
(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 (sqrt (pow (* (+ x (fma hi (/ (+ x hi) lo) hi)) (/ 1.0 lo)) 2.0))))
double code(double lo, double hi, double x) {
return 1.0 - sqrt(pow(((x + fma(hi, ((x + hi) / lo), hi)) * (1.0 / lo)), 2.0));
}
function code(lo, hi, x) return Float64(1.0 - sqrt((Float64(Float64(x + fma(hi, Float64(Float64(x + hi) / lo), hi)) * Float64(1.0 / lo)) ^ 2.0))) end
code[lo_, hi_, x_] := N[(1.0 - N[Sqrt[N[Power[N[(N[(x + N[(hi * N[(N[(x + hi), $MachinePrecision] / lo), $MachinePrecision] + hi), $MachinePrecision]), $MachinePrecision] * N[(1.0 / lo), $MachinePrecision]), $MachinePrecision], 2.0], $MachinePrecision]], $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
1 - \sqrt{{\left(\left(x + \mathsf{fma}\left(hi, \frac{x + hi}{lo}, hi\right)\right) \cdot \frac{1}{lo}\right)}^{2}}
\end{array}
Initial program 3.1%
Taylor expanded in lo around -inf 3.1%
mul-1-neg3.1%
associate--l+3.1%
associate-/l*14.3%
Simplified14.3%
add-sqr-sqrt9.3%
sqrt-unprod13.7%
pow213.7%
Applied egg-rr13.7%
fma-neg19.3%
Simplified19.3%
div-inv19.3%
add-sqr-sqrt0.0%
sqrt-unprod0.7%
sqr-neg0.7%
sqrt-unprod0.9%
add-sqr-sqrt0.9%
sub-neg0.9%
add-sqr-sqrt0.0%
sqrt-unprod0.7%
sqr-neg0.7%
sqrt-unprod19.4%
add-sqr-sqrt19.4%
Applied egg-rr19.4%
Final simplification19.4%
(FPCore (lo hi x) :precision binary64 (- 1.0 (sqrt (pow (/ (+ x (* hi (+ (/ (- x hi) lo) -1.0))) lo) 2.0))))
double code(double lo, double hi, double x) {
return 1.0 - sqrt(pow(((x + (hi * (((x - hi) / lo) + -1.0))) / 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 - sqrt((((x + (hi * (((x - hi) / lo) + (-1.0d0)))) / lo) ** 2.0d0))
end function
public static double code(double lo, double hi, double x) {
return 1.0 - Math.sqrt(Math.pow(((x + (hi * (((x - hi) / lo) + -1.0))) / lo), 2.0));
}
def code(lo, hi, x): return 1.0 - math.sqrt(math.pow(((x + (hi * (((x - hi) / lo) + -1.0))) / lo), 2.0))
function code(lo, hi, x) return Float64(1.0 - sqrt((Float64(Float64(x + Float64(hi * Float64(Float64(Float64(x - hi) / lo) + -1.0))) / lo) ^ 2.0))) end
function tmp = code(lo, hi, x) tmp = 1.0 - sqrt((((x + (hi * (((x - hi) / lo) + -1.0))) / lo) ^ 2.0)); end
code[lo_, hi_, x_] := N[(1.0 - N[Sqrt[N[Power[N[(N[(x + N[(hi * N[(N[(N[(x - hi), $MachinePrecision] / lo), $MachinePrecision] + -1.0), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] / lo), $MachinePrecision], 2.0], $MachinePrecision]], $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
1 - \sqrt{{\left(\frac{x + hi \cdot \left(\frac{x - hi}{lo} + -1\right)}{lo}\right)}^{2}}
\end{array}
Initial program 3.1%
Taylor expanded in lo around -inf 3.1%
mul-1-neg3.1%
associate--l+3.1%
associate-/l*14.3%
Simplified14.3%
add-sqr-sqrt9.3%
sqrt-unprod13.7%
pow213.7%
Applied egg-rr13.7%
fma-neg19.3%
Simplified19.3%
Taylor expanded in hi around 0 19.4%
sub-neg19.4%
+-commutative19.4%
mul-1-neg19.4%
sub-neg19.4%
div-sub19.3%
metadata-eval19.3%
Simplified19.3%
Final simplification19.3%
(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 (/ (- lo) hi))
double code(double lo, double hi, double x) {
return -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 = -lo / hi
end function
public static double code(double lo, double hi, double x) {
return -lo / hi;
}
def code(lo, hi, x): return -lo / hi
function code(lo, hi, x) return Float64(Float64(-lo) / hi) end
function tmp = code(lo, hi, x) tmp = -lo / hi; end
code[lo_, hi_, x_] := N[((-lo) / hi), $MachinePrecision]
\begin{array}{l}
\\
\frac{-lo}{hi}
\end{array}
Initial program 3.1%
Taylor expanded in lo around 0 18.8%
+-commutative18.8%
mul-1-neg18.8%
unsub-neg18.8%
+-commutative18.8%
mul-1-neg18.8%
unsub-neg18.8%
Simplified18.8%
Taylor expanded in x around 0 18.8%
neg-mul-118.8%
distribute-neg-frac218.8%
Simplified18.8%
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 18.6%
Final simplification18.6%
herbie shell --seed 2024059
(FPCore (lo hi x)
:name "xlohi (overflows)"
:precision binary64
:pre (and (< lo -1e+308) (> hi 1e+308))
(/ (- x lo) (- hi lo)))