
(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 11 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
(let* ((t_0 (/ x (pow lo 2.0))))
(/
(- -1.0 (pow (* (/ (- x hi) lo) (- -1.0 (/ hi lo))) 3.0))
(-
-1.0
(-
(/ (* x (+ 1.0 (/ x lo))) lo)
(* hi (+ (/ 1.0 lo) (+ t_0 (/ (* x (- (/ 1.0 lo) t_0)) lo)))))))))
double code(double lo, double hi, double x) {
double t_0 = x / pow(lo, 2.0);
return (-1.0 - pow((((x - hi) / lo) * (-1.0 - (hi / lo))), 3.0)) / (-1.0 - (((x * (1.0 + (x / lo))) / lo) - (hi * ((1.0 / lo) + (t_0 + ((x * ((1.0 / lo) - t_0)) / lo))))));
}
real(8) function code(lo, hi, x)
real(8), intent (in) :: lo
real(8), intent (in) :: hi
real(8), intent (in) :: x
real(8) :: t_0
t_0 = x / (lo ** 2.0d0)
code = ((-1.0d0) - ((((x - hi) / lo) * ((-1.0d0) - (hi / lo))) ** 3.0d0)) / ((-1.0d0) - (((x * (1.0d0 + (x / lo))) / lo) - (hi * ((1.0d0 / lo) + (t_0 + ((x * ((1.0d0 / lo) - t_0)) / lo))))))
end function
public static double code(double lo, double hi, double x) {
double t_0 = x / Math.pow(lo, 2.0);
return (-1.0 - Math.pow((((x - hi) / lo) * (-1.0 - (hi / lo))), 3.0)) / (-1.0 - (((x * (1.0 + (x / lo))) / lo) - (hi * ((1.0 / lo) + (t_0 + ((x * ((1.0 / lo) - t_0)) / lo))))));
}
def code(lo, hi, x): t_0 = x / math.pow(lo, 2.0) return (-1.0 - math.pow((((x - hi) / lo) * (-1.0 - (hi / lo))), 3.0)) / (-1.0 - (((x * (1.0 + (x / lo))) / lo) - (hi * ((1.0 / lo) + (t_0 + ((x * ((1.0 / lo) - t_0)) / lo))))))
function code(lo, hi, x) t_0 = Float64(x / (lo ^ 2.0)) return Float64(Float64(-1.0 - (Float64(Float64(Float64(x - hi) / lo) * Float64(-1.0 - Float64(hi / lo))) ^ 3.0)) / Float64(-1.0 - Float64(Float64(Float64(x * Float64(1.0 + Float64(x / lo))) / lo) - Float64(hi * Float64(Float64(1.0 / lo) + Float64(t_0 + Float64(Float64(x * Float64(Float64(1.0 / lo) - t_0)) / lo))))))) end
function tmp = code(lo, hi, x) t_0 = x / (lo ^ 2.0); tmp = (-1.0 - ((((x - hi) / lo) * (-1.0 - (hi / lo))) ^ 3.0)) / (-1.0 - (((x * (1.0 + (x / lo))) / lo) - (hi * ((1.0 / lo) + (t_0 + ((x * ((1.0 / lo) - t_0)) / lo)))))); end
code[lo_, hi_, x_] := Block[{t$95$0 = N[(x / N[Power[lo, 2.0], $MachinePrecision]), $MachinePrecision]}, N[(N[(-1.0 - N[Power[N[(N[(N[(x - hi), $MachinePrecision] / lo), $MachinePrecision] * N[(-1.0 - N[(hi / lo), $MachinePrecision]), $MachinePrecision]), $MachinePrecision], 3.0], $MachinePrecision]), $MachinePrecision] / N[(-1.0 - N[(N[(N[(x * N[(1.0 + N[(x / lo), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] / lo), $MachinePrecision] - N[(hi * N[(N[(1.0 / lo), $MachinePrecision] + N[(t$95$0 + N[(N[(x * N[(N[(1.0 / lo), $MachinePrecision] - t$95$0), $MachinePrecision]), $MachinePrecision] / lo), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}
\\
\begin{array}{l}
t_0 := \frac{x}{{lo}^{2}}\\
\frac{-1 - {\left(\frac{x - hi}{lo} \cdot \left(-1 - \frac{hi}{lo}\right)\right)}^{3}}{-1 - \left(\frac{x \cdot \left(1 + \frac{x}{lo}\right)}{lo} - hi \cdot \left(\frac{1}{lo} + \left(t\_0 + \frac{x \cdot \left(\frac{1}{lo} - t\_0\right)}{lo}\right)\right)\right)}
\end{array}
\end{array}
Initial program 3.1%
Taylor expanded in lo around inf 0.0%
Simplified18.9%
flip3-+18.9%
frac-2neg18.9%
metadata-eval18.9%
+-commutative18.9%
metadata-eval18.9%
Applied egg-rr18.9%
distribute-neg-in18.9%
metadata-eval18.9%
unsub-neg18.9%
distribute-neg-in18.9%
metadata-eval18.9%
unsub-neg18.9%
unpow218.9%
*-rgt-identity18.9%
distribute-lft-out--18.9%
Simplified18.9%
Taylor expanded in hi around 0 24.2%
Taylor expanded in hi around 0 32.4%
Final simplification32.4%
(FPCore (lo hi x) :precision binary64 (/ (- -1.0 (pow (* (/ (- x hi) lo) (- -1.0 (/ hi lo))) 3.0)) (+ -1.0 (/ (- hi x) lo))))
double code(double lo, double hi, double x) {
return (-1.0 - pow((((x - hi) / lo) * (-1.0 - (hi / lo))), 3.0)) / (-1.0 + ((hi - x) / 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 - hi) / lo) * ((-1.0d0) - (hi / lo))) ** 3.0d0)) / ((-1.0d0) + ((hi - x) / lo))
end function
public static double code(double lo, double hi, double x) {
return (-1.0 - Math.pow((((x - hi) / lo) * (-1.0 - (hi / lo))), 3.0)) / (-1.0 + ((hi - x) / lo));
}
def code(lo, hi, x): return (-1.0 - math.pow((((x - hi) / lo) * (-1.0 - (hi / lo))), 3.0)) / (-1.0 + ((hi - x) / lo))
function code(lo, hi, x) return Float64(Float64(-1.0 - (Float64(Float64(Float64(x - hi) / lo) * Float64(-1.0 - Float64(hi / lo))) ^ 3.0)) / Float64(-1.0 + Float64(Float64(hi - x) / lo))) end
function tmp = code(lo, hi, x) tmp = (-1.0 - ((((x - hi) / lo) * (-1.0 - (hi / lo))) ^ 3.0)) / (-1.0 + ((hi - x) / lo)); end
code[lo_, hi_, x_] := N[(N[(-1.0 - N[Power[N[(N[(N[(x - hi), $MachinePrecision] / lo), $MachinePrecision] * N[(-1.0 - N[(hi / lo), $MachinePrecision]), $MachinePrecision]), $MachinePrecision], 3.0], $MachinePrecision]), $MachinePrecision] / N[(-1.0 + N[(N[(hi - x), $MachinePrecision] / lo), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\frac{-1 - {\left(\frac{x - hi}{lo} \cdot \left(-1 - \frac{hi}{lo}\right)\right)}^{3}}{-1 + \frac{hi - x}{lo}}
\end{array}
Initial program 3.1%
Taylor expanded in lo around inf 0.0%
Simplified18.9%
flip3-+18.9%
frac-2neg18.9%
metadata-eval18.9%
+-commutative18.9%
metadata-eval18.9%
Applied egg-rr18.9%
distribute-neg-in18.9%
metadata-eval18.9%
unsub-neg18.9%
distribute-neg-in18.9%
metadata-eval18.9%
unsub-neg18.9%
unpow218.9%
*-rgt-identity18.9%
distribute-lft-out--18.9%
Simplified18.9%
Taylor expanded in hi around 0 24.2%
Taylor expanded in lo around inf 32.4%
mul-1-neg32.4%
distribute-neg-frac232.4%
Simplified32.4%
Final simplification32.4%
(FPCore (lo hi x) :precision binary64 (* x (+ (/ (pow (/ hi lo) 2.0) x) (/ (- -1.0 (/ hi lo)) lo))))
double code(double lo, double hi, double x) {
return x * ((pow((hi / lo), 2.0) / x) + ((-1.0 - (hi / lo)) / 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 * ((((hi / lo) ** 2.0d0) / x) + (((-1.0d0) - (hi / lo)) / lo))
end function
public static double code(double lo, double hi, double x) {
return x * ((Math.pow((hi / lo), 2.0) / x) + ((-1.0 - (hi / lo)) / lo));
}
def code(lo, hi, x): return x * ((math.pow((hi / lo), 2.0) / x) + ((-1.0 - (hi / lo)) / lo))
function code(lo, hi, x) return Float64(x * Float64(Float64((Float64(hi / lo) ^ 2.0) / x) + Float64(Float64(-1.0 - Float64(hi / lo)) / lo))) end
function tmp = code(lo, hi, x) tmp = x * ((((hi / lo) ^ 2.0) / x) + ((-1.0 - (hi / lo)) / lo)); end
code[lo_, hi_, x_] := N[(x * N[(N[(N[Power[N[(hi / lo), $MachinePrecision], 2.0], $MachinePrecision] / x), $MachinePrecision] + N[(N[(-1.0 - N[(hi / lo), $MachinePrecision]), $MachinePrecision] / lo), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
x \cdot \left(\frac{{\left(\frac{hi}{lo}\right)}^{2}}{x} + \frac{-1 - \frac{hi}{lo}}{lo}\right)
\end{array}
Initial program 3.1%
Taylor expanded in lo around inf 0.0%
Simplified18.9%
Taylor expanded in x around inf 18.8%
+-commutative18.8%
mul-1-neg18.8%
unsub-neg18.8%
Simplified18.9%
Taylor expanded in hi around inf 0.0%
associate-/r*0.0%
unpow20.0%
unpow20.0%
times-frac19.5%
unpow219.5%
Simplified19.5%
Final simplification19.5%
(FPCore (lo hi x) :precision binary64 (+ 1.0 (* (/ (- hi x) lo) (fabs (+ 1.0 (/ hi lo))))))
double code(double lo, double hi, double x) {
return 1.0 + (((hi - x) / lo) * fabs((1.0 + (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 = 1.0d0 + (((hi - x) / lo) * abs((1.0d0 + (hi / lo))))
end function
public static double code(double lo, double hi, double x) {
return 1.0 + (((hi - x) / lo) * Math.abs((1.0 + (hi / lo))));
}
def code(lo, hi, x): return 1.0 + (((hi - x) / lo) * math.fabs((1.0 + (hi / lo))))
function code(lo, hi, x) return Float64(1.0 + Float64(Float64(Float64(hi - x) / lo) * abs(Float64(1.0 + Float64(hi / lo))))) end
function tmp = code(lo, hi, x) tmp = 1.0 + (((hi - x) / lo) * abs((1.0 + (hi / lo)))); end
code[lo_, hi_, x_] := N[(1.0 + N[(N[(N[(hi - x), $MachinePrecision] / lo), $MachinePrecision] * N[Abs[N[(1.0 + N[(hi / lo), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
1 + \frac{hi - x}{lo} \cdot \left|1 + \frac{hi}{lo}\right|
\end{array}
Initial program 3.1%
Taylor expanded in lo around inf 0.0%
Simplified18.9%
add-sqr-sqrt10.0%
sqrt-unprod19.4%
pow219.4%
+-commutative19.4%
Applied egg-rr19.4%
unpow219.4%
rem-sqrt-square19.4%
Simplified19.4%
Final simplification19.4%
(FPCore (lo hi x) :precision binary64 (+ 1.0 (* hi (/ (fabs (+ 1.0 (/ hi lo))) lo))))
double code(double lo, double hi, double x) {
return 1.0 + (hi * (fabs((1.0 + (hi / lo))) / 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 + (hi * (abs((1.0d0 + (hi / lo))) / lo))
end function
public static double code(double lo, double hi, double x) {
return 1.0 + (hi * (Math.abs((1.0 + (hi / lo))) / lo));
}
def code(lo, hi, x): return 1.0 + (hi * (math.fabs((1.0 + (hi / lo))) / lo))
function code(lo, hi, x) return Float64(1.0 + Float64(hi * Float64(abs(Float64(1.0 + Float64(hi / lo))) / lo))) end
function tmp = code(lo, hi, x) tmp = 1.0 + (hi * (abs((1.0 + (hi / lo))) / lo)); end
code[lo_, hi_, x_] := N[(1.0 + N[(hi * N[(N[Abs[N[(1.0 + N[(hi / lo), $MachinePrecision]), $MachinePrecision]], $MachinePrecision] / lo), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
1 + hi \cdot \frac{\left|1 + \frac{hi}{lo}\right|}{lo}
\end{array}
Initial program 3.1%
Taylor expanded in lo around inf 0.0%
Simplified18.9%
add-sqr-sqrt10.0%
sqrt-unprod19.4%
pow219.4%
+-commutative19.4%
Applied egg-rr19.4%
unpow219.4%
rem-sqrt-square19.4%
Simplified19.4%
Taylor expanded in hi around inf 19.4%
associate-/l*19.4%
Simplified19.4%
Final simplification19.4%
(FPCore (lo hi x) :precision binary64 (* x (+ (/ (+ 1.0 (/ (* hi (+ 1.0 (/ hi lo))) lo)) x) (/ -1.0 lo))))
double code(double lo, double hi, double x) {
return x * (((1.0 + ((hi * (1.0 + (hi / lo))) / lo)) / x) + (-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 = x * (((1.0d0 + ((hi * (1.0d0 + (hi / lo))) / lo)) / x) + ((-1.0d0) / lo))
end function
public static double code(double lo, double hi, double x) {
return x * (((1.0 + ((hi * (1.0 + (hi / lo))) / lo)) / x) + (-1.0 / lo));
}
def code(lo, hi, x): return x * (((1.0 + ((hi * (1.0 + (hi / lo))) / lo)) / x) + (-1.0 / lo))
function code(lo, hi, x) return Float64(x * Float64(Float64(Float64(1.0 + Float64(Float64(hi * Float64(1.0 + Float64(hi / lo))) / lo)) / x) + Float64(-1.0 / lo))) end
function tmp = code(lo, hi, x) tmp = x * (((1.0 + ((hi * (1.0 + (hi / lo))) / lo)) / x) + (-1.0 / lo)); end
code[lo_, hi_, x_] := N[(x * N[(N[(N[(1.0 + N[(N[(hi * N[(1.0 + N[(hi / lo), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] / lo), $MachinePrecision]), $MachinePrecision] / x), $MachinePrecision] + N[(-1.0 / lo), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
x \cdot \left(\frac{1 + \frac{hi \cdot \left(1 + \frac{hi}{lo}\right)}{lo}}{x} + \frac{-1}{lo}\right)
\end{array}
Initial program 3.1%
Taylor expanded in lo around inf 0.0%
Simplified18.9%
Taylor expanded in x around inf 18.8%
+-commutative18.8%
mul-1-neg18.8%
unsub-neg18.8%
Simplified18.9%
Taylor expanded in x around 0 18.9%
Taylor expanded in hi around 0 18.9%
Final simplification18.9%
(FPCore (lo hi x) :precision binary64 (+ 1.0 (* (/ (- x hi) lo) (- -1.0 (/ hi lo)))))
double code(double lo, double hi, double x) {
return 1.0 + (((x - hi) / lo) * (-1.0 - (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 = 1.0d0 + (((x - hi) / lo) * ((-1.0d0) - (hi / lo)))
end function
public static double code(double lo, double hi, double x) {
return 1.0 + (((x - hi) / lo) * (-1.0 - (hi / lo)));
}
def code(lo, hi, x): return 1.0 + (((x - hi) / lo) * (-1.0 - (hi / lo)))
function code(lo, hi, x) return Float64(1.0 + Float64(Float64(Float64(x - hi) / lo) * Float64(-1.0 - Float64(hi / lo)))) end
function tmp = code(lo, hi, x) tmp = 1.0 + (((x - hi) / lo) * (-1.0 - (hi / lo))); end
code[lo_, hi_, x_] := N[(1.0 + N[(N[(N[(x - hi), $MachinePrecision] / lo), $MachinePrecision] * N[(-1.0 - N[(hi / lo), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
1 + \frac{x - hi}{lo} \cdot \left(-1 - \frac{hi}{lo}\right)
\end{array}
Initial program 3.1%
Taylor expanded in lo around inf 0.0%
Simplified18.9%
Final simplification18.9%
(FPCore (lo hi x) :precision binary64 (- 1.0 (* hi (/ (- -1.0 (/ hi lo)) lo))))
double code(double lo, double hi, double x) {
return 1.0 - (hi * ((-1.0 - (hi / lo)) / 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 - (hi * (((-1.0d0) - (hi / lo)) / lo))
end function
public static double code(double lo, double hi, double x) {
return 1.0 - (hi * ((-1.0 - (hi / lo)) / lo));
}
def code(lo, hi, x): return 1.0 - (hi * ((-1.0 - (hi / lo)) / lo))
function code(lo, hi, x) return Float64(1.0 - Float64(hi * Float64(Float64(-1.0 - Float64(hi / lo)) / lo))) end
function tmp = code(lo, hi, x) tmp = 1.0 - (hi * ((-1.0 - (hi / lo)) / lo)); end
code[lo_, hi_, x_] := N[(1.0 - N[(hi * N[(N[(-1.0 - N[(hi / lo), $MachinePrecision]), $MachinePrecision] / lo), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
1 - hi \cdot \frac{-1 - \frac{hi}{lo}}{lo}
\end{array}
Initial program 3.1%
Taylor expanded in lo around inf 0.0%
Simplified18.9%
Taylor expanded in x around 0 18.9%
associate-/l*18.9%
Simplified18.9%
Final simplification18.9%
(FPCore (lo hi x) :precision binary64 (- 1.0 (/ x lo)))
double code(double lo, double hi, double x) {
return 1.0 - (x / 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)
end function
public static double code(double lo, double hi, double x) {
return 1.0 - (x / lo);
}
def code(lo, hi, x): return 1.0 - (x / lo)
function code(lo, hi, x) return Float64(1.0 - Float64(x / lo)) end
function tmp = code(lo, hi, x) tmp = 1.0 - (x / lo); end
code[lo_, hi_, x_] := N[(1.0 - N[(x / lo), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
1 - \frac{x}{lo}
\end{array}
Initial program 3.1%
Taylor expanded in hi around 0 18.7%
div-sub18.7%
sub-neg18.7%
*-inverses18.7%
metadata-eval18.7%
distribute-lft-in18.7%
metadata-eval18.7%
+-commutative18.7%
mul-1-neg18.7%
unsub-neg18.7%
Simplified18.7%
Final simplification18.7%
(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 18.8%
Final simplification18.8%
(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%
Final simplification18.7%
herbie shell --seed 2024067
(FPCore (lo hi x)
:name "xlohi (overflows)"
:precision binary64
:pre (and (< lo -1e+308) (> hi 1e+308))
(/ (- x lo) (- hi lo)))