Rust f64::asinh

Percentage Accurate: 31.3% → 99.8%

Time: 1.9s

Alternatives: 5

Speedup: 2.2×

Specification

Math

\[\begin{array}{l} \\ \mathsf{copysign}\left(\log \left(\left|x\right| + \sqrt{x \cdot x + 1}\right), x\right) \end{array} \]

FPCore

(FPCore (x)
 :precision binary64
 (copysign (log (+ (fabs x) (sqrt (+ (* x x) 1.0)))) x))

C

double code(double x) {
	return copysign(log((fabs(x) + sqrt(((x * x) + 1.0)))), x);
}

Java

public static double code(double x) {
	return Math.copySign(Math.log((Math.abs(x) + Math.sqrt(((x * x) + 1.0)))), x);
}

Python

def code(x):
	return math.copysign(math.log((math.fabs(x) + math.sqrt(((x * x) + 1.0)))), x)

Julia

function code(x)
	return copysign(log(Float64(abs(x) + sqrt(Float64(Float64(x * x) + 1.0)))), x)
end

MATLAB

function tmp = code(x)
	tmp = sign(x) * abs(log((abs(x) + sqrt(((x * x) + 1.0)))));
end

Wolfram

code[x_] := N[With[{TMP1 = Abs[N[Log[N[(N[Abs[x], $MachinePrecision] + N[Sqrt[N[(N[(x * x), $MachinePrecision] + 1.0), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]], $MachinePrecision]], TMP2 = Sign[x]}, TMP1 * If[TMP2 == 0, 1, TMP2]], $MachinePrecision]

Initial Program: 31.3% accurate, 1.0× speedup

Math

\[\begin{array}{l} \\ \mathsf{copysign}\left(\log \left(\left|x\right| + \sqrt{x \cdot x + 1}\right), x\right) \end{array} \]

FPCore

(FPCore (x)
 :precision binary64
 (copysign (log (+ (fabs x) (sqrt (+ (* x x) 1.0)))) x))

C

double code(double x) {
	return copysign(log((fabs(x) + sqrt(((x * x) + 1.0)))), x);
}

Java

public static double code(double x) {
	return Math.copySign(Math.log((Math.abs(x) + Math.sqrt(((x * x) + 1.0)))), x);
}

Python

def code(x):
	return math.copysign(math.log((math.fabs(x) + math.sqrt(((x * x) + 1.0)))), x)

Julia

function code(x)
	return copysign(log(Float64(abs(x) + sqrt(Float64(Float64(x * x) + 1.0)))), x)
end

MATLAB

function tmp = code(x)
	tmp = sign(x) * abs(log((abs(x) + sqrt(((x * x) + 1.0)))));
end

Wolfram

code[x_] := N[With[{TMP1 = Abs[N[Log[N[(N[Abs[x], $MachinePrecision] + N[Sqrt[N[(N[(x * x), $MachinePrecision] + 1.0), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]], $MachinePrecision]], TMP2 = Sign[x]}, TMP1 * If[TMP2 == 0, 1, TMP2]], $MachinePrecision]

Alternative 1: 99.8% accurate, 1.1× speedup

Math

\[\begin{array}{l} \\ \mathsf{copysign}\left(\sinh^{-1} x, x\right) \end{array} \]

FPCore

(FPCore (x) :precision binary64 (copysign (asinh x) x))

C

double code(double x) {
	return copysign(asinh(x), x);
}

Python

def code(x):
	return math.copysign(math.asinh(x), x)

Julia

function code(x)
	return copysign(asinh(x), x)
end

MATLAB

function tmp = code(x)
	tmp = sign(x) * abs(asinh(x));
end

Wolfram

code[x_] := N[With[{TMP1 = Abs[N[ArcSinh[x], $MachinePrecision]], TMP2 = Sign[x]}, TMP1 * If[TMP2 == 0, 1, TMP2]], $MachinePrecision]

Derivation

1. Initial program 31.3%

   \[\mathsf{copysign}\left(\log \left(\left|x\right| + \sqrt{x \cdot x + 1}\right), x\right) \]
2. Step-by-step derivation

   1. lift-log.f64 N/A

      \[\leadsto \mathsf{copysign}\left(\color{blue}{\log \left(\left|x\right| + \sqrt{x \cdot x + 1}\right)}, x\right) \]

   2. lift-+.f64 N/A

      \[\leadsto \mathsf{copysign}\left(\log \color{blue}{\left(\left|x\right| + \sqrt{x \cdot x + 1}\right)}, x\right) \]

   3. lift-fabs.f64 N/A

      \[\leadsto \mathsf{copysign}\left(\log \left(\color{blue}{\left|x\right|} + \sqrt{x \cdot x + 1}\right), x\right) \]

   4. lift-sqrt.f64 N/A

      \[\leadsto \mathsf{copysign}\left(\log \left(\left|x\right| + \color{blue}{\sqrt{x \cdot x + 1}}\right), x\right) \]

   5. lift-+.f64 N/A

      \[\leadsto \mathsf{copysign}\left(\log \left(\left|x\right| + \sqrt{\color{blue}{x \cdot x + 1}}\right), x\right) \]

   6. lift-*.f64 N/A

      \[\leadsto \mathsf{copysign}\left(\log \left(\left|x\right| + \sqrt{\color{blue}{x \cdot x} + 1}\right), x\right) \]

   7. pow2 N/A

      \[\leadsto \mathsf{copysign}\left(\log \left(\left|x\right| + \sqrt{\color{blue}{{x}^{2}} + 1}\right), x\right) \]

   8. +-commutative N/A

      \[\leadsto \mathsf{copysign}\left(\log \left(\left|x\right| + \sqrt{\color{blue}{1 + {x}^{2}}}\right), x\right) \]

   9. +-commutative N/A

      \[\leadsto \mathsf{copysign}\left(\log \left(\left|x\right| + \sqrt{\color{blue}{{x}^{2} + 1}}\right), x\right) \]

   10. pow2 N/A

       \[\leadsto \mathsf{copysign}\left(\log \left(\left|x\right| + \sqrt{\color{blue}{x \cdot x} + 1}\right), x\right) \]

   11. sqr-abs-rev N/A

       \[\leadsto \mathsf{copysign}\left(\log \left(\left|x\right| + \sqrt{\color{blue}{\left|x\right| \cdot \left|x\right|} + 1}\right), x\right) \]

   12. asinh-def-rev N/A

       \[\leadsto \mathsf{copysign}\left(\color{blue}{\sinh^{-1} \left(\left|x\right|\right)}, x\right) \]

   13. rem-sqrt-square-rev N/A

       \[\leadsto \mathsf{copysign}\left(\sinh^{-1} \color{blue}{\left(\sqrt{x \cdot x}\right)}, x\right) \]

   14. pow2 N/A

       \[\leadsto \mathsf{copysign}\left(\sinh^{-1} \left(\sqrt{\color{blue}{{x}^{2}}}\right), x\right) \]

   15. sqrt-pow1 N/A

       \[\leadsto \mathsf{copysign}\left(\sinh^{-1} \color{blue}{\left({x}^{\left(\frac{2}{2}\right)}\right)}, x\right) \]

   16. metadata-eval N/A

       \[\leadsto \mathsf{copysign}\left(\sinh^{-1} \left({x}^{\color{blue}{1}}\right), x\right) \]

   17. unpow1 N/A

       \[\leadsto \mathsf{copysign}\left(\sinh^{-1} \color{blue}{x}, x\right) \]

   18. lower-asinh.f64 99.8

       \[\leadsto \mathsf{copysign}\left(\color{blue}{\sinh^{-1} x}, x\right) \]

3. Applied rewrites 99.8%

   \[\leadsto \mathsf{copysign}\left(\color{blue}{\sinh^{-1} x}, x\right) \]
4. Add Preprocessing

Alternative 2: 52.1% accurate, 1.6× speedup

Math

\[\begin{array}{l} \\ \mathsf{copysign}\left(\mathsf{fma}\left(\mathsf{fma}\left(-0.044642857142857144, x \cdot x, 0.075\right) \cdot \left(x \cdot x\right) - 0.16666666666666666, x \cdot x, 1\right) \cdot x, x\right) \end{array} \]

FPCore

(FPCore (x)
 :precision binary64
 (copysign
  (*
   (fma
    (-
     (* (fma -0.044642857142857144 (* x x) 0.075) (* x x))
     0.16666666666666666)
    (* x x)
    1.0)
   x)
  x))

C

double code(double x) {
	return copysign((fma(((fma(-0.044642857142857144, (x * x), 0.075) * (x * x)) - 0.16666666666666666), (x * x), 1.0) * x), x);
}

Julia

function code(x)
	return copysign(Float64(fma(Float64(Float64(fma(-0.044642857142857144, Float64(x * x), 0.075) * Float64(x * x)) - 0.16666666666666666), Float64(x * x), 1.0) * x), x)
end

Wolfram

code[x_] := N[With[{TMP1 = Abs[N[(N[(N[(N[(N[(-0.044642857142857144 * N[(x * x), $MachinePrecision] + 0.075), $MachinePrecision] * N[(x * x), $MachinePrecision]), $MachinePrecision] - 0.16666666666666666), $MachinePrecision] * N[(x * x), $MachinePrecision] + 1.0), $MachinePrecision] * x), $MachinePrecision]], TMP2 = Sign[x]}, TMP1 * If[TMP2 == 0, 1, TMP2]], $MachinePrecision]

Derivation

1. Initial program 31.3%

   \[\mathsf{copysign}\left(\log \left(\left|x\right| + \sqrt{x \cdot x + 1}\right), x\right) \]
2. Step-by-step derivation

   1. lift-log.f64 N/A

      \[\leadsto \mathsf{copysign}\left(\color{blue}{\log \left(\left|x\right| + \sqrt{x \cdot x + 1}\right)}, x\right) \]

   2. lift-+.f64 N/A

      \[\leadsto \mathsf{copysign}\left(\log \color{blue}{\left(\left|x\right| + \sqrt{x \cdot x + 1}\right)}, x\right) \]

   3. lift-fabs.f64 N/A

      \[\leadsto \mathsf{copysign}\left(\log \left(\color{blue}{\left|x\right|} + \sqrt{x \cdot x + 1}\right), x\right) \]

   4. lift-sqrt.f64 N/A

      \[\leadsto \mathsf{copysign}\left(\log \left(\left|x\right| + \color{blue}{\sqrt{x \cdot x + 1}}\right), x\right) \]

   5. lift-+.f64 N/A

      \[\leadsto \mathsf{copysign}\left(\log \left(\left|x\right| + \sqrt{\color{blue}{x \cdot x + 1}}\right), x\right) \]

   6. lift-*.f64 N/A

      \[\leadsto \mathsf{copysign}\left(\log \left(\left|x\right| + \sqrt{\color{blue}{x \cdot x} + 1}\right), x\right) \]

   7. pow2 N/A

      \[\leadsto \mathsf{copysign}\left(\log \left(\left|x\right| + \sqrt{\color{blue}{{x}^{2}} + 1}\right), x\right) \]

   8. +-commutative N/A

      \[\leadsto \mathsf{copysign}\left(\log \left(\left|x\right| + \sqrt{\color{blue}{1 + {x}^{2}}}\right), x\right) \]

   9. +-commutative N/A

      \[\leadsto \mathsf{copysign}\left(\log \left(\left|x\right| + \sqrt{\color{blue}{{x}^{2} + 1}}\right), x\right) \]

   10. pow2 N/A

       \[\leadsto \mathsf{copysign}\left(\log \left(\left|x\right| + \sqrt{\color{blue}{x \cdot x} + 1}\right), x\right) \]

   11. sqr-abs-rev N/A

       \[\leadsto \mathsf{copysign}\left(\log \left(\left|x\right| + \sqrt{\color{blue}{\left|x\right| \cdot \left|x\right|} + 1}\right), x\right) \]

   12. asinh-def-rev N/A

       \[\leadsto \mathsf{copysign}\left(\color{blue}{\sinh^{-1} \left(\left|x\right|\right)}, x\right) \]

   13. rem-sqrt-square-rev N/A

       \[\leadsto \mathsf{copysign}\left(\sinh^{-1} \color{blue}{\left(\sqrt{x \cdot x}\right)}, x\right) \]

   14. pow2 N/A

       \[\leadsto \mathsf{copysign}\left(\sinh^{-1} \left(\sqrt{\color{blue}{{x}^{2}}}\right), x\right) \]

   15. sqrt-pow1 N/A

       \[\leadsto \mathsf{copysign}\left(\sinh^{-1} \color{blue}{\left({x}^{\left(\frac{2}{2}\right)}\right)}, x\right) \]

   16. metadata-eval N/A

       \[\leadsto \mathsf{copysign}\left(\sinh^{-1} \left({x}^{\color{blue}{1}}\right), x\right) \]

   17. unpow1 N/A

       \[\leadsto \mathsf{copysign}\left(\sinh^{-1} \color{blue}{x}, x\right) \]

   18. lower-asinh.f64 99.8

       \[\leadsto \mathsf{copysign}\left(\color{blue}{\sinh^{-1} x}, x\right) \]

3. Applied rewrites 99.8%

   \[\leadsto \mathsf{copysign}\left(\color{blue}{\sinh^{-1} x}, x\right) \]

4. Taylor expanded in x around 0

   \[\leadsto \mathsf{copysign}\left(\color{blue}{x \cdot \left(1 + {x}^{2} \cdot \left({x}^{2} \cdot \left(\frac{3}{40} + \frac{-5}{112} \cdot {x}^{2}\right) - \frac{1}{6}\right)\right)}, x\right) \]
5. Step-by-step derivation

   1. *-commutative N/A

      \[\leadsto \mathsf{copysign}\left(\left(1 + {x}^{2} \cdot \left({x}^{2} \cdot \left(\frac{3}{40} + \frac{-5}{112} \cdot {x}^{2}\right) - \frac{1}{6}\right)\right) \cdot \color{blue}{x}, x\right) \]

   2. lower-*.f64 N/A

      \[\leadsto \mathsf{copysign}\left(\left(1 + {x}^{2} \cdot \left({x}^{2} \cdot \left(\frac{3}{40} + \frac{-5}{112} \cdot {x}^{2}\right) - \frac{1}{6}\right)\right) \cdot \color{blue}{x}, x\right) \]

6. Applied rewrites 51.4%

   \[\leadsto \mathsf{copysign}\left(\color{blue}{\mathsf{fma}\left(\mathsf{fma}\left(-0.044642857142857144, x \cdot x, 0.075\right) \cdot \left(x \cdot x\right) - 0.16666666666666666, x \cdot x, 1\right) \cdot x}, x\right) \]
7. Add Preprocessing

Alternative 3: 51.5% accurate, 1.7× speedup

Math

\[\begin{array}{l} \\ \mathsf{copysign}\left(\mathsf{fma}\left(0.075 \cdot \left(x \cdot x\right) - 0.16666666666666666, x \cdot x, 1\right) \cdot x, x\right) \end{array} \]

FPCore

(FPCore (x)
 :precision binary64
 (copysign
  (* (fma (- (* 0.075 (* x x)) 0.16666666666666666) (* x x) 1.0) x)
  x))

C

double code(double x) {
	return copysign((fma(((0.075 * (x * x)) - 0.16666666666666666), (x * x), 1.0) * x), x);
}

Julia

function code(x)
	return copysign(Float64(fma(Float64(Float64(0.075 * Float64(x * x)) - 0.16666666666666666), Float64(x * x), 1.0) * x), x)
end

Wolfram

code[x_] := N[With[{TMP1 = Abs[N[(N[(N[(N[(0.075 * N[(x * x), $MachinePrecision]), $MachinePrecision] - 0.16666666666666666), $MachinePrecision] * N[(x * x), $MachinePrecision] + 1.0), $MachinePrecision] * x), $MachinePrecision]], TMP2 = Sign[x]}, TMP1 * If[TMP2 == 0, 1, TMP2]], $MachinePrecision]

Derivation

1. Initial program 31.3%

   \[\mathsf{copysign}\left(\log \left(\left|x\right| + \sqrt{x \cdot x + 1}\right), x\right) \]

2. Taylor expanded in x around 0

   \[\leadsto \mathsf{copysign}\left(\color{blue}{\log \left(1 + \left|x\right|\right) + {x}^{2} \cdot \left(\frac{-1}{24} \cdot \left({x}^{2} \cdot \left(3 \cdot \frac{1}{1 + \left|x\right|} + 3 \cdot \frac{1}{{\left(1 + \left|x\right|\right)}^{2}}\right)\right) + \frac{1}{2} \cdot \frac{1}{1 + \left|x\right|}\right)}, x\right) \]
3. Step-by-step derivation

   1. +-commutative N/A

      \[\leadsto \mathsf{copysign}\left({x}^{2} \cdot \left(\frac{-1}{24} \cdot \left({x}^{2} \cdot \left(3 \cdot \frac{1}{1 + \left|x\right|} + 3 \cdot \frac{1}{{\left(1 + \left|x\right|\right)}^{2}}\right)\right) + \frac{1}{2} \cdot \frac{1}{1 + \left|x\right|}\right) + \color{blue}{\log \left(1 + \left|x\right|\right)}, x\right) \]

   2. *-commutative N/A

      \[\leadsto \mathsf{copysign}\left(\left(\frac{-1}{24} \cdot \left({x}^{2} \cdot \left(3 \cdot \frac{1}{1 + \left|x\right|} + 3 \cdot \frac{1}{{\left(1 + \left|x\right|\right)}^{2}}\right)\right) + \frac{1}{2} \cdot \frac{1}{1 + \left|x\right|}\right) \cdot {x}^{2} + \log \color{blue}{\left(1 + \left|x\right|\right)}, x\right) \]

   3. lower-fma.f64 N/A

      \[\leadsto \mathsf{copysign}\left(\mathsf{fma}\left(\frac{-1}{24} \cdot \left({x}^{2} \cdot \left(3 \cdot \frac{1}{1 + \left|x\right|} + 3 \cdot \frac{1}{{\left(1 + \left|x\right|\right)}^{2}}\right)\right) + \frac{1}{2} \cdot \frac{1}{1 + \left|x\right|}, \color{blue}{{x}^{2}}, \log \left(1 + \left|x\right|\right)\right), x\right) \]

4. Applied rewrites 50.5%

   \[\leadsto \mathsf{copysign}\left(\color{blue}{\mathsf{fma}\left(\mathsf{fma}\left(-0.041666666666666664 \cdot \left(x \cdot x\right), \frac{3}{\left(1 + x\right) \cdot \left(1 + x\right)} + \frac{3}{1 + x}, \frac{0.5}{1 + x}\right), x \cdot x, \mathsf{log1p}\left(x\right)\right)}, x\right) \]

5. Taylor expanded in x around 0

   \[\leadsto \mathsf{copysign}\left(x \cdot \color{blue}{\left(1 + {x}^{2} \cdot \left(\frac{3}{40} \cdot {x}^{2} - \frac{1}{6}\right)\right)}, x\right) \]
6. Step-by-step derivation

   1. *-commutative N/A

      \[\leadsto \mathsf{copysign}\left(\left(1 + {x}^{2} \cdot \left(\frac{3}{40} \cdot {x}^{2} - \frac{1}{6}\right)\right) \cdot x, x\right) \]

   2. lower-*.f64 N/A

      \[\leadsto \mathsf{copysign}\left(\left(1 + {x}^{2} \cdot \left(\frac{3}{40} \cdot {x}^{2} - \frac{1}{6}\right)\right) \cdot x, x\right) \]

   3. +-commutative N/A

      \[\leadsto \mathsf{copysign}\left(\left({x}^{2} \cdot \left(\frac{3}{40} \cdot {x}^{2} - \frac{1}{6}\right) + 1\right) \cdot x, x\right) \]

   4. *-commutative N/A

      \[\leadsto \mathsf{copysign}\left(\left(\left(\frac{3}{40} \cdot {x}^{2} - \frac{1}{6}\right) \cdot {x}^{2} + 1\right) \cdot x, x\right) \]

   5. lower-fma.f64 N/A

      \[\leadsto \mathsf{copysign}\left(\mathsf{fma}\left(\frac{3}{40} \cdot {x}^{2} - \frac{1}{6}, {x}^{2}, 1\right) \cdot x, x\right) \]

   6. lower--.f64 N/A

      \[\leadsto \mathsf{copysign}\left(\mathsf{fma}\left(\frac{3}{40} \cdot {x}^{2} - \frac{1}{6}, {x}^{2}, 1\right) \cdot x, x\right) \]

   7. lower-*.f64 N/A

      \[\leadsto \mathsf{copysign}\left(\mathsf{fma}\left(\frac{3}{40} \cdot {x}^{2} - \frac{1}{6}, {x}^{2}, 1\right) \cdot x, x\right) \]

   8. pow2 N/A

      \[\leadsto \mathsf{copysign}\left(\mathsf{fma}\left(\frac{3}{40} \cdot \left(x \cdot x\right) - \frac{1}{6}, {x}^{2}, 1\right) \cdot x, x\right) \]

   9. lift-*.f64 N/A

      \[\leadsto \mathsf{copysign}\left(\mathsf{fma}\left(\frac{3}{40} \cdot \left(x \cdot x\right) - \frac{1}{6}, {x}^{2}, 1\right) \cdot x, x\right) \]

   10. pow2 N/A

       \[\leadsto \mathsf{copysign}\left(\mathsf{fma}\left(\frac{3}{40} \cdot \left(x \cdot x\right) - \frac{1}{6}, x \cdot x, 1\right) \cdot x, x\right) \]

   11. lift-*.f64 51.4

       \[\leadsto \mathsf{copysign}\left(\mathsf{fma}\left(0.075 \cdot \left(x \cdot x\right) - 0.16666666666666666, x \cdot x, 1\right) \cdot x, x\right) \]

7. Applied rewrites 51.4%

   \[\leadsto \mathsf{copysign}\left(\mathsf{fma}\left(0.075 \cdot \left(x \cdot x\right) - 0.16666666666666666, x \cdot x, 1\right) \cdot \color{blue}{x}, x\right) \]
8. Add Preprocessing

Alternative 4: 51.4% accurate, 1.9× speedup

Math

\[\begin{array}{l} \\ \mathsf{copysign}\left(\mathsf{fma}\left(-0.16666666666666666, x \cdot x, 1\right) \cdot x, x\right) \end{array} \]

FPCore

(FPCore (x)
 :precision binary64
 (copysign (* (fma -0.16666666666666666 (* x x) 1.0) x) x))

C

double code(double x) {
	return copysign((fma(-0.16666666666666666, (x * x), 1.0) * x), x);
}

Julia

function code(x)
	return copysign(Float64(fma(-0.16666666666666666, Float64(x * x), 1.0) * x), x)
end

Wolfram

code[x_] := N[With[{TMP1 = Abs[N[(N[(-0.16666666666666666 * N[(x * x), $MachinePrecision] + 1.0), $MachinePrecision] * x), $MachinePrecision]], TMP2 = Sign[x]}, TMP1 * If[TMP2 == 0, 1, TMP2]], $MachinePrecision]

Derivation

1. Initial program 31.3%

   \[\mathsf{copysign}\left(\log \left(\left|x\right| + \sqrt{x \cdot x + 1}\right), x\right) \]

2. Taylor expanded in x around 0

   \[\leadsto \mathsf{copysign}\left(\color{blue}{\log \left(1 + \left|x\right|\right) + {x}^{2} \cdot \left(\frac{-1}{24} \cdot \left({x}^{2} \cdot \left(3 \cdot \frac{1}{1 + \left|x\right|} + 3 \cdot \frac{1}{{\left(1 + \left|x\right|\right)}^{2}}\right)\right) + \frac{1}{2} \cdot \frac{1}{1 + \left|x\right|}\right)}, x\right) \]
3. Step-by-step derivation

   1. +-commutative N/A

      \[\leadsto \mathsf{copysign}\left({x}^{2} \cdot \left(\frac{-1}{24} \cdot \left({x}^{2} \cdot \left(3 \cdot \frac{1}{1 + \left|x\right|} + 3 \cdot \frac{1}{{\left(1 + \left|x\right|\right)}^{2}}\right)\right) + \frac{1}{2} \cdot \frac{1}{1 + \left|x\right|}\right) + \color{blue}{\log \left(1 + \left|x\right|\right)}, x\right) \]

   2. *-commutative N/A

      \[\leadsto \mathsf{copysign}\left(\left(\frac{-1}{24} \cdot \left({x}^{2} \cdot \left(3 \cdot \frac{1}{1 + \left|x\right|} + 3 \cdot \frac{1}{{\left(1 + \left|x\right|\right)}^{2}}\right)\right) + \frac{1}{2} \cdot \frac{1}{1 + \left|x\right|}\right) \cdot {x}^{2} + \log \color{blue}{\left(1 + \left|x\right|\right)}, x\right) \]

   3. lower-fma.f64 N/A

      \[\leadsto \mathsf{copysign}\left(\mathsf{fma}\left(\frac{-1}{24} \cdot \left({x}^{2} \cdot \left(3 \cdot \frac{1}{1 + \left|x\right|} + 3 \cdot \frac{1}{{\left(1 + \left|x\right|\right)}^{2}}\right)\right) + \frac{1}{2} \cdot \frac{1}{1 + \left|x\right|}, \color{blue}{{x}^{2}}, \log \left(1 + \left|x\right|\right)\right), x\right) \]

4. Applied rewrites 50.5%

   \[\leadsto \mathsf{copysign}\left(\color{blue}{\mathsf{fma}\left(\mathsf{fma}\left(-0.041666666666666664 \cdot \left(x \cdot x\right), \frac{3}{\left(1 + x\right) \cdot \left(1 + x\right)} + \frac{3}{1 + x}, \frac{0.5}{1 + x}\right), x \cdot x, \mathsf{log1p}\left(x\right)\right)}, x\right) \]

5. Taylor expanded in x around 0

   \[\leadsto \mathsf{copysign}\left(x \cdot \color{blue}{\left(1 + \frac{-1}{6} \cdot {x}^{2}\right)}, x\right) \]
6. Step-by-step derivation

   1. *-commutative N/A

      \[\leadsto \mathsf{copysign}\left(\left(1 + \frac{-1}{6} \cdot {x}^{2}\right) \cdot x, x\right) \]

   2. lower-*.f64 N/A

      \[\leadsto \mathsf{copysign}\left(\left(1 + \frac{-1}{6} \cdot {x}^{2}\right) \cdot x, x\right) \]

   3. +-commutative N/A

      \[\leadsto \mathsf{copysign}\left(\left(\frac{-1}{6} \cdot {x}^{2} + 1\right) \cdot x, x\right) \]

   4. lower-fma.f64 N/A

      \[\leadsto \mathsf{copysign}\left(\mathsf{fma}\left(\frac{-1}{6}, {x}^{2}, 1\right) \cdot x, x\right) \]

   5. pow2 N/A

      \[\leadsto \mathsf{copysign}\left(\mathsf{fma}\left(\frac{-1}{6}, x \cdot x, 1\right) \cdot x, x\right) \]

   6. lift-*.f64 51.5

      \[\leadsto \mathsf{copysign}\left(\mathsf{fma}\left(-0.16666666666666666, x \cdot x, 1\right) \cdot x, x\right) \]

7. Applied rewrites 51.5%

   \[\leadsto \mathsf{copysign}\left(\mathsf{fma}\left(-0.16666666666666666, x \cdot x, 1\right) \cdot \color{blue}{x}, x\right) \]
8. Add Preprocessing

Alternative 5: 51.4% accurate, 2.2× speedup

Math

\[\begin{array}{l} \\ \mathsf{copysign}\left(x, x\right) \end{array} \]

FPCore

(FPCore (x) :precision binary64 (copysign x x))

C

double code(double x) {
	return copysign(x, x);
}

Java

public static double code(double x) {
	return Math.copySign(x, x);
}

Python

def code(x):
	return math.copysign(x, x)

Julia

function code(x)
	return copysign(x, x)
end

MATLAB

function tmp = code(x)
	tmp = sign(x) * abs(x);
end

Wolfram

code[x_] := N[With[{TMP1 = Abs[x], TMP2 = Sign[x]}, TMP1 * If[TMP2 == 0, 1, TMP2]], $MachinePrecision]

Derivation

1. Initial program 31.3%

   \[\mathsf{copysign}\left(\log \left(\left|x\right| + \sqrt{x \cdot x + 1}\right), x\right) \]

2. Taylor expanded in x around 0

   \[\leadsto \mathsf{copysign}\left(\color{blue}{\log \left(1 + \left|x\right|\right) + {x}^{2} \cdot \left(\frac{-1}{24} \cdot \left({x}^{2} \cdot \left(3 \cdot \frac{1}{1 + \left|x\right|} + 3 \cdot \frac{1}{{\left(1 + \left|x\right|\right)}^{2}}\right)\right) + \frac{1}{2} \cdot \frac{1}{1 + \left|x\right|}\right)}, x\right) \]
3. Step-by-step derivation

   1. +-commutative N/A

      \[\leadsto \mathsf{copysign}\left({x}^{2} \cdot \left(\frac{-1}{24} \cdot \left({x}^{2} \cdot \left(3 \cdot \frac{1}{1 + \left|x\right|} + 3 \cdot \frac{1}{{\left(1 + \left|x\right|\right)}^{2}}\right)\right) + \frac{1}{2} \cdot \frac{1}{1 + \left|x\right|}\right) + \color{blue}{\log \left(1 + \left|x\right|\right)}, x\right) \]

   2. *-commutative N/A

      \[\leadsto \mathsf{copysign}\left(\left(\frac{-1}{24} \cdot \left({x}^{2} \cdot \left(3 \cdot \frac{1}{1 + \left|x\right|} + 3 \cdot \frac{1}{{\left(1 + \left|x\right|\right)}^{2}}\right)\right) + \frac{1}{2} \cdot \frac{1}{1 + \left|x\right|}\right) \cdot {x}^{2} + \log \color{blue}{\left(1 + \left|x\right|\right)}, x\right) \]

   3. lower-fma.f64 N/A

      \[\leadsto \mathsf{copysign}\left(\mathsf{fma}\left(\frac{-1}{24} \cdot \left({x}^{2} \cdot \left(3 \cdot \frac{1}{1 + \left|x\right|} + 3 \cdot \frac{1}{{\left(1 + \left|x\right|\right)}^{2}}\right)\right) + \frac{1}{2} \cdot \frac{1}{1 + \left|x\right|}, \color{blue}{{x}^{2}}, \log \left(1 + \left|x\right|\right)\right), x\right) \]

4. Applied rewrites 50.5%

   \[\leadsto \mathsf{copysign}\left(\color{blue}{\mathsf{fma}\left(\mathsf{fma}\left(-0.041666666666666664 \cdot \left(x \cdot x\right), \frac{3}{\left(1 + x\right) \cdot \left(1 + x\right)} + \frac{3}{1 + x}, \frac{0.5}{1 + x}\right), x \cdot x, \mathsf{log1p}\left(x\right)\right)}, x\right) \]

5. Taylor expanded in x around 0

   \[\leadsto \mathsf{copysign}\left(x, x\right) \]
6. Step-by-step derivation

7. Applied rewrites 52.1%

   \[\leadsto \mathsf{copysign}\left(x, x\right) \]
8. Add Preprocessing

Reproduce

herbie shell --seed 2025101 
(FPCore (x)
  :name "Rust f64::asinh"
  :precision binary64
  (copysign (log (+ (fabs x) (sqrt (+ (* x x) 1.0)))) x))