x], $MachinePrecision] code[x$95$m_] := N[(N[Sqrt[2.0], $MachinePrecision] / N[(1.0 / x$95$m), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
x_m = \left|x\right|
\\
\frac{\sqrt{2}}{\frac{1}{x\_m}}
\end{array}
Initial program 53.5%
pow1/2N/A
associate-*r*N/A
unpow-prod-downN/A
*-lowering-*.f64N/A
pow-lowering-pow.f64N/A
*-lowering-*.f64N/A
pow1/2N/A
sqrt-lowering-sqrt.f6451.3%
Applied egg-rr51.3%
unpow1/2N/A
sqrt-lowering-sqrt.f64N/A
*-lowering-*.f6451.3%
Applied egg-rr51.3%
sqrt-prodN/A
pow1/2N/A
associate-*l*N/A
rem-square-sqrtN/A
metadata-evalN/A
pow-sqrN/A
pow-prod-downN/A
metadata-evalN/A
metadata-evalN/A
pow-to-expN/A
neg-logN/A
distribute-lft-neg-inN/A
rec-expN/A
pow-to-expN/A
associate-/r/N/A
div-invN/A
associate-/r*N/A
/-lowering-/.f64N/A
Applied egg-rr52.2%
x_m = (fabs.f64 x) (FPCore (x_m) :precision binary64 (/ x_m (pow 0.25 0.25)))
x_m = fabs(x);
double code(double x_m) {
return x_m / pow(0.25, 0.25);
}
x_m = abs(x)
real(8) function code(x_m)
real(8), intent (in) :: x_m
code = x_m / (0.25d0 ** 0.25d0)
end function
x_m = Math.abs(x);
public static double code(double x_m) {
return x_m / Math.pow(0.25, 0.25);
}
x_m = math.fabs(x) def code(x_m): return x_m / math.pow(0.25, 0.25)
x_m = abs(x) function code(x_m) return Float64(x_m / (0.25 ^ 0.25)) end
x_m = abs(x); function tmp = code(x_m) tmp = x_m / (0.25 ^ 0.25); end
x_m = N[Abs[x], $MachinePrecision] code[x$95$m_] := N[(x$95$m / N[Power[0.25, 0.25], $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
x_m = \left|x\right|
\\
\frac{x\_m}{{0.25}^{0.25}}
\end{array}
Initial program 53.5%
pow1/2N/A
rem-square-sqrtN/A
pow1/2N/A
pow1/2N/A
associate-*l*N/A
associate-*r*N/A
unpow-prod-downN/A
unpow-prod-downN/A
pow1/2N/A
sqrt-pow2N/A
*-commutativeN/A
*-lowering-*.f64N/A
Applied egg-rr51.3%
Taylor expanded in x around 0
exp-to-powN/A
*-commutativeN/A
rem-exp-logN/A
prod-expN/A
+-commutativeN/A
remove-double-negN/A
sub-negN/A
exp-diffN/A
rem-exp-logN/A
/-lowering-/.f64N/A
*-commutativeN/A
distribute-lft-neg-inN/A
exp-prodN/A
exp-negN/A
rem-exp-logN/A
metadata-evalN/A
pow-lowering-pow.f6452.2%
Simplified52.2%
x_m = (fabs.f64 x) (FPCore (x_m) :precision binary64 (* x_m (sqrt 2.0)))
x_m = fabs(x);
double code(double x_m) {
return x_m * sqrt(2.0);
}
x_m = abs(x)
real(8) function code(x_m)
real(8), intent (in) :: x_m
code = x_m * sqrt(2.0d0)
end function
x_m = Math.abs(x);
public static double code(double x_m) {
return x_m * Math.sqrt(2.0);
}
x_m = math.fabs(x) def code(x_m): return x_m * math.sqrt(2.0)
x_m = abs(x) function code(x_m) return Float64(x_m * sqrt(2.0)) end
x_m = abs(x); function tmp = code(x_m) tmp = x_m * sqrt(2.0); end
x_m = N[Abs[x], $MachinePrecision] code[x$95$m_] := N[(x$95$m * N[Sqrt[2.0], $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
x_m = \left|x\right|
\\
x\_m \cdot \sqrt{2}
\end{array}
Initial program 53.5%
sqrt-prodN/A
pow1/2N/A
sqrt-prodN/A
rem-square-sqrtN/A
*-lowering-*.f64N/A
pow1/2N/A
sqrt-lowering-sqrt.f6452.2%
Applied egg-rr52.2%
Final simplification52.2%
herbie shell --seed 2024161
(FPCore (x)
:name "sqrt C (should all be same)"
:precision binary64
(sqrt (* 2.0 (* x x))))