Expression 4, p15

Percentage Accurate: 100.0% → 100.0%
Time: 5.2s
Alternatives: 5
Speedup: 1.0×

Specification

?
\[\left(5 \leq a \land a \leq 10\right) \land \left(0 \leq b \land b \leq 0.001\right)\]
\[\begin{array}{l} \\ \left(a + b\right) \cdot \left(a + b\right) \end{array} \]
(FPCore (a b) :precision binary64 (* (+ a b) (+ a b)))
double code(double a, double b) {
	return (a + b) * (a + b);
}
real(8) function code(a, b)
    real(8), intent (in) :: a
    real(8), intent (in) :: b
    code = (a + b) * (a + b)
end function
public static double code(double a, double b) {
	return (a + b) * (a + b);
}
def code(a, b):
	return (a + b) * (a + b)
function code(a, b)
	return Float64(Float64(a + b) * Float64(a + b))
end
function tmp = code(a, b)
	tmp = (a + b) * (a + b);
end
code[a_, b_] := N[(N[(a + b), $MachinePrecision] * N[(a + b), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
\left(a + b\right) \cdot \left(a + b\right)
\end{array}

Sampling outcomes in binary64 precision:

Local Percentage Accuracy vs ?

The average percentage accuracy by input value. Horizontal axis shows value of an input variable; the variable is choosen in the title. Vertical axis is accuracy; higher is better. Red represent the original program, while blue represents Herbie's suggestion. These can be toggled with buttons below the plot. The line is an average while dots represent individual samples.

Accuracy vs Speed?

Herbie found 5 alternatives:

AlternativeAccuracySpeedup
The accuracy (vertical axis) and speed (horizontal axis) of each alternatives. Up and to the right is better. The red square shows the initial program, and each blue circle shows an alternative.The line shows the best available speed-accuracy tradeoffs.

Initial Program: 100.0% accurate, 1.0× speedup?

\[\begin{array}{l} \\ \left(a + b\right) \cdot \left(a + b\right) \end{array} \]
(FPCore (a b) :precision binary64 (* (+ a b) (+ a b)))
double code(double a, double b) {
	return (a + b) * (a + b);
}
real(8) function code(a, b)
    real(8), intent (in) :: a
    real(8), intent (in) :: b
    code = (a + b) * (a + b)
end function
public static double code(double a, double b) {
	return (a + b) * (a + b);
}
def code(a, b):
	return (a + b) * (a + b)
function code(a, b)
	return Float64(Float64(a + b) * Float64(a + b))
end
function tmp = code(a, b)
	tmp = (a + b) * (a + b);
end
code[a_, b_] := N[(N[(a + b), $MachinePrecision] * N[(a + b), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
\left(a + b\right) \cdot \left(a + b\right)
\end{array}

Alternative 1: 100.0% accurate, 0.6× speedup?

\[\begin{array}{l} [a, b] = \mathsf{sort}([a, b])\\ \\ a \cdot \left(b + \left(b + a\right)\right) + b \cdot b \end{array} \]
NOTE: a and b should be sorted in increasing order before calling this function.
(FPCore (a b) :precision binary64 (+ (* a (+ b (+ b a))) (* b b)))
assert(a < b);
double code(double a, double b) {
	return (a * (b + (b + a))) + (b * b);
}
NOTE: a and b should be sorted in increasing order before calling this function.
real(8) function code(a, b)
    real(8), intent (in) :: a
    real(8), intent (in) :: b
    code = (a * (b + (b + a))) + (b * b)
end function
assert a < b;
public static double code(double a, double b) {
	return (a * (b + (b + a))) + (b * b);
}
[a, b] = sort([a, b])
def code(a, b):
	return (a * (b + (b + a))) + (b * b)
a, b = sort([a, b])
function code(a, b)
	return Float64(Float64(a * Float64(b + Float64(b + a))) + Float64(b * b))
end
a, b = num2cell(sort([a, b])){:}
function tmp = code(a, b)
	tmp = (a * (b + (b + a))) + (b * b);
end
NOTE: a and b should be sorted in increasing order before calling this function.
code[a_, b_] := N[(N[(a * N[(b + N[(b + a), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] + N[(b * b), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
[a, b] = \mathsf{sort}([a, b])\\
\\
a \cdot \left(b + \left(b + a\right)\right) + b \cdot b
\end{array}
Derivation
  1. Initial program 100.0%

    \[\left(a + b\right) \cdot \left(a + b\right) \]
  2. Add Preprocessing
  3. Step-by-step derivation
    1. distribute-rgt-inN/A

      \[\leadsto a \cdot \left(a + b\right) + \color{blue}{b \cdot \left(a + b\right)} \]
    2. distribute-rgt-inN/A

      \[\leadsto a \cdot \left(a + b\right) + \left(a \cdot b + \color{blue}{b \cdot b}\right) \]
    3. associate-+r+N/A

      \[\leadsto \left(a \cdot \left(a + b\right) + a \cdot b\right) + \color{blue}{b \cdot b} \]
    4. +-lowering-+.f64N/A

      \[\leadsto \mathsf{+.f64}\left(\left(a \cdot \left(a + b\right) + a \cdot b\right), \color{blue}{\left(b \cdot b\right)}\right) \]
    5. +-lowering-+.f64N/A

      \[\leadsto \mathsf{+.f64}\left(\mathsf{+.f64}\left(\left(a \cdot \left(a + b\right)\right), \left(a \cdot b\right)\right), \left(\color{blue}{b} \cdot b\right)\right) \]
    6. *-lowering-*.f64N/A

      \[\leadsto \mathsf{+.f64}\left(\mathsf{+.f64}\left(\mathsf{*.f64}\left(a, \left(a + b\right)\right), \left(a \cdot b\right)\right), \left(b \cdot b\right)\right) \]
    7. +-lowering-+.f64N/A

      \[\leadsto \mathsf{+.f64}\left(\mathsf{+.f64}\left(\mathsf{*.f64}\left(a, \mathsf{+.f64}\left(a, b\right)\right), \left(a \cdot b\right)\right), \left(b \cdot b\right)\right) \]
    8. *-lowering-*.f64N/A

      \[\leadsto \mathsf{+.f64}\left(\mathsf{+.f64}\left(\mathsf{*.f64}\left(a, \mathsf{+.f64}\left(a, b\right)\right), \mathsf{*.f64}\left(a, b\right)\right), \left(b \cdot b\right)\right) \]
    9. *-lowering-*.f64100.0%

      \[\leadsto \mathsf{+.f64}\left(\mathsf{+.f64}\left(\mathsf{*.f64}\left(a, \mathsf{+.f64}\left(a, b\right)\right), \mathsf{*.f64}\left(a, b\right)\right), \mathsf{*.f64}\left(b, \color{blue}{b}\right)\right) \]
  4. Applied egg-rr100.0%

    \[\leadsto \color{blue}{\left(a \cdot \left(a + b\right) + a \cdot b\right) + b \cdot b} \]
  5. Step-by-step derivation
    1. distribute-lft-outN/A

      \[\leadsto \mathsf{+.f64}\left(\left(a \cdot \left(\left(a + b\right) + b\right)\right), \mathsf{*.f64}\left(\color{blue}{b}, b\right)\right) \]
    2. *-commutativeN/A

      \[\leadsto \mathsf{+.f64}\left(\left(\left(\left(a + b\right) + b\right) \cdot a\right), \mathsf{*.f64}\left(\color{blue}{b}, b\right)\right) \]
    3. *-lowering-*.f64N/A

      \[\leadsto \mathsf{+.f64}\left(\mathsf{*.f64}\left(\left(\left(a + b\right) + b\right), a\right), \mathsf{*.f64}\left(\color{blue}{b}, b\right)\right) \]
    4. +-commutativeN/A

      \[\leadsto \mathsf{+.f64}\left(\mathsf{*.f64}\left(\left(b + \left(a + b\right)\right), a\right), \mathsf{*.f64}\left(b, b\right)\right) \]
    5. +-lowering-+.f64N/A

      \[\leadsto \mathsf{+.f64}\left(\mathsf{*.f64}\left(\mathsf{+.f64}\left(b, \left(a + b\right)\right), a\right), \mathsf{*.f64}\left(b, b\right)\right) \]
    6. +-lowering-+.f64100.0%

      \[\leadsto \mathsf{+.f64}\left(\mathsf{*.f64}\left(\mathsf{+.f64}\left(b, \mathsf{+.f64}\left(a, b\right)\right), a\right), \mathsf{*.f64}\left(b, b\right)\right) \]
  6. Applied egg-rr100.0%

    \[\leadsto \color{blue}{\left(b + \left(a + b\right)\right) \cdot a} + b \cdot b \]
  7. Final simplification100.0%

    \[\leadsto a \cdot \left(b + \left(b + a\right)\right) + b \cdot b \]
  8. Add Preprocessing

Alternative 2: 100.0% accurate, 1.0× speedup?

\[\begin{array}{l} [a, b] = \mathsf{sort}([a, b])\\ \\ \left(b + a\right) \cdot \left(b + a\right) \end{array} \]
NOTE: a and b should be sorted in increasing order before calling this function.
(FPCore (a b) :precision binary64 (* (+ b a) (+ b a)))
assert(a < b);
double code(double a, double b) {
	return (b + a) * (b + a);
}
NOTE: a and b should be sorted in increasing order before calling this function.
real(8) function code(a, b)
    real(8), intent (in) :: a
    real(8), intent (in) :: b
    code = (b + a) * (b + a)
end function
assert a < b;
public static double code(double a, double b) {
	return (b + a) * (b + a);
}
[a, b] = sort([a, b])
def code(a, b):
	return (b + a) * (b + a)
a, b = sort([a, b])
function code(a, b)
	return Float64(Float64(b + a) * Float64(b + a))
end
a, b = num2cell(sort([a, b])){:}
function tmp = code(a, b)
	tmp = (b + a) * (b + a);
end
NOTE: a and b should be sorted in increasing order before calling this function.
code[a_, b_] := N[(N[(b + a), $MachinePrecision] * N[(b + a), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
[a, b] = \mathsf{sort}([a, b])\\
\\
\left(b + a\right) \cdot \left(b + a\right)
\end{array}
Derivation
  1. Initial program 100.0%

    \[\left(a + b\right) \cdot \left(a + b\right) \]
  2. Add Preprocessing
  3. Final simplification100.0%

    \[\leadsto \left(b + a\right) \cdot \left(b + a\right) \]
  4. Add Preprocessing

Alternative 3: 99.7% accurate, 1.0× speedup?

\[\begin{array}{l} [a, b] = \mathsf{sort}([a, b])\\ \\ b \cdot \left(b + a \cdot 2\right) \end{array} \]
NOTE: a and b should be sorted in increasing order before calling this function.
(FPCore (a b) :precision binary64 (* b (+ b (* a 2.0))))
assert(a < b);
double code(double a, double b) {
	return b * (b + (a * 2.0));
}
NOTE: a and b should be sorted in increasing order before calling this function.
real(8) function code(a, b)
    real(8), intent (in) :: a
    real(8), intent (in) :: b
    code = b * (b + (a * 2.0d0))
end function
assert a < b;
public static double code(double a, double b) {
	return b * (b + (a * 2.0));
}
[a, b] = sort([a, b])
def code(a, b):
	return b * (b + (a * 2.0))
a, b = sort([a, b])
function code(a, b)
	return Float64(b * Float64(b + Float64(a * 2.0)))
end
a, b = num2cell(sort([a, b])){:}
function tmp = code(a, b)
	tmp = b * (b + (a * 2.0));
end
NOTE: a and b should be sorted in increasing order before calling this function.
code[a_, b_] := N[(b * N[(b + N[(a * 2.0), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
[a, b] = \mathsf{sort}([a, b])\\
\\
b \cdot \left(b + a \cdot 2\right)
\end{array}
Derivation
  1. Initial program 100.0%

    \[\left(a + b\right) \cdot \left(a + b\right) \]
  2. Add Preprocessing
  3. Taylor expanded in a around 0

    \[\leadsto \color{blue}{2 \cdot \left(a \cdot b\right) + {b}^{2}} \]
  4. Step-by-step derivation
    1. fma-defineN/A

      \[\leadsto \mathsf{fma}\left(2, \color{blue}{a \cdot b}, {b}^{2}\right) \]
    2. *-rgt-identityN/A

      \[\leadsto \mathsf{fma}\left(2, a \cdot \left(b \cdot \color{blue}{1}\right), {b}^{2}\right) \]
    3. *-inversesN/A

      \[\leadsto \mathsf{fma}\left(2, a \cdot \left(b \cdot \frac{b}{\color{blue}{b}}\right), {b}^{2}\right) \]
    4. associate-/l*N/A

      \[\leadsto \mathsf{fma}\left(2, a \cdot \frac{b \cdot b}{\color{blue}{b}}, {b}^{2}\right) \]
    5. unpow2N/A

      \[\leadsto \mathsf{fma}\left(2, a \cdot \frac{{b}^{2}}{b}, {b}^{2}\right) \]
    6. associate-/l*N/A

      \[\leadsto \mathsf{fma}\left(2, \frac{a \cdot {b}^{2}}{\color{blue}{b}}, {b}^{2}\right) \]
    7. associate-*l/N/A

      \[\leadsto \mathsf{fma}\left(2, \frac{a}{b} \cdot \color{blue}{{b}^{2}}, {b}^{2}\right) \]
    8. fma-defineN/A

      \[\leadsto 2 \cdot \left(\frac{a}{b} \cdot {b}^{2}\right) + \color{blue}{{b}^{2}} \]
    9. associate-*l*N/A

      \[\leadsto \left(2 \cdot \frac{a}{b}\right) \cdot {b}^{2} + {\color{blue}{b}}^{2} \]
    10. *-lft-identityN/A

      \[\leadsto \left(2 \cdot \frac{a}{b}\right) \cdot {b}^{2} + 1 \cdot \color{blue}{{b}^{2}} \]
    11. distribute-rgt-inN/A

      \[\leadsto {b}^{2} \cdot \color{blue}{\left(2 \cdot \frac{a}{b} + 1\right)} \]
    12. +-commutativeN/A

      \[\leadsto {b}^{2} \cdot \left(1 + \color{blue}{2 \cdot \frac{a}{b}}\right) \]
    13. unpow2N/A

      \[\leadsto \left(b \cdot b\right) \cdot \left(\color{blue}{1} + 2 \cdot \frac{a}{b}\right) \]
    14. associate-*l*N/A

      \[\leadsto b \cdot \color{blue}{\left(b \cdot \left(1 + 2 \cdot \frac{a}{b}\right)\right)} \]
    15. *-lowering-*.f64N/A

      \[\leadsto \mathsf{*.f64}\left(b, \color{blue}{\left(b \cdot \left(1 + 2 \cdot \frac{a}{b}\right)\right)}\right) \]
    16. distribute-lft-inN/A

      \[\leadsto \mathsf{*.f64}\left(b, \left(b \cdot 1 + \color{blue}{b \cdot \left(2 \cdot \frac{a}{b}\right)}\right)\right) \]
    17. *-rgt-identityN/A

      \[\leadsto \mathsf{*.f64}\left(b, \left(b + \color{blue}{b} \cdot \left(2 \cdot \frac{a}{b}\right)\right)\right) \]
    18. *-commutativeN/A

      \[\leadsto \mathsf{*.f64}\left(b, \left(b + \left(2 \cdot \frac{a}{b}\right) \cdot \color{blue}{b}\right)\right) \]
    19. associate-*r/N/A

      \[\leadsto \mathsf{*.f64}\left(b, \left(b + \frac{2 \cdot a}{b} \cdot b\right)\right) \]
    20. associate-*l/N/A

      \[\leadsto \mathsf{*.f64}\left(b, \left(b + \frac{\left(2 \cdot a\right) \cdot b}{\color{blue}{b}}\right)\right) \]
    21. associate-/l*N/A

      \[\leadsto \mathsf{*.f64}\left(b, \left(b + \left(2 \cdot a\right) \cdot \color{blue}{\frac{b}{b}}\right)\right) \]
    22. *-inversesN/A

      \[\leadsto \mathsf{*.f64}\left(b, \left(b + \left(2 \cdot a\right) \cdot 1\right)\right) \]
    23. *-rgt-identityN/A

      \[\leadsto \mathsf{*.f64}\left(b, \left(b + 2 \cdot \color{blue}{a}\right)\right) \]
    24. +-lowering-+.f64N/A

      \[\leadsto \mathsf{*.f64}\left(b, \mathsf{+.f64}\left(b, \color{blue}{\left(2 \cdot a\right)}\right)\right) \]
    25. *-lowering-*.f645.1%

      \[\leadsto \mathsf{*.f64}\left(b, \mathsf{+.f64}\left(b, \mathsf{*.f64}\left(2, \color{blue}{a}\right)\right)\right) \]
  5. Simplified5.1%

    \[\leadsto \color{blue}{b \cdot \left(b + 2 \cdot a\right)} \]
  6. Final simplification5.1%

    \[\leadsto b \cdot \left(b + a \cdot 2\right) \]
  7. Add Preprocessing

Alternative 4: 98.7% accurate, 1.4× speedup?

\[\begin{array}{l} [a, b] = \mathsf{sort}([a, b])\\ \\ b \cdot \left(b + a\right) \end{array} \]
NOTE: a and b should be sorted in increasing order before calling this function.
(FPCore (a b) :precision binary64 (* b (+ b a)))
assert(a < b);
double code(double a, double b) {
	return b * (b + a);
}
NOTE: a and b should be sorted in increasing order before calling this function.
real(8) function code(a, b)
    real(8), intent (in) :: a
    real(8), intent (in) :: b
    code = b * (b + a)
end function
assert a < b;
public static double code(double a, double b) {
	return b * (b + a);
}
[a, b] = sort([a, b])
def code(a, b):
	return b * (b + a)
a, b = sort([a, b])
function code(a, b)
	return Float64(b * Float64(b + a))
end
a, b = num2cell(sort([a, b])){:}
function tmp = code(a, b)
	tmp = b * (b + a);
end
NOTE: a and b should be sorted in increasing order before calling this function.
code[a_, b_] := N[(b * N[(b + a), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
[a, b] = \mathsf{sort}([a, b])\\
\\
b \cdot \left(b + a\right)
\end{array}
Derivation
  1. Initial program 100.0%

    \[\left(a + b\right) \cdot \left(a + b\right) \]
  2. Add Preprocessing
  3. Taylor expanded in a around 0

    \[\leadsto \mathsf{*.f64}\left(\mathsf{+.f64}\left(a, b\right), \color{blue}{b}\right) \]
  4. Step-by-step derivation
    1. Simplified5.1%

      \[\leadsto \left(a + b\right) \cdot \color{blue}{b} \]
    2. Final simplification5.1%

      \[\leadsto b \cdot \left(b + a\right) \]
    3. Add Preprocessing

    Alternative 5: 98.6% accurate, 2.3× speedup?

    \[\begin{array}{l} [a, b] = \mathsf{sort}([a, b])\\ \\ b \cdot b \end{array} \]
    NOTE: a and b should be sorted in increasing order before calling this function.
    (FPCore (a b) :precision binary64 (* b b))
    assert(a < b);
    double code(double a, double b) {
    	return b * b;
    }
    
    NOTE: a and b should be sorted in increasing order before calling this function.
    real(8) function code(a, b)
        real(8), intent (in) :: a
        real(8), intent (in) :: b
        code = b * b
    end function
    
    assert a < b;
    public static double code(double a, double b) {
    	return b * b;
    }
    
    [a, b] = sort([a, b])
    def code(a, b):
    	return b * b
    
    a, b = sort([a, b])
    function code(a, b)
    	return Float64(b * b)
    end
    
    a, b = num2cell(sort([a, b])){:}
    function tmp = code(a, b)
    	tmp = b * b;
    end
    
    NOTE: a and b should be sorted in increasing order before calling this function.
    code[a_, b_] := N[(b * b), $MachinePrecision]
    
    \begin{array}{l}
    [a, b] = \mathsf{sort}([a, b])\\
    \\
    b \cdot b
    \end{array}
    
    Derivation
    1. Initial program 100.0%

      \[\left(a + b\right) \cdot \left(a + b\right) \]
    2. Add Preprocessing
    3. Taylor expanded in a around 0

      \[\leadsto \color{blue}{{b}^{2}} \]
    4. Step-by-step derivation
      1. unpow2N/A

        \[\leadsto b \cdot \color{blue}{b} \]
      2. *-lowering-*.f644.0%

        \[\leadsto \mathsf{*.f64}\left(b, \color{blue}{b}\right) \]
    5. Simplified4.0%

      \[\leadsto \color{blue}{b \cdot b} \]
    6. Add Preprocessing

    Developer Target 1: 100.0% accurate, 0.5× speedup?

    \[\begin{array}{l} \\ \left(\left(b \cdot a + b \cdot b\right) + b \cdot a\right) + a \cdot a \end{array} \]
    (FPCore (a b) :precision binary64 (+ (+ (+ (* b a) (* b b)) (* b a)) (* a a)))
    double code(double a, double b) {
    	return (((b * a) + (b * b)) + (b * a)) + (a * a);
    }
    
    real(8) function code(a, b)
        real(8), intent (in) :: a
        real(8), intent (in) :: b
        code = (((b * a) + (b * b)) + (b * a)) + (a * a)
    end function
    
    public static double code(double a, double b) {
    	return (((b * a) + (b * b)) + (b * a)) + (a * a);
    }
    
    def code(a, b):
    	return (((b * a) + (b * b)) + (b * a)) + (a * a)
    
    function code(a, b)
    	return Float64(Float64(Float64(Float64(b * a) + Float64(b * b)) + Float64(b * a)) + Float64(a * a))
    end
    
    function tmp = code(a, b)
    	tmp = (((b * a) + (b * b)) + (b * a)) + (a * a);
    end
    
    code[a_, b_] := N[(N[(N[(N[(b * a), $MachinePrecision] + N[(b * b), $MachinePrecision]), $MachinePrecision] + N[(b * a), $MachinePrecision]), $MachinePrecision] + N[(a * a), $MachinePrecision]), $MachinePrecision]
    
    \begin{array}{l}
    
    \\
    \left(\left(b \cdot a + b \cdot b\right) + b \cdot a\right) + a \cdot a
    \end{array}
    

    Reproduce

    ?
    herbie shell --seed 2024149 
    (FPCore (a b)
      :name "Expression 4, p15"
      :precision binary64
      :pre (and (and (<= 5.0 a) (<= a 10.0)) (and (<= 0.0 b) (<= b 0.001)))
    
      :alt
      (! :herbie-platform default (+ (+ (+ (* b a) (* b b)) (* b a)) (* a a)))
    
      (* (+ a b) (+ a b)))