sqrt D (should all be same)

Percentage Accurate: 53.8% → 99.5%

Time: 11.6s

Alternatives: 6

Speedup: 4.9×

Specification

Math

\[\begin{array}{l} \\ \sqrt{2 \cdot {x}^{2}} \end{array} \]

FPCore

(FPCore (x) :precision binary64 (sqrt (* 2.0 (pow x 2.0))))

C

double code(double x) {
	return sqrt((2.0 * pow(x, 2.0)));
}

Fortran

real(8) function code(x)
    real(8), intent (in) :: x
    code = sqrt((2.0d0 * (x ** 2.0d0)))
end function

Java

public static double code(double x) {
	return Math.sqrt((2.0 * Math.pow(x, 2.0)));
}

Python

def code(x):
	return math.sqrt((2.0 * math.pow(x, 2.0)))

Julia

function code(x)
	return sqrt(Float64(2.0 * (x ^ 2.0)))
end

MATLAB

function tmp = code(x)
	tmp = sqrt((2.0 * (x ^ 2.0)));
end

Wolfram

code[x_] := N[Sqrt[N[(2.0 * N[Power[x, 2.0], $MachinePrecision]), $MachinePrecision]], $MachinePrecision]

Initial Program: 53.8% accurate, 1.0× speedup

Math

\[\begin{array}{l} \\ \sqrt{2 \cdot {x}^{2}} \end{array} \]

FPCore

(FPCore (x) :precision binary64 (sqrt (* 2.0 (pow x 2.0))))

C

double code(double x) {
	return sqrt((2.0 * pow(x, 2.0)));
}

Fortran

real(8) function code(x)
    real(8), intent (in) :: x
    code = sqrt((2.0d0 * (x ** 2.0d0)))
end function

Java

public static double code(double x) {
	return Math.sqrt((2.0 * Math.pow(x, 2.0)));
}

Python

def code(x):
	return math.sqrt((2.0 * math.pow(x, 2.0)))

Julia

function code(x)
	return sqrt(Float64(2.0 * (x ^ 2.0)))
end

MATLAB

function tmp = code(x)
	tmp = sqrt((2.0 * (x ^ 2.0)));
end

Wolfram

code[x_] := N[Sqrt[N[(2.0 * N[Power[x, 2.0], $MachinePrecision]), $MachinePrecision]], $MachinePrecision]

Alternative 1: 99.5% accurate, 0.4× speedup

Math

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;x \leq -1 \cdot 10^{-310}:\\ \;\;\;\;\left(\left(-x\right) \cdot {64}^{0.0625}\right) \cdot {16}^{0.03125}\\ \mathbf{else}:\\ \;\;\;\;\left(\left({4}^{0.125} \cdot x\right) \cdot {4}^{0.0625}\right) \cdot {4}^{0.0625}\\ \end{array} \end{array} \]

FPCore

(FPCore (x)
 :precision binary64
 (if (<= x -1e-310)
   (* (* (- x) (pow 64.0 0.0625)) (pow 16.0 0.03125))
   (* (* (* (pow 4.0 0.125) x) (pow 4.0 0.0625)) (pow 4.0 0.0625))))

C

double code(double x) {
	double tmp;
	if (x <= -1e-310) {
		tmp = (-x * pow(64.0, 0.0625)) * pow(16.0, 0.03125);
	} else {
		tmp = ((pow(4.0, 0.125) * x) * pow(4.0, 0.0625)) * pow(4.0, 0.0625);
	}
	return tmp;
}

Fortran

real(8) function code(x)
    real(8), intent (in) :: x
    real(8) :: tmp
    if (x <= (-1d-310)) then
        tmp = (-x * (64.0d0 ** 0.0625d0)) * (16.0d0 ** 0.03125d0)
    else
        tmp = (((4.0d0 ** 0.125d0) * x) * (4.0d0 ** 0.0625d0)) * (4.0d0 ** 0.0625d0)
    end if
    code = tmp
end function

Java

public static double code(double x) {
	double tmp;
	if (x <= -1e-310) {
		tmp = (-x * Math.pow(64.0, 0.0625)) * Math.pow(16.0, 0.03125);
	} else {
		tmp = ((Math.pow(4.0, 0.125) * x) * Math.pow(4.0, 0.0625)) * Math.pow(4.0, 0.0625);
	}
	return tmp;
}

Python

def code(x):
	tmp = 0
	if x <= -1e-310:
		tmp = (-x * math.pow(64.0, 0.0625)) * math.pow(16.0, 0.03125)
	else:
		tmp = ((math.pow(4.0, 0.125) * x) * math.pow(4.0, 0.0625)) * math.pow(4.0, 0.0625)
	return tmp

Julia

function code(x)
	tmp = 0.0
	if (x <= -1e-310)
		tmp = Float64(Float64(Float64(-x) * (64.0 ^ 0.0625)) * (16.0 ^ 0.03125));
	else
		tmp = Float64(Float64(Float64((4.0 ^ 0.125) * x) * (4.0 ^ 0.0625)) * (4.0 ^ 0.0625));
	end
	return tmp
end

MATLAB

function tmp_2 = code(x)
	tmp = 0.0;
	if (x <= -1e-310)
		tmp = (-x * (64.0 ^ 0.0625)) * (16.0 ^ 0.03125);
	else
		tmp = (((4.0 ^ 0.125) * x) * (4.0 ^ 0.0625)) * (4.0 ^ 0.0625);
	end
	tmp_2 = tmp;
end

Wolfram

code[x_] := If[LessEqual[x, -1e-310], N[(N[((-x) * N[Power[64.0, 0.0625], $MachinePrecision]), $MachinePrecision] * N[Power[16.0, 0.03125], $MachinePrecision]), $MachinePrecision], N[(N[(N[(N[Power[4.0, 0.125], $MachinePrecision] * x), $MachinePrecision] * N[Power[4.0, 0.0625], $MachinePrecision]), $MachinePrecision] * N[Power[4.0, 0.0625], $MachinePrecision]), $MachinePrecision]]

Derivation

1. Split input into 2 regimes

2. if x < -9.999999999999969e-311

   1. Initial program 53.4%

      \[\sqrt{2 \cdot {x}^{2}} \]
   2. Add Preprocessing

   3. Taylor expanded in x around -inf

      \[\leadsto \color{blue}{-1 \cdot \left(x \cdot \sqrt{2}\right)} \]
   4. Step-by-step derivation

      1. associate-*r* N/A

         \[\leadsto \color{blue}{\left(-1 \cdot x\right) \cdot \sqrt{2}} \]

      2. lower-*.f64 N/A

         \[\leadsto \color{blue}{\left(-1 \cdot x\right) \cdot \sqrt{2}} \]

      3. mul-1-neg N/A

         \[\leadsto \color{blue}{\left(\mathsf{neg}\left(x\right)\right)} \cdot \sqrt{2} \]

      4. lower-neg.f64 N/A

         \[\leadsto \color{blue}{\left(-x\right)} \cdot \sqrt{2} \]

      5. lower-sqrt.f64 99.3

         \[\leadsto \left(-x\right) \cdot \color{blue}{\sqrt{2}} \]

   5. Applied rewrites 99.3%

      \[\leadsto \color{blue}{\left(-x\right) \cdot \sqrt{2}} \]
   6. Step-by-step derivation

   7. Applied rewrites 99.1%

      \[\leadsto \left(-x\right) \cdot {\left({4}^{0.125}\right)}^{\color{blue}{2}} \]
   8. Step-by-step derivation

   9. Applied rewrites 99.6%

      \[\leadsto {16}^{0.03125} \cdot \color{blue}{\left({64}^{0.0625} \cdot \left(-x\right)\right)} \]

   if -9.999999999999969e-311 < x

   1. Initial program 57.0%

      \[\sqrt{2 \cdot {x}^{2}} \]
   2. Add Preprocessing

   4. Applied rewrites 99.3%

      \[\leadsto \color{blue}{\sqrt{2} \cdot x} \]
   5. Step-by-step derivation

      1. lift-*.f64 N/A

         \[\leadsto \color{blue}{\sqrt{2} \cdot x} \]

      2. lift-sqrt.f64 N/A

         \[\leadsto \color{blue}{\sqrt{2}} \cdot x \]

      3. pow1/2 N/A

         \[\leadsto \color{blue}{{2}^{\frac{1}{2}}} \cdot x \]

      4. sqr-pow N/A

         \[\leadsto \color{blue}{\left({2}^{\left(\frac{\frac{1}{2}}{2}\right)} \cdot {2}^{\left(\frac{\frac{1}{2}}{2}\right)}\right)} \cdot x \]

      5. associate-*l* N/A

         \[\leadsto \color{blue}{{2}^{\left(\frac{\frac{1}{2}}{2}\right)} \cdot \left({2}^{\left(\frac{\frac{1}{2}}{2}\right)} \cdot x\right)} \]

      6. sqr-pow N/A

         \[\leadsto \color{blue}{\left({2}^{\left(\frac{\frac{\frac{1}{2}}{2}}{2}\right)} \cdot {2}^{\left(\frac{\frac{\frac{1}{2}}{2}}{2}\right)}\right)} \cdot \left({2}^{\left(\frac{\frac{1}{2}}{2}\right)} \cdot x\right) \]

      7. associate-*l* N/A

         \[\leadsto \color{blue}{{2}^{\left(\frac{\frac{\frac{1}{2}}{2}}{2}\right)} \cdot \left({2}^{\left(\frac{\frac{\frac{1}{2}}{2}}{2}\right)} \cdot \left({2}^{\left(\frac{\frac{1}{2}}{2}\right)} \cdot x\right)\right)} \]

      8. lower-*.f64 N/A

         \[\leadsto \color{blue}{{2}^{\left(\frac{\frac{\frac{1}{2}}{2}}{2}\right)} \cdot \left({2}^{\left(\frac{\frac{\frac{1}{2}}{2}}{2}\right)} \cdot \left({2}^{\left(\frac{\frac{1}{2}}{2}\right)} \cdot x\right)\right)} \]

      9. sqr-pow N/A

         \[\leadsto \color{blue}{\left({2}^{\left(\frac{\frac{\frac{\frac{1}{2}}{2}}{2}}{2}\right)} \cdot {2}^{\left(\frac{\frac{\frac{\frac{1}{2}}{2}}{2}}{2}\right)}\right)} \cdot \left({2}^{\left(\frac{\frac{\frac{1}{2}}{2}}{2}\right)} \cdot \left({2}^{\left(\frac{\frac{1}{2}}{2}\right)} \cdot x\right)\right) \]

      10. pow-prod-down N/A

          \[\leadsto \color{blue}{{\left(2 \cdot 2\right)}^{\left(\frac{\frac{\frac{\frac{1}{2}}{2}}{2}}{2}\right)}} \cdot \left({2}^{\left(\frac{\frac{\frac{1}{2}}{2}}{2}\right)} \cdot \left({2}^{\left(\frac{\frac{1}{2}}{2}\right)} \cdot x\right)\right) \]

      11. lower-pow.f64 N/A

          \[\leadsto \color{blue}{{\left(2 \cdot 2\right)}^{\left(\frac{\frac{\frac{\frac{1}{2}}{2}}{2}}{2}\right)}} \cdot \left({2}^{\left(\frac{\frac{\frac{1}{2}}{2}}{2}\right)} \cdot \left({2}^{\left(\frac{\frac{1}{2}}{2}\right)} \cdot x\right)\right) \]

      12. metadata-eval N/A

          \[\leadsto {\color{blue}{4}}^{\left(\frac{\frac{\frac{\frac{1}{2}}{2}}{2}}{2}\right)} \cdot \left({2}^{\left(\frac{\frac{\frac{1}{2}}{2}}{2}\right)} \cdot \left({2}^{\left(\frac{\frac{1}{2}}{2}\right)} \cdot x\right)\right) \]

      13. metadata-eval N/A

          \[\leadsto {4}^{\left(\frac{\frac{\color{blue}{\frac{1}{4}}}{2}}{2}\right)} \cdot \left({2}^{\left(\frac{\frac{\frac{1}{2}}{2}}{2}\right)} \cdot \left({2}^{\left(\frac{\frac{1}{2}}{2}\right)} \cdot x\right)\right) \]

      14. metadata-eval N/A

          \[\leadsto {4}^{\left(\frac{\color{blue}{\frac{1}{8}}}{2}\right)} \cdot \left({2}^{\left(\frac{\frac{\frac{1}{2}}{2}}{2}\right)} \cdot \left({2}^{\left(\frac{\frac{1}{2}}{2}\right)} \cdot x\right)\right) \]

      15. metadata-eval N/A

          \[\leadsto {4}^{\color{blue}{\frac{1}{16}}} \cdot \left({2}^{\left(\frac{\frac{\frac{1}{2}}{2}}{2}\right)} \cdot \left({2}^{\left(\frac{\frac{1}{2}}{2}\right)} \cdot x\right)\right) \]

      16. *-commutative N/A

          \[\leadsto {4}^{\frac{1}{16}} \cdot \left({2}^{\left(\frac{\frac{\frac{1}{2}}{2}}{2}\right)} \cdot \color{blue}{\left(x \cdot {2}^{\left(\frac{\frac{1}{2}}{2}\right)}\right)}\right) \]

      17. lower-*.f64 N/A

          \[\leadsto {4}^{\frac{1}{16}} \cdot \color{blue}{\left({2}^{\left(\frac{\frac{\frac{1}{2}}{2}}{2}\right)} \cdot \left(x \cdot {2}^{\left(\frac{\frac{1}{2}}{2}\right)}\right)\right)} \]

   6. Applied rewrites 99.5%

      \[\leadsto \color{blue}{{4}^{0.0625} \cdot \left({4}^{0.0625} \cdot \left({4}^{0.125} \cdot x\right)\right)} \]
3. Recombined 2 regimes into one program.

4. Final simplification 99.5%

   \[\leadsto \begin{array}{l} \mathbf{if}\;x \leq -1 \cdot 10^{-310}:\\ \;\;\;\;\left(\left(-x\right) \cdot {64}^{0.0625}\right) \cdot {16}^{0.03125}\\ \mathbf{else}:\\ \;\;\;\;\left(\left({4}^{0.125} \cdot x\right) \cdot {4}^{0.0625}\right) \cdot {4}^{0.0625}\\ \end{array} \]
5. Add Preprocessing

Alternative 2: 99.5% accurate, 0.5× speedup

Math

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;x \leq -1 \cdot 10^{-310}:\\ \;\;\;\;\left(\left(-x\right) \cdot {64}^{0.0625}\right) \cdot {16}^{0.03125}\\ \mathbf{else}:\\ \;\;\;\;\sqrt{x} \cdot \sqrt{2 \cdot x}\\ \end{array} \end{array} \]

FPCore

(FPCore (x)
 :precision binary64
 (if (<= x -1e-310)
   (* (* (- x) (pow 64.0 0.0625)) (pow 16.0 0.03125))
   (* (sqrt x) (sqrt (* 2.0 x)))))

C

double code(double x) {
	double tmp;
	if (x <= -1e-310) {
		tmp = (-x * pow(64.0, 0.0625)) * pow(16.0, 0.03125);
	} else {
		tmp = sqrt(x) * sqrt((2.0 * x));
	}
	return tmp;
}

Fortran

real(8) function code(x)
    real(8), intent (in) :: x
    real(8) :: tmp
    if (x <= (-1d-310)) then
        tmp = (-x * (64.0d0 ** 0.0625d0)) * (16.0d0 ** 0.03125d0)
    else
        tmp = sqrt(x) * sqrt((2.0d0 * x))
    end if
    code = tmp
end function

Java

public static double code(double x) {
	double tmp;
	if (x <= -1e-310) {
		tmp = (-x * Math.pow(64.0, 0.0625)) * Math.pow(16.0, 0.03125);
	} else {
		tmp = Math.sqrt(x) * Math.sqrt((2.0 * x));
	}
	return tmp;
}

Python

def code(x):
	tmp = 0
	if x <= -1e-310:
		tmp = (-x * math.pow(64.0, 0.0625)) * math.pow(16.0, 0.03125)
	else:
		tmp = math.sqrt(x) * math.sqrt((2.0 * x))
	return tmp

Julia

function code(x)
	tmp = 0.0
	if (x <= -1e-310)
		tmp = Float64(Float64(Float64(-x) * (64.0 ^ 0.0625)) * (16.0 ^ 0.03125));
	else
		tmp = Float64(sqrt(x) * sqrt(Float64(2.0 * x)));
	end
	return tmp
end

MATLAB

function tmp_2 = code(x)
	tmp = 0.0;
	if (x <= -1e-310)
		tmp = (-x * (64.0 ^ 0.0625)) * (16.0 ^ 0.03125);
	else
		tmp = sqrt(x) * sqrt((2.0 * x));
	end
	tmp_2 = tmp;
end

Wolfram

code[x_] := If[LessEqual[x, -1e-310], N[(N[((-x) * N[Power[64.0, 0.0625], $MachinePrecision]), $MachinePrecision] * N[Power[16.0, 0.03125], $MachinePrecision]), $MachinePrecision], N[(N[Sqrt[x], $MachinePrecision] * N[Sqrt[N[(2.0 * x), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]]

Derivation

1. Split input into 2 regimes

2. if x < -9.999999999999969e-311

   1. Initial program 53.4%

      \[\sqrt{2 \cdot {x}^{2}} \]
   2. Add Preprocessing

   3. Taylor expanded in x around -inf

      \[\leadsto \color{blue}{-1 \cdot \left(x \cdot \sqrt{2}\right)} \]
   4. Step-by-step derivation

      1. associate-*r* N/A

         \[\leadsto \color{blue}{\left(-1 \cdot x\right) \cdot \sqrt{2}} \]

      2. lower-*.f64 N/A

         \[\leadsto \color{blue}{\left(-1 \cdot x\right) \cdot \sqrt{2}} \]

      3. mul-1-neg N/A

         \[\leadsto \color{blue}{\left(\mathsf{neg}\left(x\right)\right)} \cdot \sqrt{2} \]

      4. lower-neg.f64 N/A

         \[\leadsto \color{blue}{\left(-x\right)} \cdot \sqrt{2} \]

      5. lower-sqrt.f64 99.3

         \[\leadsto \left(-x\right) \cdot \color{blue}{\sqrt{2}} \]

   5. Applied rewrites 99.3%

      \[\leadsto \color{blue}{\left(-x\right) \cdot \sqrt{2}} \]
   6. Step-by-step derivation

   7. Applied rewrites 99.1%

      \[\leadsto \left(-x\right) \cdot {\left({4}^{0.125}\right)}^{\color{blue}{2}} \]
   8. Step-by-step derivation

   9. Applied rewrites 99.6%

      \[\leadsto {16}^{0.03125} \cdot \color{blue}{\left({64}^{0.0625} \cdot \left(-x\right)\right)} \]

   if -9.999999999999969e-311 < x

   1. Initial program 57.0%

      \[\sqrt{2 \cdot {x}^{2}} \]
   2. Add Preprocessing

   4. Applied rewrites 99.3%

      \[\leadsto \color{blue}{\sqrt{2} \cdot x} \]
   5. Step-by-step derivation

      1. lift-*.f64 N/A

         \[\leadsto \color{blue}{\sqrt{2} \cdot x} \]

      2. unpow1 N/A

         \[\leadsto \sqrt{2} \cdot \color{blue}{{x}^{1}} \]

      3. metadata-eval N/A

         \[\leadsto \sqrt{2} \cdot {x}^{\color{blue}{\left(\frac{2}{2}\right)}} \]

      4. sqr-pow N/A

         \[\leadsto \sqrt{2} \cdot \color{blue}{\left({x}^{\left(\frac{\frac{2}{2}}{2}\right)} \cdot {x}^{\left(\frac{\frac{2}{2}}{2}\right)}\right)} \]

      5. associate-*r* N/A

         \[\leadsto \color{blue}{\left(\sqrt{2} \cdot {x}^{\left(\frac{\frac{2}{2}}{2}\right)}\right) \cdot {x}^{\left(\frac{\frac{2}{2}}{2}\right)}} \]

      6. lift-sqrt.f64 N/A

         \[\leadsto \left(\color{blue}{\sqrt{2}} \cdot {x}^{\left(\frac{\frac{2}{2}}{2}\right)}\right) \cdot {x}^{\left(\frac{\frac{2}{2}}{2}\right)} \]

      7. pow1/2 N/A

         \[\leadsto \left(\color{blue}{{2}^{\frac{1}{2}}} \cdot {x}^{\left(\frac{\frac{2}{2}}{2}\right)}\right) \cdot {x}^{\left(\frac{\frac{2}{2}}{2}\right)} \]

      8. metadata-eval N/A

         \[\leadsto \left({2}^{\frac{1}{2}} \cdot {x}^{\left(\frac{\color{blue}{1}}{2}\right)}\right) \cdot {x}^{\left(\frac{\frac{2}{2}}{2}\right)} \]

      9. metadata-eval N/A

         \[\leadsto \left({2}^{\frac{1}{2}} \cdot {x}^{\color{blue}{\frac{1}{2}}}\right) \cdot {x}^{\left(\frac{\frac{2}{2}}{2}\right)} \]

      10. unpow-prod-down N/A

          \[\leadsto \color{blue}{{\left(2 \cdot x\right)}^{\frac{1}{2}}} \cdot {x}^{\left(\frac{\frac{2}{2}}{2}\right)} \]

      11. lower-*.f64 N/A

          \[\leadsto \color{blue}{{\left(2 \cdot x\right)}^{\frac{1}{2}} \cdot {x}^{\left(\frac{\frac{2}{2}}{2}\right)}} \]

      12. pow1/2 N/A

          \[\leadsto \color{blue}{\sqrt{2 \cdot x}} \cdot {x}^{\left(\frac{\frac{2}{2}}{2}\right)} \]

      13. lower-sqrt.f64 N/A

          \[\leadsto \color{blue}{\sqrt{2 \cdot x}} \cdot {x}^{\left(\frac{\frac{2}{2}}{2}\right)} \]

      14. *-commutative N/A

          \[\leadsto \sqrt{\color{blue}{x \cdot 2}} \cdot {x}^{\left(\frac{\frac{2}{2}}{2}\right)} \]

      15. lower-*.f64 N/A

          \[\leadsto \sqrt{\color{blue}{x \cdot 2}} \cdot {x}^{\left(\frac{\frac{2}{2}}{2}\right)} \]

      16. metadata-eval N/A

          \[\leadsto \sqrt{x \cdot 2} \cdot {x}^{\left(\frac{\color{blue}{1}}{2}\right)} \]

      17. metadata-eval N/A

          \[\leadsto \sqrt{x \cdot 2} \cdot {x}^{\color{blue}{\frac{1}{2}}} \]

      18. pow1/2 N/A

          \[\leadsto \sqrt{x \cdot 2} \cdot \color{blue}{\sqrt{x}} \]

      19. lower-sqrt.f64 99.4

          \[\leadsto \sqrt{x \cdot 2} \cdot \color{blue}{\sqrt{x}} \]

   6. Applied rewrites 99.4%

      \[\leadsto \color{blue}{\sqrt{x \cdot 2} \cdot \sqrt{x}} \]
3. Recombined 2 regimes into one program.

4. Final simplification 99.5%

   \[\leadsto \begin{array}{l} \mathbf{if}\;x \leq -1 \cdot 10^{-310}:\\ \;\;\;\;\left(\left(-x\right) \cdot {64}^{0.0625}\right) \cdot {16}^{0.03125}\\ \mathbf{else}:\\ \;\;\;\;\sqrt{x} \cdot \sqrt{2 \cdot x}\\ \end{array} \]
5. Add Preprocessing

Alternative 3: 99.4% accurate, 3.2× speedup

Math

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;x \leq -1 \cdot 10^{-310}:\\ \;\;\;\;\sqrt{2} \cdot \left(-x\right)\\ \mathbf{else}:\\ \;\;\;\;\sqrt{x} \cdot \sqrt{2 \cdot x}\\ \end{array} \end{array} \]

FPCore

(FPCore (x)
 :precision binary64
 (if (<= x -1e-310) (* (sqrt 2.0) (- x)) (* (sqrt x) (sqrt (* 2.0 x)))))

C

double code(double x) {
	double tmp;
	if (x <= -1e-310) {
		tmp = sqrt(2.0) * -x;
	} else {
		tmp = sqrt(x) * sqrt((2.0 * x));
	}
	return tmp;
}

Fortran

real(8) function code(x)
    real(8), intent (in) :: x
    real(8) :: tmp
    if (x <= (-1d-310)) then
        tmp = sqrt(2.0d0) * -x
    else
        tmp = sqrt(x) * sqrt((2.0d0 * x))
    end if
    code = tmp
end function

Java

public static double code(double x) {
	double tmp;
	if (x <= -1e-310) {
		tmp = Math.sqrt(2.0) * -x;
	} else {
		tmp = Math.sqrt(x) * Math.sqrt((2.0 * x));
	}
	return tmp;
}

Python

def code(x):
	tmp = 0
	if x <= -1e-310:
		tmp = math.sqrt(2.0) * -x
	else:
		tmp = math.sqrt(x) * math.sqrt((2.0 * x))
	return tmp

Julia

function code(x)
	tmp = 0.0
	if (x <= -1e-310)
		tmp = Float64(sqrt(2.0) * Float64(-x));
	else
		tmp = Float64(sqrt(x) * sqrt(Float64(2.0 * x)));
	end
	return tmp
end

MATLAB

function tmp_2 = code(x)
	tmp = 0.0;
	if (x <= -1e-310)
		tmp = sqrt(2.0) * -x;
	else
		tmp = sqrt(x) * sqrt((2.0 * x));
	end
	tmp_2 = tmp;
end

Wolfram

code[x_] := If[LessEqual[x, -1e-310], N[(N[Sqrt[2.0], $MachinePrecision] * (-x)), $MachinePrecision], N[(N[Sqrt[x], $MachinePrecision] * N[Sqrt[N[(2.0 * x), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]]

Derivation

1. Split input into 2 regimes

2. if x < -9.999999999999969e-311

   1. Initial program 53.4%

      \[\sqrt{2 \cdot {x}^{2}} \]
   2. Add Preprocessing

   3. Taylor expanded in x around -inf

      \[\leadsto \color{blue}{-1 \cdot \left(x \cdot \sqrt{2}\right)} \]
   4. Step-by-step derivation

      1. associate-*r* N/A

         \[\leadsto \color{blue}{\left(-1 \cdot x\right) \cdot \sqrt{2}} \]

      2. lower-*.f64 N/A

         \[\leadsto \color{blue}{\left(-1 \cdot x\right) \cdot \sqrt{2}} \]

      3. mul-1-neg N/A

         \[\leadsto \color{blue}{\left(\mathsf{neg}\left(x\right)\right)} \cdot \sqrt{2} \]

      4. lower-neg.f64 N/A

         \[\leadsto \color{blue}{\left(-x\right)} \cdot \sqrt{2} \]

      5. lower-sqrt.f64 99.3

         \[\leadsto \left(-x\right) \cdot \color{blue}{\sqrt{2}} \]

   5. Applied rewrites 99.3%

      \[\leadsto \color{blue}{\left(-x\right) \cdot \sqrt{2}} \]

   if -9.999999999999969e-311 < x

   1. Initial program 57.0%

      \[\sqrt{2 \cdot {x}^{2}} \]
   2. Add Preprocessing

   4. Applied rewrites 99.3%

      \[\leadsto \color{blue}{\sqrt{2} \cdot x} \]
   5. Step-by-step derivation

      1. lift-*.f64 N/A

         \[\leadsto \color{blue}{\sqrt{2} \cdot x} \]

      2. unpow1 N/A

         \[\leadsto \sqrt{2} \cdot \color{blue}{{x}^{1}} \]

      3. metadata-eval N/A

         \[\leadsto \sqrt{2} \cdot {x}^{\color{blue}{\left(\frac{2}{2}\right)}} \]

      4. sqr-pow N/A

         \[\leadsto \sqrt{2} \cdot \color{blue}{\left({x}^{\left(\frac{\frac{2}{2}}{2}\right)} \cdot {x}^{\left(\frac{\frac{2}{2}}{2}\right)}\right)} \]

      5. associate-*r* N/A

         \[\leadsto \color{blue}{\left(\sqrt{2} \cdot {x}^{\left(\frac{\frac{2}{2}}{2}\right)}\right) \cdot {x}^{\left(\frac{\frac{2}{2}}{2}\right)}} \]

      6. lift-sqrt.f64 N/A

         \[\leadsto \left(\color{blue}{\sqrt{2}} \cdot {x}^{\left(\frac{\frac{2}{2}}{2}\right)}\right) \cdot {x}^{\left(\frac{\frac{2}{2}}{2}\right)} \]

      7. pow1/2 N/A

         \[\leadsto \left(\color{blue}{{2}^{\frac{1}{2}}} \cdot {x}^{\left(\frac{\frac{2}{2}}{2}\right)}\right) \cdot {x}^{\left(\frac{\frac{2}{2}}{2}\right)} \]

      8. metadata-eval N/A

         \[\leadsto \left({2}^{\frac{1}{2}} \cdot {x}^{\left(\frac{\color{blue}{1}}{2}\right)}\right) \cdot {x}^{\left(\frac{\frac{2}{2}}{2}\right)} \]

      9. metadata-eval N/A

         \[\leadsto \left({2}^{\frac{1}{2}} \cdot {x}^{\color{blue}{\frac{1}{2}}}\right) \cdot {x}^{\left(\frac{\frac{2}{2}}{2}\right)} \]

      10. unpow-prod-down N/A

          \[\leadsto \color{blue}{{\left(2 \cdot x\right)}^{\frac{1}{2}}} \cdot {x}^{\left(\frac{\frac{2}{2}}{2}\right)} \]

      11. lower-*.f64 N/A

          \[\leadsto \color{blue}{{\left(2 \cdot x\right)}^{\frac{1}{2}} \cdot {x}^{\left(\frac{\frac{2}{2}}{2}\right)}} \]

      12. pow1/2 N/A

          \[\leadsto \color{blue}{\sqrt{2 \cdot x}} \cdot {x}^{\left(\frac{\frac{2}{2}}{2}\right)} \]

      13. lower-sqrt.f64 N/A

          \[\leadsto \color{blue}{\sqrt{2 \cdot x}} \cdot {x}^{\left(\frac{\frac{2}{2}}{2}\right)} \]

      14. *-commutative N/A

          \[\leadsto \sqrt{\color{blue}{x \cdot 2}} \cdot {x}^{\left(\frac{\frac{2}{2}}{2}\right)} \]

      15. lower-*.f64 N/A

          \[\leadsto \sqrt{\color{blue}{x \cdot 2}} \cdot {x}^{\left(\frac{\frac{2}{2}}{2}\right)} \]

      16. metadata-eval N/A

          \[\leadsto \sqrt{x \cdot 2} \cdot {x}^{\left(\frac{\color{blue}{1}}{2}\right)} \]

      17. metadata-eval N/A

          \[\leadsto \sqrt{x \cdot 2} \cdot {x}^{\color{blue}{\frac{1}{2}}} \]

      18. pow1/2 N/A

          \[\leadsto \sqrt{x \cdot 2} \cdot \color{blue}{\sqrt{x}} \]

      19. lower-sqrt.f64 99.4

          \[\leadsto \sqrt{x \cdot 2} \cdot \color{blue}{\sqrt{x}} \]

   6. Applied rewrites 99.4%

      \[\leadsto \color{blue}{\sqrt{x \cdot 2} \cdot \sqrt{x}} \]
3. Recombined 2 regimes into one program.

4. Final simplification 99.4%

   \[\leadsto \begin{array}{l} \mathbf{if}\;x \leq -1 \cdot 10^{-310}:\\ \;\;\;\;\sqrt{2} \cdot \left(-x\right)\\ \mathbf{else}:\\ \;\;\;\;\sqrt{x} \cdot \sqrt{2 \cdot x}\\ \end{array} \]
5. Add Preprocessing

Alternative 4: 99.3% accurate, 4.9× speedup

Math

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;x \leq -1 \cdot 10^{-310}:\\ \;\;\;\;\sqrt{2} \cdot \left(-x\right)\\ \mathbf{else}:\\ \;\;\;\;\sqrt{2} \cdot x\\ \end{array} \end{array} \]

FPCore

(FPCore (x)
 :precision binary64
 (if (<= x -1e-310) (* (sqrt 2.0) (- x)) (* (sqrt 2.0) x)))

C

double code(double x) {
	double tmp;
	if (x <= -1e-310) {
		tmp = sqrt(2.0) * -x;
	} else {
		tmp = sqrt(2.0) * x;
	}
	return tmp;
}

Fortran

real(8) function code(x)
    real(8), intent (in) :: x
    real(8) :: tmp
    if (x <= (-1d-310)) then
        tmp = sqrt(2.0d0) * -x
    else
        tmp = sqrt(2.0d0) * x
    end if
    code = tmp
end function

Java

public static double code(double x) {
	double tmp;
	if (x <= -1e-310) {
		tmp = Math.sqrt(2.0) * -x;
	} else {
		tmp = Math.sqrt(2.0) * x;
	}
	return tmp;
}

Python

def code(x):
	tmp = 0
	if x <= -1e-310:
		tmp = math.sqrt(2.0) * -x
	else:
		tmp = math.sqrt(2.0) * x
	return tmp

Julia

function code(x)
	tmp = 0.0
	if (x <= -1e-310)
		tmp = Float64(sqrt(2.0) * Float64(-x));
	else
		tmp = Float64(sqrt(2.0) * x);
	end
	return tmp
end

MATLAB

function tmp_2 = code(x)
	tmp = 0.0;
	if (x <= -1e-310)
		tmp = sqrt(2.0) * -x;
	else
		tmp = sqrt(2.0) * x;
	end
	tmp_2 = tmp;
end

Wolfram

code[x_] := If[LessEqual[x, -1e-310], N[(N[Sqrt[2.0], $MachinePrecision] * (-x)), $MachinePrecision], N[(N[Sqrt[2.0], $MachinePrecision] * x), $MachinePrecision]]

Derivation

1. Split input into 2 regimes

2. if x < -9.999999999999969e-311

   1. Initial program 53.4%

      \[\sqrt{2 \cdot {x}^{2}} \]
   2. Add Preprocessing

   3. Taylor expanded in x around -inf

      \[\leadsto \color{blue}{-1 \cdot \left(x \cdot \sqrt{2}\right)} \]
   4. Step-by-step derivation

      1. associate-*r* N/A

         \[\leadsto \color{blue}{\left(-1 \cdot x\right) \cdot \sqrt{2}} \]

      2. lower-*.f64 N/A

         \[\leadsto \color{blue}{\left(-1 \cdot x\right) \cdot \sqrt{2}} \]

      3. mul-1-neg N/A

         \[\leadsto \color{blue}{\left(\mathsf{neg}\left(x\right)\right)} \cdot \sqrt{2} \]

      4. lower-neg.f64 N/A

         \[\leadsto \color{blue}{\left(-x\right)} \cdot \sqrt{2} \]

      5. lower-sqrt.f64 99.3

         \[\leadsto \left(-x\right) \cdot \color{blue}{\sqrt{2}} \]

   5. Applied rewrites 99.3%

      \[\leadsto \color{blue}{\left(-x\right) \cdot \sqrt{2}} \]

   if -9.999999999999969e-311 < x

   1. Initial program 57.0%

      \[\sqrt{2 \cdot {x}^{2}} \]
   2. Add Preprocessing

   4. Applied rewrites 99.3%

      \[\leadsto \color{blue}{\sqrt{2} \cdot x} \]
3. Recombined 2 regimes into one program.

4. Final simplification 99.3%

   \[\leadsto \begin{array}{l} \mathbf{if}\;x \leq -1 \cdot 10^{-310}:\\ \;\;\;\;\sqrt{2} \cdot \left(-x\right)\\ \mathbf{else}:\\ \;\;\;\;\sqrt{2} \cdot x\\ \end{array} \]
5. Add Preprocessing

Alternative 5: 53.4% accurate, 5.3× speedup

Math

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;x \leq -4 \cdot 10^{-206}:\\ \;\;\;\;\sqrt{2}\\ \mathbf{else}:\\ \;\;\;\;\sqrt{2} \cdot x\\ \end{array} \end{array} \]

FPCore

(FPCore (x)
 :precision binary64
 (if (<= x -4e-206) (sqrt 2.0) (* (sqrt 2.0) x)))

C

double code(double x) {
	double tmp;
	if (x <= -4e-206) {
		tmp = sqrt(2.0);
	} else {
		tmp = sqrt(2.0) * x;
	}
	return tmp;
}

Fortran

real(8) function code(x)
    real(8), intent (in) :: x
    real(8) :: tmp
    if (x <= (-4d-206)) then
        tmp = sqrt(2.0d0)
    else
        tmp = sqrt(2.0d0) * x
    end if
    code = tmp
end function

Java

public static double code(double x) {
	double tmp;
	if (x <= -4e-206) {
		tmp = Math.sqrt(2.0);
	} else {
		tmp = Math.sqrt(2.0) * x;
	}
	return tmp;
}

Python

def code(x):
	tmp = 0
	if x <= -4e-206:
		tmp = math.sqrt(2.0)
	else:
		tmp = math.sqrt(2.0) * x
	return tmp

Julia

function code(x)
	tmp = 0.0
	if (x <= -4e-206)
		tmp = sqrt(2.0);
	else
		tmp = Float64(sqrt(2.0) * x);
	end
	return tmp
end

MATLAB

function tmp_2 = code(x)
	tmp = 0.0;
	if (x <= -4e-206)
		tmp = sqrt(2.0);
	else
		tmp = sqrt(2.0) * x;
	end
	tmp_2 = tmp;
end

Wolfram

code[x_] := If[LessEqual[x, -4e-206], N[Sqrt[2.0], $MachinePrecision], N[(N[Sqrt[2.0], $MachinePrecision] * x), $MachinePrecision]]

Derivation

1. Split input into 2 regimes

2. if x < -4.00000000000000011e-206

   1. Initial program 62.0%

      \[\sqrt{2 \cdot {x}^{2}} \]
   2. Add Preprocessing

   4. Applied rewrites 5.8%

      \[\leadsto \color{blue}{\sqrt{2}} \]

   if -4.00000000000000011e-206 < x

   1. Initial program 49.8%

      \[\sqrt{2 \cdot {x}^{2}} \]
   2. Add Preprocessing

   4. Applied rewrites 85.8%

      \[\leadsto \color{blue}{\sqrt{2} \cdot x} \]
3. Recombined 2 regimes into one program.
4. Add Preprocessing

Alternative 6: 5.4% accurate, 10.6× speedup

Math

\[\begin{array}{l} \\ \sqrt{2} \end{array} \]

FPCore

(FPCore (x) :precision binary64 (sqrt 2.0))

C

double code(double x) {
	return sqrt(2.0);
}

Fortran

real(8) function code(x)
    real(8), intent (in) :: x
    code = sqrt(2.0d0)
end function

Java

public static double code(double x) {
	return Math.sqrt(2.0);
}

Python

def code(x):
	return math.sqrt(2.0)

Julia

function code(x)
	return sqrt(2.0)
end

MATLAB

function tmp = code(x)
	tmp = sqrt(2.0);
end

Wolfram

code[x_] := N[Sqrt[2.0], $MachinePrecision]

Derivation

1. Initial program 55.1%

   \[\sqrt{2 \cdot {x}^{2}} \]
2. Add Preprocessing

4. Applied rewrites 5.5%

   \[\leadsto \color{blue}{\sqrt{2}} \]
5. Add Preprocessing

Reproduce

herbie shell --seed 2024268 
(FPCore (x)
  :name "sqrt D (should all be same)"
  :precision binary64
  (sqrt (* 2.0 (pow x 2.0))))