Rust f32::asinh

Percentage Accurate: 37.8% → 99.5%
Time: 1.9s
Alternatives: 6
Speedup: 5.8×

Specification

?
\[\begin{array}{l} \\ \mathsf{copysign}\left(\log \left(\left|x\right| + \sqrt{x \cdot x + 1}\right), x\right) \end{array} \]
(FPCore (x)
 :precision binary32
 (copysign (log (+ (fabs x) (sqrt (+ (* x x) 1.0)))) x))
float code(float x) {
	return copysignf(logf((fabsf(x) + sqrtf(((x * x) + 1.0f)))), x);
}
function code(x)
	return copysign(log(Float32(abs(x) + sqrt(Float32(Float32(x * x) + Float32(1.0))))), x)
end
function tmp = code(x)
	tmp = sign(x) * abs(log((abs(x) + sqrt(((x * x) + single(1.0))))));
end
\begin{array}{l}

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

Local Percentage Accuracy vs ?

The average percentage accuracy by input value. Horizontal axis shows value of an input variable; the variable is choosen in the title. Vertical axis is accuracy; higher is better. Red represent the original program, while blue represents Herbie's suggestion. These can be toggled with buttons below the plot. The line is an average while dots represent individual samples.

Accuracy vs Speed?

Herbie found 6 alternatives:

AlternativeAccuracySpeedup
The accuracy (vertical axis) and speed (horizontal axis) of each alternatives. Up and to the right is better. The red square shows the initial program, and each blue circle shows an alternative.The line shows the best available speed-accuracy tradeoffs.

Initial Program: 37.8% accurate, 1.0× speedup?

\[\begin{array}{l} \\ \mathsf{copysign}\left(\log \left(\left|x\right| + \sqrt{x \cdot x + 1}\right), x\right) \end{array} \]
(FPCore (x)
 :precision binary32
 (copysign (log (+ (fabs x) (sqrt (+ (* x x) 1.0)))) x))
float code(float x) {
	return copysignf(logf((fabsf(x) + sqrtf(((x * x) + 1.0f)))), x);
}
function code(x)
	return copysign(log(Float32(abs(x) + sqrt(Float32(Float32(x * x) + Float32(1.0))))), x)
end
function tmp = code(x)
	tmp = sign(x) * abs(log((abs(x) + sqrt(((x * x) + single(1.0))))));
end
\begin{array}{l}

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

Alternative 1: 99.5% accurate, 1.7× speedup?

\[\begin{array}{l} \\ \mathsf{copysign}\left(\sinh^{-1} x, x\right) \end{array} \]
(FPCore (x) :precision binary32 (copysign (asinh x) x))
float code(float x) {
	return copysignf(asinhf(x), x);
}
function code(x)
	return copysign(asinh(x), x)
end
function tmp = code(x)
	tmp = sign(x) * abs(asinh(x));
end
\begin{array}{l}

\\
\mathsf{copysign}\left(\sinh^{-1} x, x\right)
\end{array}
Derivation
  1. Initial program 37.8%

    \[\mathsf{copysign}\left(\log \left(\left|x\right| + \sqrt{x \cdot x + 1}\right), x\right) \]
  2. Step-by-step derivation
    1. lift-log.f32N/A

      \[\leadsto \mathsf{copysign}\left(\color{blue}{\log \left(\left|x\right| + \sqrt{x \cdot x + 1}\right)}, x\right) \]
    2. lift-+.f32N/A

      \[\leadsto \mathsf{copysign}\left(\log \color{blue}{\left(\left|x\right| + \sqrt{x \cdot x + 1}\right)}, x\right) \]
    3. lift-fabs.f32N/A

      \[\leadsto \mathsf{copysign}\left(\log \left(\color{blue}{\left|x\right|} + \sqrt{x \cdot x + 1}\right), x\right) \]
    4. lift-sqrt.f32N/A

      \[\leadsto \mathsf{copysign}\left(\log \left(\left|x\right| + \color{blue}{\sqrt{x \cdot x + 1}}\right), x\right) \]
    5. lift-*.f32N/A

      \[\leadsto \mathsf{copysign}\left(\log \left(\left|x\right| + \sqrt{\color{blue}{x \cdot x} + 1}\right), x\right) \]
    6. lift-+.f32N/A

      \[\leadsto \mathsf{copysign}\left(\log \left(\left|x\right| + \sqrt{\color{blue}{x \cdot x + 1}}\right), x\right) \]
    7. sqr-abs-revN/A

      \[\leadsto \mathsf{copysign}\left(\log \left(\left|x\right| + \sqrt{\color{blue}{\left|x\right| \cdot \left|x\right|} + 1}\right), x\right) \]
    8. asinh-def-revN/A

      \[\leadsto \mathsf{copysign}\left(\color{blue}{\sinh^{-1} \left(\left|x\right|\right)}, x\right) \]
    9. rem-sqrt-square-revN/A

      \[\leadsto \mathsf{copysign}\left(\sinh^{-1} \color{blue}{\left(\sqrt{x \cdot x}\right)}, x\right) \]
    10. pow2N/A

      \[\leadsto \mathsf{copysign}\left(\sinh^{-1} \left(\sqrt{\color{blue}{{x}^{2}}}\right), x\right) \]
    11. sqrt-pow1N/A

      \[\leadsto \mathsf{copysign}\left(\sinh^{-1} \color{blue}{\left({x}^{\left(\frac{2}{2}\right)}\right)}, x\right) \]
    12. metadata-evalN/A

      \[\leadsto \mathsf{copysign}\left(\sinh^{-1} \left({x}^{\color{blue}{1}}\right), x\right) \]
    13. unpow1N/A

      \[\leadsto \mathsf{copysign}\left(\sinh^{-1} \color{blue}{x}, x\right) \]
    14. lower-asinh.f3299.5

      \[\leadsto \mathsf{copysign}\left(\color{blue}{\sinh^{-1} x}, x\right) \]
  3. Applied rewrites99.5%

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

Alternative 2: 83.7% accurate, 1.0× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;x \leq -10:\\ \;\;\;\;\mathsf{copysign}\left(\log \left(-x\right), x\right)\\ \mathbf{elif}\;x \leq 2:\\ \;\;\;\;\mathsf{copysign}\left(x, x\right)\\ \mathbf{else}:\\ \;\;\;\;\mathsf{copysign}\left(\log \left(x + x\right), x\right)\\ \end{array} \end{array} \]
(FPCore (x)
 :precision binary32
 (if (<= x -10.0)
   (copysign (log (- x)) x)
   (if (<= x 2.0) (copysign x x) (copysign (log (+ x x)) x))))
float code(float x) {
	float tmp;
	if (x <= -10.0f) {
		tmp = copysignf(logf(-x), x);
	} else if (x <= 2.0f) {
		tmp = copysignf(x, x);
	} else {
		tmp = copysignf(logf((x + x)), x);
	}
	return tmp;
}
function code(x)
	tmp = Float32(0.0)
	if (x <= Float32(-10.0))
		tmp = copysign(log(Float32(-x)), x);
	elseif (x <= Float32(2.0))
		tmp = copysign(x, x);
	else
		tmp = copysign(log(Float32(x + x)), x);
	end
	return tmp
end
function tmp_2 = code(x)
	tmp = single(0.0);
	if (x <= single(-10.0))
		tmp = sign(x) * abs(log(-x));
	elseif (x <= single(2.0))
		tmp = sign(x) * abs(x);
	else
		tmp = sign(x) * abs(log((x + x)));
	end
	tmp_2 = tmp;
end
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;x \leq -10:\\
\;\;\;\;\mathsf{copysign}\left(\log \left(-x\right), x\right)\\

\mathbf{elif}\;x \leq 2:\\
\;\;\;\;\mathsf{copysign}\left(x, x\right)\\

\mathbf{else}:\\
\;\;\;\;\mathsf{copysign}\left(\log \left(x + x\right), x\right)\\


\end{array}
\end{array}
Derivation
  1. Split input into 3 regimes
  2. if x < -10

    1. Initial program 50.6%

      \[\mathsf{copysign}\left(\log \left(\left|x\right| + \sqrt{x \cdot x + 1}\right), x\right) \]
    2. Taylor expanded in x around -inf

      \[\leadsto \mathsf{copysign}\left(\log \color{blue}{\left(-1 \cdot x\right)}, x\right) \]
    3. Step-by-step derivation
      1. mul-1-negN/A

        \[\leadsto \mathsf{copysign}\left(\log \left(\mathsf{neg}\left(x\right)\right), x\right) \]
      2. lower-neg.f3244.6

        \[\leadsto \mathsf{copysign}\left(\log \left(-x\right), x\right) \]
    4. Applied rewrites44.6%

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

    if -10 < x < 2

    1. Initial program 23.8%

      \[\mathsf{copysign}\left(\log \left(\left|x\right| + \sqrt{x \cdot x + 1}\right), x\right) \]
    2. Step-by-step derivation
      1. lift-log.f32N/A

        \[\leadsto \mathsf{copysign}\left(\color{blue}{\log \left(\left|x\right| + \sqrt{x \cdot x + 1}\right)}, x\right) \]
      2. lift-+.f32N/A

        \[\leadsto \mathsf{copysign}\left(\log \color{blue}{\left(\left|x\right| + \sqrt{x \cdot x + 1}\right)}, x\right) \]
      3. lift-fabs.f32N/A

        \[\leadsto \mathsf{copysign}\left(\log \left(\color{blue}{\left|x\right|} + \sqrt{x \cdot x + 1}\right), x\right) \]
      4. lift-sqrt.f32N/A

        \[\leadsto \mathsf{copysign}\left(\log \left(\left|x\right| + \color{blue}{\sqrt{x \cdot x + 1}}\right), x\right) \]
      5. lift-*.f32N/A

        \[\leadsto \mathsf{copysign}\left(\log \left(\left|x\right| + \sqrt{\color{blue}{x \cdot x} + 1}\right), x\right) \]
      6. lift-+.f32N/A

        \[\leadsto \mathsf{copysign}\left(\log \left(\left|x\right| + \sqrt{\color{blue}{x \cdot x + 1}}\right), x\right) \]
      7. sqr-abs-revN/A

        \[\leadsto \mathsf{copysign}\left(\log \left(\left|x\right| + \sqrt{\color{blue}{\left|x\right| \cdot \left|x\right|} + 1}\right), x\right) \]
      8. asinh-def-revN/A

        \[\leadsto \mathsf{copysign}\left(\color{blue}{\sinh^{-1} \left(\left|x\right|\right)}, x\right) \]
      9. rem-sqrt-square-revN/A

        \[\leadsto \mathsf{copysign}\left(\sinh^{-1} \color{blue}{\left(\sqrt{x \cdot x}\right)}, x\right) \]
      10. pow2N/A

        \[\leadsto \mathsf{copysign}\left(\sinh^{-1} \left(\sqrt{\color{blue}{{x}^{2}}}\right), x\right) \]
      11. sqrt-pow1N/A

        \[\leadsto \mathsf{copysign}\left(\sinh^{-1} \color{blue}{\left({x}^{\left(\frac{2}{2}\right)}\right)}, x\right) \]
      12. metadata-evalN/A

        \[\leadsto \mathsf{copysign}\left(\sinh^{-1} \left({x}^{\color{blue}{1}}\right), x\right) \]
      13. unpow1N/A

        \[\leadsto \mathsf{copysign}\left(\sinh^{-1} \color{blue}{x}, x\right) \]
      14. lower-asinh.f3299.9

        \[\leadsto \mathsf{copysign}\left(\color{blue}{\sinh^{-1} x}, x\right) \]
    3. Applied rewrites99.9%

      \[\leadsto \color{blue}{\mathsf{copysign}\left(\sinh^{-1} x, x\right)} \]
    4. Taylor expanded in x around 0

      \[\leadsto \mathsf{copysign}\left(\color{blue}{x}, x\right) \]
    5. Step-by-step derivation
      1. unpow196.2

        \[\leadsto \mathsf{copysign}\left(x, x\right) \]
      2. metadata-eval96.2

        \[\leadsto \mathsf{copysign}\left(x, x\right) \]
      3. sqrt-pow196.2

        \[\leadsto \mathsf{copysign}\left(x, x\right) \]
      4. pow296.2

        \[\leadsto \mathsf{copysign}\left(x, x\right) \]
      5. rem-sqrt-square-rev96.2

        \[\leadsto \mathsf{copysign}\left(x, x\right) \]
      6. asinh-def-rev96.2

        \[\leadsto \mathsf{copysign}\left(x, x\right) \]
      7. sqr-abs-rev96.2

        \[\leadsto \mathsf{copysign}\left(x, x\right) \]
      8. pow296.2

        \[\leadsto \mathsf{copysign}\left(x, x\right) \]
      9. +-commutative96.2

        \[\leadsto \mathsf{copysign}\left(x, x\right) \]
      10. +-commutative96.2

        \[\leadsto \mathsf{copysign}\left(x, x\right) \]
      11. pow296.2

        \[\leadsto \mathsf{copysign}\left(x, x\right) \]
    6. Applied rewrites96.2%

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

    if 2 < x

    1. Initial program 53.3%

      \[\mathsf{copysign}\left(\log \left(\left|x\right| + \sqrt{x \cdot x + 1}\right), x\right) \]
    2. Step-by-step derivation
      1. lift-+.f32N/A

        \[\leadsto \mathsf{copysign}\left(\log \color{blue}{\left(\left|x\right| + \sqrt{x \cdot x + 1}\right)}, x\right) \]
      2. lift-fabs.f32N/A

        \[\leadsto \mathsf{copysign}\left(\log \left(\color{blue}{\left|x\right|} + \sqrt{x \cdot x + 1}\right), x\right) \]
      3. lift-sqrt.f32N/A

        \[\leadsto \mathsf{copysign}\left(\log \left(\left|x\right| + \color{blue}{\sqrt{x \cdot x + 1}}\right), x\right) \]
      4. lift-*.f32N/A

        \[\leadsto \mathsf{copysign}\left(\log \left(\left|x\right| + \sqrt{\color{blue}{x \cdot x} + 1}\right), x\right) \]
      5. lift-+.f32N/A

        \[\leadsto \mathsf{copysign}\left(\log \left(\left|x\right| + \sqrt{\color{blue}{x \cdot x + 1}}\right), x\right) \]
      6. +-commutativeN/A

        \[\leadsto \mathsf{copysign}\left(\log \color{blue}{\left(\sqrt{x \cdot x + 1} + \left|x\right|\right)}, x\right) \]
      7. rem-sqrt-square-revN/A

        \[\leadsto \mathsf{copysign}\left(\log \left(\sqrt{x \cdot x + 1} + \color{blue}{\sqrt{x \cdot x}}\right), x\right) \]
      8. pow2N/A

        \[\leadsto \mathsf{copysign}\left(\log \left(\sqrt{x \cdot x + 1} + \sqrt{\color{blue}{{x}^{2}}}\right), x\right) \]
      9. sqrt-pow1N/A

        \[\leadsto \mathsf{copysign}\left(\log \left(\sqrt{x \cdot x + 1} + \color{blue}{{x}^{\left(\frac{2}{2}\right)}}\right), x\right) \]
      10. metadata-evalN/A

        \[\leadsto \mathsf{copysign}\left(\log \left(\sqrt{x \cdot x + 1} + {x}^{\color{blue}{1}}\right), x\right) \]
      11. unpow1N/A

        \[\leadsto \mathsf{copysign}\left(\log \left(\sqrt{x \cdot x + 1} + \color{blue}{x}\right), x\right) \]
      12. lower-+.f32N/A

        \[\leadsto \mathsf{copysign}\left(\log \color{blue}{\left(\sqrt{x \cdot x + 1} + x\right)}, x\right) \]
      13. lower-sqrt.f32N/A

        \[\leadsto \mathsf{copysign}\left(\log \left(\color{blue}{\sqrt{x \cdot x + 1}} + x\right), x\right) \]
      14. lower-fma.f3253.3

        \[\leadsto \mathsf{copysign}\left(\log \left(\sqrt{\color{blue}{\mathsf{fma}\left(x, x, 1\right)}} + x\right), x\right) \]
    3. Applied rewrites53.3%

      \[\leadsto \mathsf{copysign}\left(\log \color{blue}{\left(\sqrt{\mathsf{fma}\left(x, x, 1\right)} + x\right)}, x\right) \]
    4. Taylor expanded in x around inf

      \[\leadsto \mathsf{copysign}\left(\log \left(\color{blue}{x} + x\right), x\right) \]
    5. Step-by-step derivation
      1. Applied rewrites97.4%

        \[\leadsto \mathsf{copysign}\left(\log \left(\color{blue}{x} + x\right), x\right) \]
    6. Recombined 3 regimes into one program.
    7. Add Preprocessing

    Alternative 3: 70.5% accurate, 0.4× speedup?

    \[\begin{array}{l} \\ \begin{array}{l} t_0 := \mathsf{copysign}\left(\log \left(\left|x\right| + \sqrt{x \cdot x + 1}\right), x\right)\\ \mathbf{if}\;t\_0 \leq -2:\\ \;\;\;\;\mathsf{copysign}\left(\log \left(-x\right), x\right)\\ \mathbf{elif}\;t\_0 \leq 1:\\ \;\;\;\;\mathsf{copysign}\left(x, x\right)\\ \mathbf{else}:\\ \;\;\;\;\mathsf{copysign}\left(\log \left(x - -1\right), x\right)\\ \end{array} \end{array} \]
    (FPCore (x)
     :precision binary32
     (let* ((t_0 (copysign (log (+ (fabs x) (sqrt (+ (* x x) 1.0)))) x)))
       (if (<= t_0 -2.0)
         (copysign (log (- x)) x)
         (if (<= t_0 1.0) (copysign x x) (copysign (log (- x -1.0)) x)))))
    float code(float x) {
    	float t_0 = copysignf(logf((fabsf(x) + sqrtf(((x * x) + 1.0f)))), x);
    	float tmp;
    	if (t_0 <= -2.0f) {
    		tmp = copysignf(logf(-x), x);
    	} else if (t_0 <= 1.0f) {
    		tmp = copysignf(x, x);
    	} else {
    		tmp = copysignf(logf((x - -1.0f)), x);
    	}
    	return tmp;
    }
    
    function code(x)
    	t_0 = copysign(log(Float32(abs(x) + sqrt(Float32(Float32(x * x) + Float32(1.0))))), x)
    	tmp = Float32(0.0)
    	if (t_0 <= Float32(-2.0))
    		tmp = copysign(log(Float32(-x)), x);
    	elseif (t_0 <= Float32(1.0))
    		tmp = copysign(x, x);
    	else
    		tmp = copysign(log(Float32(x - Float32(-1.0))), x);
    	end
    	return tmp
    end
    
    function tmp_2 = code(x)
    	t_0 = sign(x) * abs(log((abs(x) + sqrt(((x * x) + single(1.0))))));
    	tmp = single(0.0);
    	if (t_0 <= single(-2.0))
    		tmp = sign(x) * abs(log(-x));
    	elseif (t_0 <= single(1.0))
    		tmp = sign(x) * abs(x);
    	else
    		tmp = sign(x) * abs(log((x - single(-1.0))));
    	end
    	tmp_2 = tmp;
    end
    
    \begin{array}{l}
    
    \\
    \begin{array}{l}
    t_0 := \mathsf{copysign}\left(\log \left(\left|x\right| + \sqrt{x \cdot x + 1}\right), x\right)\\
    \mathbf{if}\;t\_0 \leq -2:\\
    \;\;\;\;\mathsf{copysign}\left(\log \left(-x\right), x\right)\\
    
    \mathbf{elif}\;t\_0 \leq 1:\\
    \;\;\;\;\mathsf{copysign}\left(x, x\right)\\
    
    \mathbf{else}:\\
    \;\;\;\;\mathsf{copysign}\left(\log \left(x - -1\right), x\right)\\
    
    
    \end{array}
    \end{array}
    
    Derivation
    1. Split input into 3 regimes
    2. if (copysign.f32 (log.f32 (+.f32 (fabs.f32 x) (sqrt.f32 (+.f32 (*.f32 x x) #s(literal 1 binary32))))) x) < -2

      1. Initial program 51.2%

        \[\mathsf{copysign}\left(\log \left(\left|x\right| + \sqrt{x \cdot x + 1}\right), x\right) \]
      2. Taylor expanded in x around -inf

        \[\leadsto \mathsf{copysign}\left(\log \color{blue}{\left(-1 \cdot x\right)}, x\right) \]
      3. Step-by-step derivation
        1. mul-1-negN/A

          \[\leadsto \mathsf{copysign}\left(\log \left(\mathsf{neg}\left(x\right)\right), x\right) \]
        2. lower-neg.f3244.4

          \[\leadsto \mathsf{copysign}\left(\log \left(-x\right), x\right) \]
      4. Applied rewrites44.4%

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

      if -2 < (copysign.f32 (log.f32 (+.f32 (fabs.f32 x) (sqrt.f32 (+.f32 (*.f32 x x) #s(literal 1 binary32))))) x) < 1

      1. Initial program 23.0%

        \[\mathsf{copysign}\left(\log \left(\left|x\right| + \sqrt{x \cdot x + 1}\right), x\right) \]
      2. Step-by-step derivation
        1. lift-log.f32N/A

          \[\leadsto \mathsf{copysign}\left(\color{blue}{\log \left(\left|x\right| + \sqrt{x \cdot x + 1}\right)}, x\right) \]
        2. lift-+.f32N/A

          \[\leadsto \mathsf{copysign}\left(\log \color{blue}{\left(\left|x\right| + \sqrt{x \cdot x + 1}\right)}, x\right) \]
        3. lift-fabs.f32N/A

          \[\leadsto \mathsf{copysign}\left(\log \left(\color{blue}{\left|x\right|} + \sqrt{x \cdot x + 1}\right), x\right) \]
        4. lift-sqrt.f32N/A

          \[\leadsto \mathsf{copysign}\left(\log \left(\left|x\right| + \color{blue}{\sqrt{x \cdot x + 1}}\right), x\right) \]
        5. lift-*.f32N/A

          \[\leadsto \mathsf{copysign}\left(\log \left(\left|x\right| + \sqrt{\color{blue}{x \cdot x} + 1}\right), x\right) \]
        6. lift-+.f32N/A

          \[\leadsto \mathsf{copysign}\left(\log \left(\left|x\right| + \sqrt{\color{blue}{x \cdot x + 1}}\right), x\right) \]
        7. sqr-abs-revN/A

          \[\leadsto \mathsf{copysign}\left(\log \left(\left|x\right| + \sqrt{\color{blue}{\left|x\right| \cdot \left|x\right|} + 1}\right), x\right) \]
        8. asinh-def-revN/A

          \[\leadsto \mathsf{copysign}\left(\color{blue}{\sinh^{-1} \left(\left|x\right|\right)}, x\right) \]
        9. rem-sqrt-square-revN/A

          \[\leadsto \mathsf{copysign}\left(\sinh^{-1} \color{blue}{\left(\sqrt{x \cdot x}\right)}, x\right) \]
        10. pow2N/A

          \[\leadsto \mathsf{copysign}\left(\sinh^{-1} \left(\sqrt{\color{blue}{{x}^{2}}}\right), x\right) \]
        11. sqrt-pow1N/A

          \[\leadsto \mathsf{copysign}\left(\sinh^{-1} \color{blue}{\left({x}^{\left(\frac{2}{2}\right)}\right)}, x\right) \]
        12. metadata-evalN/A

          \[\leadsto \mathsf{copysign}\left(\sinh^{-1} \left({x}^{\color{blue}{1}}\right), x\right) \]
        13. unpow1N/A

          \[\leadsto \mathsf{copysign}\left(\sinh^{-1} \color{blue}{x}, x\right) \]
        14. lower-asinh.f3299.9

          \[\leadsto \mathsf{copysign}\left(\color{blue}{\sinh^{-1} x}, x\right) \]
      3. Applied rewrites99.9%

        \[\leadsto \color{blue}{\mathsf{copysign}\left(\sinh^{-1} x, x\right)} \]
      4. Taylor expanded in x around 0

        \[\leadsto \mathsf{copysign}\left(\color{blue}{x}, x\right) \]
      5. Step-by-step derivation
        1. unpow196.9

          \[\leadsto \mathsf{copysign}\left(x, x\right) \]
        2. metadata-eval96.9

          \[\leadsto \mathsf{copysign}\left(x, x\right) \]
        3. sqrt-pow196.9

          \[\leadsto \mathsf{copysign}\left(x, x\right) \]
        4. pow296.9

          \[\leadsto \mathsf{copysign}\left(x, x\right) \]
        5. rem-sqrt-square-rev96.9

          \[\leadsto \mathsf{copysign}\left(x, x\right) \]
        6. asinh-def-rev96.9

          \[\leadsto \mathsf{copysign}\left(x, x\right) \]
        7. sqr-abs-rev96.9

          \[\leadsto \mathsf{copysign}\left(x, x\right) \]
        8. pow296.9

          \[\leadsto \mathsf{copysign}\left(x, x\right) \]
        9. +-commutative96.9

          \[\leadsto \mathsf{copysign}\left(x, x\right) \]
        10. +-commutative96.9

          \[\leadsto \mathsf{copysign}\left(x, x\right) \]
        11. pow296.9

          \[\leadsto \mathsf{copysign}\left(x, x\right) \]
      6. Applied rewrites96.9%

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

      if 1 < (copysign.f32 (log.f32 (+.f32 (fabs.f32 x) (sqrt.f32 (+.f32 (*.f32 x x) #s(literal 1 binary32))))) x)

      1. Initial program 53.6%

        \[\mathsf{copysign}\left(\log \left(\left|x\right| + \sqrt{x \cdot x + 1}\right), x\right) \]
      2. Step-by-step derivation
        1. lift-+.f32N/A

          \[\leadsto \mathsf{copysign}\left(\log \color{blue}{\left(\left|x\right| + \sqrt{x \cdot x + 1}\right)}, x\right) \]
        2. lift-fabs.f32N/A

          \[\leadsto \mathsf{copysign}\left(\log \left(\color{blue}{\left|x\right|} + \sqrt{x \cdot x + 1}\right), x\right) \]
        3. lift-sqrt.f32N/A

          \[\leadsto \mathsf{copysign}\left(\log \left(\left|x\right| + \color{blue}{\sqrt{x \cdot x + 1}}\right), x\right) \]
        4. lift-*.f32N/A

          \[\leadsto \mathsf{copysign}\left(\log \left(\left|x\right| + \sqrt{\color{blue}{x \cdot x} + 1}\right), x\right) \]
        5. lift-+.f32N/A

          \[\leadsto \mathsf{copysign}\left(\log \left(\left|x\right| + \sqrt{\color{blue}{x \cdot x + 1}}\right), x\right) \]
        6. +-commutativeN/A

          \[\leadsto \mathsf{copysign}\left(\log \color{blue}{\left(\sqrt{x \cdot x + 1} + \left|x\right|\right)}, x\right) \]
        7. rem-sqrt-square-revN/A

          \[\leadsto \mathsf{copysign}\left(\log \left(\sqrt{x \cdot x + 1} + \color{blue}{\sqrt{x \cdot x}}\right), x\right) \]
        8. pow2N/A

          \[\leadsto \mathsf{copysign}\left(\log \left(\sqrt{x \cdot x + 1} + \sqrt{\color{blue}{{x}^{2}}}\right), x\right) \]
        9. sqrt-pow1N/A

          \[\leadsto \mathsf{copysign}\left(\log \left(\sqrt{x \cdot x + 1} + \color{blue}{{x}^{\left(\frac{2}{2}\right)}}\right), x\right) \]
        10. metadata-evalN/A

          \[\leadsto \mathsf{copysign}\left(\log \left(\sqrt{x \cdot x + 1} + {x}^{\color{blue}{1}}\right), x\right) \]
        11. unpow1N/A

          \[\leadsto \mathsf{copysign}\left(\log \left(\sqrt{x \cdot x + 1} + \color{blue}{x}\right), x\right) \]
        12. lower-+.f32N/A

          \[\leadsto \mathsf{copysign}\left(\log \color{blue}{\left(\sqrt{x \cdot x + 1} + x\right)}, x\right) \]
        13. lower-sqrt.f32N/A

          \[\leadsto \mathsf{copysign}\left(\log \left(\color{blue}{\sqrt{x \cdot x + 1}} + x\right), x\right) \]
        14. lower-fma.f3253.6

          \[\leadsto \mathsf{copysign}\left(\log \left(\sqrt{\color{blue}{\mathsf{fma}\left(x, x, 1\right)}} + x\right), x\right) \]
      3. Applied rewrites53.6%

        \[\leadsto \mathsf{copysign}\left(\log \color{blue}{\left(\sqrt{\mathsf{fma}\left(x, x, 1\right)} + x\right)}, x\right) \]
      4. Taylor expanded in x around -inf

        \[\leadsto \mathsf{copysign}\left(\log \color{blue}{\left(\frac{\frac{-1}{2}}{x}\right)}, x\right) \]
      5. Step-by-step derivation
        1. lower-/.f32-0.0

          \[\leadsto \mathsf{copysign}\left(\log \left(\frac{-0.5}{\color{blue}{x}}\right), x\right) \]
      6. Applied rewrites-0.0%

        \[\leadsto \mathsf{copysign}\left(\log \color{blue}{\left(\frac{-0.5}{x}\right)}, x\right) \]
      7. Taylor expanded in x around 0

        \[\leadsto \mathsf{copysign}\left(\log \color{blue}{\left(1 + x\right)}, x\right) \]
      8. Step-by-step derivation
        1. +-commutativeN/A

          \[\leadsto \mathsf{copysign}\left(\log \left(x + \color{blue}{1}\right), x\right) \]
        2. metadata-evalN/A

          \[\leadsto \mathsf{copysign}\left(\log \left(x + 1 \cdot \color{blue}{1}\right), x\right) \]
        3. fp-cancel-sign-sub-invN/A

          \[\leadsto \mathsf{copysign}\left(\log \left(x - \color{blue}{\left(\mathsf{neg}\left(1\right)\right) \cdot 1}\right), x\right) \]
        4. metadata-evalN/A

          \[\leadsto \mathsf{copysign}\left(\log \left(x - -1 \cdot 1\right), x\right) \]
        5. metadata-evalN/A

          \[\leadsto \mathsf{copysign}\left(\log \left(x - -1\right), x\right) \]
        6. lower--.f3244.2

          \[\leadsto \mathsf{copysign}\left(\log \left(x - \color{blue}{-1}\right), x\right) \]
      9. Applied rewrites44.2%

        \[\leadsto \mathsf{copysign}\left(\log \color{blue}{\left(x - -1\right)}, x\right) \]
    3. Recombined 3 regimes into one program.
    4. Add Preprocessing

    Alternative 4: 70.5% accurate, 0.4× speedup?

    \[\begin{array}{l} \\ \begin{array}{l} t_0 := \mathsf{copysign}\left(\log \left(\left|x\right| + \sqrt{x \cdot x + 1}\right), x\right)\\ \mathbf{if}\;t\_0 \leq -2:\\ \;\;\;\;\mathsf{copysign}\left(\log \left(-x\right), x\right)\\ \mathbf{elif}\;t\_0 \leq 1:\\ \;\;\;\;\mathsf{copysign}\left(x, x\right)\\ \mathbf{else}:\\ \;\;\;\;\mathsf{copysign}\left(\log x, x\right)\\ \end{array} \end{array} \]
    (FPCore (x)
     :precision binary32
     (let* ((t_0 (copysign (log (+ (fabs x) (sqrt (+ (* x x) 1.0)))) x)))
       (if (<= t_0 -2.0)
         (copysign (log (- x)) x)
         (if (<= t_0 1.0) (copysign x x) (copysign (log x) x)))))
    float code(float x) {
    	float t_0 = copysignf(logf((fabsf(x) + sqrtf(((x * x) + 1.0f)))), x);
    	float tmp;
    	if (t_0 <= -2.0f) {
    		tmp = copysignf(logf(-x), x);
    	} else if (t_0 <= 1.0f) {
    		tmp = copysignf(x, x);
    	} else {
    		tmp = copysignf(logf(x), x);
    	}
    	return tmp;
    }
    
    function code(x)
    	t_0 = copysign(log(Float32(abs(x) + sqrt(Float32(Float32(x * x) + Float32(1.0))))), x)
    	tmp = Float32(0.0)
    	if (t_0 <= Float32(-2.0))
    		tmp = copysign(log(Float32(-x)), x);
    	elseif (t_0 <= Float32(1.0))
    		tmp = copysign(x, x);
    	else
    		tmp = copysign(log(x), x);
    	end
    	return tmp
    end
    
    function tmp_2 = code(x)
    	t_0 = sign(x) * abs(log((abs(x) + sqrt(((x * x) + single(1.0))))));
    	tmp = single(0.0);
    	if (t_0 <= single(-2.0))
    		tmp = sign(x) * abs(log(-x));
    	elseif (t_0 <= single(1.0))
    		tmp = sign(x) * abs(x);
    	else
    		tmp = sign(x) * abs(log(x));
    	end
    	tmp_2 = tmp;
    end
    
    \begin{array}{l}
    
    \\
    \begin{array}{l}
    t_0 := \mathsf{copysign}\left(\log \left(\left|x\right| + \sqrt{x \cdot x + 1}\right), x\right)\\
    \mathbf{if}\;t\_0 \leq -2:\\
    \;\;\;\;\mathsf{copysign}\left(\log \left(-x\right), x\right)\\
    
    \mathbf{elif}\;t\_0 \leq 1:\\
    \;\;\;\;\mathsf{copysign}\left(x, x\right)\\
    
    \mathbf{else}:\\
    \;\;\;\;\mathsf{copysign}\left(\log x, x\right)\\
    
    
    \end{array}
    \end{array}
    
    Derivation
    1. Split input into 3 regimes
    2. if (copysign.f32 (log.f32 (+.f32 (fabs.f32 x) (sqrt.f32 (+.f32 (*.f32 x x) #s(literal 1 binary32))))) x) < -2

      1. Initial program 51.2%

        \[\mathsf{copysign}\left(\log \left(\left|x\right| + \sqrt{x \cdot x + 1}\right), x\right) \]
      2. Taylor expanded in x around -inf

        \[\leadsto \mathsf{copysign}\left(\log \color{blue}{\left(-1 \cdot x\right)}, x\right) \]
      3. Step-by-step derivation
        1. mul-1-negN/A

          \[\leadsto \mathsf{copysign}\left(\log \left(\mathsf{neg}\left(x\right)\right), x\right) \]
        2. lower-neg.f3244.4

          \[\leadsto \mathsf{copysign}\left(\log \left(-x\right), x\right) \]
      4. Applied rewrites44.4%

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

      if -2 < (copysign.f32 (log.f32 (+.f32 (fabs.f32 x) (sqrt.f32 (+.f32 (*.f32 x x) #s(literal 1 binary32))))) x) < 1

      1. Initial program 23.0%

        \[\mathsf{copysign}\left(\log \left(\left|x\right| + \sqrt{x \cdot x + 1}\right), x\right) \]
      2. Step-by-step derivation
        1. lift-log.f32N/A

          \[\leadsto \mathsf{copysign}\left(\color{blue}{\log \left(\left|x\right| + \sqrt{x \cdot x + 1}\right)}, x\right) \]
        2. lift-+.f32N/A

          \[\leadsto \mathsf{copysign}\left(\log \color{blue}{\left(\left|x\right| + \sqrt{x \cdot x + 1}\right)}, x\right) \]
        3. lift-fabs.f32N/A

          \[\leadsto \mathsf{copysign}\left(\log \left(\color{blue}{\left|x\right|} + \sqrt{x \cdot x + 1}\right), x\right) \]
        4. lift-sqrt.f32N/A

          \[\leadsto \mathsf{copysign}\left(\log \left(\left|x\right| + \color{blue}{\sqrt{x \cdot x + 1}}\right), x\right) \]
        5. lift-*.f32N/A

          \[\leadsto \mathsf{copysign}\left(\log \left(\left|x\right| + \sqrt{\color{blue}{x \cdot x} + 1}\right), x\right) \]
        6. lift-+.f32N/A

          \[\leadsto \mathsf{copysign}\left(\log \left(\left|x\right| + \sqrt{\color{blue}{x \cdot x + 1}}\right), x\right) \]
        7. sqr-abs-revN/A

          \[\leadsto \mathsf{copysign}\left(\log \left(\left|x\right| + \sqrt{\color{blue}{\left|x\right| \cdot \left|x\right|} + 1}\right), x\right) \]
        8. asinh-def-revN/A

          \[\leadsto \mathsf{copysign}\left(\color{blue}{\sinh^{-1} \left(\left|x\right|\right)}, x\right) \]
        9. rem-sqrt-square-revN/A

          \[\leadsto \mathsf{copysign}\left(\sinh^{-1} \color{blue}{\left(\sqrt{x \cdot x}\right)}, x\right) \]
        10. pow2N/A

          \[\leadsto \mathsf{copysign}\left(\sinh^{-1} \left(\sqrt{\color{blue}{{x}^{2}}}\right), x\right) \]
        11. sqrt-pow1N/A

          \[\leadsto \mathsf{copysign}\left(\sinh^{-1} \color{blue}{\left({x}^{\left(\frac{2}{2}\right)}\right)}, x\right) \]
        12. metadata-evalN/A

          \[\leadsto \mathsf{copysign}\left(\sinh^{-1} \left({x}^{\color{blue}{1}}\right), x\right) \]
        13. unpow1N/A

          \[\leadsto \mathsf{copysign}\left(\sinh^{-1} \color{blue}{x}, x\right) \]
        14. lower-asinh.f3299.9

          \[\leadsto \mathsf{copysign}\left(\color{blue}{\sinh^{-1} x}, x\right) \]
      3. Applied rewrites99.9%

        \[\leadsto \color{blue}{\mathsf{copysign}\left(\sinh^{-1} x, x\right)} \]
      4. Taylor expanded in x around 0

        \[\leadsto \mathsf{copysign}\left(\color{blue}{x}, x\right) \]
      5. Step-by-step derivation
        1. unpow196.9

          \[\leadsto \mathsf{copysign}\left(x, x\right) \]
        2. metadata-eval96.9

          \[\leadsto \mathsf{copysign}\left(x, x\right) \]
        3. sqrt-pow196.9

          \[\leadsto \mathsf{copysign}\left(x, x\right) \]
        4. pow296.9

          \[\leadsto \mathsf{copysign}\left(x, x\right) \]
        5. rem-sqrt-square-rev96.9

          \[\leadsto \mathsf{copysign}\left(x, x\right) \]
        6. asinh-def-rev96.9

          \[\leadsto \mathsf{copysign}\left(x, x\right) \]
        7. sqr-abs-rev96.9

          \[\leadsto \mathsf{copysign}\left(x, x\right) \]
        8. pow296.9

          \[\leadsto \mathsf{copysign}\left(x, x\right) \]
        9. +-commutative96.9

          \[\leadsto \mathsf{copysign}\left(x, x\right) \]
        10. +-commutative96.9

          \[\leadsto \mathsf{copysign}\left(x, x\right) \]
        11. pow296.9

          \[\leadsto \mathsf{copysign}\left(x, x\right) \]
      6. Applied rewrites96.9%

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

      if 1 < (copysign.f32 (log.f32 (+.f32 (fabs.f32 x) (sqrt.f32 (+.f32 (*.f32 x x) #s(literal 1 binary32))))) x)

      1. Initial program 53.6%

        \[\mathsf{copysign}\left(\log \left(\left|x\right| + \sqrt{x \cdot x + 1}\right), x\right) \]
      2. Taylor expanded in x around inf

        \[\leadsto \mathsf{copysign}\left(\log \color{blue}{x}, x\right) \]
      3. Step-by-step derivation
        1. Applied rewrites44.1%

          \[\leadsto \mathsf{copysign}\left(\log \color{blue}{x}, x\right) \]
      4. Recombined 3 regimes into one program.
      5. Add Preprocessing

      Alternative 5: 62.0% accurate, 0.6× speedup?

      \[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;\mathsf{copysign}\left(\log \left(\left|x\right| + \sqrt{x \cdot x + 1}\right), x\right) \leq 1:\\ \;\;\;\;\mathsf{copysign}\left(x, x\right)\\ \mathbf{else}:\\ \;\;\;\;\mathsf{copysign}\left(\log x, x\right)\\ \end{array} \end{array} \]
      (FPCore (x)
       :precision binary32
       (if (<= (copysign (log (+ (fabs x) (sqrt (+ (* x x) 1.0)))) x) 1.0)
         (copysign x x)
         (copysign (log x) x)))
      float code(float x) {
      	float tmp;
      	if (copysignf(logf((fabsf(x) + sqrtf(((x * x) + 1.0f)))), x) <= 1.0f) {
      		tmp = copysignf(x, x);
      	} else {
      		tmp = copysignf(logf(x), x);
      	}
      	return tmp;
      }
      
      function code(x)
      	tmp = Float32(0.0)
      	if (copysign(log(Float32(abs(x) + sqrt(Float32(Float32(x * x) + Float32(1.0))))), x) <= Float32(1.0))
      		tmp = copysign(x, x);
      	else
      		tmp = copysign(log(x), x);
      	end
      	return tmp
      end
      
      function tmp_2 = code(x)
      	tmp = single(0.0);
      	if ((sign(x) * abs(log((abs(x) + sqrt(((x * x) + single(1.0))))))) <= single(1.0))
      		tmp = sign(x) * abs(x);
      	else
      		tmp = sign(x) * abs(log(x));
      	end
      	tmp_2 = tmp;
      end
      
      \begin{array}{l}
      
      \\
      \begin{array}{l}
      \mathbf{if}\;\mathsf{copysign}\left(\log \left(\left|x\right| + \sqrt{x \cdot x + 1}\right), x\right) \leq 1:\\
      \;\;\;\;\mathsf{copysign}\left(x, x\right)\\
      
      \mathbf{else}:\\
      \;\;\;\;\mathsf{copysign}\left(\log x, x\right)\\
      
      
      \end{array}
      \end{array}
      
      Derivation
      1. Split input into 2 regimes
      2. if (copysign.f32 (log.f32 (+.f32 (fabs.f32 x) (sqrt.f32 (+.f32 (*.f32 x x) #s(literal 1 binary32))))) x) < 1

        1. Initial program 32.5%

          \[\mathsf{copysign}\left(\log \left(\left|x\right| + \sqrt{x \cdot x + 1}\right), x\right) \]
        2. Step-by-step derivation
          1. lift-log.f32N/A

            \[\leadsto \mathsf{copysign}\left(\color{blue}{\log \left(\left|x\right| + \sqrt{x \cdot x + 1}\right)}, x\right) \]
          2. lift-+.f32N/A

            \[\leadsto \mathsf{copysign}\left(\log \color{blue}{\left(\left|x\right| + \sqrt{x \cdot x + 1}\right)}, x\right) \]
          3. lift-fabs.f32N/A

            \[\leadsto \mathsf{copysign}\left(\log \left(\color{blue}{\left|x\right|} + \sqrt{x \cdot x + 1}\right), x\right) \]
          4. lift-sqrt.f32N/A

            \[\leadsto \mathsf{copysign}\left(\log \left(\left|x\right| + \color{blue}{\sqrt{x \cdot x + 1}}\right), x\right) \]
          5. lift-*.f32N/A

            \[\leadsto \mathsf{copysign}\left(\log \left(\left|x\right| + \sqrt{\color{blue}{x \cdot x} + 1}\right), x\right) \]
          6. lift-+.f32N/A

            \[\leadsto \mathsf{copysign}\left(\log \left(\left|x\right| + \sqrt{\color{blue}{x \cdot x + 1}}\right), x\right) \]
          7. sqr-abs-revN/A

            \[\leadsto \mathsf{copysign}\left(\log \left(\left|x\right| + \sqrt{\color{blue}{\left|x\right| \cdot \left|x\right|} + 1}\right), x\right) \]
          8. asinh-def-revN/A

            \[\leadsto \mathsf{copysign}\left(\color{blue}{\sinh^{-1} \left(\left|x\right|\right)}, x\right) \]
          9. rem-sqrt-square-revN/A

            \[\leadsto \mathsf{copysign}\left(\sinh^{-1} \color{blue}{\left(\sqrt{x \cdot x}\right)}, x\right) \]
          10. pow2N/A

            \[\leadsto \mathsf{copysign}\left(\sinh^{-1} \left(\sqrt{\color{blue}{{x}^{2}}}\right), x\right) \]
          11. sqrt-pow1N/A

            \[\leadsto \mathsf{copysign}\left(\sinh^{-1} \color{blue}{\left({x}^{\left(\frac{2}{2}\right)}\right)}, x\right) \]
          12. metadata-evalN/A

            \[\leadsto \mathsf{copysign}\left(\sinh^{-1} \left({x}^{\color{blue}{1}}\right), x\right) \]
          13. unpow1N/A

            \[\leadsto \mathsf{copysign}\left(\sinh^{-1} \color{blue}{x}, x\right) \]
          14. lower-asinh.f3299.7

            \[\leadsto \mathsf{copysign}\left(\color{blue}{\sinh^{-1} x}, x\right) \]
        3. Applied rewrites99.7%

          \[\leadsto \color{blue}{\mathsf{copysign}\left(\sinh^{-1} x, x\right)} \]
        4. Taylor expanded in x around 0

          \[\leadsto \mathsf{copysign}\left(\color{blue}{x}, x\right) \]
        5. Step-by-step derivation
          1. unpow168.1

            \[\leadsto \mathsf{copysign}\left(x, x\right) \]
          2. metadata-eval68.1

            \[\leadsto \mathsf{copysign}\left(x, x\right) \]
          3. sqrt-pow168.1

            \[\leadsto \mathsf{copysign}\left(x, x\right) \]
          4. pow268.1

            \[\leadsto \mathsf{copysign}\left(x, x\right) \]
          5. rem-sqrt-square-rev68.1

            \[\leadsto \mathsf{copysign}\left(x, x\right) \]
          6. asinh-def-rev68.1

            \[\leadsto \mathsf{copysign}\left(x, x\right) \]
          7. sqr-abs-rev68.1

            \[\leadsto \mathsf{copysign}\left(x, x\right) \]
          8. pow268.1

            \[\leadsto \mathsf{copysign}\left(x, x\right) \]
          9. +-commutative68.1

            \[\leadsto \mathsf{copysign}\left(x, x\right) \]
          10. +-commutative68.1

            \[\leadsto \mathsf{copysign}\left(x, x\right) \]
          11. pow268.1

            \[\leadsto \mathsf{copysign}\left(x, x\right) \]
        6. Applied rewrites68.1%

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

        if 1 < (copysign.f32 (log.f32 (+.f32 (fabs.f32 x) (sqrt.f32 (+.f32 (*.f32 x x) #s(literal 1 binary32))))) x)

        1. Initial program 53.6%

          \[\mathsf{copysign}\left(\log \left(\left|x\right| + \sqrt{x \cdot x + 1}\right), x\right) \]
        2. Taylor expanded in x around inf

          \[\leadsto \mathsf{copysign}\left(\log \color{blue}{x}, x\right) \]
        3. Step-by-step derivation
          1. Applied rewrites44.1%

            \[\leadsto \mathsf{copysign}\left(\log \color{blue}{x}, x\right) \]
        4. Recombined 2 regimes into one program.
        5. Add Preprocessing

        Alternative 6: 53.9% accurate, 5.8× speedup?

        \[\begin{array}{l} \\ \mathsf{copysign}\left(x, x\right) \end{array} \]
        (FPCore (x) :precision binary32 (copysign x x))
        float code(float x) {
        	return copysignf(x, x);
        }
        
        function code(x)
        	return copysign(x, x)
        end
        
        function tmp = code(x)
        	tmp = sign(x) * abs(x);
        end
        
        \begin{array}{l}
        
        \\
        \mathsf{copysign}\left(x, x\right)
        \end{array}
        
        Derivation
        1. Initial program 37.8%

          \[\mathsf{copysign}\left(\log \left(\left|x\right| + \sqrt{x \cdot x + 1}\right), x\right) \]
        2. Step-by-step derivation
          1. lift-log.f32N/A

            \[\leadsto \mathsf{copysign}\left(\color{blue}{\log \left(\left|x\right| + \sqrt{x \cdot x + 1}\right)}, x\right) \]
          2. lift-+.f32N/A

            \[\leadsto \mathsf{copysign}\left(\log \color{blue}{\left(\left|x\right| + \sqrt{x \cdot x + 1}\right)}, x\right) \]
          3. lift-fabs.f32N/A

            \[\leadsto \mathsf{copysign}\left(\log \left(\color{blue}{\left|x\right|} + \sqrt{x \cdot x + 1}\right), x\right) \]
          4. lift-sqrt.f32N/A

            \[\leadsto \mathsf{copysign}\left(\log \left(\left|x\right| + \color{blue}{\sqrt{x \cdot x + 1}}\right), x\right) \]
          5. lift-*.f32N/A

            \[\leadsto \mathsf{copysign}\left(\log \left(\left|x\right| + \sqrt{\color{blue}{x \cdot x} + 1}\right), x\right) \]
          6. lift-+.f32N/A

            \[\leadsto \mathsf{copysign}\left(\log \left(\left|x\right| + \sqrt{\color{blue}{x \cdot x + 1}}\right), x\right) \]
          7. sqr-abs-revN/A

            \[\leadsto \mathsf{copysign}\left(\log \left(\left|x\right| + \sqrt{\color{blue}{\left|x\right| \cdot \left|x\right|} + 1}\right), x\right) \]
          8. asinh-def-revN/A

            \[\leadsto \mathsf{copysign}\left(\color{blue}{\sinh^{-1} \left(\left|x\right|\right)}, x\right) \]
          9. rem-sqrt-square-revN/A

            \[\leadsto \mathsf{copysign}\left(\sinh^{-1} \color{blue}{\left(\sqrt{x \cdot x}\right)}, x\right) \]
          10. pow2N/A

            \[\leadsto \mathsf{copysign}\left(\sinh^{-1} \left(\sqrt{\color{blue}{{x}^{2}}}\right), x\right) \]
          11. sqrt-pow1N/A

            \[\leadsto \mathsf{copysign}\left(\sinh^{-1} \color{blue}{\left({x}^{\left(\frac{2}{2}\right)}\right)}, x\right) \]
          12. metadata-evalN/A

            \[\leadsto \mathsf{copysign}\left(\sinh^{-1} \left({x}^{\color{blue}{1}}\right), x\right) \]
          13. unpow1N/A

            \[\leadsto \mathsf{copysign}\left(\sinh^{-1} \color{blue}{x}, x\right) \]
          14. lower-asinh.f3299.5

            \[\leadsto \mathsf{copysign}\left(\color{blue}{\sinh^{-1} x}, x\right) \]
        3. Applied rewrites99.5%

          \[\leadsto \color{blue}{\mathsf{copysign}\left(\sinh^{-1} x, x\right)} \]
        4. Taylor expanded in x around 0

          \[\leadsto \mathsf{copysign}\left(\color{blue}{x}, x\right) \]
        5. Step-by-step derivation
          1. unpow153.9

            \[\leadsto \mathsf{copysign}\left(x, x\right) \]
          2. metadata-eval53.9

            \[\leadsto \mathsf{copysign}\left(x, x\right) \]
          3. sqrt-pow153.9

            \[\leadsto \mathsf{copysign}\left(x, x\right) \]
          4. pow253.9

            \[\leadsto \mathsf{copysign}\left(x, x\right) \]
          5. rem-sqrt-square-rev53.9

            \[\leadsto \mathsf{copysign}\left(x, x\right) \]
          6. asinh-def-rev53.9

            \[\leadsto \mathsf{copysign}\left(x, x\right) \]
          7. sqr-abs-rev53.9

            \[\leadsto \mathsf{copysign}\left(x, x\right) \]
          8. pow253.9

            \[\leadsto \mathsf{copysign}\left(x, x\right) \]
          9. +-commutative53.9

            \[\leadsto \mathsf{copysign}\left(x, x\right) \]
          10. +-commutative53.9

            \[\leadsto \mathsf{copysign}\left(x, x\right) \]
          11. pow253.9

            \[\leadsto \mathsf{copysign}\left(x, x\right) \]
        6. Applied rewrites53.9%

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

        Developer Target 1: 99.6% accurate, 0.4× speedup?

        \[\begin{array}{l} \\ \begin{array}{l} t_0 := \frac{1}{\left|x\right|}\\ \mathsf{copysign}\left(\mathsf{log1p}\left(\left|x\right| + \frac{\left|x\right|}{\mathsf{hypot}\left(1, t\_0\right) + t\_0}\right), x\right) \end{array} \end{array} \]
        (FPCore (x)
         :precision binary32
         (let* ((t_0 (/ 1.0 (fabs x))))
           (copysign (log1p (+ (fabs x) (/ (fabs x) (+ (hypot 1.0 t_0) t_0)))) x)))
        float code(float x) {
        	float t_0 = 1.0f / fabsf(x);
        	return copysignf(log1pf((fabsf(x) + (fabsf(x) / (hypotf(1.0f, t_0) + t_0)))), x);
        }
        
        function code(x)
        	t_0 = Float32(Float32(1.0) / abs(x))
        	return copysign(log1p(Float32(abs(x) + Float32(abs(x) / Float32(hypot(Float32(1.0), t_0) + t_0)))), x)
        end
        
        \begin{array}{l}
        
        \\
        \begin{array}{l}
        t_0 := \frac{1}{\left|x\right|}\\
        \mathsf{copysign}\left(\mathsf{log1p}\left(\left|x\right| + \frac{\left|x\right|}{\mathsf{hypot}\left(1, t\_0\right) + t\_0}\right), x\right)
        \end{array}
        \end{array}
        

        Reproduce

        ?
        herbie shell --seed 2025112 
        (FPCore (x)
          :name "Rust f32::asinh"
          :precision binary32
        
          :alt
          (! :herbie-platform c (let* ((ax (fabs x)) (ix (/ 1 ax))) (copysign (log1p (+ ax (/ ax (+ (hypot 1 ix) ix)))) x)))
        
          (copysign (log (+ (fabs x) (sqrt (+ (* x x) 1.0)))) x))