
(FPCore (x y) :precision binary64 (+ x (/ (- x y) 2.0)))
double code(double x, double y) {
return x + ((x - y) / 2.0);
}
real(8) function code(x, y)
real(8), intent (in) :: x
real(8), intent (in) :: y
code = x + ((x - y) / 2.0d0)
end function
public static double code(double x, double y) {
return x + ((x - y) / 2.0);
}
def code(x, y): return x + ((x - y) / 2.0)
function code(x, y) return Float64(x + Float64(Float64(x - y) / 2.0)) end
function tmp = code(x, y) tmp = x + ((x - y) / 2.0); end
code[x_, y_] := N[(x + N[(N[(x - y), $MachinePrecision] / 2.0), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
x + \frac{x - y}{2}
\end{array}
Sampling outcomes in binary64 precision:
Herbie found 4 alternatives:
| Alternative | Accuracy | Speedup |
|---|
(FPCore (x y) :precision binary64 (+ x (/ (- x y) 2.0)))
double code(double x, double y) {
return x + ((x - y) / 2.0);
}
real(8) function code(x, y)
real(8), intent (in) :: x
real(8), intent (in) :: y
code = x + ((x - y) / 2.0d0)
end function
public static double code(double x, double y) {
return x + ((x - y) / 2.0);
}
def code(x, y): return x + ((x - y) / 2.0)
function code(x, y) return Float64(x + Float64(Float64(x - y) / 2.0)) end
function tmp = code(x, y) tmp = x + ((x - y) / 2.0); end
code[x_, y_] := N[(x + N[(N[(x - y), $MachinePrecision] / 2.0), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
x + \frac{x - y}{2}
\end{array}
(FPCore (x y) :precision binary64 (fma x 1.5 (* y -0.5)))
double code(double x, double y) {
return fma(x, 1.5, (y * -0.5));
}
function code(x, y) return fma(x, 1.5, Float64(y * -0.5)) end
code[x_, y_] := N[(x * 1.5 + N[(y * -0.5), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\mathsf{fma}\left(x, 1.5, y \cdot -0.5\right)
\end{array}
Initial program 99.9%
div-sub99.9%
associate-+r-99.9%
remove-double-neg99.9%
distribute-frac-neg99.9%
sub-neg99.9%
neg-mul-199.9%
*-commutative99.9%
associate-/l*99.9%
*-rgt-identity99.9%
metadata-eval99.9%
distribute-lft-out--99.9%
fma-neg100.0%
metadata-eval100.0%
metadata-eval100.0%
metadata-eval100.0%
distribute-frac-neg100.0%
neg-mul-1100.0%
*-commutative100.0%
associate-/l*100.0%
metadata-eval100.0%
Simplified100.0%
Final simplification100.0%
(FPCore (x y)
:precision binary64
(if (or (<= x -7e+109)
(not (or (<= x -2.1e+83) (and (not (<= x -6.6e+38)) (<= x 2.1e-24)))))
(* x 1.5)
(* y -0.5)))
double code(double x, double y) {
double tmp;
if ((x <= -7e+109) || !((x <= -2.1e+83) || (!(x <= -6.6e+38) && (x <= 2.1e-24)))) {
tmp = x * 1.5;
} else {
tmp = y * -0.5;
}
return tmp;
}
real(8) function code(x, y)
real(8), intent (in) :: x
real(8), intent (in) :: y
real(8) :: tmp
if ((x <= (-7d+109)) .or. (.not. (x <= (-2.1d+83)) .or. (.not. (x <= (-6.6d+38))) .and. (x <= 2.1d-24))) then
tmp = x * 1.5d0
else
tmp = y * (-0.5d0)
end if
code = tmp
end function
public static double code(double x, double y) {
double tmp;
if ((x <= -7e+109) || !((x <= -2.1e+83) || (!(x <= -6.6e+38) && (x <= 2.1e-24)))) {
tmp = x * 1.5;
} else {
tmp = y * -0.5;
}
return tmp;
}
def code(x, y): tmp = 0 if (x <= -7e+109) or not ((x <= -2.1e+83) or (not (x <= -6.6e+38) and (x <= 2.1e-24))): tmp = x * 1.5 else: tmp = y * -0.5 return tmp
function code(x, y) tmp = 0.0 if ((x <= -7e+109) || !((x <= -2.1e+83) || (!(x <= -6.6e+38) && (x <= 2.1e-24)))) tmp = Float64(x * 1.5); else tmp = Float64(y * -0.5); end return tmp end
function tmp_2 = code(x, y) tmp = 0.0; if ((x <= -7e+109) || ~(((x <= -2.1e+83) || (~((x <= -6.6e+38)) && (x <= 2.1e-24))))) tmp = x * 1.5; else tmp = y * -0.5; end tmp_2 = tmp; end
code[x_, y_] := If[Or[LessEqual[x, -7e+109], N[Not[Or[LessEqual[x, -2.1e+83], And[N[Not[LessEqual[x, -6.6e+38]], $MachinePrecision], LessEqual[x, 2.1e-24]]]], $MachinePrecision]], N[(x * 1.5), $MachinePrecision], N[(y * -0.5), $MachinePrecision]]
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;x \leq -7 \cdot 10^{+109} \lor \neg \left(x \leq -2.1 \cdot 10^{+83} \lor \neg \left(x \leq -6.6 \cdot 10^{+38}\right) \land x \leq 2.1 \cdot 10^{-24}\right):\\
\;\;\;\;x \cdot 1.5\\
\mathbf{else}:\\
\;\;\;\;y \cdot -0.5\\
\end{array}
\end{array}
if x < -6.99999999999999966e109 or -2.10000000000000002e83 < x < -6.5999999999999998e38 or 2.0999999999999999e-24 < x Initial program 99.8%
Taylor expanded in x around inf 80.4%
if -6.99999999999999966e109 < x < -2.10000000000000002e83 or -6.5999999999999998e38 < x < 2.0999999999999999e-24Initial program 100.0%
Taylor expanded in x around 0 81.0%
Final simplification80.7%
(FPCore (x y) :precision binary64 (+ x (/ (- x y) 2.0)))
double code(double x, double y) {
return x + ((x - y) / 2.0);
}
real(8) function code(x, y)
real(8), intent (in) :: x
real(8), intent (in) :: y
code = x + ((x - y) / 2.0d0)
end function
public static double code(double x, double y) {
return x + ((x - y) / 2.0);
}
def code(x, y): return x + ((x - y) / 2.0)
function code(x, y) return Float64(x + Float64(Float64(x - y) / 2.0)) end
function tmp = code(x, y) tmp = x + ((x - y) / 2.0); end
code[x_, y_] := N[(x + N[(N[(x - y), $MachinePrecision] / 2.0), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
x + \frac{x - y}{2}
\end{array}
Initial program 99.9%
Final simplification99.9%
(FPCore (x y) :precision binary64 (* y -0.5))
double code(double x, double y) {
return y * -0.5;
}
real(8) function code(x, y)
real(8), intent (in) :: x
real(8), intent (in) :: y
code = y * (-0.5d0)
end function
public static double code(double x, double y) {
return y * -0.5;
}
def code(x, y): return y * -0.5
function code(x, y) return Float64(y * -0.5) end
function tmp = code(x, y) tmp = y * -0.5; end
code[x_, y_] := N[(y * -0.5), $MachinePrecision]
\begin{array}{l}
\\
y \cdot -0.5
\end{array}
Initial program 99.9%
Taylor expanded in x around 0 50.4%
Final simplification50.4%
(FPCore (x y) :precision binary64 (- (* 1.5 x) (* 0.5 y)))
double code(double x, double y) {
return (1.5 * x) - (0.5 * y);
}
real(8) function code(x, y)
real(8), intent (in) :: x
real(8), intent (in) :: y
code = (1.5d0 * x) - (0.5d0 * y)
end function
public static double code(double x, double y) {
return (1.5 * x) - (0.5 * y);
}
def code(x, y): return (1.5 * x) - (0.5 * y)
function code(x, y) return Float64(Float64(1.5 * x) - Float64(0.5 * y)) end
function tmp = code(x, y) tmp = (1.5 * x) - (0.5 * y); end
code[x_, y_] := N[(N[(1.5 * x), $MachinePrecision] - N[(0.5 * y), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
1.5 \cdot x - 0.5 \cdot y
\end{array}
herbie shell --seed 2024077
(FPCore (x y)
:name "Graphics.Rendering.Chart.Axis.Types:hBufferRect from Chart-1.5.3"
:precision binary64
:alt
(- (* 1.5 x) (* 0.5 y))
(+ x (/ (- x y) 2.0)))