Quotient of sum of exps

Percentage Accurate: 99.1% → 99.1%
Time: 5.8s
Alternatives: 14
Speedup: 1.0×

Specification

?
\[\begin{array}{l} \\ \frac{e^{a}}{e^{a} + e^{b}} \end{array} \]
(FPCore (a b) :precision binary64 (/ (exp a) (+ (exp a) (exp b))))
double code(double a, double b) {
	return exp(a) / (exp(a) + exp(b));
}
real(8) function code(a, b)
    real(8), intent (in) :: a
    real(8), intent (in) :: b
    code = exp(a) / (exp(a) + exp(b))
end function
public static double code(double a, double b) {
	return Math.exp(a) / (Math.exp(a) + Math.exp(b));
}
def code(a, b):
	return math.exp(a) / (math.exp(a) + math.exp(b))
function code(a, b)
	return Float64(exp(a) / Float64(exp(a) + exp(b)))
end
function tmp = code(a, b)
	tmp = exp(a) / (exp(a) + exp(b));
end
code[a_, b_] := N[(N[Exp[a], $MachinePrecision] / N[(N[Exp[a], $MachinePrecision] + N[Exp[b], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
\frac{e^{a}}{e^{a} + e^{b}}
\end{array}

Sampling outcomes in binary64 precision:

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 14 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: 99.1% accurate, 1.0× speedup?

\[\begin{array}{l} \\ \frac{e^{a}}{e^{a} + e^{b}} \end{array} \]
(FPCore (a b) :precision binary64 (/ (exp a) (+ (exp a) (exp b))))
double code(double a, double b) {
	return exp(a) / (exp(a) + exp(b));
}
real(8) function code(a, b)
    real(8), intent (in) :: a
    real(8), intent (in) :: b
    code = exp(a) / (exp(a) + exp(b))
end function
public static double code(double a, double b) {
	return Math.exp(a) / (Math.exp(a) + Math.exp(b));
}
def code(a, b):
	return math.exp(a) / (math.exp(a) + math.exp(b))
function code(a, b)
	return Float64(exp(a) / Float64(exp(a) + exp(b)))
end
function tmp = code(a, b)
	tmp = exp(a) / (exp(a) + exp(b));
end
code[a_, b_] := N[(N[Exp[a], $MachinePrecision] / N[(N[Exp[a], $MachinePrecision] + N[Exp[b], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
\frac{e^{a}}{e^{a} + e^{b}}
\end{array}

Alternative 1: 99.1% accurate, 1.0× speedup?

\[\begin{array}{l} \\ \frac{e^{a}}{e^{a} + e^{b}} \end{array} \]
(FPCore (a b) :precision binary64 (/ (exp a) (+ (exp a) (exp b))))
double code(double a, double b) {
	return exp(a) / (exp(a) + exp(b));
}
real(8) function code(a, b)
    real(8), intent (in) :: a
    real(8), intent (in) :: b
    code = exp(a) / (exp(a) + exp(b))
end function
public static double code(double a, double b) {
	return Math.exp(a) / (Math.exp(a) + Math.exp(b));
}
def code(a, b):
	return math.exp(a) / (math.exp(a) + math.exp(b))
function code(a, b)
	return Float64(exp(a) / Float64(exp(a) + exp(b)))
end
function tmp = code(a, b)
	tmp = exp(a) / (exp(a) + exp(b));
end
code[a_, b_] := N[(N[Exp[a], $MachinePrecision] / N[(N[Exp[a], $MachinePrecision] + N[Exp[b], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
\frac{e^{a}}{e^{a} + e^{b}}
\end{array}
Derivation
  1. Initial program 98.8%

    \[\frac{e^{a}}{e^{a} + e^{b}} \]
  2. Add Preprocessing
  3. Add Preprocessing

Alternative 2: 52.9% accurate, 0.7× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;\frac{e^{a}}{e^{a} + e^{b}} \leq 0.49:\\ \;\;\;\;{\left(\mathsf{fma}\left(0.5 \cdot b, b, 2\right)\right)}^{-1}\\ \mathbf{else}:\\ \;\;\;\;0.5\\ \end{array} \end{array} \]
(FPCore (a b)
 :precision binary64
 (if (<= (/ (exp a) (+ (exp a) (exp b))) 0.49)
   (pow (fma (* 0.5 b) b 2.0) -1.0)
   0.5))
double code(double a, double b) {
	double tmp;
	if ((exp(a) / (exp(a) + exp(b))) <= 0.49) {
		tmp = pow(fma((0.5 * b), b, 2.0), -1.0);
	} else {
		tmp = 0.5;
	}
	return tmp;
}
function code(a, b)
	tmp = 0.0
	if (Float64(exp(a) / Float64(exp(a) + exp(b))) <= 0.49)
		tmp = fma(Float64(0.5 * b), b, 2.0) ^ -1.0;
	else
		tmp = 0.5;
	end
	return tmp
end
code[a_, b_] := If[LessEqual[N[(N[Exp[a], $MachinePrecision] / N[(N[Exp[a], $MachinePrecision] + N[Exp[b], $MachinePrecision]), $MachinePrecision]), $MachinePrecision], 0.49], N[Power[N[(N[(0.5 * b), $MachinePrecision] * b + 2.0), $MachinePrecision], -1.0], $MachinePrecision], 0.5]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;\frac{e^{a}}{e^{a} + e^{b}} \leq 0.49:\\
\;\;\;\;{\left(\mathsf{fma}\left(0.5 \cdot b, b, 2\right)\right)}^{-1}\\

\mathbf{else}:\\
\;\;\;\;0.5\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if (/.f64 (exp.f64 a) (+.f64 (exp.f64 a) (exp.f64 b))) < 0.48999999999999999

    1. Initial program 100.0%

      \[\frac{e^{a}}{e^{a} + e^{b}} \]
    2. Add Preprocessing
    3. Taylor expanded in a around 0

      \[\leadsto \color{blue}{\frac{1}{1 + e^{b}}} \]
    4. Step-by-step derivation
      1. lower-/.f64N/A

        \[\leadsto \color{blue}{\frac{1}{1 + e^{b}}} \]
      2. +-commutativeN/A

        \[\leadsto \frac{1}{\color{blue}{e^{b} + 1}} \]
      3. lower-+.f64N/A

        \[\leadsto \frac{1}{\color{blue}{e^{b} + 1}} \]
      4. lower-exp.f6466.1

        \[\leadsto \frac{1}{\color{blue}{e^{b}} + 1} \]
    5. Applied rewrites66.1%

      \[\leadsto \color{blue}{\frac{1}{e^{b} + 1}} \]
    6. Taylor expanded in b around 0

      \[\leadsto \frac{1}{2 + \color{blue}{b \cdot \left(1 + \frac{1}{2} \cdot b\right)}} \]
    7. Step-by-step derivation
      1. Applied rewrites35.4%

        \[\leadsto \frac{1}{\mathsf{fma}\left(\mathsf{fma}\left(0.5, b, 1\right), \color{blue}{b}, 2\right)} \]
      2. Taylor expanded in b around inf

        \[\leadsto \frac{1}{\mathsf{fma}\left(\frac{1}{2} \cdot b, b, 2\right)} \]
      3. Step-by-step derivation
        1. Applied rewrites35.3%

          \[\leadsto \frac{1}{\mathsf{fma}\left(0.5 \cdot b, b, 2\right)} \]

        if 0.48999999999999999 < (/.f64 (exp.f64 a) (+.f64 (exp.f64 a) (exp.f64 b)))

        1. Initial program 97.8%

          \[\frac{e^{a}}{e^{a} + e^{b}} \]
        2. Add Preprocessing
        3. Taylor expanded in a around 0

          \[\leadsto \color{blue}{\frac{1}{1 + e^{b}}} \]
        4. Step-by-step derivation
          1. lower-/.f64N/A

            \[\leadsto \color{blue}{\frac{1}{1 + e^{b}}} \]
          2. +-commutativeN/A

            \[\leadsto \frac{1}{\color{blue}{e^{b} + 1}} \]
          3. lower-+.f64N/A

            \[\leadsto \frac{1}{\color{blue}{e^{b} + 1}} \]
          4. lower-exp.f6497.1

            \[\leadsto \frac{1}{\color{blue}{e^{b}} + 1} \]
        5. Applied rewrites97.1%

          \[\leadsto \color{blue}{\frac{1}{e^{b} + 1}} \]
        6. Taylor expanded in b around 0

          \[\leadsto \frac{1}{2} \]
        7. Step-by-step derivation
          1. Applied rewrites70.3%

            \[\leadsto 0.5 \]
        8. Recombined 2 regimes into one program.
        9. Final simplification54.3%

          \[\leadsto \begin{array}{l} \mathbf{if}\;\frac{e^{a}}{e^{a} + e^{b}} \leq 0.49:\\ \;\;\;\;{\left(\mathsf{fma}\left(0.5 \cdot b, b, 2\right)\right)}^{-1}\\ \mathbf{else}:\\ \;\;\;\;0.5\\ \end{array} \]
        10. Add Preprocessing

        Alternative 3: 98.4% accurate, 1.5× speedup?

        \[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;a \leq -520000:\\ \;\;\;\;\frac{e^{a}}{2}\\ \mathbf{else}:\\ \;\;\;\;{\left(e^{b} + 1\right)}^{-1}\\ \end{array} \end{array} \]
        (FPCore (a b)
         :precision binary64
         (if (<= a -520000.0) (/ (exp a) 2.0) (pow (+ (exp b) 1.0) -1.0)))
        double code(double a, double b) {
        	double tmp;
        	if (a <= -520000.0) {
        		tmp = exp(a) / 2.0;
        	} else {
        		tmp = pow((exp(b) + 1.0), -1.0);
        	}
        	return tmp;
        }
        
        real(8) function code(a, b)
            real(8), intent (in) :: a
            real(8), intent (in) :: b
            real(8) :: tmp
            if (a <= (-520000.0d0)) then
                tmp = exp(a) / 2.0d0
            else
                tmp = (exp(b) + 1.0d0) ** (-1.0d0)
            end if
            code = tmp
        end function
        
        public static double code(double a, double b) {
        	double tmp;
        	if (a <= -520000.0) {
        		tmp = Math.exp(a) / 2.0;
        	} else {
        		tmp = Math.pow((Math.exp(b) + 1.0), -1.0);
        	}
        	return tmp;
        }
        
        def code(a, b):
        	tmp = 0
        	if a <= -520000.0:
        		tmp = math.exp(a) / 2.0
        	else:
        		tmp = math.pow((math.exp(b) + 1.0), -1.0)
        	return tmp
        
        function code(a, b)
        	tmp = 0.0
        	if (a <= -520000.0)
        		tmp = Float64(exp(a) / 2.0);
        	else
        		tmp = Float64(exp(b) + 1.0) ^ -1.0;
        	end
        	return tmp
        end
        
        function tmp_2 = code(a, b)
        	tmp = 0.0;
        	if (a <= -520000.0)
        		tmp = exp(a) / 2.0;
        	else
        		tmp = (exp(b) + 1.0) ^ -1.0;
        	end
        	tmp_2 = tmp;
        end
        
        code[a_, b_] := If[LessEqual[a, -520000.0], N[(N[Exp[a], $MachinePrecision] / 2.0), $MachinePrecision], N[Power[N[(N[Exp[b], $MachinePrecision] + 1.0), $MachinePrecision], -1.0], $MachinePrecision]]
        
        \begin{array}{l}
        
        \\
        \begin{array}{l}
        \mathbf{if}\;a \leq -520000:\\
        \;\;\;\;\frac{e^{a}}{2}\\
        
        \mathbf{else}:\\
        \;\;\;\;{\left(e^{b} + 1\right)}^{-1}\\
        
        
        \end{array}
        \end{array}
        
        Derivation
        1. Split input into 2 regimes
        2. if a < -5.2e5

          1. Initial program 98.4%

            \[\frac{e^{a}}{e^{a} + e^{b}} \]
          2. Add Preprocessing
          3. Taylor expanded in b around 0

            \[\leadsto \frac{e^{a}}{\color{blue}{1 + e^{a}}} \]
          4. Step-by-step derivation
            1. +-commutativeN/A

              \[\leadsto \frac{e^{a}}{\color{blue}{e^{a} + 1}} \]
            2. lower-+.f64N/A

              \[\leadsto \frac{e^{a}}{\color{blue}{e^{a} + 1}} \]
            3. lower-exp.f64100.0

              \[\leadsto \frac{e^{a}}{\color{blue}{e^{a}} + 1} \]
          5. Applied rewrites100.0%

            \[\leadsto \frac{e^{a}}{\color{blue}{e^{a} + 1}} \]
          6. Taylor expanded in a around 0

            \[\leadsto \frac{e^{a}}{2} \]
          7. Step-by-step derivation
            1. Applied rewrites100.0%

              \[\leadsto \frac{e^{a}}{2} \]

            if -5.2e5 < a

            1. Initial program 99.0%

              \[\frac{e^{a}}{e^{a} + e^{b}} \]
            2. Add Preprocessing
            3. Taylor expanded in a around 0

              \[\leadsto \color{blue}{\frac{1}{1 + e^{b}}} \]
            4. Step-by-step derivation
              1. lower-/.f64N/A

                \[\leadsto \color{blue}{\frac{1}{1 + e^{b}}} \]
              2. +-commutativeN/A

                \[\leadsto \frac{1}{\color{blue}{e^{b} + 1}} \]
              3. lower-+.f64N/A

                \[\leadsto \frac{1}{\color{blue}{e^{b} + 1}} \]
              4. lower-exp.f6498.4

                \[\leadsto \frac{1}{\color{blue}{e^{b}} + 1} \]
            5. Applied rewrites98.4%

              \[\leadsto \color{blue}{\frac{1}{e^{b} + 1}} \]
          8. Recombined 2 regimes into one program.
          9. Final simplification98.8%

            \[\leadsto \begin{array}{l} \mathbf{if}\;a \leq -520000:\\ \;\;\;\;\frac{e^{a}}{2}\\ \mathbf{else}:\\ \;\;\;\;{\left(e^{b} + 1\right)}^{-1}\\ \end{array} \]
          10. Add Preprocessing

          Alternative 4: 70.8% accurate, 2.1× speedup?

          \[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;b \leq 4.8 \cdot 10^{+82}:\\ \;\;\;\;\frac{1}{\mathsf{fma}\left(\mathsf{fma}\left(\mathsf{fma}\left(0.16666666666666666, a, 0.5\right), a, 1\right), a, 2\right)}\\ \mathbf{else}:\\ \;\;\;\;{\left(\mathsf{fma}\left(\mathsf{fma}\left(\mathsf{fma}\left(0.16666666666666666, b, 0.5\right), \sqrt{b} \cdot \sqrt{b}, 1\right), b, 2\right)\right)}^{-1}\\ \end{array} \end{array} \]
          (FPCore (a b)
           :precision binary64
           (if (<= b 4.8e+82)
             (/ 1.0 (fma (fma (fma 0.16666666666666666 a 0.5) a 1.0) a 2.0))
             (pow
              (fma (fma (fma 0.16666666666666666 b 0.5) (* (sqrt b) (sqrt b)) 1.0) b 2.0)
              -1.0)))
          double code(double a, double b) {
          	double tmp;
          	if (b <= 4.8e+82) {
          		tmp = 1.0 / fma(fma(fma(0.16666666666666666, a, 0.5), a, 1.0), a, 2.0);
          	} else {
          		tmp = pow(fma(fma(fma(0.16666666666666666, b, 0.5), (sqrt(b) * sqrt(b)), 1.0), b, 2.0), -1.0);
          	}
          	return tmp;
          }
          
          function code(a, b)
          	tmp = 0.0
          	if (b <= 4.8e+82)
          		tmp = Float64(1.0 / fma(fma(fma(0.16666666666666666, a, 0.5), a, 1.0), a, 2.0));
          	else
          		tmp = fma(fma(fma(0.16666666666666666, b, 0.5), Float64(sqrt(b) * sqrt(b)), 1.0), b, 2.0) ^ -1.0;
          	end
          	return tmp
          end
          
          code[a_, b_] := If[LessEqual[b, 4.8e+82], N[(1.0 / N[(N[(N[(0.16666666666666666 * a + 0.5), $MachinePrecision] * a + 1.0), $MachinePrecision] * a + 2.0), $MachinePrecision]), $MachinePrecision], N[Power[N[(N[(N[(0.16666666666666666 * b + 0.5), $MachinePrecision] * N[(N[Sqrt[b], $MachinePrecision] * N[Sqrt[b], $MachinePrecision]), $MachinePrecision] + 1.0), $MachinePrecision] * b + 2.0), $MachinePrecision], -1.0], $MachinePrecision]]
          
          \begin{array}{l}
          
          \\
          \begin{array}{l}
          \mathbf{if}\;b \leq 4.8 \cdot 10^{+82}:\\
          \;\;\;\;\frac{1}{\mathsf{fma}\left(\mathsf{fma}\left(\mathsf{fma}\left(0.16666666666666666, a, 0.5\right), a, 1\right), a, 2\right)}\\
          
          \mathbf{else}:\\
          \;\;\;\;{\left(\mathsf{fma}\left(\mathsf{fma}\left(\mathsf{fma}\left(0.16666666666666666, b, 0.5\right), \sqrt{b} \cdot \sqrt{b}, 1\right), b, 2\right)\right)}^{-1}\\
          
          
          \end{array}
          \end{array}
          
          Derivation
          1. Split input into 2 regimes
          2. if b < 4.79999999999999996e82

            1. Initial program 98.5%

              \[\frac{e^{a}}{e^{a} + e^{b}} \]
            2. Add Preprocessing
            3. Taylor expanded in b around 0

              \[\leadsto \frac{e^{a}}{\color{blue}{1 + e^{a}}} \]
            4. Step-by-step derivation
              1. +-commutativeN/A

                \[\leadsto \frac{e^{a}}{\color{blue}{e^{a} + 1}} \]
              2. lower-+.f64N/A

                \[\leadsto \frac{e^{a}}{\color{blue}{e^{a} + 1}} \]
              3. lower-exp.f6471.4

                \[\leadsto \frac{e^{a}}{\color{blue}{e^{a}} + 1} \]
            5. Applied rewrites71.4%

              \[\leadsto \frac{e^{a}}{\color{blue}{e^{a} + 1}} \]
            6. Taylor expanded in a around 0

              \[\leadsto \frac{e^{a}}{2 + \color{blue}{a \cdot \left(1 + a \cdot \left(\frac{1}{2} + \frac{1}{6} \cdot a\right)\right)}} \]
            7. Step-by-step derivation
              1. Applied rewrites71.4%

                \[\leadsto \frac{e^{a}}{\mathsf{fma}\left(\mathsf{fma}\left(\mathsf{fma}\left(0.16666666666666666, a, 0.5\right), a, 1\right), \color{blue}{a}, 2\right)} \]
              2. Taylor expanded in a around 0

                \[\leadsto \frac{\color{blue}{1}}{\mathsf{fma}\left(\mathsf{fma}\left(\mathsf{fma}\left(\frac{1}{6}, a, \frac{1}{2}\right), a, 1\right), a, 2\right)} \]
              3. Step-by-step derivation
                1. Applied rewrites64.8%

                  \[\leadsto \frac{\color{blue}{1}}{\mathsf{fma}\left(\mathsf{fma}\left(\mathsf{fma}\left(0.16666666666666666, a, 0.5\right), a, 1\right), a, 2\right)} \]

                if 4.79999999999999996e82 < b

                1. Initial program 100.0%

                  \[\frac{e^{a}}{e^{a} + e^{b}} \]
                2. Add Preprocessing
                3. Taylor expanded in a around 0

                  \[\leadsto \color{blue}{\frac{1}{1 + e^{b}}} \]
                4. Step-by-step derivation
                  1. lower-/.f64N/A

                    \[\leadsto \color{blue}{\frac{1}{1 + e^{b}}} \]
                  2. +-commutativeN/A

                    \[\leadsto \frac{1}{\color{blue}{e^{b} + 1}} \]
                  3. lower-+.f64N/A

                    \[\leadsto \frac{1}{\color{blue}{e^{b} + 1}} \]
                  4. lower-exp.f64100.0

                    \[\leadsto \frac{1}{\color{blue}{e^{b}} + 1} \]
                5. Applied rewrites100.0%

                  \[\leadsto \color{blue}{\frac{1}{e^{b} + 1}} \]
                6. Taylor expanded in b around 0

                  \[\leadsto \frac{1}{2 + \color{blue}{b \cdot \left(1 + b \cdot \left(\frac{1}{2} + \frac{1}{6} \cdot b\right)\right)}} \]
                7. Step-by-step derivation
                  1. Applied rewrites87.6%

                    \[\leadsto \frac{1}{\mathsf{fma}\left(\mathsf{fma}\left(\mathsf{fma}\left(0.16666666666666666, b, 0.5\right), b, 1\right), \color{blue}{b}, 2\right)} \]
                  2. Step-by-step derivation
                    1. Applied rewrites87.6%

                      \[\leadsto \frac{1}{\mathsf{fma}\left(\mathsf{fma}\left(\mathsf{fma}\left(0.16666666666666666, b, 0.5\right), \sqrt{b} \cdot \sqrt{b}, 1\right), b, 2\right)} \]
                  3. Recombined 2 regimes into one program.
                  4. Final simplification69.4%

                    \[\leadsto \begin{array}{l} \mathbf{if}\;b \leq 4.8 \cdot 10^{+82}:\\ \;\;\;\;\frac{1}{\mathsf{fma}\left(\mathsf{fma}\left(\mathsf{fma}\left(0.16666666666666666, a, 0.5\right), a, 1\right), a, 2\right)}\\ \mathbf{else}:\\ \;\;\;\;{\left(\mathsf{fma}\left(\mathsf{fma}\left(\mathsf{fma}\left(0.16666666666666666, b, 0.5\right), \sqrt{b} \cdot \sqrt{b}, 1\right), b, 2\right)\right)}^{-1}\\ \end{array} \]
                  5. Add Preprocessing

                  Alternative 5: 77.2% accurate, 2.5× speedup?

                  \[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;b \leq 1.85 \cdot 10^{+99}:\\ \;\;\;\;\frac{e^{a}}{2}\\ \mathbf{else}:\\ \;\;\;\;{\left(\left(\mathsf{fma}\left(0.16666666666666666, b, 0.5\right) \cdot b\right) \cdot b\right)}^{-1}\\ \end{array} \end{array} \]
                  (FPCore (a b)
                   :precision binary64
                   (if (<= b 1.85e+99)
                     (/ (exp a) 2.0)
                     (pow (* (* (fma 0.16666666666666666 b 0.5) b) b) -1.0)))
                  double code(double a, double b) {
                  	double tmp;
                  	if (b <= 1.85e+99) {
                  		tmp = exp(a) / 2.0;
                  	} else {
                  		tmp = pow(((fma(0.16666666666666666, b, 0.5) * b) * b), -1.0);
                  	}
                  	return tmp;
                  }
                  
                  function code(a, b)
                  	tmp = 0.0
                  	if (b <= 1.85e+99)
                  		tmp = Float64(exp(a) / 2.0);
                  	else
                  		tmp = Float64(Float64(fma(0.16666666666666666, b, 0.5) * b) * b) ^ -1.0;
                  	end
                  	return tmp
                  end
                  
                  code[a_, b_] := If[LessEqual[b, 1.85e+99], N[(N[Exp[a], $MachinePrecision] / 2.0), $MachinePrecision], N[Power[N[(N[(N[(0.16666666666666666 * b + 0.5), $MachinePrecision] * b), $MachinePrecision] * b), $MachinePrecision], -1.0], $MachinePrecision]]
                  
                  \begin{array}{l}
                  
                  \\
                  \begin{array}{l}
                  \mathbf{if}\;b \leq 1.85 \cdot 10^{+99}:\\
                  \;\;\;\;\frac{e^{a}}{2}\\
                  
                  \mathbf{else}:\\
                  \;\;\;\;{\left(\left(\mathsf{fma}\left(0.16666666666666666, b, 0.5\right) \cdot b\right) \cdot b\right)}^{-1}\\
                  
                  
                  \end{array}
                  \end{array}
                  
                  Derivation
                  1. Split input into 2 regimes
                  2. if b < 1.85000000000000005e99

                    1. Initial program 98.6%

                      \[\frac{e^{a}}{e^{a} + e^{b}} \]
                    2. Add Preprocessing
                    3. Taylor expanded in b around 0

                      \[\leadsto \frac{e^{a}}{\color{blue}{1 + e^{a}}} \]
                    4. Step-by-step derivation
                      1. +-commutativeN/A

                        \[\leadsto \frac{e^{a}}{\color{blue}{e^{a} + 1}} \]
                      2. lower-+.f64N/A

                        \[\leadsto \frac{e^{a}}{\color{blue}{e^{a} + 1}} \]
                      3. lower-exp.f6470.3

                        \[\leadsto \frac{e^{a}}{\color{blue}{e^{a}} + 1} \]
                    5. Applied rewrites70.3%

                      \[\leadsto \frac{e^{a}}{\color{blue}{e^{a} + 1}} \]
                    6. Taylor expanded in a around 0

                      \[\leadsto \frac{e^{a}}{2} \]
                    7. Step-by-step derivation
                      1. Applied rewrites69.7%

                        \[\leadsto \frac{e^{a}}{2} \]

                      if 1.85000000000000005e99 < b

                      1. Initial program 100.0%

                        \[\frac{e^{a}}{e^{a} + e^{b}} \]
                      2. Add Preprocessing
                      3. Taylor expanded in a around 0

                        \[\leadsto \color{blue}{\frac{1}{1 + e^{b}}} \]
                      4. Step-by-step derivation
                        1. lower-/.f64N/A

                          \[\leadsto \color{blue}{\frac{1}{1 + e^{b}}} \]
                        2. +-commutativeN/A

                          \[\leadsto \frac{1}{\color{blue}{e^{b} + 1}} \]
                        3. lower-+.f64N/A

                          \[\leadsto \frac{1}{\color{blue}{e^{b} + 1}} \]
                        4. lower-exp.f64100.0

                          \[\leadsto \frac{1}{\color{blue}{e^{b}} + 1} \]
                      5. Applied rewrites100.0%

                        \[\leadsto \color{blue}{\frac{1}{e^{b} + 1}} \]
                      6. Taylor expanded in b around 0

                        \[\leadsto \frac{1}{2 + \color{blue}{b \cdot \left(1 + b \cdot \left(\frac{1}{2} + \frac{1}{6} \cdot b\right)\right)}} \]
                      7. Step-by-step derivation
                        1. Applied rewrites98.1%

                          \[\leadsto \frac{1}{\mathsf{fma}\left(\mathsf{fma}\left(\mathsf{fma}\left(0.16666666666666666, b, 0.5\right), b, 1\right), \color{blue}{b}, 2\right)} \]
                        2. Taylor expanded in b around inf

                          \[\leadsto \frac{1}{{b}^{3} \cdot \left(\frac{1}{6} + \color{blue}{\frac{1}{2} \cdot \frac{1}{b}}\right)} \]
                        3. Step-by-step derivation
                          1. Applied rewrites98.1%

                            \[\leadsto \frac{1}{\left(\mathsf{fma}\left(0.16666666666666666, b, 0.5\right) \cdot b\right) \cdot b} \]
                        4. Recombined 2 regimes into one program.
                        5. Final simplification74.8%

                          \[\leadsto \begin{array}{l} \mathbf{if}\;b \leq 1.85 \cdot 10^{+99}:\\ \;\;\;\;\frac{e^{a}}{2}\\ \mathbf{else}:\\ \;\;\;\;{\left(\left(\mathsf{fma}\left(0.16666666666666666, b, 0.5\right) \cdot b\right) \cdot b\right)}^{-1}\\ \end{array} \]
                        6. Add Preprocessing

                        Alternative 6: 70.8% accurate, 2.5× speedup?

                        \[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;b \leq 4.8 \cdot 10^{+82}:\\ \;\;\;\;\frac{1}{\mathsf{fma}\left(\mathsf{fma}\left(\mathsf{fma}\left(0.16666666666666666, a, 0.5\right), a, 1\right), a, 2\right)}\\ \mathbf{else}:\\ \;\;\;\;{\left(\mathsf{fma}\left(\left(b \cdot b\right) \cdot 0.16666666666666666, b, 2\right)\right)}^{-1}\\ \end{array} \end{array} \]
                        (FPCore (a b)
                         :precision binary64
                         (if (<= b 4.8e+82)
                           (/ 1.0 (fma (fma (fma 0.16666666666666666 a 0.5) a 1.0) a 2.0))
                           (pow (fma (* (* b b) 0.16666666666666666) b 2.0) -1.0)))
                        double code(double a, double b) {
                        	double tmp;
                        	if (b <= 4.8e+82) {
                        		tmp = 1.0 / fma(fma(fma(0.16666666666666666, a, 0.5), a, 1.0), a, 2.0);
                        	} else {
                        		tmp = pow(fma(((b * b) * 0.16666666666666666), b, 2.0), -1.0);
                        	}
                        	return tmp;
                        }
                        
                        function code(a, b)
                        	tmp = 0.0
                        	if (b <= 4.8e+82)
                        		tmp = Float64(1.0 / fma(fma(fma(0.16666666666666666, a, 0.5), a, 1.0), a, 2.0));
                        	else
                        		tmp = fma(Float64(Float64(b * b) * 0.16666666666666666), b, 2.0) ^ -1.0;
                        	end
                        	return tmp
                        end
                        
                        code[a_, b_] := If[LessEqual[b, 4.8e+82], N[(1.0 / N[(N[(N[(0.16666666666666666 * a + 0.5), $MachinePrecision] * a + 1.0), $MachinePrecision] * a + 2.0), $MachinePrecision]), $MachinePrecision], N[Power[N[(N[(N[(b * b), $MachinePrecision] * 0.16666666666666666), $MachinePrecision] * b + 2.0), $MachinePrecision], -1.0], $MachinePrecision]]
                        
                        \begin{array}{l}
                        
                        \\
                        \begin{array}{l}
                        \mathbf{if}\;b \leq 4.8 \cdot 10^{+82}:\\
                        \;\;\;\;\frac{1}{\mathsf{fma}\left(\mathsf{fma}\left(\mathsf{fma}\left(0.16666666666666666, a, 0.5\right), a, 1\right), a, 2\right)}\\
                        
                        \mathbf{else}:\\
                        \;\;\;\;{\left(\mathsf{fma}\left(\left(b \cdot b\right) \cdot 0.16666666666666666, b, 2\right)\right)}^{-1}\\
                        
                        
                        \end{array}
                        \end{array}
                        
                        Derivation
                        1. Split input into 2 regimes
                        2. if b < 4.79999999999999996e82

                          1. Initial program 98.5%

                            \[\frac{e^{a}}{e^{a} + e^{b}} \]
                          2. Add Preprocessing
                          3. Taylor expanded in b around 0

                            \[\leadsto \frac{e^{a}}{\color{blue}{1 + e^{a}}} \]
                          4. Step-by-step derivation
                            1. +-commutativeN/A

                              \[\leadsto \frac{e^{a}}{\color{blue}{e^{a} + 1}} \]
                            2. lower-+.f64N/A

                              \[\leadsto \frac{e^{a}}{\color{blue}{e^{a} + 1}} \]
                            3. lower-exp.f6471.4

                              \[\leadsto \frac{e^{a}}{\color{blue}{e^{a}} + 1} \]
                          5. Applied rewrites71.4%

                            \[\leadsto \frac{e^{a}}{\color{blue}{e^{a} + 1}} \]
                          6. Taylor expanded in a around 0

                            \[\leadsto \frac{e^{a}}{2 + \color{blue}{a \cdot \left(1 + a \cdot \left(\frac{1}{2} + \frac{1}{6} \cdot a\right)\right)}} \]
                          7. Step-by-step derivation
                            1. Applied rewrites71.4%

                              \[\leadsto \frac{e^{a}}{\mathsf{fma}\left(\mathsf{fma}\left(\mathsf{fma}\left(0.16666666666666666, a, 0.5\right), a, 1\right), \color{blue}{a}, 2\right)} \]
                            2. Taylor expanded in a around 0

                              \[\leadsto \frac{\color{blue}{1}}{\mathsf{fma}\left(\mathsf{fma}\left(\mathsf{fma}\left(\frac{1}{6}, a, \frac{1}{2}\right), a, 1\right), a, 2\right)} \]
                            3. Step-by-step derivation
                              1. Applied rewrites64.8%

                                \[\leadsto \frac{\color{blue}{1}}{\mathsf{fma}\left(\mathsf{fma}\left(\mathsf{fma}\left(0.16666666666666666, a, 0.5\right), a, 1\right), a, 2\right)} \]

                              if 4.79999999999999996e82 < b

                              1. Initial program 100.0%

                                \[\frac{e^{a}}{e^{a} + e^{b}} \]
                              2. Add Preprocessing
                              3. Taylor expanded in a around 0

                                \[\leadsto \color{blue}{\frac{1}{1 + e^{b}}} \]
                              4. Step-by-step derivation
                                1. lower-/.f64N/A

                                  \[\leadsto \color{blue}{\frac{1}{1 + e^{b}}} \]
                                2. +-commutativeN/A

                                  \[\leadsto \frac{1}{\color{blue}{e^{b} + 1}} \]
                                3. lower-+.f64N/A

                                  \[\leadsto \frac{1}{\color{blue}{e^{b} + 1}} \]
                                4. lower-exp.f64100.0

                                  \[\leadsto \frac{1}{\color{blue}{e^{b}} + 1} \]
                              5. Applied rewrites100.0%

                                \[\leadsto \color{blue}{\frac{1}{e^{b} + 1}} \]
                              6. Taylor expanded in b around 0

                                \[\leadsto \frac{1}{2 + \color{blue}{b \cdot \left(1 + b \cdot \left(\frac{1}{2} + \frac{1}{6} \cdot b\right)\right)}} \]
                              7. Step-by-step derivation
                                1. Applied rewrites87.6%

                                  \[\leadsto \frac{1}{\mathsf{fma}\left(\mathsf{fma}\left(\mathsf{fma}\left(0.16666666666666666, b, 0.5\right), b, 1\right), \color{blue}{b}, 2\right)} \]
                                2. Taylor expanded in b around inf

                                  \[\leadsto \frac{1}{\mathsf{fma}\left(\frac{1}{6} \cdot {b}^{2}, b, 2\right)} \]
                                3. Step-by-step derivation
                                  1. Applied rewrites87.6%

                                    \[\leadsto \frac{1}{\mathsf{fma}\left(\left(b \cdot b\right) \cdot 0.16666666666666666, b, 2\right)} \]
                                4. Recombined 2 regimes into one program.
                                5. Final simplification69.4%

                                  \[\leadsto \begin{array}{l} \mathbf{if}\;b \leq 4.8 \cdot 10^{+82}:\\ \;\;\;\;\frac{1}{\mathsf{fma}\left(\mathsf{fma}\left(\mathsf{fma}\left(0.16666666666666666, a, 0.5\right), a, 1\right), a, 2\right)}\\ \mathbf{else}:\\ \;\;\;\;{\left(\mathsf{fma}\left(\left(b \cdot b\right) \cdot 0.16666666666666666, b, 2\right)\right)}^{-1}\\ \end{array} \]
                                6. Add Preprocessing

                                Alternative 7: 67.9% accurate, 2.5× speedup?

                                \[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;b \leq 3.2 \cdot 10^{+81}:\\ \;\;\;\;\frac{1 + a}{\mathsf{fma}\left(\mathsf{fma}\left(0.5, a, 1\right), a, 2\right)}\\ \mathbf{else}:\\ \;\;\;\;{\left(\mathsf{fma}\left(\left(b \cdot b\right) \cdot 0.16666666666666666, b, 2\right)\right)}^{-1}\\ \end{array} \end{array} \]
                                (FPCore (a b)
                                 :precision binary64
                                 (if (<= b 3.2e+81)
                                   (/ (+ 1.0 a) (fma (fma 0.5 a 1.0) a 2.0))
                                   (pow (fma (* (* b b) 0.16666666666666666) b 2.0) -1.0)))
                                double code(double a, double b) {
                                	double tmp;
                                	if (b <= 3.2e+81) {
                                		tmp = (1.0 + a) / fma(fma(0.5, a, 1.0), a, 2.0);
                                	} else {
                                		tmp = pow(fma(((b * b) * 0.16666666666666666), b, 2.0), -1.0);
                                	}
                                	return tmp;
                                }
                                
                                function code(a, b)
                                	tmp = 0.0
                                	if (b <= 3.2e+81)
                                		tmp = Float64(Float64(1.0 + a) / fma(fma(0.5, a, 1.0), a, 2.0));
                                	else
                                		tmp = fma(Float64(Float64(b * b) * 0.16666666666666666), b, 2.0) ^ -1.0;
                                	end
                                	return tmp
                                end
                                
                                code[a_, b_] := If[LessEqual[b, 3.2e+81], N[(N[(1.0 + a), $MachinePrecision] / N[(N[(0.5 * a + 1.0), $MachinePrecision] * a + 2.0), $MachinePrecision]), $MachinePrecision], N[Power[N[(N[(N[(b * b), $MachinePrecision] * 0.16666666666666666), $MachinePrecision] * b + 2.0), $MachinePrecision], -1.0], $MachinePrecision]]
                                
                                \begin{array}{l}
                                
                                \\
                                \begin{array}{l}
                                \mathbf{if}\;b \leq 3.2 \cdot 10^{+81}:\\
                                \;\;\;\;\frac{1 + a}{\mathsf{fma}\left(\mathsf{fma}\left(0.5, a, 1\right), a, 2\right)}\\
                                
                                \mathbf{else}:\\
                                \;\;\;\;{\left(\mathsf{fma}\left(\left(b \cdot b\right) \cdot 0.16666666666666666, b, 2\right)\right)}^{-1}\\
                                
                                
                                \end{array}
                                \end{array}
                                
                                Derivation
                                1. Split input into 2 regimes
                                2. if b < 3.2e81

                                  1. Initial program 98.5%

                                    \[\frac{e^{a}}{e^{a} + e^{b}} \]
                                  2. Add Preprocessing
                                  3. Taylor expanded in b around 0

                                    \[\leadsto \frac{e^{a}}{\color{blue}{1 + e^{a}}} \]
                                  4. Step-by-step derivation
                                    1. +-commutativeN/A

                                      \[\leadsto \frac{e^{a}}{\color{blue}{e^{a} + 1}} \]
                                    2. lower-+.f64N/A

                                      \[\leadsto \frac{e^{a}}{\color{blue}{e^{a} + 1}} \]
                                    3. lower-exp.f6471.4

                                      \[\leadsto \frac{e^{a}}{\color{blue}{e^{a}} + 1} \]
                                  5. Applied rewrites71.4%

                                    \[\leadsto \frac{e^{a}}{\color{blue}{e^{a} + 1}} \]
                                  6. Taylor expanded in a around 0

                                    \[\leadsto \frac{e^{a}}{2 + \color{blue}{a \cdot \left(1 + \frac{1}{2} \cdot a\right)}} \]
                                  7. Step-by-step derivation
                                    1. Applied rewrites71.4%

                                      \[\leadsto \frac{e^{a}}{\mathsf{fma}\left(\mathsf{fma}\left(0.5, a, 1\right), \color{blue}{a}, 2\right)} \]
                                    2. Taylor expanded in a around 0

                                      \[\leadsto \frac{\color{blue}{1 + a}}{\mathsf{fma}\left(\mathsf{fma}\left(\frac{1}{2}, a, 1\right), a, 2\right)} \]
                                    3. Step-by-step derivation
                                      1. lower-+.f6461.8

                                        \[\leadsto \frac{\color{blue}{1 + a}}{\mathsf{fma}\left(\mathsf{fma}\left(0.5, a, 1\right), a, 2\right)} \]
                                    4. Applied rewrites61.8%

                                      \[\leadsto \frac{\color{blue}{1 + a}}{\mathsf{fma}\left(\mathsf{fma}\left(0.5, a, 1\right), a, 2\right)} \]

                                    if 3.2e81 < b

                                    1. Initial program 100.0%

                                      \[\frac{e^{a}}{e^{a} + e^{b}} \]
                                    2. Add Preprocessing
                                    3. Taylor expanded in a around 0

                                      \[\leadsto \color{blue}{\frac{1}{1 + e^{b}}} \]
                                    4. Step-by-step derivation
                                      1. lower-/.f64N/A

                                        \[\leadsto \color{blue}{\frac{1}{1 + e^{b}}} \]
                                      2. +-commutativeN/A

                                        \[\leadsto \frac{1}{\color{blue}{e^{b} + 1}} \]
                                      3. lower-+.f64N/A

                                        \[\leadsto \frac{1}{\color{blue}{e^{b} + 1}} \]
                                      4. lower-exp.f64100.0

                                        \[\leadsto \frac{1}{\color{blue}{e^{b}} + 1} \]
                                    5. Applied rewrites100.0%

                                      \[\leadsto \color{blue}{\frac{1}{e^{b} + 1}} \]
                                    6. Taylor expanded in b around 0

                                      \[\leadsto \frac{1}{2 + \color{blue}{b \cdot \left(1 + b \cdot \left(\frac{1}{2} + \frac{1}{6} \cdot b\right)\right)}} \]
                                    7. Step-by-step derivation
                                      1. Applied rewrites87.6%

                                        \[\leadsto \frac{1}{\mathsf{fma}\left(\mathsf{fma}\left(\mathsf{fma}\left(0.16666666666666666, b, 0.5\right), b, 1\right), \color{blue}{b}, 2\right)} \]
                                      2. Taylor expanded in b around inf

                                        \[\leadsto \frac{1}{\mathsf{fma}\left(\frac{1}{6} \cdot {b}^{2}, b, 2\right)} \]
                                      3. Step-by-step derivation
                                        1. Applied rewrites87.6%

                                          \[\leadsto \frac{1}{\mathsf{fma}\left(\left(b \cdot b\right) \cdot 0.16666666666666666, b, 2\right)} \]
                                      4. Recombined 2 regimes into one program.
                                      5. Final simplification67.1%

                                        \[\leadsto \begin{array}{l} \mathbf{if}\;b \leq 3.2 \cdot 10^{+81}:\\ \;\;\;\;\frac{1 + a}{\mathsf{fma}\left(\mathsf{fma}\left(0.5, a, 1\right), a, 2\right)}\\ \mathbf{else}:\\ \;\;\;\;{\left(\mathsf{fma}\left(\left(b \cdot b\right) \cdot 0.16666666666666666, b, 2\right)\right)}^{-1}\\ \end{array} \]
                                      6. Add Preprocessing

                                      Alternative 8: 67.9% accurate, 2.5× speedup?

                                      \[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;b \leq 3.2 \cdot 10^{+81}:\\ \;\;\;\;\frac{1 + a}{\mathsf{fma}\left(\mathsf{fma}\left(0.5, a, 1\right), a, 2\right)}\\ \mathbf{else}:\\ \;\;\;\;{\left(\left(\mathsf{fma}\left(0.16666666666666666, b, 0.5\right) \cdot b\right) \cdot b\right)}^{-1}\\ \end{array} \end{array} \]
                                      (FPCore (a b)
                                       :precision binary64
                                       (if (<= b 3.2e+81)
                                         (/ (+ 1.0 a) (fma (fma 0.5 a 1.0) a 2.0))
                                         (pow (* (* (fma 0.16666666666666666 b 0.5) b) b) -1.0)))
                                      double code(double a, double b) {
                                      	double tmp;
                                      	if (b <= 3.2e+81) {
                                      		tmp = (1.0 + a) / fma(fma(0.5, a, 1.0), a, 2.0);
                                      	} else {
                                      		tmp = pow(((fma(0.16666666666666666, b, 0.5) * b) * b), -1.0);
                                      	}
                                      	return tmp;
                                      }
                                      
                                      function code(a, b)
                                      	tmp = 0.0
                                      	if (b <= 3.2e+81)
                                      		tmp = Float64(Float64(1.0 + a) / fma(fma(0.5, a, 1.0), a, 2.0));
                                      	else
                                      		tmp = Float64(Float64(fma(0.16666666666666666, b, 0.5) * b) * b) ^ -1.0;
                                      	end
                                      	return tmp
                                      end
                                      
                                      code[a_, b_] := If[LessEqual[b, 3.2e+81], N[(N[(1.0 + a), $MachinePrecision] / N[(N[(0.5 * a + 1.0), $MachinePrecision] * a + 2.0), $MachinePrecision]), $MachinePrecision], N[Power[N[(N[(N[(0.16666666666666666 * b + 0.5), $MachinePrecision] * b), $MachinePrecision] * b), $MachinePrecision], -1.0], $MachinePrecision]]
                                      
                                      \begin{array}{l}
                                      
                                      \\
                                      \begin{array}{l}
                                      \mathbf{if}\;b \leq 3.2 \cdot 10^{+81}:\\
                                      \;\;\;\;\frac{1 + a}{\mathsf{fma}\left(\mathsf{fma}\left(0.5, a, 1\right), a, 2\right)}\\
                                      
                                      \mathbf{else}:\\
                                      \;\;\;\;{\left(\left(\mathsf{fma}\left(0.16666666666666666, b, 0.5\right) \cdot b\right) \cdot b\right)}^{-1}\\
                                      
                                      
                                      \end{array}
                                      \end{array}
                                      
                                      Derivation
                                      1. Split input into 2 regimes
                                      2. if b < 3.2e81

                                        1. Initial program 98.5%

                                          \[\frac{e^{a}}{e^{a} + e^{b}} \]
                                        2. Add Preprocessing
                                        3. Taylor expanded in b around 0

                                          \[\leadsto \frac{e^{a}}{\color{blue}{1 + e^{a}}} \]
                                        4. Step-by-step derivation
                                          1. +-commutativeN/A

                                            \[\leadsto \frac{e^{a}}{\color{blue}{e^{a} + 1}} \]
                                          2. lower-+.f64N/A

                                            \[\leadsto \frac{e^{a}}{\color{blue}{e^{a} + 1}} \]
                                          3. lower-exp.f6471.4

                                            \[\leadsto \frac{e^{a}}{\color{blue}{e^{a}} + 1} \]
                                        5. Applied rewrites71.4%

                                          \[\leadsto \frac{e^{a}}{\color{blue}{e^{a} + 1}} \]
                                        6. Taylor expanded in a around 0

                                          \[\leadsto \frac{e^{a}}{2 + \color{blue}{a \cdot \left(1 + \frac{1}{2} \cdot a\right)}} \]
                                        7. Step-by-step derivation
                                          1. Applied rewrites71.4%

                                            \[\leadsto \frac{e^{a}}{\mathsf{fma}\left(\mathsf{fma}\left(0.5, a, 1\right), \color{blue}{a}, 2\right)} \]
                                          2. Taylor expanded in a around 0

                                            \[\leadsto \frac{\color{blue}{1 + a}}{\mathsf{fma}\left(\mathsf{fma}\left(\frac{1}{2}, a, 1\right), a, 2\right)} \]
                                          3. Step-by-step derivation
                                            1. lower-+.f6461.8

                                              \[\leadsto \frac{\color{blue}{1 + a}}{\mathsf{fma}\left(\mathsf{fma}\left(0.5, a, 1\right), a, 2\right)} \]
                                          4. Applied rewrites61.8%

                                            \[\leadsto \frac{\color{blue}{1 + a}}{\mathsf{fma}\left(\mathsf{fma}\left(0.5, a, 1\right), a, 2\right)} \]

                                          if 3.2e81 < b

                                          1. Initial program 100.0%

                                            \[\frac{e^{a}}{e^{a} + e^{b}} \]
                                          2. Add Preprocessing
                                          3. Taylor expanded in a around 0

                                            \[\leadsto \color{blue}{\frac{1}{1 + e^{b}}} \]
                                          4. Step-by-step derivation
                                            1. lower-/.f64N/A

                                              \[\leadsto \color{blue}{\frac{1}{1 + e^{b}}} \]
                                            2. +-commutativeN/A

                                              \[\leadsto \frac{1}{\color{blue}{e^{b} + 1}} \]
                                            3. lower-+.f64N/A

                                              \[\leadsto \frac{1}{\color{blue}{e^{b} + 1}} \]
                                            4. lower-exp.f64100.0

                                              \[\leadsto \frac{1}{\color{blue}{e^{b}} + 1} \]
                                          5. Applied rewrites100.0%

                                            \[\leadsto \color{blue}{\frac{1}{e^{b} + 1}} \]
                                          6. Taylor expanded in b around 0

                                            \[\leadsto \frac{1}{2 + \color{blue}{b \cdot \left(1 + b \cdot \left(\frac{1}{2} + \frac{1}{6} \cdot b\right)\right)}} \]
                                          7. Step-by-step derivation
                                            1. Applied rewrites87.6%

                                              \[\leadsto \frac{1}{\mathsf{fma}\left(\mathsf{fma}\left(\mathsf{fma}\left(0.16666666666666666, b, 0.5\right), b, 1\right), \color{blue}{b}, 2\right)} \]
                                            2. Taylor expanded in b around inf

                                              \[\leadsto \frac{1}{{b}^{3} \cdot \left(\frac{1}{6} + \color{blue}{\frac{1}{2} \cdot \frac{1}{b}}\right)} \]
                                            3. Step-by-step derivation
                                              1. Applied rewrites87.6%

                                                \[\leadsto \frac{1}{\left(\mathsf{fma}\left(0.16666666666666666, b, 0.5\right) \cdot b\right) \cdot b} \]
                                            4. Recombined 2 regimes into one program.
                                            5. Final simplification67.1%

                                              \[\leadsto \begin{array}{l} \mathbf{if}\;b \leq 3.2 \cdot 10^{+81}:\\ \;\;\;\;\frac{1 + a}{\mathsf{fma}\left(\mathsf{fma}\left(0.5, a, 1\right), a, 2\right)}\\ \mathbf{else}:\\ \;\;\;\;{\left(\left(\mathsf{fma}\left(0.16666666666666666, b, 0.5\right) \cdot b\right) \cdot b\right)}^{-1}\\ \end{array} \]
                                            6. Add Preprocessing

                                            Alternative 9: 53.5% accurate, 2.6× speedup?

                                            \[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;b \leq -2.5:\\ \;\;\;\;0.5\\ \mathbf{else}:\\ \;\;\;\;{\left(\mathsf{fma}\left(\mathsf{fma}\left(0.5, b, 1\right), b, 2\right)\right)}^{-1}\\ \end{array} \end{array} \]
                                            (FPCore (a b)
                                             :precision binary64
                                             (if (<= b -2.5) 0.5 (pow (fma (fma 0.5 b 1.0) b 2.0) -1.0)))
                                            double code(double a, double b) {
                                            	double tmp;
                                            	if (b <= -2.5) {
                                            		tmp = 0.5;
                                            	} else {
                                            		tmp = pow(fma(fma(0.5, b, 1.0), b, 2.0), -1.0);
                                            	}
                                            	return tmp;
                                            }
                                            
                                            function code(a, b)
                                            	tmp = 0.0
                                            	if (b <= -2.5)
                                            		tmp = 0.5;
                                            	else
                                            		tmp = fma(fma(0.5, b, 1.0), b, 2.0) ^ -1.0;
                                            	end
                                            	return tmp
                                            end
                                            
                                            code[a_, b_] := If[LessEqual[b, -2.5], 0.5, N[Power[N[(N[(0.5 * b + 1.0), $MachinePrecision] * b + 2.0), $MachinePrecision], -1.0], $MachinePrecision]]
                                            
                                            \begin{array}{l}
                                            
                                            \\
                                            \begin{array}{l}
                                            \mathbf{if}\;b \leq -2.5:\\
                                            \;\;\;\;0.5\\
                                            
                                            \mathbf{else}:\\
                                            \;\;\;\;{\left(\mathsf{fma}\left(\mathsf{fma}\left(0.5, b, 1\right), b, 2\right)\right)}^{-1}\\
                                            
                                            
                                            \end{array}
                                            \end{array}
                                            
                                            Derivation
                                            1. Split input into 2 regimes
                                            2. if b < -2.5

                                              1. Initial program 97.8%

                                                \[\frac{e^{a}}{e^{a} + e^{b}} \]
                                              2. Add Preprocessing
                                              3. Taylor expanded in a around 0

                                                \[\leadsto \color{blue}{\frac{1}{1 + e^{b}}} \]
                                              4. Step-by-step derivation
                                                1. lower-/.f64N/A

                                                  \[\leadsto \color{blue}{\frac{1}{1 + e^{b}}} \]
                                                2. +-commutativeN/A

                                                  \[\leadsto \frac{1}{\color{blue}{e^{b} + 1}} \]
                                                3. lower-+.f64N/A

                                                  \[\leadsto \frac{1}{\color{blue}{e^{b} + 1}} \]
                                                4. lower-exp.f6497.8

                                                  \[\leadsto \frac{1}{\color{blue}{e^{b}} + 1} \]
                                              5. Applied rewrites97.8%

                                                \[\leadsto \color{blue}{\frac{1}{e^{b} + 1}} \]
                                              6. Taylor expanded in b around 0

                                                \[\leadsto \frac{1}{2} \]
                                              7. Step-by-step derivation
                                                1. Applied rewrites18.4%

                                                  \[\leadsto 0.5 \]

                                                if -2.5 < b

                                                1. Initial program 99.0%

                                                  \[\frac{e^{a}}{e^{a} + e^{b}} \]
                                                2. Add Preprocessing
                                                3. Taylor expanded in a around 0

                                                  \[\leadsto \color{blue}{\frac{1}{1 + e^{b}}} \]
                                                4. Step-by-step derivation
                                                  1. lower-/.f64N/A

                                                    \[\leadsto \color{blue}{\frac{1}{1 + e^{b}}} \]
                                                  2. +-commutativeN/A

                                                    \[\leadsto \frac{1}{\color{blue}{e^{b} + 1}} \]
                                                  3. lower-+.f64N/A

                                                    \[\leadsto \frac{1}{\color{blue}{e^{b} + 1}} \]
                                                  4. lower-exp.f6479.7

                                                    \[\leadsto \frac{1}{\color{blue}{e^{b}} + 1} \]
                                                5. Applied rewrites79.7%

                                                  \[\leadsto \color{blue}{\frac{1}{e^{b} + 1}} \]
                                                6. Taylor expanded in b around 0

                                                  \[\leadsto \frac{1}{2 + \color{blue}{b \cdot \left(1 + \frac{1}{2} \cdot b\right)}} \]
                                                7. Step-by-step derivation
                                                  1. Applied rewrites62.4%

                                                    \[\leadsto \frac{1}{\mathsf{fma}\left(\mathsf{fma}\left(0.5, b, 1\right), \color{blue}{b}, 2\right)} \]
                                                8. Recombined 2 regimes into one program.
                                                9. Final simplification54.7%

                                                  \[\leadsto \begin{array}{l} \mathbf{if}\;b \leq -2.5:\\ \;\;\;\;0.5\\ \mathbf{else}:\\ \;\;\;\;{\left(\mathsf{fma}\left(\mathsf{fma}\left(0.5, b, 1\right), b, 2\right)\right)}^{-1}\\ \end{array} \]
                                                10. Add Preprocessing

                                                Alternative 10: 53.0% accurate, 2.6× speedup?

                                                \[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;b \leq 1.2:\\ \;\;\;\;0.5\\ \mathbf{else}:\\ \;\;\;\;{\left(\mathsf{fma}\left(0.5, b, 1\right) \cdot b\right)}^{-1}\\ \end{array} \end{array} \]
                                                (FPCore (a b)
                                                 :precision binary64
                                                 (if (<= b 1.2) 0.5 (pow (* (fma 0.5 b 1.0) b) -1.0)))
                                                double code(double a, double b) {
                                                	double tmp;
                                                	if (b <= 1.2) {
                                                		tmp = 0.5;
                                                	} else {
                                                		tmp = pow((fma(0.5, b, 1.0) * b), -1.0);
                                                	}
                                                	return tmp;
                                                }
                                                
                                                function code(a, b)
                                                	tmp = 0.0
                                                	if (b <= 1.2)
                                                		tmp = 0.5;
                                                	else
                                                		tmp = Float64(fma(0.5, b, 1.0) * b) ^ -1.0;
                                                	end
                                                	return tmp
                                                end
                                                
                                                code[a_, b_] := If[LessEqual[b, 1.2], 0.5, N[Power[N[(N[(0.5 * b + 1.0), $MachinePrecision] * b), $MachinePrecision], -1.0], $MachinePrecision]]
                                                
                                                \begin{array}{l}
                                                
                                                \\
                                                \begin{array}{l}
                                                \mathbf{if}\;b \leq 1.2:\\
                                                \;\;\;\;0.5\\
                                                
                                                \mathbf{else}:\\
                                                \;\;\;\;{\left(\mathsf{fma}\left(0.5, b, 1\right) \cdot b\right)}^{-1}\\
                                                
                                                
                                                \end{array}
                                                \end{array}
                                                
                                                Derivation
                                                1. Split input into 2 regimes
                                                2. if b < 1.19999999999999996

                                                  1. Initial program 98.3%

                                                    \[\frac{e^{a}}{e^{a} + e^{b}} \]
                                                  2. Add Preprocessing
                                                  3. Taylor expanded in a around 0

                                                    \[\leadsto \color{blue}{\frac{1}{1 + e^{b}}} \]
                                                  4. Step-by-step derivation
                                                    1. lower-/.f64N/A

                                                      \[\leadsto \color{blue}{\frac{1}{1 + e^{b}}} \]
                                                    2. +-commutativeN/A

                                                      \[\leadsto \frac{1}{\color{blue}{e^{b} + 1}} \]
                                                    3. lower-+.f64N/A

                                                      \[\leadsto \frac{1}{\color{blue}{e^{b} + 1}} \]
                                                    4. lower-exp.f6475.8

                                                      \[\leadsto \frac{1}{\color{blue}{e^{b}} + 1} \]
                                                  5. Applied rewrites75.8%

                                                    \[\leadsto \color{blue}{\frac{1}{e^{b} + 1}} \]
                                                  6. Taylor expanded in b around 0

                                                    \[\leadsto \frac{1}{2} \]
                                                  7. Step-by-step derivation
                                                    1. Applied rewrites54.8%

                                                      \[\leadsto 0.5 \]

                                                    if 1.19999999999999996 < b

                                                    1. Initial program 100.0%

                                                      \[\frac{e^{a}}{e^{a} + e^{b}} \]
                                                    2. Add Preprocessing
                                                    3. Taylor expanded in a around 0

                                                      \[\leadsto \color{blue}{\frac{1}{1 + e^{b}}} \]
                                                    4. Step-by-step derivation
                                                      1. lower-/.f64N/A

                                                        \[\leadsto \color{blue}{\frac{1}{1 + e^{b}}} \]
                                                      2. +-commutativeN/A

                                                        \[\leadsto \frac{1}{\color{blue}{e^{b} + 1}} \]
                                                      3. lower-+.f64N/A

                                                        \[\leadsto \frac{1}{\color{blue}{e^{b} + 1}} \]
                                                      4. lower-exp.f64100.0

                                                        \[\leadsto \frac{1}{\color{blue}{e^{b}} + 1} \]
                                                    5. Applied rewrites100.0%

                                                      \[\leadsto \color{blue}{\frac{1}{e^{b} + 1}} \]
                                                    6. Taylor expanded in b around 0

                                                      \[\leadsto \frac{1}{2 + \color{blue}{b \cdot \left(1 + \frac{1}{2} \cdot b\right)}} \]
                                                    7. Step-by-step derivation
                                                      1. Applied rewrites52.9%

                                                        \[\leadsto \frac{1}{\mathsf{fma}\left(\mathsf{fma}\left(0.5, b, 1\right), \color{blue}{b}, 2\right)} \]
                                                      2. Taylor expanded in b around inf

                                                        \[\leadsto \frac{1}{{b}^{2} \cdot \left(\frac{1}{2} + \color{blue}{\frac{1}{b}}\right)} \]
                                                      3. Step-by-step derivation
                                                        1. Applied rewrites52.9%

                                                          \[\leadsto \frac{1}{\mathsf{fma}\left(0.5, b, 1\right) \cdot b} \]
                                                      4. Recombined 2 regimes into one program.
                                                      5. Final simplification54.3%

                                                        \[\leadsto \begin{array}{l} \mathbf{if}\;b \leq 1.2:\\ \;\;\;\;0.5\\ \mathbf{else}:\\ \;\;\;\;{\left(\mathsf{fma}\left(0.5, b, 1\right) \cdot b\right)}^{-1}\\ \end{array} \]
                                                      6. Add Preprocessing

                                                      Alternative 11: 63.4% accurate, 2.7× speedup?

                                                      \[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;b \leq 3.2 \cdot 10^{+81}:\\ \;\;\;\;\frac{1 + a}{\mathsf{fma}\left(\mathsf{fma}\left(0.5, a, 1\right), a, 2\right)}\\ \mathbf{else}:\\ \;\;\;\;{\left(\left(b \cdot b\right) \cdot 0.5\right)}^{-1}\\ \end{array} \end{array} \]
                                                      (FPCore (a b)
                                                       :precision binary64
                                                       (if (<= b 3.2e+81)
                                                         (/ (+ 1.0 a) (fma (fma 0.5 a 1.0) a 2.0))
                                                         (pow (* (* b b) 0.5) -1.0)))
                                                      double code(double a, double b) {
                                                      	double tmp;
                                                      	if (b <= 3.2e+81) {
                                                      		tmp = (1.0 + a) / fma(fma(0.5, a, 1.0), a, 2.0);
                                                      	} else {
                                                      		tmp = pow(((b * b) * 0.5), -1.0);
                                                      	}
                                                      	return tmp;
                                                      }
                                                      
                                                      function code(a, b)
                                                      	tmp = 0.0
                                                      	if (b <= 3.2e+81)
                                                      		tmp = Float64(Float64(1.0 + a) / fma(fma(0.5, a, 1.0), a, 2.0));
                                                      	else
                                                      		tmp = Float64(Float64(b * b) * 0.5) ^ -1.0;
                                                      	end
                                                      	return tmp
                                                      end
                                                      
                                                      code[a_, b_] := If[LessEqual[b, 3.2e+81], N[(N[(1.0 + a), $MachinePrecision] / N[(N[(0.5 * a + 1.0), $MachinePrecision] * a + 2.0), $MachinePrecision]), $MachinePrecision], N[Power[N[(N[(b * b), $MachinePrecision] * 0.5), $MachinePrecision], -1.0], $MachinePrecision]]
                                                      
                                                      \begin{array}{l}
                                                      
                                                      \\
                                                      \begin{array}{l}
                                                      \mathbf{if}\;b \leq 3.2 \cdot 10^{+81}:\\
                                                      \;\;\;\;\frac{1 + a}{\mathsf{fma}\left(\mathsf{fma}\left(0.5, a, 1\right), a, 2\right)}\\
                                                      
                                                      \mathbf{else}:\\
                                                      \;\;\;\;{\left(\left(b \cdot b\right) \cdot 0.5\right)}^{-1}\\
                                                      
                                                      
                                                      \end{array}
                                                      \end{array}
                                                      
                                                      Derivation
                                                      1. Split input into 2 regimes
                                                      2. if b < 3.2e81

                                                        1. Initial program 98.5%

                                                          \[\frac{e^{a}}{e^{a} + e^{b}} \]
                                                        2. Add Preprocessing
                                                        3. Taylor expanded in b around 0

                                                          \[\leadsto \frac{e^{a}}{\color{blue}{1 + e^{a}}} \]
                                                        4. Step-by-step derivation
                                                          1. +-commutativeN/A

                                                            \[\leadsto \frac{e^{a}}{\color{blue}{e^{a} + 1}} \]
                                                          2. lower-+.f64N/A

                                                            \[\leadsto \frac{e^{a}}{\color{blue}{e^{a} + 1}} \]
                                                          3. lower-exp.f6471.4

                                                            \[\leadsto \frac{e^{a}}{\color{blue}{e^{a}} + 1} \]
                                                        5. Applied rewrites71.4%

                                                          \[\leadsto \frac{e^{a}}{\color{blue}{e^{a} + 1}} \]
                                                        6. Taylor expanded in a around 0

                                                          \[\leadsto \frac{e^{a}}{2 + \color{blue}{a \cdot \left(1 + \frac{1}{2} \cdot a\right)}} \]
                                                        7. Step-by-step derivation
                                                          1. Applied rewrites71.4%

                                                            \[\leadsto \frac{e^{a}}{\mathsf{fma}\left(\mathsf{fma}\left(0.5, a, 1\right), \color{blue}{a}, 2\right)} \]
                                                          2. Taylor expanded in a around 0

                                                            \[\leadsto \frac{\color{blue}{1 + a}}{\mathsf{fma}\left(\mathsf{fma}\left(\frac{1}{2}, a, 1\right), a, 2\right)} \]
                                                          3. Step-by-step derivation
                                                            1. lower-+.f6461.8

                                                              \[\leadsto \frac{\color{blue}{1 + a}}{\mathsf{fma}\left(\mathsf{fma}\left(0.5, a, 1\right), a, 2\right)} \]
                                                          4. Applied rewrites61.8%

                                                            \[\leadsto \frac{\color{blue}{1 + a}}{\mathsf{fma}\left(\mathsf{fma}\left(0.5, a, 1\right), a, 2\right)} \]

                                                          if 3.2e81 < b

                                                          1. Initial program 100.0%

                                                            \[\frac{e^{a}}{e^{a} + e^{b}} \]
                                                          2. Add Preprocessing
                                                          3. Taylor expanded in a around 0

                                                            \[\leadsto \color{blue}{\frac{1}{1 + e^{b}}} \]
                                                          4. Step-by-step derivation
                                                            1. lower-/.f64N/A

                                                              \[\leadsto \color{blue}{\frac{1}{1 + e^{b}}} \]
                                                            2. +-commutativeN/A

                                                              \[\leadsto \frac{1}{\color{blue}{e^{b} + 1}} \]
                                                            3. lower-+.f64N/A

                                                              \[\leadsto \frac{1}{\color{blue}{e^{b} + 1}} \]
                                                            4. lower-exp.f64100.0

                                                              \[\leadsto \frac{1}{\color{blue}{e^{b}} + 1} \]
                                                          5. Applied rewrites100.0%

                                                            \[\leadsto \color{blue}{\frac{1}{e^{b} + 1}} \]
                                                          6. Taylor expanded in b around 0

                                                            \[\leadsto \frac{1}{2 + \color{blue}{b \cdot \left(1 + \frac{1}{2} \cdot b\right)}} \]
                                                          7. Step-by-step derivation
                                                            1. Applied rewrites74.7%

                                                              \[\leadsto \frac{1}{\mathsf{fma}\left(\mathsf{fma}\left(0.5, b, 1\right), \color{blue}{b}, 2\right)} \]
                                                            2. Taylor expanded in b around inf

                                                              \[\leadsto \frac{1}{\frac{1}{2} \cdot {b}^{\color{blue}{2}}} \]
                                                            3. Step-by-step derivation
                                                              1. Applied rewrites74.7%

                                                                \[\leadsto \frac{1}{\left(b \cdot b\right) \cdot 0.5} \]
                                                            4. Recombined 2 regimes into one program.
                                                            5. Final simplification64.4%

                                                              \[\leadsto \begin{array}{l} \mathbf{if}\;b \leq 3.2 \cdot 10^{+81}:\\ \;\;\;\;\frac{1 + a}{\mathsf{fma}\left(\mathsf{fma}\left(0.5, a, 1\right), a, 2\right)}\\ \mathbf{else}:\\ \;\;\;\;{\left(\left(b \cdot b\right) \cdot 0.5\right)}^{-1}\\ \end{array} \]
                                                            6. Add Preprocessing

                                                            Alternative 12: 63.2% accurate, 2.7× speedup?

                                                            \[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;b \leq 3.2 \cdot 10^{+81}:\\ \;\;\;\;\frac{1}{\mathsf{fma}\left(\mathsf{fma}\left(0.5, a, 1\right), a, 2\right)}\\ \mathbf{else}:\\ \;\;\;\;{\left(\left(b \cdot b\right) \cdot 0.5\right)}^{-1}\\ \end{array} \end{array} \]
                                                            (FPCore (a b)
                                                             :precision binary64
                                                             (if (<= b 3.2e+81)
                                                               (/ 1.0 (fma (fma 0.5 a 1.0) a 2.0))
                                                               (pow (* (* b b) 0.5) -1.0)))
                                                            double code(double a, double b) {
                                                            	double tmp;
                                                            	if (b <= 3.2e+81) {
                                                            		tmp = 1.0 / fma(fma(0.5, a, 1.0), a, 2.0);
                                                            	} else {
                                                            		tmp = pow(((b * b) * 0.5), -1.0);
                                                            	}
                                                            	return tmp;
                                                            }
                                                            
                                                            function code(a, b)
                                                            	tmp = 0.0
                                                            	if (b <= 3.2e+81)
                                                            		tmp = Float64(1.0 / fma(fma(0.5, a, 1.0), a, 2.0));
                                                            	else
                                                            		tmp = Float64(Float64(b * b) * 0.5) ^ -1.0;
                                                            	end
                                                            	return tmp
                                                            end
                                                            
                                                            code[a_, b_] := If[LessEqual[b, 3.2e+81], N[(1.0 / N[(N[(0.5 * a + 1.0), $MachinePrecision] * a + 2.0), $MachinePrecision]), $MachinePrecision], N[Power[N[(N[(b * b), $MachinePrecision] * 0.5), $MachinePrecision], -1.0], $MachinePrecision]]
                                                            
                                                            \begin{array}{l}
                                                            
                                                            \\
                                                            \begin{array}{l}
                                                            \mathbf{if}\;b \leq 3.2 \cdot 10^{+81}:\\
                                                            \;\;\;\;\frac{1}{\mathsf{fma}\left(\mathsf{fma}\left(0.5, a, 1\right), a, 2\right)}\\
                                                            
                                                            \mathbf{else}:\\
                                                            \;\;\;\;{\left(\left(b \cdot b\right) \cdot 0.5\right)}^{-1}\\
                                                            
                                                            
                                                            \end{array}
                                                            \end{array}
                                                            
                                                            Derivation
                                                            1. Split input into 2 regimes
                                                            2. if b < 3.2e81

                                                              1. Initial program 98.5%

                                                                \[\frac{e^{a}}{e^{a} + e^{b}} \]
                                                              2. Add Preprocessing
                                                              3. Taylor expanded in b around 0

                                                                \[\leadsto \frac{e^{a}}{\color{blue}{1 + e^{a}}} \]
                                                              4. Step-by-step derivation
                                                                1. +-commutativeN/A

                                                                  \[\leadsto \frac{e^{a}}{\color{blue}{e^{a} + 1}} \]
                                                                2. lower-+.f64N/A

                                                                  \[\leadsto \frac{e^{a}}{\color{blue}{e^{a} + 1}} \]
                                                                3. lower-exp.f6471.4

                                                                  \[\leadsto \frac{e^{a}}{\color{blue}{e^{a}} + 1} \]
                                                              5. Applied rewrites71.4%

                                                                \[\leadsto \frac{e^{a}}{\color{blue}{e^{a} + 1}} \]
                                                              6. Taylor expanded in a around 0

                                                                \[\leadsto \frac{e^{a}}{2 + \color{blue}{a \cdot \left(1 + \frac{1}{2} \cdot a\right)}} \]
                                                              7. Step-by-step derivation
                                                                1. Applied rewrites71.4%

                                                                  \[\leadsto \frac{e^{a}}{\mathsf{fma}\left(\mathsf{fma}\left(0.5, a, 1\right), \color{blue}{a}, 2\right)} \]
                                                                2. Taylor expanded in a around 0

                                                                  \[\leadsto \frac{\color{blue}{1}}{\mathsf{fma}\left(\mathsf{fma}\left(\frac{1}{2}, a, 1\right), a, 2\right)} \]
                                                                3. Step-by-step derivation
                                                                  1. Applied rewrites61.5%

                                                                    \[\leadsto \frac{\color{blue}{1}}{\mathsf{fma}\left(\mathsf{fma}\left(0.5, a, 1\right), a, 2\right)} \]

                                                                  if 3.2e81 < b

                                                                  1. Initial program 100.0%

                                                                    \[\frac{e^{a}}{e^{a} + e^{b}} \]
                                                                  2. Add Preprocessing
                                                                  3. Taylor expanded in a around 0

                                                                    \[\leadsto \color{blue}{\frac{1}{1 + e^{b}}} \]
                                                                  4. Step-by-step derivation
                                                                    1. lower-/.f64N/A

                                                                      \[\leadsto \color{blue}{\frac{1}{1 + e^{b}}} \]
                                                                    2. +-commutativeN/A

                                                                      \[\leadsto \frac{1}{\color{blue}{e^{b} + 1}} \]
                                                                    3. lower-+.f64N/A

                                                                      \[\leadsto \frac{1}{\color{blue}{e^{b} + 1}} \]
                                                                    4. lower-exp.f64100.0

                                                                      \[\leadsto \frac{1}{\color{blue}{e^{b}} + 1} \]
                                                                  5. Applied rewrites100.0%

                                                                    \[\leadsto \color{blue}{\frac{1}{e^{b} + 1}} \]
                                                                  6. Taylor expanded in b around 0

                                                                    \[\leadsto \frac{1}{2 + \color{blue}{b \cdot \left(1 + \frac{1}{2} \cdot b\right)}} \]
                                                                  7. Step-by-step derivation
                                                                    1. Applied rewrites74.7%

                                                                      \[\leadsto \frac{1}{\mathsf{fma}\left(\mathsf{fma}\left(0.5, b, 1\right), \color{blue}{b}, 2\right)} \]
                                                                    2. Taylor expanded in b around inf

                                                                      \[\leadsto \frac{1}{\frac{1}{2} \cdot {b}^{\color{blue}{2}}} \]
                                                                    3. Step-by-step derivation
                                                                      1. Applied rewrites74.7%

                                                                        \[\leadsto \frac{1}{\left(b \cdot b\right) \cdot 0.5} \]
                                                                    4. Recombined 2 regimes into one program.
                                                                    5. Final simplification64.2%

                                                                      \[\leadsto \begin{array}{l} \mathbf{if}\;b \leq 3.2 \cdot 10^{+81}:\\ \;\;\;\;\frac{1}{\mathsf{fma}\left(\mathsf{fma}\left(0.5, a, 1\right), a, 2\right)}\\ \mathbf{else}:\\ \;\;\;\;{\left(\left(b \cdot b\right) \cdot 0.5\right)}^{-1}\\ \end{array} \]
                                                                    6. Add Preprocessing

                                                                    Alternative 13: 53.0% accurate, 2.7× speedup?

                                                                    \[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;b \leq 2:\\ \;\;\;\;0.5\\ \mathbf{else}:\\ \;\;\;\;{\left(\left(b \cdot b\right) \cdot 0.5\right)}^{-1}\\ \end{array} \end{array} \]
                                                                    (FPCore (a b)
                                                                     :precision binary64
                                                                     (if (<= b 2.0) 0.5 (pow (* (* b b) 0.5) -1.0)))
                                                                    double code(double a, double b) {
                                                                    	double tmp;
                                                                    	if (b <= 2.0) {
                                                                    		tmp = 0.5;
                                                                    	} else {
                                                                    		tmp = pow(((b * b) * 0.5), -1.0);
                                                                    	}
                                                                    	return tmp;
                                                                    }
                                                                    
                                                                    real(8) function code(a, b)
                                                                        real(8), intent (in) :: a
                                                                        real(8), intent (in) :: b
                                                                        real(8) :: tmp
                                                                        if (b <= 2.0d0) then
                                                                            tmp = 0.5d0
                                                                        else
                                                                            tmp = ((b * b) * 0.5d0) ** (-1.0d0)
                                                                        end if
                                                                        code = tmp
                                                                    end function
                                                                    
                                                                    public static double code(double a, double b) {
                                                                    	double tmp;
                                                                    	if (b <= 2.0) {
                                                                    		tmp = 0.5;
                                                                    	} else {
                                                                    		tmp = Math.pow(((b * b) * 0.5), -1.0);
                                                                    	}
                                                                    	return tmp;
                                                                    }
                                                                    
                                                                    def code(a, b):
                                                                    	tmp = 0
                                                                    	if b <= 2.0:
                                                                    		tmp = 0.5
                                                                    	else:
                                                                    		tmp = math.pow(((b * b) * 0.5), -1.0)
                                                                    	return tmp
                                                                    
                                                                    function code(a, b)
                                                                    	tmp = 0.0
                                                                    	if (b <= 2.0)
                                                                    		tmp = 0.5;
                                                                    	else
                                                                    		tmp = Float64(Float64(b * b) * 0.5) ^ -1.0;
                                                                    	end
                                                                    	return tmp
                                                                    end
                                                                    
                                                                    function tmp_2 = code(a, b)
                                                                    	tmp = 0.0;
                                                                    	if (b <= 2.0)
                                                                    		tmp = 0.5;
                                                                    	else
                                                                    		tmp = ((b * b) * 0.5) ^ -1.0;
                                                                    	end
                                                                    	tmp_2 = tmp;
                                                                    end
                                                                    
                                                                    code[a_, b_] := If[LessEqual[b, 2.0], 0.5, N[Power[N[(N[(b * b), $MachinePrecision] * 0.5), $MachinePrecision], -1.0], $MachinePrecision]]
                                                                    
                                                                    \begin{array}{l}
                                                                    
                                                                    \\
                                                                    \begin{array}{l}
                                                                    \mathbf{if}\;b \leq 2:\\
                                                                    \;\;\;\;0.5\\
                                                                    
                                                                    \mathbf{else}:\\
                                                                    \;\;\;\;{\left(\left(b \cdot b\right) \cdot 0.5\right)}^{-1}\\
                                                                    
                                                                    
                                                                    \end{array}
                                                                    \end{array}
                                                                    
                                                                    Derivation
                                                                    1. Split input into 2 regimes
                                                                    2. if b < 2

                                                                      1. Initial program 98.3%

                                                                        \[\frac{e^{a}}{e^{a} + e^{b}} \]
                                                                      2. Add Preprocessing
                                                                      3. Taylor expanded in a around 0

                                                                        \[\leadsto \color{blue}{\frac{1}{1 + e^{b}}} \]
                                                                      4. Step-by-step derivation
                                                                        1. lower-/.f64N/A

                                                                          \[\leadsto \color{blue}{\frac{1}{1 + e^{b}}} \]
                                                                        2. +-commutativeN/A

                                                                          \[\leadsto \frac{1}{\color{blue}{e^{b} + 1}} \]
                                                                        3. lower-+.f64N/A

                                                                          \[\leadsto \frac{1}{\color{blue}{e^{b} + 1}} \]
                                                                        4. lower-exp.f6475.8

                                                                          \[\leadsto \frac{1}{\color{blue}{e^{b}} + 1} \]
                                                                      5. Applied rewrites75.8%

                                                                        \[\leadsto \color{blue}{\frac{1}{e^{b} + 1}} \]
                                                                      6. Taylor expanded in b around 0

                                                                        \[\leadsto \frac{1}{2} \]
                                                                      7. Step-by-step derivation
                                                                        1. Applied rewrites54.8%

                                                                          \[\leadsto 0.5 \]

                                                                        if 2 < b

                                                                        1. Initial program 100.0%

                                                                          \[\frac{e^{a}}{e^{a} + e^{b}} \]
                                                                        2. Add Preprocessing
                                                                        3. Taylor expanded in a around 0

                                                                          \[\leadsto \color{blue}{\frac{1}{1 + e^{b}}} \]
                                                                        4. Step-by-step derivation
                                                                          1. lower-/.f64N/A

                                                                            \[\leadsto \color{blue}{\frac{1}{1 + e^{b}}} \]
                                                                          2. +-commutativeN/A

                                                                            \[\leadsto \frac{1}{\color{blue}{e^{b} + 1}} \]
                                                                          3. lower-+.f64N/A

                                                                            \[\leadsto \frac{1}{\color{blue}{e^{b} + 1}} \]
                                                                          4. lower-exp.f64100.0

                                                                            \[\leadsto \frac{1}{\color{blue}{e^{b}} + 1} \]
                                                                        5. Applied rewrites100.0%

                                                                          \[\leadsto \color{blue}{\frac{1}{e^{b} + 1}} \]
                                                                        6. Taylor expanded in b around 0

                                                                          \[\leadsto \frac{1}{2 + \color{blue}{b \cdot \left(1 + \frac{1}{2} \cdot b\right)}} \]
                                                                        7. Step-by-step derivation
                                                                          1. Applied rewrites52.9%

                                                                            \[\leadsto \frac{1}{\mathsf{fma}\left(\mathsf{fma}\left(0.5, b, 1\right), \color{blue}{b}, 2\right)} \]
                                                                          2. Taylor expanded in b around inf

                                                                            \[\leadsto \frac{1}{\frac{1}{2} \cdot {b}^{\color{blue}{2}}} \]
                                                                          3. Step-by-step derivation
                                                                            1. Applied rewrites52.9%

                                                                              \[\leadsto \frac{1}{\left(b \cdot b\right) \cdot 0.5} \]
                                                                          4. Recombined 2 regimes into one program.
                                                                          5. Final simplification54.3%

                                                                            \[\leadsto \begin{array}{l} \mathbf{if}\;b \leq 2:\\ \;\;\;\;0.5\\ \mathbf{else}:\\ \;\;\;\;{\left(\left(b \cdot b\right) \cdot 0.5\right)}^{-1}\\ \end{array} \]
                                                                          6. Add Preprocessing

                                                                          Alternative 14: 39.4% accurate, 315.0× speedup?

                                                                          \[\begin{array}{l} \\ 0.5 \end{array} \]
                                                                          (FPCore (a b) :precision binary64 0.5)
                                                                          double code(double a, double b) {
                                                                          	return 0.5;
                                                                          }
                                                                          
                                                                          real(8) function code(a, b)
                                                                              real(8), intent (in) :: a
                                                                              real(8), intent (in) :: b
                                                                              code = 0.5d0
                                                                          end function
                                                                          
                                                                          public static double code(double a, double b) {
                                                                          	return 0.5;
                                                                          }
                                                                          
                                                                          def code(a, b):
                                                                          	return 0.5
                                                                          
                                                                          function code(a, b)
                                                                          	return 0.5
                                                                          end
                                                                          
                                                                          function tmp = code(a, b)
                                                                          	tmp = 0.5;
                                                                          end
                                                                          
                                                                          code[a_, b_] := 0.5
                                                                          
                                                                          \begin{array}{l}
                                                                          
                                                                          \\
                                                                          0.5
                                                                          \end{array}
                                                                          
                                                                          Derivation
                                                                          1. Initial program 98.8%

                                                                            \[\frac{e^{a}}{e^{a} + e^{b}} \]
                                                                          2. Add Preprocessing
                                                                          3. Taylor expanded in a around 0

                                                                            \[\leadsto \color{blue}{\frac{1}{1 + e^{b}}} \]
                                                                          4. Step-by-step derivation
                                                                            1. lower-/.f64N/A

                                                                              \[\leadsto \color{blue}{\frac{1}{1 + e^{b}}} \]
                                                                            2. +-commutativeN/A

                                                                              \[\leadsto \frac{1}{\color{blue}{e^{b} + 1}} \]
                                                                            3. lower-+.f64N/A

                                                                              \[\leadsto \frac{1}{\color{blue}{e^{b} + 1}} \]
                                                                            4. lower-exp.f6482.9

                                                                              \[\leadsto \frac{1}{\color{blue}{e^{b}} + 1} \]
                                                                          5. Applied rewrites82.9%

                                                                            \[\leadsto \color{blue}{\frac{1}{e^{b} + 1}} \]
                                                                          6. Taylor expanded in b around 0

                                                                            \[\leadsto \frac{1}{2} \]
                                                                          7. Step-by-step derivation
                                                                            1. Applied rewrites39.7%

                                                                              \[\leadsto 0.5 \]
                                                                            2. Add Preprocessing

                                                                            Developer Target 1: 100.0% accurate, 2.7× speedup?

                                                                            \[\begin{array}{l} \\ \frac{1}{1 + e^{b - a}} \end{array} \]
                                                                            (FPCore (a b) :precision binary64 (/ 1.0 (+ 1.0 (exp (- b a)))))
                                                                            double code(double a, double b) {
                                                                            	return 1.0 / (1.0 + exp((b - a)));
                                                                            }
                                                                            
                                                                            real(8) function code(a, b)
                                                                                real(8), intent (in) :: a
                                                                                real(8), intent (in) :: b
                                                                                code = 1.0d0 / (1.0d0 + exp((b - a)))
                                                                            end function
                                                                            
                                                                            public static double code(double a, double b) {
                                                                            	return 1.0 / (1.0 + Math.exp((b - a)));
                                                                            }
                                                                            
                                                                            def code(a, b):
                                                                            	return 1.0 / (1.0 + math.exp((b - a)))
                                                                            
                                                                            function code(a, b)
                                                                            	return Float64(1.0 / Float64(1.0 + exp(Float64(b - a))))
                                                                            end
                                                                            
                                                                            function tmp = code(a, b)
                                                                            	tmp = 1.0 / (1.0 + exp((b - a)));
                                                                            end
                                                                            
                                                                            code[a_, b_] := N[(1.0 / N[(1.0 + N[Exp[N[(b - a), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
                                                                            
                                                                            \begin{array}{l}
                                                                            
                                                                            \\
                                                                            \frac{1}{1 + e^{b - a}}
                                                                            \end{array}
                                                                            

                                                                            Reproduce

                                                                            ?
                                                                            herbie shell --seed 2024339 
                                                                            (FPCore (a b)
                                                                              :name "Quotient of sum of exps"
                                                                              :precision binary64
                                                                            
                                                                              :alt
                                                                              (! :herbie-platform default (/ 1 (+ 1 (exp (- b a)))))
                                                                            
                                                                              (/ (exp a) (+ (exp a) (exp b))))