
(FPCore (x eps) :precision binary64 (- (cos (+ x eps)) (cos x)))
double code(double x, double eps) {
return cos((x + eps)) - cos(x);
}
real(8) function code(x, eps)
real(8), intent (in) :: x
real(8), intent (in) :: eps
code = cos((x + eps)) - cos(x)
end function
public static double code(double x, double eps) {
return Math.cos((x + eps)) - Math.cos(x);
}
def code(x, eps): return math.cos((x + eps)) - math.cos(x)
function code(x, eps) return Float64(cos(Float64(x + eps)) - cos(x)) end
function tmp = code(x, eps) tmp = cos((x + eps)) - cos(x); end
code[x_, eps_] := N[(N[Cos[N[(x + eps), $MachinePrecision]], $MachinePrecision] - N[Cos[x], $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\cos \left(x + \varepsilon\right) - \cos x
\end{array}
Sampling outcomes in binary64 precision:
Herbie found 10 alternatives:
| Alternative | Accuracy | Speedup |
|---|
(FPCore (x eps) :precision binary64 (- (cos (+ x eps)) (cos x)))
double code(double x, double eps) {
return cos((x + eps)) - cos(x);
}
real(8) function code(x, eps)
real(8), intent (in) :: x
real(8), intent (in) :: eps
code = cos((x + eps)) - cos(x)
end function
public static double code(double x, double eps) {
return Math.cos((x + eps)) - Math.cos(x);
}
def code(x, eps): return math.cos((x + eps)) - math.cos(x)
function code(x, eps) return Float64(cos(Float64(x + eps)) - cos(x)) end
function tmp = code(x, eps) tmp = cos((x + eps)) - cos(x); end
code[x_, eps_] := N[(N[Cos[N[(x + eps), $MachinePrecision]], $MachinePrecision] - N[Cos[x], $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\cos \left(x + \varepsilon\right) - \cos x
\end{array}
(FPCore (x eps) :precision binary64 (* (* (fma (sin x) (cos (* eps 0.5)) (* (cos x) (sin (* eps 0.5)))) (sin (* 0.5 eps))) -2.0))
double code(double x, double eps) {
return (fma(sin(x), cos((eps * 0.5)), (cos(x) * sin((eps * 0.5)))) * sin((0.5 * eps))) * -2.0;
}
function code(x, eps) return Float64(Float64(fma(sin(x), cos(Float64(eps * 0.5)), Float64(cos(x) * sin(Float64(eps * 0.5)))) * sin(Float64(0.5 * eps))) * -2.0) end
code[x_, eps_] := N[(N[(N[(N[Sin[x], $MachinePrecision] * N[Cos[N[(eps * 0.5), $MachinePrecision]], $MachinePrecision] + N[(N[Cos[x], $MachinePrecision] * N[Sin[N[(eps * 0.5), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]), $MachinePrecision] * N[Sin[N[(0.5 * eps), $MachinePrecision]], $MachinePrecision]), $MachinePrecision] * -2.0), $MachinePrecision]
\begin{array}{l}
\\
\left(\mathsf{fma}\left(\sin x, \cos \left(\varepsilon \cdot 0.5\right), \cos x \cdot \sin \left(\varepsilon \cdot 0.5\right)\right) \cdot \sin \left(0.5 \cdot \varepsilon\right)\right) \cdot -2
\end{array}
Initial program 52.0%
lift--.f64N/A
lift-cos.f64N/A
lift-cos.f64N/A
diff-cosN/A
*-commutativeN/A
lower-*.f64N/A
Applied rewrites99.6%
lift-sin.f64N/A
lift-*.f64N/A
lift-fma.f64N/A
distribute-rgt-inN/A
*-commutativeN/A
sin-sumN/A
lower-fma.f64N/A
lower-sin.f64N/A
*-commutativeN/A
associate-*r*N/A
metadata-evalN/A
lower-*.f64N/A
lower-cos.f64N/A
*-commutativeN/A
lower-*.f64N/A
+-lft-identityN/A
lift-+.f64N/A
lift-*.f64N/A
lift-sin.f64N/A
lower-*.f64N/A
Applied rewrites99.8%
Final simplification99.8%
(FPCore (x eps) :precision binary64 (* (* (sin (fma 0.5 eps x)) (sin (* 0.5 eps))) -2.0))
double code(double x, double eps) {
return (sin(fma(0.5, eps, x)) * sin((0.5 * eps))) * -2.0;
}
function code(x, eps) return Float64(Float64(sin(fma(0.5, eps, x)) * sin(Float64(0.5 * eps))) * -2.0) end
code[x_, eps_] := N[(N[(N[Sin[N[(0.5 * eps + x), $MachinePrecision]], $MachinePrecision] * N[Sin[N[(0.5 * eps), $MachinePrecision]], $MachinePrecision]), $MachinePrecision] * -2.0), $MachinePrecision]
\begin{array}{l}
\\
\left(\sin \left(\mathsf{fma}\left(0.5, \varepsilon, x\right)\right) \cdot \sin \left(0.5 \cdot \varepsilon\right)\right) \cdot -2
\end{array}
Initial program 52.0%
lift--.f64N/A
lift-cos.f64N/A
lift-cos.f64N/A
diff-cosN/A
*-commutativeN/A
lower-*.f64N/A
Applied rewrites99.6%
Taylor expanded in x around inf
*-commutativeN/A
metadata-evalN/A
cancel-sign-sub-invN/A
lower-*.f64N/A
lower-sin.f64N/A
cancel-sign-sub-invN/A
metadata-evalN/A
distribute-lft-inN/A
associate-*r*N/A
metadata-evalN/A
*-lft-identityN/A
lower-fma.f64N/A
lower-sin.f64N/A
lower-*.f6499.6
Applied rewrites99.6%
(FPCore (x eps)
:precision binary64
(*
(*
(sin (fma 0.5 eps x))
(*
(fma
(fma
(fma -1.5500992063492063e-6 (* eps eps) 0.00026041666666666666)
(* eps eps)
-0.020833333333333332)
(* eps eps)
0.5)
eps))
-2.0))
double code(double x, double eps) {
return (sin(fma(0.5, eps, x)) * (fma(fma(fma(-1.5500992063492063e-6, (eps * eps), 0.00026041666666666666), (eps * eps), -0.020833333333333332), (eps * eps), 0.5) * eps)) * -2.0;
}
function code(x, eps) return Float64(Float64(sin(fma(0.5, eps, x)) * Float64(fma(fma(fma(-1.5500992063492063e-6, Float64(eps * eps), 0.00026041666666666666), Float64(eps * eps), -0.020833333333333332), Float64(eps * eps), 0.5) * eps)) * -2.0) end
code[x_, eps_] := N[(N[(N[Sin[N[(0.5 * eps + x), $MachinePrecision]], $MachinePrecision] * N[(N[(N[(N[(-1.5500992063492063e-6 * N[(eps * eps), $MachinePrecision] + 0.00026041666666666666), $MachinePrecision] * N[(eps * eps), $MachinePrecision] + -0.020833333333333332), $MachinePrecision] * N[(eps * eps), $MachinePrecision] + 0.5), $MachinePrecision] * eps), $MachinePrecision]), $MachinePrecision] * -2.0), $MachinePrecision]
\begin{array}{l}
\\
\left(\sin \left(\mathsf{fma}\left(0.5, \varepsilon, x\right)\right) \cdot \left(\mathsf{fma}\left(\mathsf{fma}\left(\mathsf{fma}\left(-1.5500992063492063 \cdot 10^{-6}, \varepsilon \cdot \varepsilon, 0.00026041666666666666\right), \varepsilon \cdot \varepsilon, -0.020833333333333332\right), \varepsilon \cdot \varepsilon, 0.5\right) \cdot \varepsilon\right)\right) \cdot -2
\end{array}
Initial program 52.0%
lift--.f64N/A
lift-cos.f64N/A
lift-cos.f64N/A
diff-cosN/A
*-commutativeN/A
lower-*.f64N/A
Applied rewrites99.6%
lift-sin.f64N/A
lift-*.f64N/A
lift-fma.f64N/A
distribute-rgt-inN/A
*-commutativeN/A
sin-sumN/A
lower-fma.f64N/A
lower-sin.f64N/A
*-commutativeN/A
associate-*r*N/A
metadata-evalN/A
lower-*.f64N/A
lower-cos.f64N/A
*-commutativeN/A
lower-*.f64N/A
+-lft-identityN/A
lift-+.f64N/A
lift-*.f64N/A
lift-sin.f64N/A
lower-*.f64N/A
Applied rewrites99.8%
Applied rewrites99.6%
Taylor expanded in eps around 0
*-commutativeN/A
lower-*.f64N/A
+-commutativeN/A
*-commutativeN/A
lower-fma.f64N/A
sub-negN/A
*-commutativeN/A
metadata-evalN/A
lower-fma.f64N/A
+-commutativeN/A
lower-fma.f64N/A
unpow2N/A
lower-*.f64N/A
unpow2N/A
lower-*.f64N/A
unpow2N/A
lower-*.f6499.5
Applied rewrites99.5%
(FPCore (x eps)
:precision binary64
(*
(*
(sin (fma 0.5 eps x))
(*
(fma
(fma 0.00026041666666666666 (* eps eps) -0.020833333333333332)
(* eps eps)
0.5)
eps))
-2.0))
double code(double x, double eps) {
return (sin(fma(0.5, eps, x)) * (fma(fma(0.00026041666666666666, (eps * eps), -0.020833333333333332), (eps * eps), 0.5) * eps)) * -2.0;
}
function code(x, eps) return Float64(Float64(sin(fma(0.5, eps, x)) * Float64(fma(fma(0.00026041666666666666, Float64(eps * eps), -0.020833333333333332), Float64(eps * eps), 0.5) * eps)) * -2.0) end
code[x_, eps_] := N[(N[(N[Sin[N[(0.5 * eps + x), $MachinePrecision]], $MachinePrecision] * N[(N[(N[(0.00026041666666666666 * N[(eps * eps), $MachinePrecision] + -0.020833333333333332), $MachinePrecision] * N[(eps * eps), $MachinePrecision] + 0.5), $MachinePrecision] * eps), $MachinePrecision]), $MachinePrecision] * -2.0), $MachinePrecision]
\begin{array}{l}
\\
\left(\sin \left(\mathsf{fma}\left(0.5, \varepsilon, x\right)\right) \cdot \left(\mathsf{fma}\left(\mathsf{fma}\left(0.00026041666666666666, \varepsilon \cdot \varepsilon, -0.020833333333333332\right), \varepsilon \cdot \varepsilon, 0.5\right) \cdot \varepsilon\right)\right) \cdot -2
\end{array}
Initial program 52.0%
lift--.f64N/A
lift-cos.f64N/A
lift-cos.f64N/A
diff-cosN/A
*-commutativeN/A
lower-*.f64N/A
Applied rewrites99.6%
lift-sin.f64N/A
lift-*.f64N/A
lift-fma.f64N/A
distribute-rgt-inN/A
*-commutativeN/A
sin-sumN/A
lower-fma.f64N/A
lower-sin.f64N/A
*-commutativeN/A
associate-*r*N/A
metadata-evalN/A
lower-*.f64N/A
lower-cos.f64N/A
*-commutativeN/A
lower-*.f64N/A
+-lft-identityN/A
lift-+.f64N/A
lift-*.f64N/A
lift-sin.f64N/A
lower-*.f64N/A
Applied rewrites99.8%
Applied rewrites99.6%
Taylor expanded in eps around 0
*-commutativeN/A
lower-*.f64N/A
+-commutativeN/A
*-commutativeN/A
lower-fma.f64N/A
sub-negN/A
metadata-evalN/A
lower-fma.f64N/A
unpow2N/A
lower-*.f64N/A
unpow2N/A
lower-*.f6499.5
Applied rewrites99.5%
(FPCore (x eps) :precision binary64 (* (* (sin (fma 0.5 eps x)) (* (fma (* -0.020833333333333332 eps) eps 0.5) eps)) -2.0))
double code(double x, double eps) {
return (sin(fma(0.5, eps, x)) * (fma((-0.020833333333333332 * eps), eps, 0.5) * eps)) * -2.0;
}
function code(x, eps) return Float64(Float64(sin(fma(0.5, eps, x)) * Float64(fma(Float64(-0.020833333333333332 * eps), eps, 0.5) * eps)) * -2.0) end
code[x_, eps_] := N[(N[(N[Sin[N[(0.5 * eps + x), $MachinePrecision]], $MachinePrecision] * N[(N[(N[(-0.020833333333333332 * eps), $MachinePrecision] * eps + 0.5), $MachinePrecision] * eps), $MachinePrecision]), $MachinePrecision] * -2.0), $MachinePrecision]
\begin{array}{l}
\\
\left(\sin \left(\mathsf{fma}\left(0.5, \varepsilon, x\right)\right) \cdot \left(\mathsf{fma}\left(-0.020833333333333332 \cdot \varepsilon, \varepsilon, 0.5\right) \cdot \varepsilon\right)\right) \cdot -2
\end{array}
Initial program 52.0%
lift--.f64N/A
lift-cos.f64N/A
lift-cos.f64N/A
diff-cosN/A
*-commutativeN/A
lower-*.f64N/A
Applied rewrites99.6%
lift-sin.f64N/A
lift-*.f64N/A
lift-fma.f64N/A
distribute-rgt-inN/A
*-commutativeN/A
sin-sumN/A
lower-fma.f64N/A
lower-sin.f64N/A
*-commutativeN/A
associate-*r*N/A
metadata-evalN/A
lower-*.f64N/A
lower-cos.f64N/A
*-commutativeN/A
lower-*.f64N/A
+-lft-identityN/A
lift-+.f64N/A
lift-*.f64N/A
lift-sin.f64N/A
lower-*.f64N/A
Applied rewrites99.8%
Applied rewrites99.6%
Taylor expanded in eps around 0
*-commutativeN/A
lower-*.f64N/A
+-commutativeN/A
unpow2N/A
associate-*r*N/A
lower-fma.f64N/A
lower-*.f6499.3
Applied rewrites99.3%
(FPCore (x eps)
:precision binary64
(let* ((t_0 (fma (* eps eps) 0.16666666666666666 -1.0)))
(*
(fma
(fma (fma 0.25 eps (* (* t_0 x) -0.16666666666666666)) x t_0)
x
(* -0.5 eps))
eps)))
double code(double x, double eps) {
double t_0 = fma((eps * eps), 0.16666666666666666, -1.0);
return fma(fma(fma(0.25, eps, ((t_0 * x) * -0.16666666666666666)), x, t_0), x, (-0.5 * eps)) * eps;
}
function code(x, eps) t_0 = fma(Float64(eps * eps), 0.16666666666666666, -1.0) return Float64(fma(fma(fma(0.25, eps, Float64(Float64(t_0 * x) * -0.16666666666666666)), x, t_0), x, Float64(-0.5 * eps)) * eps) end
code[x_, eps_] := Block[{t$95$0 = N[(N[(eps * eps), $MachinePrecision] * 0.16666666666666666 + -1.0), $MachinePrecision]}, N[(N[(N[(N[(0.25 * eps + N[(N[(t$95$0 * x), $MachinePrecision] * -0.16666666666666666), $MachinePrecision]), $MachinePrecision] * x + t$95$0), $MachinePrecision] * x + N[(-0.5 * eps), $MachinePrecision]), $MachinePrecision] * eps), $MachinePrecision]]
\begin{array}{l}
\\
\begin{array}{l}
t_0 := \mathsf{fma}\left(\varepsilon \cdot \varepsilon, 0.16666666666666666, -1\right)\\
\mathsf{fma}\left(\mathsf{fma}\left(\mathsf{fma}\left(0.25, \varepsilon, \left(t\_0 \cdot x\right) \cdot -0.16666666666666666\right), x, t\_0\right), x, -0.5 \cdot \varepsilon\right) \cdot \varepsilon
\end{array}
\end{array}
Initial program 52.0%
Taylor expanded in eps around 0
*-commutativeN/A
lower-*.f64N/A
Applied rewrites99.1%
Taylor expanded in x around 0
Applied rewrites97.9%
(FPCore (x eps) :precision binary64 (fma (- x) eps (* (* (fma (* 0.25 x) x -0.5) eps) eps)))
double code(double x, double eps) {
return fma(-x, eps, ((fma((0.25 * x), x, -0.5) * eps) * eps));
}
function code(x, eps) return fma(Float64(-x), eps, Float64(Float64(fma(Float64(0.25 * x), x, -0.5) * eps) * eps)) end
code[x_, eps_] := N[((-x) * eps + N[(N[(N[(N[(0.25 * x), $MachinePrecision] * x + -0.5), $MachinePrecision] * eps), $MachinePrecision] * eps), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\mathsf{fma}\left(-x, \varepsilon, \left(\mathsf{fma}\left(0.25 \cdot x, x, -0.5\right) \cdot \varepsilon\right) \cdot \varepsilon\right)
\end{array}
Initial program 52.0%
Taylor expanded in eps around 0
*-commutativeN/A
lower-*.f64N/A
Applied rewrites99.1%
Taylor expanded in x around 0
Applied rewrites97.1%
Taylor expanded in eps around 0
Applied rewrites97.2%
Applied rewrites97.3%
(FPCore (x eps) :precision binary64 (* (fma (fma (* eps eps) 0.16666666666666666 -1.0) x (* -0.5 eps)) eps))
double code(double x, double eps) {
return fma(fma((eps * eps), 0.16666666666666666, -1.0), x, (-0.5 * eps)) * eps;
}
function code(x, eps) return Float64(fma(fma(Float64(eps * eps), 0.16666666666666666, -1.0), x, Float64(-0.5 * eps)) * eps) end
code[x_, eps_] := N[(N[(N[(N[(eps * eps), $MachinePrecision] * 0.16666666666666666 + -1.0), $MachinePrecision] * x + N[(-0.5 * eps), $MachinePrecision]), $MachinePrecision] * eps), $MachinePrecision]
\begin{array}{l}
\\
\mathsf{fma}\left(\mathsf{fma}\left(\varepsilon \cdot \varepsilon, 0.16666666666666666, -1\right), x, -0.5 \cdot \varepsilon\right) \cdot \varepsilon
\end{array}
Initial program 52.0%
Taylor expanded in eps around 0
*-commutativeN/A
lower-*.f64N/A
Applied rewrites99.1%
Taylor expanded in x around 0
Applied rewrites97.2%
(FPCore (x eps) :precision binary64 (* eps (- (* -0.5 eps) x)))
double code(double x, double eps) {
return eps * ((-0.5 * eps) - x);
}
real(8) function code(x, eps)
real(8), intent (in) :: x
real(8), intent (in) :: eps
code = eps * (((-0.5d0) * eps) - x)
end function
public static double code(double x, double eps) {
return eps * ((-0.5 * eps) - x);
}
def code(x, eps): return eps * ((-0.5 * eps) - x)
function code(x, eps) return Float64(eps * Float64(Float64(-0.5 * eps) - x)) end
function tmp = code(x, eps) tmp = eps * ((-0.5 * eps) - x); end
code[x_, eps_] := N[(eps * N[(N[(-0.5 * eps), $MachinePrecision] - x), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\varepsilon \cdot \left(-0.5 \cdot \varepsilon - x\right)
\end{array}
Initial program 52.0%
Taylor expanded in eps around 0
*-commutativeN/A
lower-*.f64N/A
Applied rewrites99.1%
Taylor expanded in x around 0
Applied rewrites97.1%
Taylor expanded in eps around 0
Applied rewrites97.2%
Taylor expanded in x around 0
Applied rewrites97.2%
(FPCore (x eps) :precision binary64 (* (- x) eps))
double code(double x, double eps) {
return -x * eps;
}
real(8) function code(x, eps)
real(8), intent (in) :: x
real(8), intent (in) :: eps
code = -x * eps
end function
public static double code(double x, double eps) {
return -x * eps;
}
def code(x, eps): return -x * eps
function code(x, eps) return Float64(Float64(-x) * eps) end
function tmp = code(x, eps) tmp = -x * eps; end
code[x_, eps_] := N[((-x) * eps), $MachinePrecision]
\begin{array}{l}
\\
\left(-x\right) \cdot \varepsilon
\end{array}
Initial program 52.0%
Taylor expanded in eps around 0
mul-1-negN/A
*-commutativeN/A
distribute-lft-neg-inN/A
lower-*.f64N/A
lower-neg.f64N/A
lower-sin.f6479.6
Applied rewrites79.6%
Taylor expanded in x around 0
Applied rewrites78.9%
(FPCore (x eps) :precision binary64 (pow (cbrt (* (* -2.0 (sin (* 0.5 (fma 2.0 x eps)))) (sin (* 0.5 eps)))) 3.0))
double code(double x, double eps) {
return pow(cbrt(((-2.0 * sin((0.5 * fma(2.0, x, eps)))) * sin((0.5 * eps)))), 3.0);
}
function code(x, eps) return cbrt(Float64(Float64(-2.0 * sin(Float64(0.5 * fma(2.0, x, eps)))) * sin(Float64(0.5 * eps)))) ^ 3.0 end
code[x_, eps_] := N[Power[N[Power[N[(N[(-2.0 * N[Sin[N[(0.5 * N[(2.0 * x + eps), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]), $MachinePrecision] * N[Sin[N[(0.5 * eps), $MachinePrecision]], $MachinePrecision]), $MachinePrecision], 1/3], $MachinePrecision], 3.0], $MachinePrecision]
\begin{array}{l}
\\
{\left(\sqrt[3]{\left(-2 \cdot \sin \left(0.5 \cdot \mathsf{fma}\left(2, x, \varepsilon\right)\right)\right) \cdot \sin \left(0.5 \cdot \varepsilon\right)}\right)}^{3}
\end{array}
herbie shell --seed 2024327
(FPCore (x eps)
:name "2cos (problem 3.3.5)"
:precision binary64
:pre (and (and (and (<= -10000.0 x) (<= x 10000.0)) (< (* 1e-16 (fabs x)) eps)) (< eps (fabs x)))
:alt
(! :herbie-platform default (pow (cbrt (* -2 (sin (* 1/2 (fma 2 x eps))) (sin (* 1/2 eps)))) 3))
(- (cos (+ x eps)) (cos x)))