Average Error: 37.1 → 0.4
Time: 14.7s
Precision: binary64
Cost: 32448
\[\sin \left(x + \varepsilon\right) - \sin x \]
\[\mathsf{fma}\left(\cos \varepsilon + -1, \sin x, \sin \varepsilon \cdot \cos x\right) \]
(FPCore (x eps) :precision binary64 (- (sin (+ x eps)) (sin x)))
(FPCore (x eps)
 :precision binary64
 (fma (+ (cos eps) -1.0) (sin x) (* (sin eps) (cos x))))
double code(double x, double eps) {
	return sin((x + eps)) - sin(x);
}
double code(double x, double eps) {
	return fma((cos(eps) + -1.0), sin(x), (sin(eps) * cos(x)));
}
function code(x, eps)
	return Float64(sin(Float64(x + eps)) - sin(x))
end
function code(x, eps)
	return fma(Float64(cos(eps) + -1.0), sin(x), Float64(sin(eps) * cos(x)))
end
code[x_, eps_] := N[(N[Sin[N[(x + eps), $MachinePrecision]], $MachinePrecision] - N[Sin[x], $MachinePrecision]), $MachinePrecision]
code[x_, eps_] := N[(N[(N[Cos[eps], $MachinePrecision] + -1.0), $MachinePrecision] * N[Sin[x], $MachinePrecision] + N[(N[Sin[eps], $MachinePrecision] * N[Cos[x], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\sin \left(x + \varepsilon\right) - \sin x
\mathsf{fma}\left(\cos \varepsilon + -1, \sin x, \sin \varepsilon \cdot \cos x\right)

Error

Target

Original37.1
Target15.2
Herbie0.4
\[2 \cdot \left(\cos \left(x + \frac{\varepsilon}{2}\right) \cdot \sin \left(\frac{\varepsilon}{2}\right)\right) \]

Derivation

  1. Initial program 37.1

    \[\sin \left(x + \varepsilon\right) - \sin x \]
  2. Applied egg-rr40.7

    \[\leadsto \color{blue}{\sqrt[3]{{\sin \left(x + \varepsilon\right)}^{3}}} - \sin x \]
  3. Applied egg-rr21.7

    \[\leadsto \color{blue}{\left(\sin x \cdot \cos \varepsilon + \cos x \cdot \sin \varepsilon\right)} - \sin x \]
  4. Taylor expanded in x around inf 21.7

    \[\leadsto \color{blue}{\left(\cos x \cdot \sin \varepsilon + \cos \varepsilon \cdot \sin x\right) - \sin x} \]
  5. Simplified0.4

    \[\leadsto \color{blue}{\mathsf{fma}\left(\cos \varepsilon + -1, \sin x, \sin \varepsilon \cdot \cos x\right)} \]
    Proof
    (fma.f64 (+.f64 (cos.f64 eps) -1) (sin.f64 x) (*.f64 (sin.f64 eps) (cos.f64 x))): 0 points increase in error, 0 points decrease in error
    (fma.f64 (+.f64 (cos.f64 eps) (Rewrite<= metadata-eval (neg.f64 1))) (sin.f64 x) (*.f64 (sin.f64 eps) (cos.f64 x))): 0 points increase in error, 0 points decrease in error
    (fma.f64 (Rewrite<= sub-neg_binary64 (-.f64 (cos.f64 eps) 1)) (sin.f64 x) (*.f64 (sin.f64 eps) (cos.f64 x))): 0 points increase in error, 0 points decrease in error
    (fma.f64 (-.f64 (cos.f64 eps) 1) (sin.f64 x) (Rewrite<= *-commutative_binary64 (*.f64 (cos.f64 x) (sin.f64 eps)))): 0 points increase in error, 0 points decrease in error
    (Rewrite=> fma-udef_binary64 (+.f64 (*.f64 (-.f64 (cos.f64 eps) 1) (sin.f64 x)) (*.f64 (cos.f64 x) (sin.f64 eps)))): 11 points increase in error, 4 points decrease in error
    (+.f64 (Rewrite<= *-commutative_binary64 (*.f64 (sin.f64 x) (-.f64 (cos.f64 eps) 1))) (*.f64 (cos.f64 x) (sin.f64 eps))): 0 points increase in error, 0 points decrease in error
    (+.f64 (Rewrite<= distribute-rgt-out--_binary64 (-.f64 (*.f64 (cos.f64 eps) (sin.f64 x)) (*.f64 1 (sin.f64 x)))) (*.f64 (cos.f64 x) (sin.f64 eps))): 6 points increase in error, 10 points decrease in error
    (+.f64 (-.f64 (*.f64 (cos.f64 eps) (sin.f64 x)) (Rewrite=> *-lft-identity_binary64 (sin.f64 x))) (*.f64 (cos.f64 x) (sin.f64 eps))): 0 points increase in error, 0 points decrease in error
    (Rewrite<= +-commutative_binary64 (+.f64 (*.f64 (cos.f64 x) (sin.f64 eps)) (-.f64 (*.f64 (cos.f64 eps) (sin.f64 x)) (sin.f64 x)))): 0 points increase in error, 0 points decrease in error
    (Rewrite<= associate--l+_binary64 (-.f64 (+.f64 (*.f64 (cos.f64 x) (sin.f64 eps)) (*.f64 (cos.f64 eps) (sin.f64 x))) (sin.f64 x))): 120 points increase in error, 7 points decrease in error
  6. Final simplification0.4

    \[\leadsto \mathsf{fma}\left(\cos \varepsilon + -1, \sin x, \sin \varepsilon \cdot \cos x\right) \]

Alternatives

Alternative 1
Error15.3
Cost26184
\[\begin{array}{l} t_0 := \mathsf{fma}\left(\cos \varepsilon + -1, \sin x, \sin \varepsilon\right)\\ \mathbf{if}\;\varepsilon \leq -4643945245.859508:\\ \;\;\;\;t_0\\ \mathbf{elif}\;\varepsilon \leq 2.469950189001108 \cdot 10^{-34}:\\ \;\;\;\;\varepsilon \cdot \left(\cos x + \sin x \cdot \left(\varepsilon \cdot -0.5\right)\right)\\ \mathbf{else}:\\ \;\;\;\;t_0\\ \end{array} \]
Alternative 2
Error15.4
Cost26184
\[\begin{array}{l} \mathbf{if}\;\varepsilon \leq -4643945245.859508:\\ \;\;\;\;\left(\sin x + \sin \varepsilon \cdot \cos x\right) - \sin x\\ \mathbf{elif}\;\varepsilon \leq 2.469950189001108 \cdot 10^{-34}:\\ \;\;\;\;\varepsilon \cdot \left(\cos x + \sin x \cdot \left(\varepsilon \cdot -0.5\right)\right)\\ \mathbf{else}:\\ \;\;\;\;\mathsf{fma}\left(\cos \varepsilon + -1, \sin x, \sin \varepsilon\right)\\ \end{array} \]
Alternative 3
Error0.4
Cost26176
\[\sin \varepsilon \cdot \cos x + \left(\cos \varepsilon + -1\right) \cdot \sin x \]
Alternative 4
Error15.7
Cost13640
\[\begin{array}{l} t_0 := \sin \varepsilon - \sin x\\ \mathbf{if}\;\varepsilon \leq -18942572.719046965:\\ \;\;\;\;t_0\\ \mathbf{elif}\;\varepsilon \leq 2.469950189001108 \cdot 10^{-34}:\\ \;\;\;\;\varepsilon \cdot \left(\cos x + \sin x \cdot \left(\varepsilon \cdot -0.5\right)\right)\\ \mathbf{else}:\\ \;\;\;\;t_0\\ \end{array} \]
Alternative 5
Error15.8
Cost13256
\[\begin{array}{l} t_0 := \sin \varepsilon - \sin x\\ \mathbf{if}\;\varepsilon \leq -18942572.719046965:\\ \;\;\;\;t_0\\ \mathbf{elif}\;\varepsilon \leq 2.469950189001108 \cdot 10^{-34}:\\ \;\;\;\;\varepsilon \cdot \cos x\\ \mathbf{else}:\\ \;\;\;\;t_0\\ \end{array} \]
Alternative 6
Error16.1
Cost6856
\[\begin{array}{l} \mathbf{if}\;\varepsilon \leq -18942572.719046965:\\ \;\;\;\;\sin \varepsilon\\ \mathbf{elif}\;\varepsilon \leq 2.469950189001108 \cdot 10^{-34}:\\ \;\;\;\;\varepsilon \cdot \cos x\\ \mathbf{else}:\\ \;\;\;\;\sin \varepsilon\\ \end{array} \]
Alternative 7
Error28.8
Cost6464
\[\sin \varepsilon \]
Alternative 8
Error45.4
Cost64
\[\varepsilon \]

Error

Reproduce

herbie shell --seed 2022306 
(FPCore (x eps)
  :name "2sin (example 3.3)"
  :precision binary64

  :herbie-target
  (* 2.0 (* (cos (+ x (/ eps 2.0))) (sin (/ eps 2.0))))

  (- (sin (+ x eps)) (sin x)))