
(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 9 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 (* -2.0 (* (sin (* eps 0.5)) (sin (fma eps 0.5 x)))))
double code(double x, double eps) {
return -2.0 * (sin((eps * 0.5)) * sin(fma(eps, 0.5, x)));
}
function code(x, eps) return Float64(-2.0 * Float64(sin(Float64(eps * 0.5)) * sin(fma(eps, 0.5, x)))) end
code[x_, eps_] := N[(-2.0 * N[(N[Sin[N[(eps * 0.5), $MachinePrecision]], $MachinePrecision] * N[Sin[N[(eps * 0.5 + x), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
-2 \cdot \left(\sin \left(\varepsilon \cdot 0.5\right) \cdot \sin \left(\mathsf{fma}\left(\varepsilon, 0.5, x\right)\right)\right)
\end{array}
Initial program 56.2%
lift--.f64N/A
lift-cos.f64N/A
lift-cos.f64N/A
diff-cosN/A
*-commutativeN/A
lower-*.f64N/A
Applied rewrites99.7%
Taylor expanded in eps 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-rgt-inN/A
*-commutativeN/A
associate-*l*N/A
metadata-evalN/A
*-rgt-identityN/A
lower-fma.f64N/A
lower-sin.f64N/A
*-commutativeN/A
lower-*.f6499.7
Applied rewrites99.7%
Final simplification99.7%
(FPCore (x eps) :precision binary64 (* (- (* (* -0.5 (cos x)) eps) (sin x)) eps))
double code(double x, double eps) {
return (((-0.5 * cos(x)) * eps) - sin(x)) * eps;
}
real(8) function code(x, eps)
real(8), intent (in) :: x
real(8), intent (in) :: eps
code = ((((-0.5d0) * cos(x)) * eps) - sin(x)) * eps
end function
public static double code(double x, double eps) {
return (((-0.5 * Math.cos(x)) * eps) - Math.sin(x)) * eps;
}
def code(x, eps): return (((-0.5 * math.cos(x)) * eps) - math.sin(x)) * eps
function code(x, eps) return Float64(Float64(Float64(Float64(-0.5 * cos(x)) * eps) - sin(x)) * eps) end
function tmp = code(x, eps) tmp = (((-0.5 * cos(x)) * eps) - sin(x)) * eps; end
code[x_, eps_] := N[(N[(N[(N[(-0.5 * N[Cos[x], $MachinePrecision]), $MachinePrecision] * eps), $MachinePrecision] - N[Sin[x], $MachinePrecision]), $MachinePrecision] * eps), $MachinePrecision]
\begin{array}{l}
\\
\left(\left(-0.5 \cdot \cos x\right) \cdot \varepsilon - \sin x\right) \cdot \varepsilon
\end{array}
Initial program 56.2%
Taylor expanded in eps around 0
*-commutativeN/A
lower-*.f64N/A
*-commutativeN/A
associate-*r*N/A
*-commutativeN/A
lower--.f64N/A
*-commutativeN/A
lower-*.f64N/A
*-commutativeN/A
lower-*.f64N/A
lower-cos.f64N/A
lower-sin.f6499.4
Applied rewrites99.4%
Final simplification99.4%
(FPCore (x eps) :precision binary64 (* (* (* eps 0.5) (sin (fma eps 0.5 x))) -2.0))
double code(double x, double eps) {
return ((eps * 0.5) * sin(fma(eps, 0.5, x))) * -2.0;
}
function code(x, eps) return Float64(Float64(Float64(eps * 0.5) * sin(fma(eps, 0.5, x))) * -2.0) end
code[x_, eps_] := N[(N[(N[(eps * 0.5), $MachinePrecision] * N[Sin[N[(eps * 0.5 + x), $MachinePrecision]], $MachinePrecision]), $MachinePrecision] * -2.0), $MachinePrecision]
\begin{array}{l}
\\
\left(\left(\varepsilon \cdot 0.5\right) \cdot \sin \left(\mathsf{fma}\left(\varepsilon, 0.5, x\right)\right)\right) \cdot -2
\end{array}
Initial program 56.2%
lift--.f64N/A
lift-cos.f64N/A
lift-cos.f64N/A
diff-cosN/A
*-commutativeN/A
lower-*.f64N/A
Applied rewrites99.7%
Taylor expanded in eps 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-rgt-inN/A
*-commutativeN/A
associate-*l*N/A
metadata-evalN/A
*-rgt-identityN/A
lower-fma.f64N/A
lower-sin.f64N/A
*-commutativeN/A
lower-*.f6499.7
Applied rewrites99.7%
Taylor expanded in eps around 0
Applied rewrites99.4%
Final simplification99.4%
(FPCore (x eps) :precision binary64 (* (fma (fma (fma 0.16666666666666666 x (* 0.25 eps)) x -1.0) x (* -0.5 eps)) eps))
double code(double x, double eps) {
return fma(fma(fma(0.16666666666666666, x, (0.25 * eps)), x, -1.0), x, (-0.5 * eps)) * eps;
}
function code(x, eps) return Float64(fma(fma(fma(0.16666666666666666, x, Float64(0.25 * eps)), x, -1.0), x, Float64(-0.5 * eps)) * eps) end
code[x_, eps_] := N[(N[(N[(N[(0.16666666666666666 * x + N[(0.25 * eps), $MachinePrecision]), $MachinePrecision] * x + -1.0), $MachinePrecision] * x + N[(-0.5 * eps), $MachinePrecision]), $MachinePrecision] * eps), $MachinePrecision]
\begin{array}{l}
\\
\mathsf{fma}\left(\mathsf{fma}\left(\mathsf{fma}\left(0.16666666666666666, x, 0.25 \cdot \varepsilon\right), x, -1\right), x, -0.5 \cdot \varepsilon\right) \cdot \varepsilon
\end{array}
Initial program 56.2%
Taylor expanded in eps around 0
*-commutativeN/A
lower-*.f64N/A
*-commutativeN/A
associate-*r*N/A
*-commutativeN/A
lower--.f64N/A
*-commutativeN/A
lower-*.f64N/A
*-commutativeN/A
lower-*.f64N/A
lower-cos.f64N/A
lower-sin.f6499.4
Applied rewrites99.4%
Taylor expanded in x around 0
Applied rewrites98.7%
(FPCore (x eps) :precision binary64 (* (fma (fma (* 0.16666666666666666 x) x -1.0) x (* -0.5 eps)) eps))
double code(double x, double eps) {
return fma(fma((0.16666666666666666 * x), x, -1.0), x, (-0.5 * eps)) * eps;
}
function code(x, eps) return Float64(fma(fma(Float64(0.16666666666666666 * x), x, -1.0), x, Float64(-0.5 * eps)) * eps) end
code[x_, eps_] := N[(N[(N[(N[(0.16666666666666666 * x), $MachinePrecision] * x + -1.0), $MachinePrecision] * x + N[(-0.5 * eps), $MachinePrecision]), $MachinePrecision] * eps), $MachinePrecision]
\begin{array}{l}
\\
\mathsf{fma}\left(\mathsf{fma}\left(0.16666666666666666 \cdot x, x, -1\right), x, -0.5 \cdot \varepsilon\right) \cdot \varepsilon
\end{array}
Initial program 56.2%
Taylor expanded in eps around 0
*-commutativeN/A
lower-*.f64N/A
*-commutativeN/A
associate-*r*N/A
*-commutativeN/A
lower--.f64N/A
*-commutativeN/A
lower-*.f64N/A
*-commutativeN/A
lower-*.f64N/A
lower-cos.f64N/A
lower-sin.f6499.4
Applied rewrites99.4%
Taylor expanded in x around 0
Applied rewrites98.7%
Taylor expanded in eps around 0
Applied rewrites98.6%
(FPCore (x eps) :precision binary64 (fma (- eps) x (* (* eps eps) -0.5)))
double code(double x, double eps) {
return fma(-eps, x, ((eps * eps) * -0.5));
}
function code(x, eps) return fma(Float64(-eps), x, Float64(Float64(eps * eps) * -0.5)) end
code[x_, eps_] := N[((-eps) * x + N[(N[(eps * eps), $MachinePrecision] * -0.5), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\mathsf{fma}\left(-\varepsilon, x, \left(\varepsilon \cdot \varepsilon\right) \cdot -0.5\right)
\end{array}
Initial program 56.2%
Taylor expanded in eps around 0
*-commutativeN/A
lower-*.f64N/A
*-commutativeN/A
associate-*r*N/A
*-commutativeN/A
lower--.f64N/A
*-commutativeN/A
lower-*.f64N/A
*-commutativeN/A
lower-*.f64N/A
lower-cos.f64N/A
lower-sin.f6499.4
Applied rewrites99.4%
Taylor expanded in x around 0
Applied rewrites98.4%
Taylor expanded in x around 0
Applied rewrites98.5%
Taylor expanded in eps around 0
Applied rewrites98.5%
(FPCore (x eps) :precision binary64 (* (fma -0.5 eps (- x)) eps))
double code(double x, double eps) {
return fma(-0.5, eps, -x) * eps;
}
function code(x, eps) return Float64(fma(-0.5, eps, Float64(-x)) * eps) end
code[x_, eps_] := N[(N[(-0.5 * eps + (-x)), $MachinePrecision] * eps), $MachinePrecision]
\begin{array}{l}
\\
\mathsf{fma}\left(-0.5, \varepsilon, -x\right) \cdot \varepsilon
\end{array}
Initial program 56.2%
Taylor expanded in eps around 0
*-commutativeN/A
lower-*.f64N/A
*-commutativeN/A
associate-*r*N/A
*-commutativeN/A
lower--.f64N/A
*-commutativeN/A
lower-*.f64N/A
*-commutativeN/A
lower-*.f64N/A
lower-cos.f64N/A
lower-sin.f6499.4
Applied rewrites99.4%
Taylor expanded in x around 0
Applied rewrites98.4%
(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 56.2%
Taylor expanded in eps around 0
associate-*r*N/A
lower-*.f64N/A
mul-1-negN/A
lower-neg.f64N/A
lower-sin.f6480.7
Applied rewrites80.7%
Taylor expanded in x around 0
Applied rewrites80.2%
(FPCore (x eps) :precision binary64 (- 1.0 1.0))
double code(double x, double eps) {
return 1.0 - 1.0;
}
real(8) function code(x, eps)
real(8), intent (in) :: x
real(8), intent (in) :: eps
code = 1.0d0 - 1.0d0
end function
public static double code(double x, double eps) {
return 1.0 - 1.0;
}
def code(x, eps): return 1.0 - 1.0
function code(x, eps) return Float64(1.0 - 1.0) end
function tmp = code(x, eps) tmp = 1.0 - 1.0; end
code[x_, eps_] := N[(1.0 - 1.0), $MachinePrecision]
\begin{array}{l}
\\
1 - 1
\end{array}
Initial program 56.2%
Taylor expanded in x around 0
lower--.f64N/A
lower-cos.f6455.4
Applied rewrites55.4%
Taylor expanded in eps around 0
Applied rewrites55.3%
(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 2024248
(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)))