
(FPCore (x) :precision binary64 (- (* (+ x 1.0) (+ x 1.0)) 1.0))
double code(double x) {
return ((x + 1.0) * (x + 1.0)) - 1.0;
}
real(8) function code(x)
real(8), intent (in) :: x
code = ((x + 1.0d0) * (x + 1.0d0)) - 1.0d0
end function
public static double code(double x) {
return ((x + 1.0) * (x + 1.0)) - 1.0;
}
def code(x): return ((x + 1.0) * (x + 1.0)) - 1.0
function code(x) return Float64(Float64(Float64(x + 1.0) * Float64(x + 1.0)) - 1.0) end
function tmp = code(x) tmp = ((x + 1.0) * (x + 1.0)) - 1.0; end
code[x_] := N[(N[(N[(x + 1.0), $MachinePrecision] * N[(x + 1.0), $MachinePrecision]), $MachinePrecision] - 1.0), $MachinePrecision]
\begin{array}{l}
\\
\left(x + 1\right) \cdot \left(x + 1\right) - 1
\end{array}
Sampling outcomes in binary64 precision:
Herbie found 3 alternatives:
| Alternative | Accuracy | Speedup |
|---|
(FPCore (x) :precision binary64 (- (* (+ x 1.0) (+ x 1.0)) 1.0))
double code(double x) {
return ((x + 1.0) * (x + 1.0)) - 1.0;
}
real(8) function code(x)
real(8), intent (in) :: x
code = ((x + 1.0d0) * (x + 1.0d0)) - 1.0d0
end function
public static double code(double x) {
return ((x + 1.0) * (x + 1.0)) - 1.0;
}
def code(x): return ((x + 1.0) * (x + 1.0)) - 1.0
function code(x) return Float64(Float64(Float64(x + 1.0) * Float64(x + 1.0)) - 1.0) end
function tmp = code(x) tmp = ((x + 1.0) * (x + 1.0)) - 1.0; end
code[x_] := N[(N[(N[(x + 1.0), $MachinePrecision] * N[(x + 1.0), $MachinePrecision]), $MachinePrecision] - 1.0), $MachinePrecision]
\begin{array}{l}
\\
\left(x + 1\right) \cdot \left(x + 1\right) - 1
\end{array}
(FPCore (x) :precision binary64 (* x (+ x 2.0)))
double code(double x) {
return x * (x + 2.0);
}
real(8) function code(x)
real(8), intent (in) :: x
code = x * (x + 2.0d0)
end function
public static double code(double x) {
return x * (x + 2.0);
}
def code(x): return x * (x + 2.0)
function code(x) return Float64(x * Float64(x + 2.0)) end
function tmp = code(x) tmp = x * (x + 2.0); end
code[x_] := N[(x * N[(x + 2.0), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
x \cdot \left(x + 2\right)
\end{array}
Initial program 54.2%
difference-of-sqr-154.2%
associate--l+100.0%
metadata-eval100.0%
+-rgt-identity100.0%
*-commutative100.0%
associate-+l+100.0%
distribute-rgt-in100.0%
sqr-neg100.0%
distribute-rgt-neg-out100.0%
distribute-lft-neg-in100.0%
mul-1-neg100.0%
metadata-eval100.0%
distribute-rgt-out100.0%
metadata-eval100.0%
mul-1-neg100.0%
metadata-eval100.0%
metadata-eval100.0%
metadata-eval100.0%
metadata-eval100.0%
distribute-neg-in100.0%
distribute-neg-in100.0%
associate-+l+100.0%
mul-1-neg100.0%
metadata-eval100.0%
Simplified100.0%
Final simplification100.0%
(FPCore (x) :precision binary64 (if (<= x -2.0) (* x x) (if (<= x 2.0) (* x 2.0) (* x x))))
double code(double x) {
double tmp;
if (x <= -2.0) {
tmp = x * x;
} else if (x <= 2.0) {
tmp = x * 2.0;
} else {
tmp = x * x;
}
return tmp;
}
real(8) function code(x)
real(8), intent (in) :: x
real(8) :: tmp
if (x <= (-2.0d0)) then
tmp = x * x
else if (x <= 2.0d0) then
tmp = x * 2.0d0
else
tmp = x * x
end if
code = tmp
end function
public static double code(double x) {
double tmp;
if (x <= -2.0) {
tmp = x * x;
} else if (x <= 2.0) {
tmp = x * 2.0;
} else {
tmp = x * x;
}
return tmp;
}
def code(x): tmp = 0 if x <= -2.0: tmp = x * x elif x <= 2.0: tmp = x * 2.0 else: tmp = x * x return tmp
function code(x) tmp = 0.0 if (x <= -2.0) tmp = Float64(x * x); elseif (x <= 2.0) tmp = Float64(x * 2.0); else tmp = Float64(x * x); end return tmp end
function tmp_2 = code(x) tmp = 0.0; if (x <= -2.0) tmp = x * x; elseif (x <= 2.0) tmp = x * 2.0; else tmp = x * x; end tmp_2 = tmp; end
code[x_] := If[LessEqual[x, -2.0], N[(x * x), $MachinePrecision], If[LessEqual[x, 2.0], N[(x * 2.0), $MachinePrecision], N[(x * x), $MachinePrecision]]]
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;x \leq -2:\\
\;\;\;\;x \cdot x\\
\mathbf{elif}\;x \leq 2:\\
\;\;\;\;x \cdot 2\\
\mathbf{else}:\\
\;\;\;\;x \cdot x\\
\end{array}
\end{array}
if x < -2 or 2 < x Initial program 100.0%
difference-of-sqr-1100.0%
associate--l+100.0%
metadata-eval100.0%
+-rgt-identity100.0%
*-commutative100.0%
associate-+l+100.0%
distribute-rgt-in100.0%
sqr-neg100.0%
distribute-rgt-neg-out100.0%
distribute-lft-neg-in100.0%
mul-1-neg100.0%
metadata-eval100.0%
distribute-rgt-out100.0%
metadata-eval100.0%
mul-1-neg100.0%
metadata-eval100.0%
metadata-eval100.0%
metadata-eval100.0%
metadata-eval100.0%
distribute-neg-in100.0%
distribute-neg-in100.0%
associate-+l+100.0%
mul-1-neg100.0%
metadata-eval100.0%
Simplified100.0%
Taylor expanded in x around inf 100.0%
unpow2100.0%
Simplified100.0%
if -2 < x < 2Initial program 9.8%
difference-of-sqr-19.8%
associate--l+100.0%
metadata-eval100.0%
+-rgt-identity100.0%
*-commutative100.0%
associate-+l+100.0%
distribute-rgt-in100.0%
sqr-neg100.0%
distribute-rgt-neg-out100.0%
distribute-lft-neg-in100.0%
mul-1-neg100.0%
metadata-eval100.0%
distribute-rgt-out100.0%
metadata-eval100.0%
mul-1-neg100.0%
metadata-eval100.0%
metadata-eval100.0%
metadata-eval100.0%
metadata-eval100.0%
distribute-neg-in100.0%
distribute-neg-in100.0%
associate-+l+100.0%
mul-1-neg100.0%
metadata-eval100.0%
Simplified100.0%
Taylor expanded in x around 0 97.2%
Final simplification98.5%
(FPCore (x) :precision binary64 (* x 2.0))
double code(double x) {
return x * 2.0;
}
real(8) function code(x)
real(8), intent (in) :: x
code = x * 2.0d0
end function
public static double code(double x) {
return x * 2.0;
}
def code(x): return x * 2.0
function code(x) return Float64(x * 2.0) end
function tmp = code(x) tmp = x * 2.0; end
code[x_] := N[(x * 2.0), $MachinePrecision]
\begin{array}{l}
\\
x \cdot 2
\end{array}
Initial program 54.2%
difference-of-sqr-154.2%
associate--l+100.0%
metadata-eval100.0%
+-rgt-identity100.0%
*-commutative100.0%
associate-+l+100.0%
distribute-rgt-in100.0%
sqr-neg100.0%
distribute-rgt-neg-out100.0%
distribute-lft-neg-in100.0%
mul-1-neg100.0%
metadata-eval100.0%
distribute-rgt-out100.0%
metadata-eval100.0%
mul-1-neg100.0%
metadata-eval100.0%
metadata-eval100.0%
metadata-eval100.0%
metadata-eval100.0%
distribute-neg-in100.0%
distribute-neg-in100.0%
associate-+l+100.0%
mul-1-neg100.0%
metadata-eval100.0%
Simplified100.0%
Taylor expanded in x around 0 51.1%
Final simplification51.1%
herbie shell --seed 2023279
(FPCore (x)
:name "Expanding a square"
:precision binary64
(- (* (+ x 1.0) (+ x 1.0)) 1.0))