
(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 9 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 x)
(fma
(* x x)
(fma
x
(* x (fma (* x x) 4.96031746031746e-5 0.002777777777777778))
0.08333333333333333)
1.0)))
double code(double x) {
return (x * x) * fma((x * x), fma(x, (x * fma((x * x), 4.96031746031746e-5, 0.002777777777777778)), 0.08333333333333333), 1.0);
}
function code(x) return Float64(Float64(x * x) * fma(Float64(x * x), fma(x, Float64(x * fma(Float64(x * x), 4.96031746031746e-5, 0.002777777777777778)), 0.08333333333333333), 1.0)) end
code[x_] := N[(N[(x * x), $MachinePrecision] * N[(N[(x * x), $MachinePrecision] * N[(x * N[(x * N[(N[(x * x), $MachinePrecision] * 4.96031746031746e-5 + 0.002777777777777778), $MachinePrecision]), $MachinePrecision] + 0.08333333333333333), $MachinePrecision] + 1.0), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\left(x \cdot x\right) \cdot \mathsf{fma}\left(x \cdot x, \mathsf{fma}\left(x, x \cdot \mathsf{fma}\left(x \cdot x, 4.96031746031746 \cdot 10^{-5}, 0.002777777777777778\right), 0.08333333333333333\right), 1\right)
\end{array}
Initial program 55.2%
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 rewrites98.6%
Taylor expanded in x around 0
lower-*.f64N/A
unpow2N/A
lower-*.f64N/A
+-commutativeN/A
lower-fma.f64N/A
unpow2N/A
lower-*.f64N/A
+-commutativeN/A
unpow2N/A
associate-*l*N/A
lower-fma.f64N/A
lower-*.f64N/A
+-commutativeN/A
*-commutativeN/A
lower-fma.f64N/A
unpow2N/A
lower-*.f6498.6
Applied rewrites98.6%
(FPCore (x)
:precision binary64
(*
x
(fma
(fma
x
(* x (fma (* x x) 4.96031746031746e-5 0.002777777777777778))
0.08333333333333333)
(* x (* x x))
x)))
double code(double x) {
return x * fma(fma(x, (x * fma((x * x), 4.96031746031746e-5, 0.002777777777777778)), 0.08333333333333333), (x * (x * x)), x);
}
function code(x) return Float64(x * fma(fma(x, Float64(x * fma(Float64(x * x), 4.96031746031746e-5, 0.002777777777777778)), 0.08333333333333333), Float64(x * Float64(x * x)), x)) end
code[x_] := N[(x * N[(N[(x * N[(x * N[(N[(x * x), $MachinePrecision] * 4.96031746031746e-5 + 0.002777777777777778), $MachinePrecision]), $MachinePrecision] + 0.08333333333333333), $MachinePrecision] * N[(x * N[(x * x), $MachinePrecision]), $MachinePrecision] + x), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
x \cdot \mathsf{fma}\left(\mathsf{fma}\left(x, x \cdot \mathsf{fma}\left(x \cdot x, 4.96031746031746 \cdot 10^{-5}, 0.002777777777777778\right), 0.08333333333333333\right), x \cdot \left(x \cdot x\right), x\right)
\end{array}
Initial program 55.2%
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 rewrites98.6%
(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(x, Float64(x * 0.002777777777777778), 0.08333333333333333)))) end
code[x_] := N[(x * x + N[(N[(x * N[(x * x), $MachinePrecision]), $MachinePrecision] * N[(x * N[(x * N[(x * 0.002777777777777778), $MachinePrecision] + 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, x \cdot 0.002777777777777778, 0.08333333333333333\right)\right)\right)
\end{array}
Initial program 55.2%
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-*.f6498.5
Applied rewrites98.5%
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-*.f6498.5
lift-fma.f64N/A
lift-*.f64N/A
associate-*l*N/A
lower-fma.f64N/A
lower-*.f6498.5
Applied rewrites98.5%
(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(x, Float64(x * fma(x, Float64(x * 0.002777777777777778), 0.08333333333333333)), 1.0))) end
code[x_] := N[(x * N[(x * N[(x * N[(x * N[(x * N[(x * 0.002777777777777778), $MachinePrecision] + 0.08333333333333333), $MachinePrecision]), $MachinePrecision] + 1.0), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
x \cdot \left(x \cdot \mathsf{fma}\left(x, x \cdot \mathsf{fma}\left(x, x \cdot 0.002777777777777778, 0.08333333333333333\right), 1\right)\right)
\end{array}
Initial program 55.2%
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-*.f6498.5
Applied rewrites98.5%
lift-*.f64N/A
lift-*.f64N/A
lift-fma.f64N/A
lift-*.f64N/A
lift-fma.f64N/A
*-commutativeN/A
lower-*.f6498.5
Applied rewrites98.5%
lift-*.f64N/A
distribute-lft-inN/A
lift-*.f64N/A
associate-*r*N/A
lift-*.f64N/A
associate-*r*N/A
lift-*.f64N/A
lift-*.f64N/A
lower-fma.f6498.5
Applied rewrites98.5%
lift-*.f64N/A
lift-*.f64N/A
lift-*.f64N/A
lift-fma.f64N/A
lift-*.f64N/A
*-commutativeN/A
distribute-lft1-inN/A
lower-*.f64N/A
Applied rewrites98.5%
Final simplification98.5%
(FPCore (x) :precision binary64 (* x (fma (* x x) (* x (fma (* x x) 0.002777777777777778 0.08333333333333333)) x)))
double code(double x) {
return x * fma((x * x), (x * fma((x * x), 0.002777777777777778, 0.08333333333333333)), x);
}
function code(x) return Float64(x * fma(Float64(x * x), Float64(x * fma(Float64(x * x), 0.002777777777777778, 0.08333333333333333)), x)) end
code[x_] := N[(x * N[(N[(x * x), $MachinePrecision] * N[(x * N[(N[(x * x), $MachinePrecision] * 0.002777777777777778 + 0.08333333333333333), $MachinePrecision]), $MachinePrecision] + x), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
x \cdot \mathsf{fma}\left(x \cdot x, x \cdot \mathsf{fma}\left(x \cdot x, 0.002777777777777778, 0.08333333333333333\right), x\right)
\end{array}
Initial program 55.2%
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-*.f6498.5
Applied rewrites98.5%
(FPCore (x) :precision binary64 (fma (* x (* x x)) (* x 0.08333333333333333) (* x x)))
double code(double x) {
return fma((x * (x * x)), (x * 0.08333333333333333), (x * x));
}
function code(x) return fma(Float64(x * Float64(x * x)), Float64(x * 0.08333333333333333), Float64(x * x)) end
code[x_] := N[(N[(x * N[(x * x), $MachinePrecision]), $MachinePrecision] * N[(x * 0.08333333333333333), $MachinePrecision] + N[(x * x), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\mathsf{fma}\left(x \cdot \left(x \cdot x\right), x \cdot 0.08333333333333333, x \cdot x\right)
\end{array}
Initial program 55.2%
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-*.f6498.5
Applied rewrites98.5%
Taylor expanded in x around 0
*-commutativeN/A
lower-*.f6498.4
Applied rewrites98.4%
lift-*.f64N/A
lift-*.f64N/A
distribute-lft-inN/A
associate-*r*N/A
lift-*.f64N/A
lift-*.f64N/A
lower-fma.f6498.4
Applied rewrites98.4%
(FPCore (x) :precision binary64 (* (* x x) (fma (* x x) 0.08333333333333333 1.0)))
double code(double x) {
return (x * x) * fma((x * x), 0.08333333333333333, 1.0);
}
function code(x) return Float64(Float64(x * x) * fma(Float64(x * x), 0.08333333333333333, 1.0)) end
code[x_] := N[(N[(x * x), $MachinePrecision] * N[(N[(x * x), $MachinePrecision] * 0.08333333333333333 + 1.0), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\left(x \cdot x\right) \cdot \mathsf{fma}\left(x \cdot x, 0.08333333333333333, 1\right)
\end{array}
Initial program 55.2%
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 rewrites98.6%
Taylor expanded in x around 0
lower-*.f64N/A
unpow2N/A
lower-*.f64N/A
+-commutativeN/A
lower-fma.f64N/A
unpow2N/A
lower-*.f64N/A
+-commutativeN/A
unpow2N/A
associate-*l*N/A
lower-fma.f64N/A
lower-*.f64N/A
+-commutativeN/A
*-commutativeN/A
lower-fma.f64N/A
unpow2N/A
lower-*.f6498.6
Applied rewrites98.6%
Taylor expanded in x around 0
Applied rewrites98.4%
(FPCore (x) :precision binary64 (* x (fma x (* (* x x) 0.08333333333333333) x)))
double code(double x) {
return x * fma(x, ((x * x) * 0.08333333333333333), x);
}
function code(x) return Float64(x * fma(x, Float64(Float64(x * x) * 0.08333333333333333), x)) end
code[x_] := N[(x * N[(x * N[(N[(x * x), $MachinePrecision] * 0.08333333333333333), $MachinePrecision] + x), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
x \cdot \mathsf{fma}\left(x, \left(x \cdot x\right) \cdot 0.08333333333333333, x\right)
\end{array}
Initial program 55.2%
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-*.f6498.4
Applied rewrites98.4%
(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 55.2%
Taylor expanded in x around 0
unpow2N/A
lower-*.f6498.1
Applied rewrites98.1%
(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 2024216
(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))))