
(FPCore (lo hi x) :precision binary64 (/ (- x lo) (- hi lo)))
double code(double lo, double hi, double x) {
return (x - lo) / (hi - lo);
}
real(8) function code(lo, hi, x)
real(8), intent (in) :: lo
real(8), intent (in) :: hi
real(8), intent (in) :: x
code = (x - lo) / (hi - lo)
end function
public static double code(double lo, double hi, double x) {
return (x - lo) / (hi - lo);
}
def code(lo, hi, x): return (x - lo) / (hi - lo)
function code(lo, hi, x) return Float64(Float64(x - lo) / Float64(hi - lo)) end
function tmp = code(lo, hi, x) tmp = (x - lo) / (hi - lo); end
code[lo_, hi_, x_] := N[(N[(x - lo), $MachinePrecision] / N[(hi - lo), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\frac{x - lo}{hi - lo}
\end{array}
Sampling outcomes in binary64 precision:
Herbie found 5 alternatives:
| Alternative | Accuracy | Speedup |
|---|
(FPCore (lo hi x) :precision binary64 (/ (- x lo) (- hi lo)))
double code(double lo, double hi, double x) {
return (x - lo) / (hi - lo);
}
real(8) function code(lo, hi, x)
real(8), intent (in) :: lo
real(8), intent (in) :: hi
real(8), intent (in) :: x
code = (x - lo) / (hi - lo)
end function
public static double code(double lo, double hi, double x) {
return (x - lo) / (hi - lo);
}
def code(lo, hi, x): return (x - lo) / (hi - lo)
function code(lo, hi, x) return Float64(Float64(x - lo) / Float64(hi - lo)) end
function tmp = code(lo, hi, x) tmp = (x - lo) / (hi - lo); end
code[lo_, hi_, x_] := N[(N[(x - lo), $MachinePrecision] / N[(hi - lo), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\frac{x - lo}{hi - lo}
\end{array}
(FPCore (lo hi x)
:precision binary64
(+
(* -1.0 (* x (- (/ 1.0 lo) (/ 1.0 x))))
(*
hi
(-
(+
(/ 1.0 lo)
(/ (cbrt (pow (* hi (- (/ 1.0 lo) (* x (pow lo -2.0)))) 3.0)) lo))
(* (/ x lo) (/ 1.0 lo))))))
double code(double lo, double hi, double x) {
return (-1.0 * (x * ((1.0 / lo) - (1.0 / x)))) + (hi * (((1.0 / lo) + (cbrt(pow((hi * ((1.0 / lo) - (x * pow(lo, -2.0)))), 3.0)) / lo)) - ((x / lo) * (1.0 / lo))));
}
public static double code(double lo, double hi, double x) {
return (-1.0 * (x * ((1.0 / lo) - (1.0 / x)))) + (hi * (((1.0 / lo) + (Math.cbrt(Math.pow((hi * ((1.0 / lo) - (x * Math.pow(lo, -2.0)))), 3.0)) / lo)) - ((x / lo) * (1.0 / lo))));
}
function code(lo, hi, x) return Float64(Float64(-1.0 * Float64(x * Float64(Float64(1.0 / lo) - Float64(1.0 / x)))) + Float64(hi * Float64(Float64(Float64(1.0 / lo) + Float64(cbrt((Float64(hi * Float64(Float64(1.0 / lo) - Float64(x * (lo ^ -2.0)))) ^ 3.0)) / lo)) - Float64(Float64(x / lo) * Float64(1.0 / lo))))) end
code[lo_, hi_, x_] := N[(N[(-1.0 * N[(x * N[(N[(1.0 / lo), $MachinePrecision] - N[(1.0 / x), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] + N[(hi * N[(N[(N[(1.0 / lo), $MachinePrecision] + N[(N[Power[N[Power[N[(hi * N[(N[(1.0 / lo), $MachinePrecision] - N[(x * N[Power[lo, -2.0], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision], 3.0], $MachinePrecision], 1/3], $MachinePrecision] / lo), $MachinePrecision]), $MachinePrecision] - N[(N[(x / lo), $MachinePrecision] * N[(1.0 / lo), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
-1 \cdot \left(x \cdot \left(\frac{1}{lo} - \frac{1}{x}\right)\right) + hi \cdot \left(\left(\frac{1}{lo} + \frac{\sqrt[3]{{\left(hi \cdot \left(\frac{1}{lo} - x \cdot {lo}^{-2}\right)\right)}^{3}}}{lo}\right) - \frac{x}{lo} \cdot \frac{1}{lo}\right)
\end{array}
Initial program 3.1%
Taylor expanded in hi around 0 18.8%
add-cbrt-cube18.8%
pow318.8%
div-inv18.8%
pow-flip18.8%
metadata-eval18.8%
Applied egg-rr18.8%
Taylor expanded in x around inf 18.9%
*-un-lft-identity18.9%
unpow218.9%
frac-times18.9%
*-commutative18.9%
Applied egg-rr18.9%
(FPCore (lo hi x) :precision binary64 (+ (* -1.0 -1.0) (* hi (- (/ (+ 1.0 (/ hi lo)) lo) (/ x (pow lo 2.0))))))
double code(double lo, double hi, double x) {
return (-1.0 * -1.0) + (hi * (((1.0 + (hi / lo)) / lo) - (x / pow(lo, 2.0))));
}
real(8) function code(lo, hi, x)
real(8), intent (in) :: lo
real(8), intent (in) :: hi
real(8), intent (in) :: x
code = ((-1.0d0) * (-1.0d0)) + (hi * (((1.0d0 + (hi / lo)) / lo) - (x / (lo ** 2.0d0))))
end function
public static double code(double lo, double hi, double x) {
return (-1.0 * -1.0) + (hi * (((1.0 + (hi / lo)) / lo) - (x / Math.pow(lo, 2.0))));
}
def code(lo, hi, x): return (-1.0 * -1.0) + (hi * (((1.0 + (hi / lo)) / lo) - (x / math.pow(lo, 2.0))))
function code(lo, hi, x) return Float64(Float64(-1.0 * -1.0) + Float64(hi * Float64(Float64(Float64(1.0 + Float64(hi / lo)) / lo) - Float64(x / (lo ^ 2.0))))) end
function tmp = code(lo, hi, x) tmp = (-1.0 * -1.0) + (hi * (((1.0 + (hi / lo)) / lo) - (x / (lo ^ 2.0)))); end
code[lo_, hi_, x_] := N[(N[(-1.0 * -1.0), $MachinePrecision] + N[(hi * N[(N[(N[(1.0 + N[(hi / lo), $MachinePrecision]), $MachinePrecision] / lo), $MachinePrecision] - N[(x / N[Power[lo, 2.0], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
-1 \cdot -1 + hi \cdot \left(\frac{1 + \frac{hi}{lo}}{lo} - \frac{x}{{lo}^{2}}\right)
\end{array}
Initial program 3.1%
Taylor expanded in hi around 0 18.8%
Taylor expanded in x around 0 18.9%
Taylor expanded in lo around inf 18.9%
(FPCore (lo hi x)
:precision binary64
(+
(* -1.0 (/ (- x lo) lo))
(*
hi
(-
(+ (/ 1.0 lo) (/ (* hi (- (/ 1.0 lo) (* (/ 1.0 lo) (/ x lo)))) lo))
(* (/ x lo) (/ 1.0 lo))))))
double code(double lo, double hi, double x) {
return (-1.0 * ((x - lo) / lo)) + (hi * (((1.0 / lo) + ((hi * ((1.0 / lo) - ((1.0 / lo) * (x / lo)))) / lo)) - ((x / lo) * (1.0 / lo))));
}
real(8) function code(lo, hi, x)
real(8), intent (in) :: lo
real(8), intent (in) :: hi
real(8), intent (in) :: x
code = ((-1.0d0) * ((x - lo) / lo)) + (hi * (((1.0d0 / lo) + ((hi * ((1.0d0 / lo) - ((1.0d0 / lo) * (x / lo)))) / lo)) - ((x / lo) * (1.0d0 / lo))))
end function
public static double code(double lo, double hi, double x) {
return (-1.0 * ((x - lo) / lo)) + (hi * (((1.0 / lo) + ((hi * ((1.0 / lo) - ((1.0 / lo) * (x / lo)))) / lo)) - ((x / lo) * (1.0 / lo))));
}
def code(lo, hi, x): return (-1.0 * ((x - lo) / lo)) + (hi * (((1.0 / lo) + ((hi * ((1.0 / lo) - ((1.0 / lo) * (x / lo)))) / lo)) - ((x / lo) * (1.0 / lo))))
function code(lo, hi, x) return Float64(Float64(-1.0 * Float64(Float64(x - lo) / lo)) + Float64(hi * Float64(Float64(Float64(1.0 / lo) + Float64(Float64(hi * Float64(Float64(1.0 / lo) - Float64(Float64(1.0 / lo) * Float64(x / lo)))) / lo)) - Float64(Float64(x / lo) * Float64(1.0 / lo))))) end
function tmp = code(lo, hi, x) tmp = (-1.0 * ((x - lo) / lo)) + (hi * (((1.0 / lo) + ((hi * ((1.0 / lo) - ((1.0 / lo) * (x / lo)))) / lo)) - ((x / lo) * (1.0 / lo)))); end
code[lo_, hi_, x_] := N[(N[(-1.0 * N[(N[(x - lo), $MachinePrecision] / lo), $MachinePrecision]), $MachinePrecision] + N[(hi * N[(N[(N[(1.0 / lo), $MachinePrecision] + N[(N[(hi * N[(N[(1.0 / lo), $MachinePrecision] - N[(N[(1.0 / lo), $MachinePrecision] * N[(x / lo), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] / lo), $MachinePrecision]), $MachinePrecision] - N[(N[(x / lo), $MachinePrecision] * N[(1.0 / lo), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
-1 \cdot \frac{x - lo}{lo} + hi \cdot \left(\left(\frac{1}{lo} + \frac{hi \cdot \left(\frac{1}{lo} - \frac{1}{lo} \cdot \frac{x}{lo}\right)}{lo}\right) - \frac{x}{lo} \cdot \frac{1}{lo}\right)
\end{array}
Initial program 3.1%
Taylor expanded in hi around 0 18.8%
*-un-lft-identity18.8%
unpow218.8%
times-frac18.8%
Applied egg-rr18.8%
*-un-lft-identity18.8%
unpow218.8%
frac-times18.8%
*-commutative18.8%
Applied egg-rr18.8%
(FPCore (lo hi x) :precision binary64 (/ (- x lo) hi))
double code(double lo, double hi, double x) {
return (x - lo) / hi;
}
real(8) function code(lo, hi, x)
real(8), intent (in) :: lo
real(8), intent (in) :: hi
real(8), intent (in) :: x
code = (x - lo) / hi
end function
public static double code(double lo, double hi, double x) {
return (x - lo) / hi;
}
def code(lo, hi, x): return (x - lo) / hi
function code(lo, hi, x) return Float64(Float64(x - lo) / hi) end
function tmp = code(lo, hi, x) tmp = (x - lo) / hi; end
code[lo_, hi_, x_] := N[(N[(x - lo), $MachinePrecision] / hi), $MachinePrecision]
\begin{array}{l}
\\
\frac{x - lo}{hi}
\end{array}
Initial program 3.1%
Taylor expanded in hi around inf 18.7%
(FPCore (lo hi x) :precision binary64 1.0)
double code(double lo, double hi, double x) {
return 1.0;
}
real(8) function code(lo, hi, x)
real(8), intent (in) :: lo
real(8), intent (in) :: hi
real(8), intent (in) :: x
code = 1.0d0
end function
public static double code(double lo, double hi, double x) {
return 1.0;
}
def code(lo, hi, x): return 1.0
function code(lo, hi, x) return 1.0 end
function tmp = code(lo, hi, x) tmp = 1.0; end
code[lo_, hi_, x_] := 1.0
\begin{array}{l}
\\
1
\end{array}
Initial program 3.1%
Taylor expanded in lo around inf 18.7%
herbie shell --seed 2024052 -o generate:simplify
(FPCore (lo hi x)
:name "xlohi (overflows)"
:precision binary64
:pre (and (< lo -1e+308) (> hi 1e+308))
(/ (- x lo) (- hi lo)))