
(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%
sub-neg99.9%
+-commutative99.9%
distribute-neg-frac99.9%
neg-mul-199.9%
associate-/l*99.8%
associate-/r/99.9%
*-commutative99.9%
fma-def99.9%
metadata-eval99.9%
remove-double-neg99.9%
neg-mul-199.9%
remove-double-neg99.9%
neg-mul-199.9%
associate-/l*99.9%
associate-/r/99.9%
distribute-rgt-out99.9%
distribute-lft-neg-in99.9%
distribute-rgt-neg-in99.9%
metadata-eval99.9%
metadata-eval99.9%
metadata-eval99.9%
Simplified99.9%
fma-udef99.9%
Applied egg-rr99.9%
+-commutative99.9%
fma-def100.0%
Applied egg-rr100.0%
Final simplification100.0%
(FPCore (x y)
:precision binary64
(if (<= y -9.5e-34)
(* y -0.5)
(if (or (<= y 4.5e-11) (and (not (<= y 4.4e+100)) (<= y 1.3e+126)))
(* x 1.5)
(* y -0.5))))
double code(double x, double y) {
double tmp;
if (y <= -9.5e-34) {
tmp = y * -0.5;
} else if ((y <= 4.5e-11) || (!(y <= 4.4e+100) && (y <= 1.3e+126))) {
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 (y <= (-9.5d-34)) then
tmp = y * (-0.5d0)
else if ((y <= 4.5d-11) .or. (.not. (y <= 4.4d+100)) .and. (y <= 1.3d+126)) 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 (y <= -9.5e-34) {
tmp = y * -0.5;
} else if ((y <= 4.5e-11) || (!(y <= 4.4e+100) && (y <= 1.3e+126))) {
tmp = x * 1.5;
} else {
tmp = y * -0.5;
}
return tmp;
}
def code(x, y): tmp = 0 if y <= -9.5e-34: tmp = y * -0.5 elif (y <= 4.5e-11) or (not (y <= 4.4e+100) and (y <= 1.3e+126)): tmp = x * 1.5 else: tmp = y * -0.5 return tmp
function code(x, y) tmp = 0.0 if (y <= -9.5e-34) tmp = Float64(y * -0.5); elseif ((y <= 4.5e-11) || (!(y <= 4.4e+100) && (y <= 1.3e+126))) 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 (y <= -9.5e-34) tmp = y * -0.5; elseif ((y <= 4.5e-11) || (~((y <= 4.4e+100)) && (y <= 1.3e+126))) tmp = x * 1.5; else tmp = y * -0.5; end tmp_2 = tmp; end
code[x_, y_] := If[LessEqual[y, -9.5e-34], N[(y * -0.5), $MachinePrecision], If[Or[LessEqual[y, 4.5e-11], And[N[Not[LessEqual[y, 4.4e+100]], $MachinePrecision], LessEqual[y, 1.3e+126]]], N[(x * 1.5), $MachinePrecision], N[(y * -0.5), $MachinePrecision]]]
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;y \leq -9.5 \cdot 10^{-34}:\\
\;\;\;\;y \cdot -0.5\\
\mathbf{elif}\;y \leq 4.5 \cdot 10^{-11} \lor \neg \left(y \leq 4.4 \cdot 10^{+100}\right) \land y \leq 1.3 \cdot 10^{+126}:\\
\;\;\;\;x \cdot 1.5\\
\mathbf{else}:\\
\;\;\;\;y \cdot -0.5\\
\end{array}
\end{array}
if y < -9.49999999999999985e-34 or 4.5e-11 < y < 4.4000000000000001e100 or 1.3e126 < y Initial program 99.9%
Taylor expanded in x around 0 79.5%
if -9.49999999999999985e-34 < y < 4.5e-11 or 4.4000000000000001e100 < y < 1.3e126Initial program 99.8%
Taylor expanded in x around inf 77.7%
Final simplification78.7%
(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 54.5%
Final simplification54.5%
(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 2023200
(FPCore (x y)
:name "Graphics.Rendering.Chart.Axis.Types:hBufferRect from Chart-1.5.3"
:precision binary64
:herbie-target
(- (* 1.5 x) (* 0.5 y))
(+ x (/ (- x y) 2.0)))