
(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*99.7%
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 -2.3e+26) (* y -0.5) (if (<= y 7.2e-85) (* x 1.5) (* y -0.5))))
double code(double x, double y) {
double tmp;
if (y <= -2.3e+26) {
tmp = y * -0.5;
} else if (y <= 7.2e-85) {
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 <= (-2.3d+26)) then
tmp = y * (-0.5d0)
else if (y <= 7.2d-85) 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 <= -2.3e+26) {
tmp = y * -0.5;
} else if (y <= 7.2e-85) {
tmp = x * 1.5;
} else {
tmp = y * -0.5;
}
return tmp;
}
def code(x, y): tmp = 0 if y <= -2.3e+26: tmp = y * -0.5 elif y <= 7.2e-85: tmp = x * 1.5 else: tmp = y * -0.5 return tmp
function code(x, y) tmp = 0.0 if (y <= -2.3e+26) tmp = Float64(y * -0.5); elseif (y <= 7.2e-85) 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 <= -2.3e+26) tmp = y * -0.5; elseif (y <= 7.2e-85) tmp = x * 1.5; else tmp = y * -0.5; end tmp_2 = tmp; end
code[x_, y_] := If[LessEqual[y, -2.3e+26], N[(y * -0.5), $MachinePrecision], If[LessEqual[y, 7.2e-85], N[(x * 1.5), $MachinePrecision], N[(y * -0.5), $MachinePrecision]]]
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;y \leq -2.3 \cdot 10^{+26}:\\
\;\;\;\;y \cdot -0.5\\
\mathbf{elif}\;y \leq 7.2 \cdot 10^{-85}:\\
\;\;\;\;x \cdot 1.5\\
\mathbf{else}:\\
\;\;\;\;y \cdot -0.5\\
\end{array}
\end{array}
if y < -2.3000000000000001e26 or 7.1999999999999996e-85 < y Initial program 99.9%
Taylor expanded in x around 0 73.7%
if -2.3000000000000001e26 < y < 7.1999999999999996e-85Initial program 99.8%
Taylor expanded in x around inf 78.7%
Final simplification75.9%
(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 50.8%
Final simplification50.8%
(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 2023257
(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)))