
(FPCore (x) :precision binary64 (+ (- (exp x) 2.0) (exp (- x))))
double code(double x) {
return (exp(x) - 2.0) + exp(-x);
}
real(8) function code(x)
real(8), intent (in) :: x
code = (exp(x) - 2.0d0) + exp(-x)
end function
public static double code(double x) {
return (Math.exp(x) - 2.0) + Math.exp(-x);
}
def code(x): return (math.exp(x) - 2.0) + math.exp(-x)
function code(x) return Float64(Float64(exp(x) - 2.0) + exp(Float64(-x))) end
function tmp = code(x) tmp = (exp(x) - 2.0) + exp(-x); end
code[x_] := N[(N[(N[Exp[x], $MachinePrecision] - 2.0), $MachinePrecision] + N[Exp[(-x)], $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\left(e^{x} - 2\right) + e^{-x}
\end{array}
Sampling outcomes in binary64 precision:
Herbie found 7 alternatives:
| Alternative | Accuracy | Speedup |
|---|
(FPCore (x) :precision binary64 (+ (- (exp x) 2.0) (exp (- x))))
double code(double x) {
return (exp(x) - 2.0) + exp(-x);
}
real(8) function code(x)
real(8), intent (in) :: x
code = (exp(x) - 2.0d0) + exp(-x)
end function
public static double code(double x) {
return (Math.exp(x) - 2.0) + Math.exp(-x);
}
def code(x): return (math.exp(x) - 2.0) + math.exp(-x)
function code(x) return Float64(Float64(exp(x) - 2.0) + exp(Float64(-x))) end
function tmp = code(x) tmp = (exp(x) - 2.0) + exp(-x); end
code[x_] := N[(N[(N[Exp[x], $MachinePrecision] - 2.0), $MachinePrecision] + N[Exp[(-x)], $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\left(e^{x} - 2\right) + e^{-x}
\end{array}
(FPCore (x)
:precision binary64
(*
x
(fma
(*
x
(fma
x
(* x (fma x (* x 4.96031746031746e-5) 0.002777777777777778))
0.08333333333333333))
(* x x)
x)))
double code(double x) {
return x * fma((x * fma(x, (x * fma(x, (x * 4.96031746031746e-5), 0.002777777777777778)), 0.08333333333333333)), (x * x), x);
}
function code(x) return Float64(x * fma(Float64(x * fma(x, Float64(x * fma(x, Float64(x * 4.96031746031746e-5), 0.002777777777777778)), 0.08333333333333333)), Float64(x * x), x)) end
code[x_] := N[(x * N[(N[(x * N[(x * N[(x * N[(x * N[(x * 4.96031746031746e-5), $MachinePrecision] + 0.002777777777777778), $MachinePrecision]), $MachinePrecision] + 0.08333333333333333), $MachinePrecision]), $MachinePrecision] * N[(x * x), $MachinePrecision] + x), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
x \cdot \mathsf{fma}\left(x \cdot \mathsf{fma}\left(x, x \cdot \mathsf{fma}\left(x, x \cdot 4.96031746031746 \cdot 10^{-5}, 0.002777777777777778\right), 0.08333333333333333\right), x \cdot x, x\right)
\end{array}
Initial program 55.1%
Taylor expanded in x around 0
unpow2N/A
associate-*l*N/A
lower-*.f64N/A
+-commutativeN/A
distribute-lft-inN/A
associate-*r*N/A
*-commutativeN/A
*-rgt-identityN/A
lower-fma.f64N/A
Applied rewrites99.1%
lift-*.f64N/A
lift-fma.f64N/A
*-commutativeN/A
lift-fma.f64N/A
flip-+N/A
associate-*l/N/A
lower-/.f64N/A
Applied rewrites99.1%
Applied rewrites99.1%
(FPCore (x) :precision binary64 (fma x x (* (* x (* x x)) (* x (fma (* x x) 0.002777777777777778 0.08333333333333333)))))
double code(double x) {
return fma(x, x, ((x * (x * x)) * (x * fma((x * x), 0.002777777777777778, 0.08333333333333333))));
}
function code(x) return fma(x, x, Float64(Float64(x * Float64(x * x)) * Float64(x * fma(Float64(x * x), 0.002777777777777778, 0.08333333333333333)))) end
code[x_] := N[(x * x + N[(N[(x * N[(x * x), $MachinePrecision]), $MachinePrecision] * N[(x * N[(N[(x * x), $MachinePrecision] * 0.002777777777777778 + 0.08333333333333333), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\mathsf{fma}\left(x, x, \left(x \cdot \left(x \cdot x\right)\right) \cdot \left(x \cdot \mathsf{fma}\left(x \cdot x, 0.002777777777777778, 0.08333333333333333\right)\right)\right)
\end{array}
Initial program 55.1%
Taylor expanded in x around 0
unpow2N/A
associate-*l*N/A
*-commutativeN/A
lower-*.f64N/A
+-commutativeN/A
distribute-lft1-inN/A
associate-*l*N/A
lower-fma.f64N/A
unpow2N/A
lower-*.f64N/A
*-commutativeN/A
lower-*.f64N/A
+-commutativeN/A
*-commutativeN/A
lower-fma.f64N/A
unpow2N/A
lower-*.f6499.1
Applied rewrites99.1%
lift-*.f64N/A
lift-*.f64N/A
lift-fma.f64N/A
lift-*.f64N/A
+-commutativeN/A
distribute-rgt-inN/A
lower-fma.f64N/A
*-commutativeN/A
associate-*r*N/A
lift-*.f64N/A
lower-*.f6499.1
Applied rewrites99.1%
(FPCore (x) :precision binary64 (* x (* x (fma (* x x) (fma (* x x) 0.002777777777777778 0.08333333333333333) 1.0))))
double code(double x) {
return x * (x * fma((x * x), fma((x * x), 0.002777777777777778, 0.08333333333333333), 1.0));
}
function code(x) return Float64(x * Float64(x * fma(Float64(x * x), fma(Float64(x * x), 0.002777777777777778, 0.08333333333333333), 1.0))) end
code[x_] := N[(x * N[(x * N[(N[(x * x), $MachinePrecision] * N[(N[(x * x), $MachinePrecision] * 0.002777777777777778 + 0.08333333333333333), $MachinePrecision] + 1.0), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
x \cdot \left(x \cdot \mathsf{fma}\left(x \cdot x, \mathsf{fma}\left(x \cdot x, 0.002777777777777778, 0.08333333333333333\right), 1\right)\right)
\end{array}
Initial program 55.1%
Taylor expanded in x around 0
unpow2N/A
associate-*l*N/A
*-commutativeN/A
lower-*.f64N/A
+-commutativeN/A
distribute-lft1-inN/A
associate-*l*N/A
lower-fma.f64N/A
unpow2N/A
lower-*.f64N/A
*-commutativeN/A
lower-*.f64N/A
+-commutativeN/A
*-commutativeN/A
lower-fma.f64N/A
unpow2N/A
lower-*.f6499.1
Applied rewrites99.1%
lift-*.f64N/A
lift-*.f64N/A
lift-fma.f64N/A
lift-*.f64N/A
lift-*.f64N/A
associate-*l*N/A
*-commutativeN/A
lower-fma.f64N/A
lower-*.f6499.1
Applied rewrites99.1%
lift-*.f64N/A
lift-fma.f64N/A
lift-*.f64N/A
lift-*.f64N/A
distribute-lft1-inN/A
lower-*.f64N/A
lift-*.f64N/A
lift-*.f64N/A
associate-*r*N/A
lift-*.f64N/A
lower-fma.f6499.1
Applied rewrites99.1%
Final simplification99.1%
(FPCore (x) :precision binary64 (fma (* x (* x (* x 0.08333333333333333))) x (* x x)))
double code(double x) {
return fma((x * (x * (x * 0.08333333333333333))), x, (x * x));
}
function code(x) return fma(Float64(x * Float64(x * Float64(x * 0.08333333333333333))), x, Float64(x * x)) end
code[x_] := N[(N[(x * N[(x * N[(x * 0.08333333333333333), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] * x + N[(x * x), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\mathsf{fma}\left(x \cdot \left(x \cdot \left(x \cdot 0.08333333333333333\right)\right), x, x \cdot x\right)
\end{array}
Initial program 55.1%
Taylor expanded in x around 0
unpow2N/A
associate-*l*N/A
lower-*.f64N/A
+-commutativeN/A
distribute-lft-inN/A
*-rgt-identityN/A
lower-fma.f64N/A
*-commutativeN/A
lower-*.f64N/A
unpow2N/A
lower-*.f6498.9
Applied rewrites98.9%
lift-*.f64N/A
lift-*.f64N/A
distribute-rgt-inN/A
lift-*.f64N/A
lower-fma.f64N/A
lower-*.f6498.9
lift-*.f64N/A
lift-*.f64N/A
associate-*l*N/A
*-commutativeN/A
lower-*.f64N/A
*-commutativeN/A
lower-*.f6498.9
Applied rewrites98.9%
(FPCore (x) :precision binary64 (* x (fma x (* 0.08333333333333333 (* x x)) x)))
double code(double x) {
return x * fma(x, (0.08333333333333333 * (x * x)), x);
}
function code(x) return Float64(x * fma(x, Float64(0.08333333333333333 * Float64(x * x)), x)) end
code[x_] := N[(x * N[(x * N[(0.08333333333333333 * N[(x * x), $MachinePrecision]), $MachinePrecision] + x), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
x \cdot \mathsf{fma}\left(x, 0.08333333333333333 \cdot \left(x \cdot x\right), x\right)
\end{array}
Initial program 55.1%
Taylor expanded in x around 0
unpow2N/A
associate-*l*N/A
lower-*.f64N/A
+-commutativeN/A
distribute-lft-inN/A
*-rgt-identityN/A
lower-fma.f64N/A
*-commutativeN/A
lower-*.f64N/A
unpow2N/A
lower-*.f6498.9
Applied rewrites98.9%
Final simplification98.9%
(FPCore (x) :precision binary64 (* x x))
double code(double x) {
return x * x;
}
real(8) function code(x)
real(8), intent (in) :: x
code = x * x
end function
public static double code(double x) {
return x * x;
}
def code(x): return x * x
function code(x) return Float64(x * x) end
function tmp = code(x) tmp = x * x; end
code[x_] := N[(x * x), $MachinePrecision]
\begin{array}{l}
\\
x \cdot x
\end{array}
Initial program 55.1%
Taylor expanded in x around 0
unpow2N/A
lower-*.f6498.4
Applied rewrites98.4%
(FPCore (x) :precision binary64 (+ 2.0 -2.0))
double code(double x) {
return 2.0 + -2.0;
}
real(8) function code(x)
real(8), intent (in) :: x
code = 2.0d0 + (-2.0d0)
end function
public static double code(double x) {
return 2.0 + -2.0;
}
def code(x): return 2.0 + -2.0
function code(x) return Float64(2.0 + -2.0) end
function tmp = code(x) tmp = 2.0 + -2.0; end
code[x_] := N[(2.0 + -2.0), $MachinePrecision]
\begin{array}{l}
\\
2 + -2
\end{array}
Initial program 55.1%
lift-exp.f64N/A
lift--.f64N/A
lift-neg.f64N/A
lift-exp.f64N/A
+-commutativeN/A
lift--.f64N/A
sub-negN/A
associate-+r+N/A
+-commutativeN/A
lift-exp.f64N/A
lift-exp.f64N/A
lift-neg.f64N/A
cosh-undefN/A
lower-fma.f64N/A
lower-cosh.f64N/A
metadata-eval55.1
Applied rewrites55.1%
Taylor expanded in x around 0
+-commutativeN/A
unpow2N/A
associate-*r*N/A
*-commutativeN/A
lower-fma.f64N/A
*-commutativeN/A
lower-*.f6453.9
Applied rewrites53.9%
lift-*.f64N/A
lift-fma.f64N/A
lower-+.f64N/A
lift-fma.f64N/A
distribute-rgt-inN/A
lift-*.f64N/A
associate-*r*N/A
lift-*.f64N/A
associate-*l*N/A
metadata-evalN/A
metadata-evalN/A
lower-fma.f6453.9
Applied rewrites53.9%
Taylor expanded in x around 0
Applied rewrites53.0%
(FPCore (x) :precision binary64 (let* ((t_0 (sinh (/ x 2.0)))) (* 4.0 (* t_0 t_0))))
double code(double x) {
double t_0 = sinh((x / 2.0));
return 4.0 * (t_0 * t_0);
}
real(8) function code(x)
real(8), intent (in) :: x
real(8) :: t_0
t_0 = sinh((x / 2.0d0))
code = 4.0d0 * (t_0 * t_0)
end function
public static double code(double x) {
double t_0 = Math.sinh((x / 2.0));
return 4.0 * (t_0 * t_0);
}
def code(x): t_0 = math.sinh((x / 2.0)) return 4.0 * (t_0 * t_0)
function code(x) t_0 = sinh(Float64(x / 2.0)) return Float64(4.0 * Float64(t_0 * t_0)) end
function tmp = code(x) t_0 = sinh((x / 2.0)); tmp = 4.0 * (t_0 * t_0); end
code[x_] := Block[{t$95$0 = N[Sinh[N[(x / 2.0), $MachinePrecision]], $MachinePrecision]}, N[(4.0 * N[(t$95$0 * t$95$0), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}
\\
\begin{array}{l}
t_0 := \sinh \left(\frac{x}{2}\right)\\
4 \cdot \left(t\_0 \cdot t\_0\right)
\end{array}
\end{array}
herbie shell --seed 2024219
(FPCore (x)
:name "exp2 (problem 3.3.7)"
:precision binary64
:pre (<= (fabs x) 710.0)
:alt
(! :herbie-platform default (* 4 (* (sinh (/ x 2)) (sinh (/ x 2)))))
(+ (- (exp x) 2.0) (exp (- x))))