
(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 5 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%
lift-+.f64N/A
lift-/.f64N/A
lift--.f64N/A
div-subN/A
associate-+r-N/A
lower--.f64N/A
+-commutativeN/A
clear-numN/A
associate-/r/N/A
lower-fma.f64N/A
metadata-evalN/A
clear-numN/A
associate-/r/N/A
lower-*.f64N/A
metadata-eval99.9
Applied rewrites99.9%
lift--.f64N/A
sub-negN/A
lift-fma.f64N/A
distribute-lft1-inN/A
metadata-evalN/A
*-commutativeN/A
lower-fma.f64N/A
lift-*.f64N/A
distribute-lft-neg-inN/A
metadata-evalN/A
lower-*.f64100.0
Applied rewrites100.0%
Final simplification100.0%
(FPCore (x y) :precision binary64 (let* ((t_0 (+ (* y -0.5) x))) (if (<= y -2.8e-19) t_0 (if (<= y 2.9e+41) (* 1.5 x) t_0))))
double code(double x, double y) {
double t_0 = (y * -0.5) + x;
double tmp;
if (y <= -2.8e-19) {
tmp = t_0;
} else if (y <= 2.9e+41) {
tmp = 1.5 * x;
} else {
tmp = t_0;
}
return tmp;
}
real(8) function code(x, y)
real(8), intent (in) :: x
real(8), intent (in) :: y
real(8) :: t_0
real(8) :: tmp
t_0 = (y * (-0.5d0)) + x
if (y <= (-2.8d-19)) then
tmp = t_0
else if (y <= 2.9d+41) then
tmp = 1.5d0 * x
else
tmp = t_0
end if
code = tmp
end function
public static double code(double x, double y) {
double t_0 = (y * -0.5) + x;
double tmp;
if (y <= -2.8e-19) {
tmp = t_0;
} else if (y <= 2.9e+41) {
tmp = 1.5 * x;
} else {
tmp = t_0;
}
return tmp;
}
def code(x, y): t_0 = (y * -0.5) + x tmp = 0 if y <= -2.8e-19: tmp = t_0 elif y <= 2.9e+41: tmp = 1.5 * x else: tmp = t_0 return tmp
function code(x, y) t_0 = Float64(Float64(y * -0.5) + x) tmp = 0.0 if (y <= -2.8e-19) tmp = t_0; elseif (y <= 2.9e+41) tmp = Float64(1.5 * x); else tmp = t_0; end return tmp end
function tmp_2 = code(x, y) t_0 = (y * -0.5) + x; tmp = 0.0; if (y <= -2.8e-19) tmp = t_0; elseif (y <= 2.9e+41) tmp = 1.5 * x; else tmp = t_0; end tmp_2 = tmp; end
code[x_, y_] := Block[{t$95$0 = N[(N[(y * -0.5), $MachinePrecision] + x), $MachinePrecision]}, If[LessEqual[y, -2.8e-19], t$95$0, If[LessEqual[y, 2.9e+41], N[(1.5 * x), $MachinePrecision], t$95$0]]]
\begin{array}{l}
\\
\begin{array}{l}
t_0 := y \cdot -0.5 + x\\
\mathbf{if}\;y \leq -2.8 \cdot 10^{-19}:\\
\;\;\;\;t\_0\\
\mathbf{elif}\;y \leq 2.9 \cdot 10^{+41}:\\
\;\;\;\;1.5 \cdot x\\
\mathbf{else}:\\
\;\;\;\;t\_0\\
\end{array}
\end{array}
if y < -2.80000000000000003e-19 or 2.89999999999999988e41 < y Initial program 99.9%
Taylor expanded in x around 0
*-commutativeN/A
lower-*.f6478.9
Applied rewrites78.9%
if -2.80000000000000003e-19 < y < 2.89999999999999988e41Initial program 99.8%
Taylor expanded in x around inf
lower-*.f6473.7
Applied rewrites73.7%
Final simplification76.2%
(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 2024230
(FPCore (x y)
:name "Graphics.Rendering.Chart.Axis.Types:hBufferRect from Chart-1.5.3"
:precision binary64
:alt
(! :herbie-platform default (- (* 3/2 x) (* 1/2 y)))
(+ x (/ (- x y) 2.0)))