math.exp on complex, real part

Percentage Accurate: 100.0% → 100.0%
Time: 2.5s
Alternatives: 7
Speedup: 1.0×

Specification

?
\[e^{re} \cdot \cos im \]
(FPCore (re im)
  :precision binary64
  (* (exp re) (cos im)))
double code(double re, double im) {
	return exp(re) * cos(im);
}
module fmin_fmax_functions
    implicit none
    private
    public fmax
    public fmin

    interface fmax
        module procedure fmax88
        module procedure fmax44
        module procedure fmax84
        module procedure fmax48
    end interface
    interface fmin
        module procedure fmin88
        module procedure fmin44
        module procedure fmin84
        module procedure fmin48
    end interface
contains
    real(8) function fmax88(x, y) result (res)
        real(8), intent (in) :: x
        real(8), intent (in) :: y
        res = merge(y, merge(x, max(x, y), y /= y), x /= x)
    end function
    real(4) function fmax44(x, y) result (res)
        real(4), intent (in) :: x
        real(4), intent (in) :: y
        res = merge(y, merge(x, max(x, y), y /= y), x /= x)
    end function
    real(8) function fmax84(x, y) result(res)
        real(8), intent (in) :: x
        real(4), intent (in) :: y
        res = merge(dble(y), merge(x, max(x, dble(y)), y /= y), x /= x)
    end function
    real(8) function fmax48(x, y) result(res)
        real(4), intent (in) :: x
        real(8), intent (in) :: y
        res = merge(y, merge(dble(x), max(dble(x), y), y /= y), x /= x)
    end function
    real(8) function fmin88(x, y) result (res)
        real(8), intent (in) :: x
        real(8), intent (in) :: y
        res = merge(y, merge(x, min(x, y), y /= y), x /= x)
    end function
    real(4) function fmin44(x, y) result (res)
        real(4), intent (in) :: x
        real(4), intent (in) :: y
        res = merge(y, merge(x, min(x, y), y /= y), x /= x)
    end function
    real(8) function fmin84(x, y) result(res)
        real(8), intent (in) :: x
        real(4), intent (in) :: y
        res = merge(dble(y), merge(x, min(x, dble(y)), y /= y), x /= x)
    end function
    real(8) function fmin48(x, y) result(res)
        real(4), intent (in) :: x
        real(8), intent (in) :: y
        res = merge(y, merge(dble(x), min(dble(x), y), y /= y), x /= x)
    end function
end module

real(8) function code(re, im)
use fmin_fmax_functions
    real(8), intent (in) :: re
    real(8), intent (in) :: im
    code = exp(re) * cos(im)
end function
public static double code(double re, double im) {
	return Math.exp(re) * Math.cos(im);
}
def code(re, im):
	return math.exp(re) * math.cos(im)
function code(re, im)
	return Float64(exp(re) * cos(im))
end
function tmp = code(re, im)
	tmp = exp(re) * cos(im);
end
code[re_, im_] := N[(N[Exp[re], $MachinePrecision] * N[Cos[im], $MachinePrecision]), $MachinePrecision]
e^{re} \cdot \cos im

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 7 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: 100.0% accurate, 1.0× speedup?

\[e^{re} \cdot \cos im \]
(FPCore (re im)
  :precision binary64
  (* (exp re) (cos im)))
double code(double re, double im) {
	return exp(re) * cos(im);
}
module fmin_fmax_functions
    implicit none
    private
    public fmax
    public fmin

    interface fmax
        module procedure fmax88
        module procedure fmax44
        module procedure fmax84
        module procedure fmax48
    end interface
    interface fmin
        module procedure fmin88
        module procedure fmin44
        module procedure fmin84
        module procedure fmin48
    end interface
contains
    real(8) function fmax88(x, y) result (res)
        real(8), intent (in) :: x
        real(8), intent (in) :: y
        res = merge(y, merge(x, max(x, y), y /= y), x /= x)
    end function
    real(4) function fmax44(x, y) result (res)
        real(4), intent (in) :: x
        real(4), intent (in) :: y
        res = merge(y, merge(x, max(x, y), y /= y), x /= x)
    end function
    real(8) function fmax84(x, y) result(res)
        real(8), intent (in) :: x
        real(4), intent (in) :: y
        res = merge(dble(y), merge(x, max(x, dble(y)), y /= y), x /= x)
    end function
    real(8) function fmax48(x, y) result(res)
        real(4), intent (in) :: x
        real(8), intent (in) :: y
        res = merge(y, merge(dble(x), max(dble(x), y), y /= y), x /= x)
    end function
    real(8) function fmin88(x, y) result (res)
        real(8), intent (in) :: x
        real(8), intent (in) :: y
        res = merge(y, merge(x, min(x, y), y /= y), x /= x)
    end function
    real(4) function fmin44(x, y) result (res)
        real(4), intent (in) :: x
        real(4), intent (in) :: y
        res = merge(y, merge(x, min(x, y), y /= y), x /= x)
    end function
    real(8) function fmin84(x, y) result(res)
        real(8), intent (in) :: x
        real(4), intent (in) :: y
        res = merge(dble(y), merge(x, min(x, dble(y)), y /= y), x /= x)
    end function
    real(8) function fmin48(x, y) result(res)
        real(4), intent (in) :: x
        real(8), intent (in) :: y
        res = merge(y, merge(dble(x), min(dble(x), y), y /= y), x /= x)
    end function
end module

real(8) function code(re, im)
use fmin_fmax_functions
    real(8), intent (in) :: re
    real(8), intent (in) :: im
    code = exp(re) * cos(im)
end function
public static double code(double re, double im) {
	return Math.exp(re) * Math.cos(im);
}
def code(re, im):
	return math.exp(re) * math.cos(im)
function code(re, im)
	return Float64(exp(re) * cos(im))
end
function tmp = code(re, im)
	tmp = exp(re) * cos(im);
end
code[re_, im_] := N[(N[Exp[re], $MachinePrecision] * N[Cos[im], $MachinePrecision]), $MachinePrecision]
e^{re} \cdot \cos im

Alternative 1: 87.3% accurate, 1.0× speedup?

\[\begin{array}{l} t_0 := e^{re} \cdot \mathsf{fma}\left(im \cdot im, -0.5, 1\right)\\ \mathbf{if}\;re \leq -0.00035:\\ \;\;\;\;t\_0\\ \mathbf{elif}\;re \leq 56000:\\ \;\;\;\;\left(1 + re\right) \cdot \cos im\\ \mathbf{else}:\\ \;\;\;\;t\_0\\ \end{array} \]
(FPCore (re im)
  :precision binary64
  (let* ((t_0 (* (exp re) (fma (* im im) -0.5 1.0))))
  (if (<= re -0.00035)
    t_0
    (if (<= re 56000.0) (* (+ 1.0 re) (cos im)) t_0))))
double code(double re, double im) {
	double t_0 = exp(re) * fma((im * im), -0.5, 1.0);
	double tmp;
	if (re <= -0.00035) {
		tmp = t_0;
	} else if (re <= 56000.0) {
		tmp = (1.0 + re) * cos(im);
	} else {
		tmp = t_0;
	}
	return tmp;
}
function code(re, im)
	t_0 = Float64(exp(re) * fma(Float64(im * im), -0.5, 1.0))
	tmp = 0.0
	if (re <= -0.00035)
		tmp = t_0;
	elseif (re <= 56000.0)
		tmp = Float64(Float64(1.0 + re) * cos(im));
	else
		tmp = t_0;
	end
	return tmp
end
code[re_, im_] := Block[{t$95$0 = N[(N[Exp[re], $MachinePrecision] * N[(N[(im * im), $MachinePrecision] * -0.5 + 1.0), $MachinePrecision]), $MachinePrecision]}, If[LessEqual[re, -0.00035], t$95$0, If[LessEqual[re, 56000.0], N[(N[(1.0 + re), $MachinePrecision] * N[Cos[im], $MachinePrecision]), $MachinePrecision], t$95$0]]]
\begin{array}{l}
t_0 := e^{re} \cdot \mathsf{fma}\left(im \cdot im, -0.5, 1\right)\\
\mathbf{if}\;re \leq -0.00035:\\
\;\;\;\;t\_0\\

\mathbf{elif}\;re \leq 56000:\\
\;\;\;\;\left(1 + re\right) \cdot \cos im\\

\mathbf{else}:\\
\;\;\;\;t\_0\\


\end{array}
Derivation
  1. Split input into 2 regimes
  2. if re < -3.5e-4 or 56000 < re

    1. Initial program 100.0%

      \[e^{re} \cdot \cos im \]
    2. Taylor expanded in im around 0

      \[\leadsto e^{re} \cdot \color{blue}{\left(1 + \frac{-1}{2} \cdot {im}^{2}\right)} \]
    3. Step-by-step derivation
      1. lower-+.f64N/A

        \[\leadsto e^{re} \cdot \left(1 + \color{blue}{\frac{-1}{2} \cdot {im}^{2}}\right) \]
      2. lower-*.f64N/A

        \[\leadsto e^{re} \cdot \left(1 + \frac{-1}{2} \cdot \color{blue}{{im}^{2}}\right) \]
      3. lower-pow.f6463.8%

        \[\leadsto e^{re} \cdot \left(1 + -0.5 \cdot {im}^{\color{blue}{2}}\right) \]
    4. Applied rewrites63.8%

      \[\leadsto e^{re} \cdot \color{blue}{\left(1 + -0.5 \cdot {im}^{2}\right)} \]
    5. Step-by-step derivation
      1. lift-+.f64N/A

        \[\leadsto e^{re} \cdot \left(1 + \color{blue}{\frac{-1}{2} \cdot {im}^{2}}\right) \]
      2. +-commutativeN/A

        \[\leadsto e^{re} \cdot \left(\frac{-1}{2} \cdot {im}^{2} + \color{blue}{1}\right) \]
      3. lift-*.f64N/A

        \[\leadsto e^{re} \cdot \left(\frac{-1}{2} \cdot {im}^{2} + 1\right) \]
      4. *-commutativeN/A

        \[\leadsto e^{re} \cdot \left({im}^{2} \cdot \frac{-1}{2} + 1\right) \]
      5. lower-fma.f6463.8%

        \[\leadsto e^{re} \cdot \mathsf{fma}\left({im}^{2}, \color{blue}{-0.5}, 1\right) \]
      6. lift-pow.f64N/A

        \[\leadsto e^{re} \cdot \mathsf{fma}\left({im}^{2}, \frac{-1}{2}, 1\right) \]
      7. unpow2N/A

        \[\leadsto e^{re} \cdot \mathsf{fma}\left(im \cdot im, \frac{-1}{2}, 1\right) \]
      8. lower-*.f6463.8%

        \[\leadsto e^{re} \cdot \mathsf{fma}\left(im \cdot im, -0.5, 1\right) \]
    6. Applied rewrites63.8%

      \[\leadsto e^{re} \cdot \mathsf{fma}\left(im \cdot im, \color{blue}{-0.5}, 1\right) \]

    if -3.5e-4 < re < 56000

    1. Initial program 100.0%

      \[e^{re} \cdot \cos im \]
    2. Taylor expanded in re around 0

      \[\leadsto \color{blue}{\left(1 + re\right)} \cdot \cos im \]
    3. Step-by-step derivation
      1. lower-+.f6451.6%

        \[\leadsto \left(1 + \color{blue}{re}\right) \cdot \cos im \]
    4. Applied rewrites51.6%

      \[\leadsto \color{blue}{\left(1 + re\right)} \cdot \cos im \]
  3. Recombined 2 regimes into one program.
  4. Add Preprocessing

Alternative 2: 86.6% accurate, 1.2× speedup?

\[\begin{array}{l} t_0 := e^{re} \cdot \mathsf{fma}\left(im \cdot im, -0.5, 1\right)\\ \mathbf{if}\;re \leq -0.00035:\\ \;\;\;\;t\_0\\ \mathbf{elif}\;re \leq 7200000000:\\ \;\;\;\;\cos im\\ \mathbf{else}:\\ \;\;\;\;t\_0\\ \end{array} \]
(FPCore (re im)
  :precision binary64
  (let* ((t_0 (* (exp re) (fma (* im im) -0.5 1.0))))
  (if (<= re -0.00035) t_0 (if (<= re 7200000000.0) (cos im) t_0))))
double code(double re, double im) {
	double t_0 = exp(re) * fma((im * im), -0.5, 1.0);
	double tmp;
	if (re <= -0.00035) {
		tmp = t_0;
	} else if (re <= 7200000000.0) {
		tmp = cos(im);
	} else {
		tmp = t_0;
	}
	return tmp;
}
function code(re, im)
	t_0 = Float64(exp(re) * fma(Float64(im * im), -0.5, 1.0))
	tmp = 0.0
	if (re <= -0.00035)
		tmp = t_0;
	elseif (re <= 7200000000.0)
		tmp = cos(im);
	else
		tmp = t_0;
	end
	return tmp
end
code[re_, im_] := Block[{t$95$0 = N[(N[Exp[re], $MachinePrecision] * N[(N[(im * im), $MachinePrecision] * -0.5 + 1.0), $MachinePrecision]), $MachinePrecision]}, If[LessEqual[re, -0.00035], t$95$0, If[LessEqual[re, 7200000000.0], N[Cos[im], $MachinePrecision], t$95$0]]]
\begin{array}{l}
t_0 := e^{re} \cdot \mathsf{fma}\left(im \cdot im, -0.5, 1\right)\\
\mathbf{if}\;re \leq -0.00035:\\
\;\;\;\;t\_0\\

\mathbf{elif}\;re \leq 7200000000:\\
\;\;\;\;\cos im\\

\mathbf{else}:\\
\;\;\;\;t\_0\\


\end{array}
Derivation
  1. Split input into 2 regimes
  2. if re < -3.5e-4 or 7.2e9 < re

    1. Initial program 100.0%

      \[e^{re} \cdot \cos im \]
    2. Taylor expanded in im around 0

      \[\leadsto e^{re} \cdot \color{blue}{\left(1 + \frac{-1}{2} \cdot {im}^{2}\right)} \]
    3. Step-by-step derivation
      1. lower-+.f64N/A

        \[\leadsto e^{re} \cdot \left(1 + \color{blue}{\frac{-1}{2} \cdot {im}^{2}}\right) \]
      2. lower-*.f64N/A

        \[\leadsto e^{re} \cdot \left(1 + \frac{-1}{2} \cdot \color{blue}{{im}^{2}}\right) \]
      3. lower-pow.f6463.8%

        \[\leadsto e^{re} \cdot \left(1 + -0.5 \cdot {im}^{\color{blue}{2}}\right) \]
    4. Applied rewrites63.8%

      \[\leadsto e^{re} \cdot \color{blue}{\left(1 + -0.5 \cdot {im}^{2}\right)} \]
    5. Step-by-step derivation
      1. lift-+.f64N/A

        \[\leadsto e^{re} \cdot \left(1 + \color{blue}{\frac{-1}{2} \cdot {im}^{2}}\right) \]
      2. +-commutativeN/A

        \[\leadsto e^{re} \cdot \left(\frac{-1}{2} \cdot {im}^{2} + \color{blue}{1}\right) \]
      3. lift-*.f64N/A

        \[\leadsto e^{re} \cdot \left(\frac{-1}{2} \cdot {im}^{2} + 1\right) \]
      4. *-commutativeN/A

        \[\leadsto e^{re} \cdot \left({im}^{2} \cdot \frac{-1}{2} + 1\right) \]
      5. lower-fma.f6463.8%

        \[\leadsto e^{re} \cdot \mathsf{fma}\left({im}^{2}, \color{blue}{-0.5}, 1\right) \]
      6. lift-pow.f64N/A

        \[\leadsto e^{re} \cdot \mathsf{fma}\left({im}^{2}, \frac{-1}{2}, 1\right) \]
      7. unpow2N/A

        \[\leadsto e^{re} \cdot \mathsf{fma}\left(im \cdot im, \frac{-1}{2}, 1\right) \]
      8. lower-*.f6463.8%

        \[\leadsto e^{re} \cdot \mathsf{fma}\left(im \cdot im, -0.5, 1\right) \]
    6. Applied rewrites63.8%

      \[\leadsto e^{re} \cdot \mathsf{fma}\left(im \cdot im, \color{blue}{-0.5}, 1\right) \]

    if -3.5e-4 < re < 7.2e9

    1. Initial program 100.0%

      \[e^{re} \cdot \cos im \]
    2. Taylor expanded in re around 0

      \[\leadsto \color{blue}{\cos im} \]
    3. Step-by-step derivation
      1. lower-cos.f6450.8%

        \[\leadsto \cos im \]
    4. Applied rewrites50.8%

      \[\leadsto \color{blue}{\cos im} \]
  3. Recombined 2 regimes into one program.
  4. Add Preprocessing

Alternative 3: 63.8% accurate, 2.1× speedup?

\[e^{re} \cdot \mathsf{fma}\left(im \cdot im, -0.5, 1\right) \]
(FPCore (re im)
  :precision binary64
  (* (exp re) (fma (* im im) -0.5 1.0)))
double code(double re, double im) {
	return exp(re) * fma((im * im), -0.5, 1.0);
}
function code(re, im)
	return Float64(exp(re) * fma(Float64(im * im), -0.5, 1.0))
end
code[re_, im_] := N[(N[Exp[re], $MachinePrecision] * N[(N[(im * im), $MachinePrecision] * -0.5 + 1.0), $MachinePrecision]), $MachinePrecision]
e^{re} \cdot \mathsf{fma}\left(im \cdot im, -0.5, 1\right)
Derivation
  1. Initial program 100.0%

    \[e^{re} \cdot \cos im \]
  2. Taylor expanded in im around 0

    \[\leadsto e^{re} \cdot \color{blue}{\left(1 + \frac{-1}{2} \cdot {im}^{2}\right)} \]
  3. Step-by-step derivation
    1. lower-+.f64N/A

      \[\leadsto e^{re} \cdot \left(1 + \color{blue}{\frac{-1}{2} \cdot {im}^{2}}\right) \]
    2. lower-*.f64N/A

      \[\leadsto e^{re} \cdot \left(1 + \frac{-1}{2} \cdot \color{blue}{{im}^{2}}\right) \]
    3. lower-pow.f6463.8%

      \[\leadsto e^{re} \cdot \left(1 + -0.5 \cdot {im}^{\color{blue}{2}}\right) \]
  4. Applied rewrites63.8%

    \[\leadsto e^{re} \cdot \color{blue}{\left(1 + -0.5 \cdot {im}^{2}\right)} \]
  5. Step-by-step derivation
    1. lift-+.f64N/A

      \[\leadsto e^{re} \cdot \left(1 + \color{blue}{\frac{-1}{2} \cdot {im}^{2}}\right) \]
    2. +-commutativeN/A

      \[\leadsto e^{re} \cdot \left(\frac{-1}{2} \cdot {im}^{2} + \color{blue}{1}\right) \]
    3. lift-*.f64N/A

      \[\leadsto e^{re} \cdot \left(\frac{-1}{2} \cdot {im}^{2} + 1\right) \]
    4. *-commutativeN/A

      \[\leadsto e^{re} \cdot \left({im}^{2} \cdot \frac{-1}{2} + 1\right) \]
    5. lower-fma.f6463.8%

      \[\leadsto e^{re} \cdot \mathsf{fma}\left({im}^{2}, \color{blue}{-0.5}, 1\right) \]
    6. lift-pow.f64N/A

      \[\leadsto e^{re} \cdot \mathsf{fma}\left({im}^{2}, \frac{-1}{2}, 1\right) \]
    7. unpow2N/A

      \[\leadsto e^{re} \cdot \mathsf{fma}\left(im \cdot im, \frac{-1}{2}, 1\right) \]
    8. lower-*.f6463.8%

      \[\leadsto e^{re} \cdot \mathsf{fma}\left(im \cdot im, -0.5, 1\right) \]
  6. Applied rewrites63.8%

    \[\leadsto e^{re} \cdot \mathsf{fma}\left(im \cdot im, \color{blue}{-0.5}, 1\right) \]
  7. Add Preprocessing

Alternative 4: 38.3% accurate, 2.0× speedup?

\[\begin{array}{l} \mathbf{if}\;re \leq -210:\\ \;\;\;\;-0.5 \cdot {im}^{2}\\ \mathbf{else}:\\ \;\;\;\;\left(re - -1\right) \cdot \mathsf{fma}\left(-0.5, im \cdot im, 1\right)\\ \end{array} \]
(FPCore (re im)
  :precision binary64
  (if (<= re -210.0)
  (* -0.5 (pow im 2.0))
  (* (- re -1.0) (fma -0.5 (* im im) 1.0))))
double code(double re, double im) {
	double tmp;
	if (re <= -210.0) {
		tmp = -0.5 * pow(im, 2.0);
	} else {
		tmp = (re - -1.0) * fma(-0.5, (im * im), 1.0);
	}
	return tmp;
}
function code(re, im)
	tmp = 0.0
	if (re <= -210.0)
		tmp = Float64(-0.5 * (im ^ 2.0));
	else
		tmp = Float64(Float64(re - -1.0) * fma(-0.5, Float64(im * im), 1.0));
	end
	return tmp
end
code[re_, im_] := If[LessEqual[re, -210.0], N[(-0.5 * N[Power[im, 2.0], $MachinePrecision]), $MachinePrecision], N[(N[(re - -1.0), $MachinePrecision] * N[(-0.5 * N[(im * im), $MachinePrecision] + 1.0), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}
\mathbf{if}\;re \leq -210:\\
\;\;\;\;-0.5 \cdot {im}^{2}\\

\mathbf{else}:\\
\;\;\;\;\left(re - -1\right) \cdot \mathsf{fma}\left(-0.5, im \cdot im, 1\right)\\


\end{array}
Derivation
  1. Split input into 2 regimes
  2. if re < -210

    1. Initial program 100.0%

      \[e^{re} \cdot \cos im \]
    2. Taylor expanded in re around 0

      \[\leadsto \color{blue}{\cos im} \]
    3. Step-by-step derivation
      1. lower-cos.f6450.8%

        \[\leadsto \cos im \]
    4. Applied rewrites50.8%

      \[\leadsto \color{blue}{\cos im} \]
    5. Taylor expanded in im around 0

      \[\leadsto 1 + \color{blue}{\frac{-1}{2} \cdot {im}^{2}} \]
    6. Step-by-step derivation
      1. lower-+.f64N/A

        \[\leadsto 1 + \frac{-1}{2} \cdot \color{blue}{{im}^{2}} \]
      2. lower-*.f64N/A

        \[\leadsto 1 + \frac{-1}{2} \cdot {im}^{\color{blue}{2}} \]
      3. lower-pow.f6430.2%

        \[\leadsto 1 + -0.5 \cdot {im}^{2} \]
    7. Applied rewrites30.2%

      \[\leadsto 1 + \color{blue}{-0.5 \cdot {im}^{2}} \]
    8. Step-by-step derivation
      1. lift-+.f64N/A

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

        \[\leadsto \frac{-1}{2} \cdot {im}^{2} + 1 \]
      3. lift-*.f64N/A

        \[\leadsto \frac{-1}{2} \cdot {im}^{2} + 1 \]
      4. lift-pow.f64N/A

        \[\leadsto \frac{-1}{2} \cdot {im}^{2} + 1 \]
      5. pow2N/A

        \[\leadsto \frac{-1}{2} \cdot \left(im \cdot im\right) + 1 \]
      6. lift-*.f64N/A

        \[\leadsto \frac{-1}{2} \cdot \left(im \cdot im\right) + 1 \]
      7. lower-fma.f6430.2%

        \[\leadsto \mathsf{fma}\left(-0.5, im \cdot \color{blue}{im}, 1\right) \]
    9. Applied rewrites30.2%

      \[\leadsto \color{blue}{\mathsf{fma}\left(-0.5, im \cdot im, 1\right)} \]
    10. Taylor expanded in im around inf

      \[\leadsto \frac{-1}{2} \cdot {im}^{\color{blue}{2}} \]
    11. Step-by-step derivation
      1. lower-*.f64N/A

        \[\leadsto \frac{-1}{2} \cdot {im}^{2} \]
      2. lower-pow.f6412.1%

        \[\leadsto -0.5 \cdot {im}^{2} \]
    12. Applied rewrites12.1%

      \[\leadsto -0.5 \cdot {im}^{\color{blue}{2}} \]

    if -210 < re

    1. Initial program 100.0%

      \[e^{re} \cdot \cos im \]
    2. Taylor expanded in re around 0

      \[\leadsto \color{blue}{\left(1 + re\right)} \cdot \cos im \]
    3. Step-by-step derivation
      1. lower-+.f6451.6%

        \[\leadsto \left(1 + \color{blue}{re}\right) \cdot \cos im \]
    4. Applied rewrites51.6%

      \[\leadsto \color{blue}{\left(1 + re\right)} \cdot \cos im \]
    5. Taylor expanded in im around 0

      \[\leadsto \left(1 + re\right) \cdot \color{blue}{\left(1 + \frac{-1}{2} \cdot {im}^{2}\right)} \]
    6. Step-by-step derivation
      1. lower-+.f64N/A

        \[\leadsto \left(1 + re\right) \cdot \left(1 + \color{blue}{\frac{-1}{2} \cdot {im}^{2}}\right) \]
      2. lower-*.f64N/A

        \[\leadsto \left(1 + re\right) \cdot \left(1 + \frac{-1}{2} \cdot \color{blue}{{im}^{2}}\right) \]
      3. lower-pow.f6431.9%

        \[\leadsto \left(1 + re\right) \cdot \left(1 + -0.5 \cdot {im}^{\color{blue}{2}}\right) \]
    7. Applied rewrites31.9%

      \[\leadsto \left(1 + re\right) \cdot \color{blue}{\left(1 + -0.5 \cdot {im}^{2}\right)} \]
    8. Step-by-step derivation
      1. lift-+.f64N/A

        \[\leadsto \left(1 + \color{blue}{re}\right) \cdot \left(1 + \frac{-1}{2} \cdot {im}^{2}\right) \]
      2. +-commutativeN/A

        \[\leadsto \left(re + \color{blue}{1}\right) \cdot \left(1 + \frac{-1}{2} \cdot {im}^{2}\right) \]
      3. add-flipN/A

        \[\leadsto \left(re - \color{blue}{\left(\mathsf{neg}\left(1\right)\right)}\right) \cdot \left(1 + \frac{-1}{2} \cdot {im}^{2}\right) \]
      4. lower--.f64N/A

        \[\leadsto \left(re - \color{blue}{\left(\mathsf{neg}\left(1\right)\right)}\right) \cdot \left(1 + \frac{-1}{2} \cdot {im}^{2}\right) \]
      5. metadata-eval31.9%

        \[\leadsto \left(re - -1\right) \cdot \left(1 + -0.5 \cdot {im}^{2}\right) \]
      6. metadata-evalN/A

        \[\leadsto \left(re - -1\right) \cdot \mathsf{Rewrite=>}\left(lift-+.f64, \left(1 + \frac{-1}{2} \cdot {im}^{2}\right)\right) \]
      7. metadata-evalN/A

        \[\leadsto \left(re - -1\right) \cdot \mathsf{Rewrite=>}\left(+-commutative, \left(\frac{-1}{2} \cdot {im}^{2} + 1\right)\right) \]
      8. metadata-evalN/A

        \[\leadsto \left(re - -1\right) \cdot \left(\mathsf{Rewrite=>}\left(lift-*.f64, \left(\frac{-1}{2} \cdot {im}^{2}\right)\right) + 1\right) \]
      9. metadata-evalN/A

        \[\leadsto \left(re - -1\right) \cdot \left(\frac{-1}{2} \cdot \mathsf{Rewrite=>}\left(lift-pow.f64, \left({im}^{2}\right)\right) + 1\right) \]
      10. metadata-evalN/A

        \[\leadsto \left(re - -1\right) \cdot \left(\frac{-1}{2} \cdot \mathsf{Rewrite<=}\left(pow2, \left(im \cdot im\right)\right) + 1\right) \]
      11. metadata-evalN/A

        \[\leadsto \left(re - -1\right) \cdot \left(\frac{-1}{2} \cdot \mathsf{Rewrite<=}\left(lift-*.f64, \left(im \cdot im\right)\right) + 1\right) \]
      12. metadata-evalN/A

        \[\leadsto \left(re - -1\right) \cdot \mathsf{Rewrite=>}\left(lower-fma.f64, \left(\mathsf{fma}\left(\frac{-1}{2}, im \cdot im, 1\right)\right)\right) \]
    9. Applied rewrites31.9%

      \[\leadsto \color{blue}{\left(re - -1\right) \cdot \mathsf{fma}\left(-0.5, im \cdot im, 1\right)} \]
  3. Recombined 2 regimes into one program.
  4. Add Preprocessing

Alternative 5: 31.9% accurate, 3.3× speedup?

\[\left(re - -1\right) \cdot \mathsf{fma}\left(-0.5, im \cdot im, 1\right) \]
(FPCore (re im)
  :precision binary64
  (* (- re -1.0) (fma -0.5 (* im im) 1.0)))
double code(double re, double im) {
	return (re - -1.0) * fma(-0.5, (im * im), 1.0);
}
function code(re, im)
	return Float64(Float64(re - -1.0) * fma(-0.5, Float64(im * im), 1.0))
end
code[re_, im_] := N[(N[(re - -1.0), $MachinePrecision] * N[(-0.5 * N[(im * im), $MachinePrecision] + 1.0), $MachinePrecision]), $MachinePrecision]
\left(re - -1\right) \cdot \mathsf{fma}\left(-0.5, im \cdot im, 1\right)
Derivation
  1. Initial program 100.0%

    \[e^{re} \cdot \cos im \]
  2. Taylor expanded in re around 0

    \[\leadsto \color{blue}{\left(1 + re\right)} \cdot \cos im \]
  3. Step-by-step derivation
    1. lower-+.f6451.6%

      \[\leadsto \left(1 + \color{blue}{re}\right) \cdot \cos im \]
  4. Applied rewrites51.6%

    \[\leadsto \color{blue}{\left(1 + re\right)} \cdot \cos im \]
  5. Taylor expanded in im around 0

    \[\leadsto \left(1 + re\right) \cdot \color{blue}{\left(1 + \frac{-1}{2} \cdot {im}^{2}\right)} \]
  6. Step-by-step derivation
    1. lower-+.f64N/A

      \[\leadsto \left(1 + re\right) \cdot \left(1 + \color{blue}{\frac{-1}{2} \cdot {im}^{2}}\right) \]
    2. lower-*.f64N/A

      \[\leadsto \left(1 + re\right) \cdot \left(1 + \frac{-1}{2} \cdot \color{blue}{{im}^{2}}\right) \]
    3. lower-pow.f6431.9%

      \[\leadsto \left(1 + re\right) \cdot \left(1 + -0.5 \cdot {im}^{\color{blue}{2}}\right) \]
  7. Applied rewrites31.9%

    \[\leadsto \left(1 + re\right) \cdot \color{blue}{\left(1 + -0.5 \cdot {im}^{2}\right)} \]
  8. Step-by-step derivation
    1. lift-+.f64N/A

      \[\leadsto \left(1 + \color{blue}{re}\right) \cdot \left(1 + \frac{-1}{2} \cdot {im}^{2}\right) \]
    2. +-commutativeN/A

      \[\leadsto \left(re + \color{blue}{1}\right) \cdot \left(1 + \frac{-1}{2} \cdot {im}^{2}\right) \]
    3. add-flipN/A

      \[\leadsto \left(re - \color{blue}{\left(\mathsf{neg}\left(1\right)\right)}\right) \cdot \left(1 + \frac{-1}{2} \cdot {im}^{2}\right) \]
    4. lower--.f64N/A

      \[\leadsto \left(re - \color{blue}{\left(\mathsf{neg}\left(1\right)\right)}\right) \cdot \left(1 + \frac{-1}{2} \cdot {im}^{2}\right) \]
    5. metadata-eval31.9%

      \[\leadsto \left(re - -1\right) \cdot \left(1 + -0.5 \cdot {im}^{2}\right) \]
    6. metadata-evalN/A

      \[\leadsto \left(re - -1\right) \cdot \mathsf{Rewrite=>}\left(lift-+.f64, \left(1 + \frac{-1}{2} \cdot {im}^{2}\right)\right) \]
    7. metadata-evalN/A

      \[\leadsto \left(re - -1\right) \cdot \mathsf{Rewrite=>}\left(+-commutative, \left(\frac{-1}{2} \cdot {im}^{2} + 1\right)\right) \]
    8. metadata-evalN/A

      \[\leadsto \left(re - -1\right) \cdot \left(\mathsf{Rewrite=>}\left(lift-*.f64, \left(\frac{-1}{2} \cdot {im}^{2}\right)\right) + 1\right) \]
    9. metadata-evalN/A

      \[\leadsto \left(re - -1\right) \cdot \left(\frac{-1}{2} \cdot \mathsf{Rewrite=>}\left(lift-pow.f64, \left({im}^{2}\right)\right) + 1\right) \]
    10. metadata-evalN/A

      \[\leadsto \left(re - -1\right) \cdot \left(\frac{-1}{2} \cdot \mathsf{Rewrite<=}\left(pow2, \left(im \cdot im\right)\right) + 1\right) \]
    11. metadata-evalN/A

      \[\leadsto \left(re - -1\right) \cdot \left(\frac{-1}{2} \cdot \mathsf{Rewrite<=}\left(lift-*.f64, \left(im \cdot im\right)\right) + 1\right) \]
    12. metadata-evalN/A

      \[\leadsto \left(re - -1\right) \cdot \mathsf{Rewrite=>}\left(lower-fma.f64, \left(\mathsf{fma}\left(\frac{-1}{2}, im \cdot im, 1\right)\right)\right) \]
  9. Applied rewrites31.9%

    \[\leadsto \color{blue}{\left(re - -1\right) \cdot \mathsf{fma}\left(-0.5, im \cdot im, 1\right)} \]
  10. Add Preprocessing

Alternative 6: 30.2% accurate, 5.4× speedup?

\[\mathsf{fma}\left(-0.5, im \cdot im, 1\right) \]
(FPCore (re im)
  :precision binary64
  (fma -0.5 (* im im) 1.0))
double code(double re, double im) {
	return fma(-0.5, (im * im), 1.0);
}
function code(re, im)
	return fma(-0.5, Float64(im * im), 1.0)
end
code[re_, im_] := N[(-0.5 * N[(im * im), $MachinePrecision] + 1.0), $MachinePrecision]
\mathsf{fma}\left(-0.5, im \cdot im, 1\right)
Derivation
  1. Initial program 100.0%

    \[e^{re} \cdot \cos im \]
  2. Taylor expanded in re around 0

    \[\leadsto \color{blue}{\cos im} \]
  3. Step-by-step derivation
    1. lower-cos.f6450.8%

      \[\leadsto \cos im \]
  4. Applied rewrites50.8%

    \[\leadsto \color{blue}{\cos im} \]
  5. Taylor expanded in im around 0

    \[\leadsto 1 + \color{blue}{\frac{-1}{2} \cdot {im}^{2}} \]
  6. Step-by-step derivation
    1. lower-+.f64N/A

      \[\leadsto 1 + \frac{-1}{2} \cdot \color{blue}{{im}^{2}} \]
    2. lower-*.f64N/A

      \[\leadsto 1 + \frac{-1}{2} \cdot {im}^{\color{blue}{2}} \]
    3. lower-pow.f6430.2%

      \[\leadsto 1 + -0.5 \cdot {im}^{2} \]
  7. Applied rewrites30.2%

    \[\leadsto 1 + \color{blue}{-0.5 \cdot {im}^{2}} \]
  8. Step-by-step derivation
    1. lift-+.f64N/A

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

      \[\leadsto \frac{-1}{2} \cdot {im}^{2} + 1 \]
    3. lift-*.f64N/A

      \[\leadsto \frac{-1}{2} \cdot {im}^{2} + 1 \]
    4. lift-pow.f64N/A

      \[\leadsto \frac{-1}{2} \cdot {im}^{2} + 1 \]
    5. pow2N/A

      \[\leadsto \frac{-1}{2} \cdot \left(im \cdot im\right) + 1 \]
    6. lift-*.f64N/A

      \[\leadsto \frac{-1}{2} \cdot \left(im \cdot im\right) + 1 \]
    7. lower-fma.f6430.2%

      \[\leadsto \mathsf{fma}\left(-0.5, im \cdot \color{blue}{im}, 1\right) \]
  9. Applied rewrites30.2%

    \[\leadsto \color{blue}{\mathsf{fma}\left(-0.5, im \cdot im, 1\right)} \]
  10. Add Preprocessing

Reproduce

?
herbie shell --seed 2025227 
(FPCore (re im)
  :name "math.exp on complex, real part"
  :precision binary64
  (* (exp re) (cos im)))