
(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%
*-lft-identity99.9%
metadata-eval99.9%
cancel-sign-sub-inv99.9%
*-lft-identity99.9%
metadata-eval99.9%
associate-*r/99.9%
associate-/l*99.9%
associate-/r/99.9%
distribute-rgt-out--99.9%
fma-neg100.0%
distribute-frac-neg100.0%
metadata-eval100.0%
metadata-eval100.0%
metadata-eval100.0%
neg-mul-1100.0%
associate-/l*99.9%
associate-/r/100.0%
*-commutative100.0%
metadata-eval100.0%
Simplified100.0%
Final simplification100.0%
(FPCore (x y)
:precision binary64
(if (<= y -9.2e+56)
(* y -0.5)
(if (or (<= y 1.3e-24) (and (not (<= y 4100000000.0)) (<= y 4.5e+30)))
(* x 1.5)
(* y -0.5))))
double code(double x, double y) {
double tmp;
if (y <= -9.2e+56) {
tmp = y * -0.5;
} else if ((y <= 1.3e-24) || (!(y <= 4100000000.0) && (y <= 4.5e+30))) {
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 <= (-9.2d+56)) then
tmp = y * (-0.5d0)
else if ((y <= 1.3d-24) .or. (.not. (y <= 4100000000.0d0)) .and. (y <= 4.5d+30)) 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 <= -9.2e+56) {
tmp = y * -0.5;
} else if ((y <= 1.3e-24) || (!(y <= 4100000000.0) && (y <= 4.5e+30))) {
tmp = x * 1.5;
} else {
tmp = y * -0.5;
}
return tmp;
}
def code(x, y): tmp = 0 if y <= -9.2e+56: tmp = y * -0.5 elif (y <= 1.3e-24) or (not (y <= 4100000000.0) and (y <= 4.5e+30)): tmp = x * 1.5 else: tmp = y * -0.5 return tmp
function code(x, y) tmp = 0.0 if (y <= -9.2e+56) tmp = Float64(y * -0.5); elseif ((y <= 1.3e-24) || (!(y <= 4100000000.0) && (y <= 4.5e+30))) 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 <= -9.2e+56) tmp = y * -0.5; elseif ((y <= 1.3e-24) || (~((y <= 4100000000.0)) && (y <= 4.5e+30))) tmp = x * 1.5; else tmp = y * -0.5; end tmp_2 = tmp; end
code[x_, y_] := If[LessEqual[y, -9.2e+56], N[(y * -0.5), $MachinePrecision], If[Or[LessEqual[y, 1.3e-24], And[N[Not[LessEqual[y, 4100000000.0]], $MachinePrecision], LessEqual[y, 4.5e+30]]], N[(x * 1.5), $MachinePrecision], N[(y * -0.5), $MachinePrecision]]]
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;y \leq -9.2 \cdot 10^{+56}:\\
\;\;\;\;y \cdot -0.5\\
\mathbf{elif}\;y \leq 1.3 \cdot 10^{-24} \lor \neg \left(y \leq 4100000000\right) \land y \leq 4.5 \cdot 10^{+30}:\\
\;\;\;\;x \cdot 1.5\\
\mathbf{else}:\\
\;\;\;\;y \cdot -0.5\\
\end{array}
\end{array}
if y < -9.20000000000000058e56 or 1.3e-24 < y < 4.1e9 or 4.49999999999999995e30 < y Initial program 100.0%
Taylor expanded in x around 0 86.6%
if -9.20000000000000058e56 < y < 1.3e-24 or 4.1e9 < y < 4.49999999999999995e30Initial program 99.8%
Taylor expanded in x around inf 77.8%
Final simplification82.1%
(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 53.9%
Final simplification53.9%
(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 2023293
(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)))