
(FPCore (N) :precision binary64 (- (log (+ N 1.0)) (log N)))
double code(double N) {
return log((N + 1.0)) - log(N);
}
real(8) function code(n)
real(8), intent (in) :: n
code = log((n + 1.0d0)) - log(n)
end function
public static double code(double N) {
return Math.log((N + 1.0)) - Math.log(N);
}
def code(N): return math.log((N + 1.0)) - math.log(N)
function code(N) return Float64(log(Float64(N + 1.0)) - log(N)) end
function tmp = code(N) tmp = log((N + 1.0)) - log(N); end
code[N_] := N[(N[Log[N[(N + 1.0), $MachinePrecision]], $MachinePrecision] - N[Log[N], $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\log \left(N + 1\right) - \log N
\end{array}
Sampling outcomes in binary64 precision:
Herbie found 6 alternatives:
| Alternative | Accuracy | Speedup |
|---|
(FPCore (N) :precision binary64 (- (log (+ N 1.0)) (log N)))
double code(double N) {
return log((N + 1.0)) - log(N);
}
real(8) function code(n)
real(8), intent (in) :: n
code = log((n + 1.0d0)) - log(n)
end function
public static double code(double N) {
return Math.log((N + 1.0)) - Math.log(N);
}
def code(N): return math.log((N + 1.0)) - math.log(N)
function code(N) return Float64(log(Float64(N + 1.0)) - log(N)) end
function tmp = code(N) tmp = log((N + 1.0)) - log(N); end
code[N_] := N[(N[Log[N[(N + 1.0), $MachinePrecision]], $MachinePrecision] - N[Log[N], $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\log \left(N + 1\right) - \log N
\end{array}
(FPCore (N) :precision binary64 (log1p (/ 1.0 N)))
double code(double N) {
return log1p((1.0 / N));
}
public static double code(double N) {
return Math.log1p((1.0 / N));
}
def code(N): return math.log1p((1.0 / N))
function code(N) return log1p(Float64(1.0 / N)) end
code[N_] := N[Log[1 + N[(1.0 / N), $MachinePrecision]], $MachinePrecision]
\begin{array}{l}
\\
\mathsf{log1p}\left(\frac{1}{N}\right)
\end{array}
Initial program 23.6%
diff-log26.3%
Applied egg-rr26.3%
*-lft-identity26.3%
associate-*l/25.9%
distribute-lft-in25.8%
lft-mult-inverse26.1%
*-rgt-identity26.1%
log1p-define99.8%
Simplified99.8%
Final simplification99.8%
(FPCore (N) :precision binary64 (/ (+ 1.0 (/ (+ -0.5 (/ (- 0.3333333333333333 (/ 0.25 N)) N)) N)) N))
double code(double N) {
return (1.0 + ((-0.5 + ((0.3333333333333333 - (0.25 / N)) / N)) / N)) / N;
}
real(8) function code(n)
real(8), intent (in) :: n
code = (1.0d0 + (((-0.5d0) + ((0.3333333333333333d0 - (0.25d0 / n)) / n)) / n)) / n
end function
public static double code(double N) {
return (1.0 + ((-0.5 + ((0.3333333333333333 - (0.25 / N)) / N)) / N)) / N;
}
def code(N): return (1.0 + ((-0.5 + ((0.3333333333333333 - (0.25 / N)) / N)) / N)) / N
function code(N) return Float64(Float64(1.0 + Float64(Float64(-0.5 + Float64(Float64(0.3333333333333333 - Float64(0.25 / N)) / N)) / N)) / N) end
function tmp = code(N) tmp = (1.0 + ((-0.5 + ((0.3333333333333333 - (0.25 / N)) / N)) / N)) / N; end
code[N_] := N[(N[(1.0 + N[(N[(-0.5 + N[(N[(0.3333333333333333 - N[(0.25 / N), $MachinePrecision]), $MachinePrecision] / N), $MachinePrecision]), $MachinePrecision] / N), $MachinePrecision]), $MachinePrecision] / N), $MachinePrecision]
\begin{array}{l}
\\
\frac{1 + \frac{-0.5 + \frac{0.3333333333333333 - \frac{0.25}{N}}{N}}{N}}{N}
\end{array}
Initial program 23.6%
diff-log26.3%
Applied egg-rr26.3%
*-lft-identity26.3%
associate-*l/25.9%
distribute-lft-in25.8%
lft-mult-inverse26.1%
*-rgt-identity26.1%
log1p-define99.8%
Simplified99.8%
add-cbrt-cube99.0%
pow399.0%
Applied egg-rr99.0%
pow1/394.2%
add-sqr-sqrt94.2%
unpow-prod-down94.2%
sqrt-pow194.2%
metadata-eval94.2%
sqrt-pow194.2%
metadata-eval94.2%
Applied egg-rr94.2%
unpow1/395.6%
unpow1/398.3%
Simplified98.3%
Taylor expanded in N around inf 95.0%
Simplified95.0%
Final simplification95.0%
(FPCore (N) :precision binary64 (/ (+ 1.0 (/ (+ -0.5 (/ 0.3333333333333333 N)) N)) N))
double code(double N) {
return (1.0 + ((-0.5 + (0.3333333333333333 / N)) / N)) / N;
}
real(8) function code(n)
real(8), intent (in) :: n
code = (1.0d0 + (((-0.5d0) + (0.3333333333333333d0 / n)) / n)) / n
end function
public static double code(double N) {
return (1.0 + ((-0.5 + (0.3333333333333333 / N)) / N)) / N;
}
def code(N): return (1.0 + ((-0.5 + (0.3333333333333333 / N)) / N)) / N
function code(N) return Float64(Float64(1.0 + Float64(Float64(-0.5 + Float64(0.3333333333333333 / N)) / N)) / N) end
function tmp = code(N) tmp = (1.0 + ((-0.5 + (0.3333333333333333 / N)) / N)) / N; end
code[N_] := N[(N[(1.0 + N[(N[(-0.5 + N[(0.3333333333333333 / N), $MachinePrecision]), $MachinePrecision] / N), $MachinePrecision]), $MachinePrecision] / N), $MachinePrecision]
\begin{array}{l}
\\
\frac{1 + \frac{-0.5 + \frac{0.3333333333333333}{N}}{N}}{N}
\end{array}
Initial program 23.6%
Taylor expanded in N around inf 93.7%
associate--l+93.7%
unpow293.7%
associate-/r*93.7%
metadata-eval93.7%
associate-*r/93.7%
associate-*r/93.7%
metadata-eval93.7%
div-sub93.7%
sub-neg93.7%
metadata-eval93.7%
+-commutative93.7%
associate-*r/93.7%
metadata-eval93.7%
Simplified93.7%
Final simplification93.7%
(FPCore (N) :precision binary64 (/ 1.0 (/ N (+ 1.0 (/ -0.5 N)))))
double code(double N) {
return 1.0 / (N / (1.0 + (-0.5 / N)));
}
real(8) function code(n)
real(8), intent (in) :: n
code = 1.0d0 / (n / (1.0d0 + ((-0.5d0) / n)))
end function
public static double code(double N) {
return 1.0 / (N / (1.0 + (-0.5 / N)));
}
def code(N): return 1.0 / (N / (1.0 + (-0.5 / N)))
function code(N) return Float64(1.0 / Float64(N / Float64(1.0 + Float64(-0.5 / N)))) end
function tmp = code(N) tmp = 1.0 / (N / (1.0 + (-0.5 / N))); end
code[N_] := N[(1.0 / N[(N / N[(1.0 + N[(-0.5 / N), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\frac{1}{\frac{N}{1 + \frac{-0.5}{N}}}
\end{array}
Initial program 23.6%
Taylor expanded in N around inf 91.2%
associate-*r/91.2%
metadata-eval91.2%
Simplified91.2%
div-inv91.1%
sub-neg91.1%
distribute-neg-frac91.1%
metadata-eval91.1%
Applied egg-rr91.1%
un-div-inv91.2%
clear-num91.2%
Applied egg-rr91.2%
Final simplification91.2%
(FPCore (N) :precision binary64 (/ (- 1.0 (/ 0.5 N)) N))
double code(double N) {
return (1.0 - (0.5 / N)) / N;
}
real(8) function code(n)
real(8), intent (in) :: n
code = (1.0d0 - (0.5d0 / n)) / n
end function
public static double code(double N) {
return (1.0 - (0.5 / N)) / N;
}
def code(N): return (1.0 - (0.5 / N)) / N
function code(N) return Float64(Float64(1.0 - Float64(0.5 / N)) / N) end
function tmp = code(N) tmp = (1.0 - (0.5 / N)) / N; end
code[N_] := N[(N[(1.0 - N[(0.5 / N), $MachinePrecision]), $MachinePrecision] / N), $MachinePrecision]
\begin{array}{l}
\\
\frac{1 - \frac{0.5}{N}}{N}
\end{array}
Initial program 23.6%
Taylor expanded in N around inf 91.2%
associate-*r/91.2%
metadata-eval91.2%
Simplified91.2%
Final simplification91.2%
(FPCore (N) :precision binary64 (/ 1.0 N))
double code(double N) {
return 1.0 / N;
}
real(8) function code(n)
real(8), intent (in) :: n
code = 1.0d0 / n
end function
public static double code(double N) {
return 1.0 / N;
}
def code(N): return 1.0 / N
function code(N) return Float64(1.0 / N) end
function tmp = code(N) tmp = 1.0 / N; end
code[N_] := N[(1.0 / N), $MachinePrecision]
\begin{array}{l}
\\
\frac{1}{N}
\end{array}
Initial program 23.6%
Taylor expanded in N around inf 84.2%
Final simplification84.2%
(FPCore (N) :precision binary64 (log1p (/ 1.0 N)))
double code(double N) {
return log1p((1.0 / N));
}
public static double code(double N) {
return Math.log1p((1.0 / N));
}
def code(N): return math.log1p((1.0 / N))
function code(N) return log1p(Float64(1.0 / N)) end
code[N_] := N[Log[1 + N[(1.0 / N), $MachinePrecision]], $MachinePrecision]
\begin{array}{l}
\\
\mathsf{log1p}\left(\frac{1}{N}\right)
\end{array}
herbie shell --seed 2024084
(FPCore (N)
:name "2log (problem 3.3.6)"
:precision binary64
:pre (and (> N 1.0) (< N 1e+40))
:alt
(log1p (/ 1.0 N))
(- (log (+ N 1.0)) (log N)))