
(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 8 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 (let* ((t_0 (sin (* eps 0.5)))) (* -2.0 (fma (* (cos (* eps 0.5)) (sin x)) t_0 (* (* (cos x) t_0) t_0)))))
double code(double x, double eps) {
double t_0 = sin((eps * 0.5));
return -2.0 * fma((cos((eps * 0.5)) * sin(x)), t_0, ((cos(x) * t_0) * t_0));
}
function code(x, eps) t_0 = sin(Float64(eps * 0.5)) return Float64(-2.0 * fma(Float64(cos(Float64(eps * 0.5)) * sin(x)), t_0, Float64(Float64(cos(x) * t_0) * t_0))) end
code[x_, eps_] := Block[{t$95$0 = N[Sin[N[(eps * 0.5), $MachinePrecision]], $MachinePrecision]}, N[(-2.0 * N[(N[(N[Cos[N[(eps * 0.5), $MachinePrecision]], $MachinePrecision] * N[Sin[x], $MachinePrecision]), $MachinePrecision] * t$95$0 + N[(N[(N[Cos[x], $MachinePrecision] * t$95$0), $MachinePrecision] * t$95$0), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}
\\
\begin{array}{l}
t_0 := \sin \left(\varepsilon \cdot 0.5\right)\\
-2 \cdot \mathsf{fma}\left(\cos \left(\varepsilon \cdot 0.5\right) \cdot \sin x, t\_0, \left(\cos x \cdot t\_0\right) \cdot t\_0\right)
\end{array}
\end{array}
Initial program 54.7%
lift--.f64N/A
lift-cos.f64N/A
lift-cos.f64N/A
diff-cosN/A
*-commutativeN/A
lower-*.f64N/A
Applied rewrites99.7%
lift-sin.f64N/A
lift-*.f64N/A
lift-fma.f64N/A
+-commutativeN/A
distribute-rgt-inN/A
*-commutativeN/A
sin-sumN/A
+-lft-identityN/A
lift-+.f64N/A
lift-*.f64N/A
lift-sin.f64N/A
lower-fma.f64N/A
Applied rewrites99.7%
lift-*.f64N/A
*-commutativeN/A
lift-fma.f64N/A
+-commutativeN/A
distribute-rgt-inN/A
lower-fma.f64N/A
Applied rewrites100.0%
Final simplification100.0%
(FPCore (x eps) :precision binary64 (let* ((t_0 (sin (* eps 0.5)))) (* (* (fma (cos (* -0.5 eps)) (sin x) (* (cos x) t_0)) t_0) -2.0)))
double code(double x, double eps) {
double t_0 = sin((eps * 0.5));
return (fma(cos((-0.5 * eps)), sin(x), (cos(x) * t_0)) * t_0) * -2.0;
}
function code(x, eps) t_0 = sin(Float64(eps * 0.5)) return Float64(Float64(fma(cos(Float64(-0.5 * eps)), sin(x), Float64(cos(x) * t_0)) * t_0) * -2.0) end
code[x_, eps_] := Block[{t$95$0 = N[Sin[N[(eps * 0.5), $MachinePrecision]], $MachinePrecision]}, N[(N[(N[(N[Cos[N[(-0.5 * eps), $MachinePrecision]], $MachinePrecision] * N[Sin[x], $MachinePrecision] + N[(N[Cos[x], $MachinePrecision] * t$95$0), $MachinePrecision]), $MachinePrecision] * t$95$0), $MachinePrecision] * -2.0), $MachinePrecision]]
\begin{array}{l}
\\
\begin{array}{l}
t_0 := \sin \left(\varepsilon \cdot 0.5\right)\\
\left(\mathsf{fma}\left(\cos \left(-0.5 \cdot \varepsilon\right), \sin x, \cos x \cdot t\_0\right) \cdot t\_0\right) \cdot -2
\end{array}
\end{array}
Initial program 54.7%
lift--.f64N/A
lift-cos.f64N/A
lift-cos.f64N/A
diff-cosN/A
*-commutativeN/A
lower-*.f64N/A
Applied rewrites99.7%
lift-sin.f64N/A
lift-*.f64N/A
lift-fma.f64N/A
+-commutativeN/A
distribute-rgt-inN/A
*-commutativeN/A
sin-sumN/A
+-lft-identityN/A
lift-+.f64N/A
lift-*.f64N/A
lift-sin.f64N/A
lower-fma.f64N/A
Applied rewrites99.7%
Taylor expanded in eps around inf
*-commutativeN/A
lower-*.f64N/A
+-commutativeN/A
lower-fma.f64N/A
metadata-evalN/A
associate-*r*N/A
mul-1-negN/A
distribute-rgt-neg-outN/A
cos-negN/A
lower-cos.f64N/A
lower-*.f64N/A
lower-sin.f64N/A
*-commutativeN/A
lower-*.f64N/A
lower-sin.f64N/A
lower-*.f64N/A
lower-cos.f64N/A
lower-sin.f64N/A
lower-*.f6499.7
Applied rewrites99.7%
Final simplification99.7%
(FPCore (x eps) :precision binary64 (* (* (sin (fma eps 0.5 x)) (sin (* eps 0.5))) -2.0))
double code(double x, double eps) {
return (sin(fma(eps, 0.5, x)) * sin((eps * 0.5))) * -2.0;
}
function code(x, eps) return Float64(Float64(sin(fma(eps, 0.5, x)) * sin(Float64(eps * 0.5))) * -2.0) end
code[x_, eps_] := N[(N[(N[Sin[N[(eps * 0.5 + x), $MachinePrecision]], $MachinePrecision] * N[Sin[N[(eps * 0.5), $MachinePrecision]], $MachinePrecision]), $MachinePrecision] * -2.0), $MachinePrecision]
\begin{array}{l}
\\
\left(\sin \left(\mathsf{fma}\left(\varepsilon, 0.5, x\right)\right) \cdot \sin \left(\varepsilon \cdot 0.5\right)\right) \cdot -2
\end{array}
Initial program 54.7%
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
Applied rewrites99.7%
(FPCore (x eps) :precision binary64 (* (* (* eps 0.5) (sin (* (fma 2.0 x eps) 0.5))) -2.0))
double code(double x, double eps) {
return ((eps * 0.5) * sin((fma(2.0, x, eps) * 0.5))) * -2.0;
}
function code(x, eps) return Float64(Float64(Float64(eps * 0.5) * sin(Float64(fma(2.0, x, eps) * 0.5))) * -2.0) end
code[x_, eps_] := N[(N[(N[(eps * 0.5), $MachinePrecision] * N[Sin[N[(N[(2.0 * x + eps), $MachinePrecision] * 0.5), $MachinePrecision]], $MachinePrecision]), $MachinePrecision] * -2.0), $MachinePrecision]
\begin{array}{l}
\\
\left(\left(\varepsilon \cdot 0.5\right) \cdot \sin \left(\mathsf{fma}\left(2, x, \varepsilon\right) \cdot 0.5\right)\right) \cdot -2
\end{array}
Initial program 54.7%
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 0
*-commutativeN/A
lower-*.f6499.4
Applied rewrites99.4%
Final simplification99.4%
(FPCore (x eps) :precision binary64 (* (- eps) (sin x)))
double code(double x, double eps) {
return -eps * sin(x);
}
real(8) function code(x, eps)
real(8), intent (in) :: x
real(8), intent (in) :: eps
code = -eps * sin(x)
end function
public static double code(double x, double eps) {
return -eps * Math.sin(x);
}
def code(x, eps): return -eps * math.sin(x)
function code(x, eps) return Float64(Float64(-eps) * sin(x)) end
function tmp = code(x, eps) tmp = -eps * sin(x); end
code[x_, eps_] := N[((-eps) * N[Sin[x], $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\left(-\varepsilon\right) \cdot \sin x
\end{array}
Initial program 54.7%
Taylor expanded in eps around 0
associate-*r*N/A
lower-*.f64N/A
mul-1-negN/A
lower-neg.f64N/A
lower-sin.f6480.8
Applied rewrites80.8%
(FPCore (x eps) :precision binary64 (* (fma (* (fma -0.008333333333333333 (* x x) 0.16666666666666666) eps) (* x x) (- eps)) x))
double code(double x, double eps) {
return fma((fma(-0.008333333333333333, (x * x), 0.16666666666666666) * eps), (x * x), -eps) * x;
}
function code(x, eps) return Float64(fma(Float64(fma(-0.008333333333333333, Float64(x * x), 0.16666666666666666) * eps), Float64(x * x), Float64(-eps)) * x) end
code[x_, eps_] := N[(N[(N[(N[(-0.008333333333333333 * N[(x * x), $MachinePrecision] + 0.16666666666666666), $MachinePrecision] * eps), $MachinePrecision] * N[(x * x), $MachinePrecision] + (-eps)), $MachinePrecision] * x), $MachinePrecision]
\begin{array}{l}
\\
\mathsf{fma}\left(\mathsf{fma}\left(-0.008333333333333333, x \cdot x, 0.16666666666666666\right) \cdot \varepsilon, x \cdot x, -\varepsilon\right) \cdot x
\end{array}
Initial program 54.7%
Taylor expanded in eps around 0
associate-*r*N/A
lower-*.f64N/A
mul-1-negN/A
lower-neg.f64N/A
lower-sin.f6480.8
Applied rewrites80.8%
Taylor expanded in x around 0
Applied rewrites80.1%
Final simplification80.1%
(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 54.7%
Taylor expanded in eps around 0
associate-*r*N/A
lower-*.f64N/A
mul-1-negN/A
lower-neg.f64N/A
lower-sin.f6480.8
Applied rewrites80.8%
Taylor expanded in x around 0
Applied rewrites80.1%
(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 54.7%
Taylor expanded in x around 0
lower--.f64N/A
lower-cos.f6453.5
Applied rewrites53.5%
Taylor expanded in eps around 0
Applied rewrites53.5%
(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 2024254
(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)))