
(FPCore (c_p c_n t s)
:precision binary64
(let* ((t_1 (/ 1.0 (+ 1.0 (exp (- t))))) (t_2 (/ 1.0 (+ 1.0 (exp (- s))))))
(/
(* (pow t_2 c_p) (pow (- 1.0 t_2) c_n))
(* (pow t_1 c_p) (pow (- 1.0 t_1) c_n)))))
double code(double c_p, double c_n, double t, double s) {
double t_1 = 1.0 / (1.0 + exp(-t));
double t_2 = 1.0 / (1.0 + exp(-s));
return (pow(t_2, c_p) * pow((1.0 - t_2), c_n)) / (pow(t_1, c_p) * pow((1.0 - t_1), c_n));
}
real(8) function code(c_p, c_n, t, s)
real(8), intent (in) :: c_p
real(8), intent (in) :: c_n
real(8), intent (in) :: t
real(8), intent (in) :: s
real(8) :: t_1
real(8) :: t_2
t_1 = 1.0d0 / (1.0d0 + exp(-t))
t_2 = 1.0d0 / (1.0d0 + exp(-s))
code = ((t_2 ** c_p) * ((1.0d0 - t_2) ** c_n)) / ((t_1 ** c_p) * ((1.0d0 - t_1) ** c_n))
end function
public static double code(double c_p, double c_n, double t, double s) {
double t_1 = 1.0 / (1.0 + Math.exp(-t));
double t_2 = 1.0 / (1.0 + Math.exp(-s));
return (Math.pow(t_2, c_p) * Math.pow((1.0 - t_2), c_n)) / (Math.pow(t_1, c_p) * Math.pow((1.0 - t_1), c_n));
}
def code(c_p, c_n, t, s): t_1 = 1.0 / (1.0 + math.exp(-t)) t_2 = 1.0 / (1.0 + math.exp(-s)) return (math.pow(t_2, c_p) * math.pow((1.0 - t_2), c_n)) / (math.pow(t_1, c_p) * math.pow((1.0 - t_1), c_n))
function code(c_p, c_n, t, s) t_1 = Float64(1.0 / Float64(1.0 + exp(Float64(-t)))) t_2 = Float64(1.0 / Float64(1.0 + exp(Float64(-s)))) return Float64(Float64((t_2 ^ c_p) * (Float64(1.0 - t_2) ^ c_n)) / Float64((t_1 ^ c_p) * (Float64(1.0 - t_1) ^ c_n))) end
function tmp = code(c_p, c_n, t, s) t_1 = 1.0 / (1.0 + exp(-t)); t_2 = 1.0 / (1.0 + exp(-s)); tmp = ((t_2 ^ c_p) * ((1.0 - t_2) ^ c_n)) / ((t_1 ^ c_p) * ((1.0 - t_1) ^ c_n)); end
code[c$95$p_, c$95$n_, t_, s_] := Block[{t$95$1 = N[(1.0 / N[(1.0 + N[Exp[(-t)], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]}, Block[{t$95$2 = N[(1.0 / N[(1.0 + N[Exp[(-s)], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]}, N[(N[(N[Power[t$95$2, c$95$p], $MachinePrecision] * N[Power[N[(1.0 - t$95$2), $MachinePrecision], c$95$n], $MachinePrecision]), $MachinePrecision] / N[(N[Power[t$95$1, c$95$p], $MachinePrecision] * N[Power[N[(1.0 - t$95$1), $MachinePrecision], c$95$n], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]]
\begin{array}{l}
\\
\begin{array}{l}
t_1 := \frac{1}{1 + e^{-t}}\\
t_2 := \frac{1}{1 + e^{-s}}\\
\frac{{t\_2}^{c\_p} \cdot {\left(1 - t\_2\right)}^{c\_n}}{{t\_1}^{c\_p} \cdot {\left(1 - t\_1\right)}^{c\_n}}
\end{array}
\end{array}
Sampling outcomes in binary64 precision:
Herbie found 4 alternatives:
| Alternative | Accuracy | Speedup |
|---|
(FPCore (c_p c_n t s)
:precision binary64
(let* ((t_1 (/ 1.0 (+ 1.0 (exp (- t))))) (t_2 (/ 1.0 (+ 1.0 (exp (- s))))))
(/
(* (pow t_2 c_p) (pow (- 1.0 t_2) c_n))
(* (pow t_1 c_p) (pow (- 1.0 t_1) c_n)))))
double code(double c_p, double c_n, double t, double s) {
double t_1 = 1.0 / (1.0 + exp(-t));
double t_2 = 1.0 / (1.0 + exp(-s));
return (pow(t_2, c_p) * pow((1.0 - t_2), c_n)) / (pow(t_1, c_p) * pow((1.0 - t_1), c_n));
}
real(8) function code(c_p, c_n, t, s)
real(8), intent (in) :: c_p
real(8), intent (in) :: c_n
real(8), intent (in) :: t
real(8), intent (in) :: s
real(8) :: t_1
real(8) :: t_2
t_1 = 1.0d0 / (1.0d0 + exp(-t))
t_2 = 1.0d0 / (1.0d0 + exp(-s))
code = ((t_2 ** c_p) * ((1.0d0 - t_2) ** c_n)) / ((t_1 ** c_p) * ((1.0d0 - t_1) ** c_n))
end function
public static double code(double c_p, double c_n, double t, double s) {
double t_1 = 1.0 / (1.0 + Math.exp(-t));
double t_2 = 1.0 / (1.0 + Math.exp(-s));
return (Math.pow(t_2, c_p) * Math.pow((1.0 - t_2), c_n)) / (Math.pow(t_1, c_p) * Math.pow((1.0 - t_1), c_n));
}
def code(c_p, c_n, t, s): t_1 = 1.0 / (1.0 + math.exp(-t)) t_2 = 1.0 / (1.0 + math.exp(-s)) return (math.pow(t_2, c_p) * math.pow((1.0 - t_2), c_n)) / (math.pow(t_1, c_p) * math.pow((1.0 - t_1), c_n))
function code(c_p, c_n, t, s) t_1 = Float64(1.0 / Float64(1.0 + exp(Float64(-t)))) t_2 = Float64(1.0 / Float64(1.0 + exp(Float64(-s)))) return Float64(Float64((t_2 ^ c_p) * (Float64(1.0 - t_2) ^ c_n)) / Float64((t_1 ^ c_p) * (Float64(1.0 - t_1) ^ c_n))) end
function tmp = code(c_p, c_n, t, s) t_1 = 1.0 / (1.0 + exp(-t)); t_2 = 1.0 / (1.0 + exp(-s)); tmp = ((t_2 ^ c_p) * ((1.0 - t_2) ^ c_n)) / ((t_1 ^ c_p) * ((1.0 - t_1) ^ c_n)); end
code[c$95$p_, c$95$n_, t_, s_] := Block[{t$95$1 = N[(1.0 / N[(1.0 + N[Exp[(-t)], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]}, Block[{t$95$2 = N[(1.0 / N[(1.0 + N[Exp[(-s)], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]}, N[(N[(N[Power[t$95$2, c$95$p], $MachinePrecision] * N[Power[N[(1.0 - t$95$2), $MachinePrecision], c$95$n], $MachinePrecision]), $MachinePrecision] / N[(N[Power[t$95$1, c$95$p], $MachinePrecision] * N[Power[N[(1.0 - t$95$1), $MachinePrecision], c$95$n], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]]
\begin{array}{l}
\\
\begin{array}{l}
t_1 := \frac{1}{1 + e^{-t}}\\
t_2 := \frac{1}{1 + e^{-s}}\\
\frac{{t\_2}^{c\_p} \cdot {\left(1 - t\_2\right)}^{c\_n}}{{t\_1}^{c\_p} \cdot {\left(1 - t\_1\right)}^{c\_n}}
\end{array}
\end{array}
(FPCore (c_p c_n t s)
:precision binary64
(let* ((t_1 (exp (- s))) (t_2 (exp (- t))))
(if (<= c_p 5e-70)
1.0
(exp
(fma
c_p
(- (log1p t_2) (log1p t_1))
(*
c_n
(- (log1p (/ 1.0 (- -1.0 t_1))) (log1p (/ -1.0 (+ 1.0 t_2))))))))))
double code(double c_p, double c_n, double t, double s) {
double t_1 = exp(-s);
double t_2 = exp(-t);
double tmp;
if (c_p <= 5e-70) {
tmp = 1.0;
} else {
tmp = exp(fma(c_p, (log1p(t_2) - log1p(t_1)), (c_n * (log1p((1.0 / (-1.0 - t_1))) - log1p((-1.0 / (1.0 + t_2)))))));
}
return tmp;
}
function code(c_p, c_n, t, s) t_1 = exp(Float64(-s)) t_2 = exp(Float64(-t)) tmp = 0.0 if (c_p <= 5e-70) tmp = 1.0; else tmp = exp(fma(c_p, Float64(log1p(t_2) - log1p(t_1)), Float64(c_n * Float64(log1p(Float64(1.0 / Float64(-1.0 - t_1))) - log1p(Float64(-1.0 / Float64(1.0 + t_2))))))); end return tmp end
code[c$95$p_, c$95$n_, t_, s_] := Block[{t$95$1 = N[Exp[(-s)], $MachinePrecision]}, Block[{t$95$2 = N[Exp[(-t)], $MachinePrecision]}, If[LessEqual[c$95$p, 5e-70], 1.0, N[Exp[N[(c$95$p * N[(N[Log[1 + t$95$2], $MachinePrecision] - N[Log[1 + t$95$1], $MachinePrecision]), $MachinePrecision] + N[(c$95$n * N[(N[Log[1 + N[(1.0 / N[(-1.0 - t$95$1), $MachinePrecision]), $MachinePrecision]], $MachinePrecision] - N[Log[1 + N[(-1.0 / N[(1.0 + t$95$2), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]]]]
\begin{array}{l}
\\
\begin{array}{l}
t_1 := e^{-s}\\
t_2 := e^{-t}\\
\mathbf{if}\;c\_p \leq 5 \cdot 10^{-70}:\\
\;\;\;\;1\\
\mathbf{else}:\\
\;\;\;\;e^{\mathsf{fma}\left(c\_p, \mathsf{log1p}\left(t\_2\right) - \mathsf{log1p}\left(t\_1\right), c\_n \cdot \left(\mathsf{log1p}\left(\frac{1}{-1 - t\_1}\right) - \mathsf{log1p}\left(\frac{-1}{1 + t\_2}\right)\right)\right)}\\
\end{array}
\end{array}
if c_p < 4.9999999999999998e-70Initial program 95.4%
Taylor expanded in c_n around 0
lower-/.f64N/A
lower-pow.f64N/A
lower-/.f64N/A
lower-+.f64N/A
lower-exp.f64N/A
lower-neg.f64N/A
lower-pow.f64N/A
lower-/.f64N/A
lower-+.f64N/A
lower-exp.f64N/A
lower-neg.f6497.4
Applied rewrites97.4%
Taylor expanded in c_p around 0
Applied rewrites99.9%
if 4.9999999999999998e-70 < c_p Initial program 83.1%
lift-/.f64N/A
lift-*.f64N/A
lift-*.f64N/A
times-fracN/A
Applied rewrites97.0%
Final simplification99.2%
(FPCore (c_p c_n t s)
:precision binary64
(if (<= c_p 750000.0)
(exp
(*
c_n
(-
(log1p (/ -1.0 (+ 1.0 (exp (- s)))))
(log1p (/ -1.0 (+ 1.0 (exp (- t))))))))
(/ (pow 0.5 c_p) 1.0)))
double code(double c_p, double c_n, double t, double s) {
double tmp;
if (c_p <= 750000.0) {
tmp = exp((c_n * (log1p((-1.0 / (1.0 + exp(-s)))) - log1p((-1.0 / (1.0 + exp(-t)))))));
} else {
tmp = pow(0.5, c_p) / 1.0;
}
return tmp;
}
public static double code(double c_p, double c_n, double t, double s) {
double tmp;
if (c_p <= 750000.0) {
tmp = Math.exp((c_n * (Math.log1p((-1.0 / (1.0 + Math.exp(-s)))) - Math.log1p((-1.0 / (1.0 + Math.exp(-t)))))));
} else {
tmp = Math.pow(0.5, c_p) / 1.0;
}
return tmp;
}
def code(c_p, c_n, t, s): tmp = 0 if c_p <= 750000.0: tmp = math.exp((c_n * (math.log1p((-1.0 / (1.0 + math.exp(-s)))) - math.log1p((-1.0 / (1.0 + math.exp(-t))))))) else: tmp = math.pow(0.5, c_p) / 1.0 return tmp
function code(c_p, c_n, t, s) tmp = 0.0 if (c_p <= 750000.0) tmp = exp(Float64(c_n * Float64(log1p(Float64(-1.0 / Float64(1.0 + exp(Float64(-s))))) - log1p(Float64(-1.0 / Float64(1.0 + exp(Float64(-t)))))))); else tmp = Float64((0.5 ^ c_p) / 1.0); end return tmp end
code[c$95$p_, c$95$n_, t_, s_] := If[LessEqual[c$95$p, 750000.0], N[Exp[N[(c$95$n * N[(N[Log[1 + N[(-1.0 / N[(1.0 + N[Exp[(-s)], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]], $MachinePrecision] - N[Log[1 + N[(-1.0 / N[(1.0 + N[Exp[(-t)], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]], $MachinePrecision], N[(N[Power[0.5, c$95$p], $MachinePrecision] / 1.0), $MachinePrecision]]
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;c\_p \leq 750000:\\
\;\;\;\;e^{c\_n \cdot \left(\mathsf{log1p}\left(\frac{-1}{1 + e^{-s}}\right) - \mathsf{log1p}\left(\frac{-1}{1 + e^{-t}}\right)\right)}\\
\mathbf{else}:\\
\;\;\;\;\frac{{0.5}^{c\_p}}{1}\\
\end{array}
\end{array}
if c_p < 7.5e5Initial program 94.9%
lift-/.f64N/A
lift-*.f64N/A
lift-*.f64N/A
times-fracN/A
Applied rewrites97.7%
Taylor expanded in c_p around 0
lower-*.f64N/A
lower--.f64N/A
sub-negN/A
lower-log1p.f64N/A
distribute-neg-fracN/A
metadata-evalN/A
lower-/.f64N/A
lower-+.f64N/A
lower-exp.f64N/A
lower-neg.f64N/A
sub-negN/A
lower-log1p.f64N/A
distribute-neg-fracN/A
Applied rewrites98.4%
if 7.5e5 < c_p Initial program 0.0%
Taylor expanded in c_n around 0
lower-/.f64N/A
lower-pow.f64N/A
lower-/.f64N/A
lower-+.f64N/A
lower-exp.f64N/A
lower-neg.f64N/A
lower-pow.f64N/A
lower-/.f64N/A
lower-+.f64N/A
lower-exp.f64N/A
lower-neg.f6428.8
Applied rewrites28.8%
Taylor expanded in c_p around 0
Applied rewrites86.2%
Taylor expanded in s around 0
Applied rewrites100.0%
(FPCore (c_p c_n t s) :precision binary64 (if (<= c_p 750000.0) 1.0 (/ (pow 0.5 c_p) 1.0)))
double code(double c_p, double c_n, double t, double s) {
double tmp;
if (c_p <= 750000.0) {
tmp = 1.0;
} else {
tmp = pow(0.5, c_p) / 1.0;
}
return tmp;
}
real(8) function code(c_p, c_n, t, s)
real(8), intent (in) :: c_p
real(8), intent (in) :: c_n
real(8), intent (in) :: t
real(8), intent (in) :: s
real(8) :: tmp
if (c_p <= 750000.0d0) then
tmp = 1.0d0
else
tmp = (0.5d0 ** c_p) / 1.0d0
end if
code = tmp
end function
public static double code(double c_p, double c_n, double t, double s) {
double tmp;
if (c_p <= 750000.0) {
tmp = 1.0;
} else {
tmp = Math.pow(0.5, c_p) / 1.0;
}
return tmp;
}
def code(c_p, c_n, t, s): tmp = 0 if c_p <= 750000.0: tmp = 1.0 else: tmp = math.pow(0.5, c_p) / 1.0 return tmp
function code(c_p, c_n, t, s) tmp = 0.0 if (c_p <= 750000.0) tmp = 1.0; else tmp = Float64((0.5 ^ c_p) / 1.0); end return tmp end
function tmp_2 = code(c_p, c_n, t, s) tmp = 0.0; if (c_p <= 750000.0) tmp = 1.0; else tmp = (0.5 ^ c_p) / 1.0; end tmp_2 = tmp; end
code[c$95$p_, c$95$n_, t_, s_] := If[LessEqual[c$95$p, 750000.0], 1.0, N[(N[Power[0.5, c$95$p], $MachinePrecision] / 1.0), $MachinePrecision]]
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;c\_p \leq 750000:\\
\;\;\;\;1\\
\mathbf{else}:\\
\;\;\;\;\frac{{0.5}^{c\_p}}{1}\\
\end{array}
\end{array}
if c_p < 7.5e5Initial program 94.9%
Taylor expanded in c_n around 0
lower-/.f64N/A
lower-pow.f64N/A
lower-/.f64N/A
lower-+.f64N/A
lower-exp.f64N/A
lower-neg.f64N/A
lower-pow.f64N/A
lower-/.f64N/A
lower-+.f64N/A
lower-exp.f64N/A
lower-neg.f6496.4
Applied rewrites96.4%
Taylor expanded in c_p around 0
Applied rewrites98.4%
if 7.5e5 < c_p Initial program 0.0%
Taylor expanded in c_n around 0
lower-/.f64N/A
lower-pow.f64N/A
lower-/.f64N/A
lower-+.f64N/A
lower-exp.f64N/A
lower-neg.f64N/A
lower-pow.f64N/A
lower-/.f64N/A
lower-+.f64N/A
lower-exp.f64N/A
lower-neg.f6428.8
Applied rewrites28.8%
Taylor expanded in c_p around 0
Applied rewrites86.2%
Taylor expanded in s around 0
Applied rewrites100.0%
(FPCore (c_p c_n t s) :precision binary64 1.0)
double code(double c_p, double c_n, double t, double s) {
return 1.0;
}
real(8) function code(c_p, c_n, t, s)
real(8), intent (in) :: c_p
real(8), intent (in) :: c_n
real(8), intent (in) :: t
real(8), intent (in) :: s
code = 1.0d0
end function
public static double code(double c_p, double c_n, double t, double s) {
return 1.0;
}
def code(c_p, c_n, t, s): return 1.0
function code(c_p, c_n, t, s) return 1.0 end
function tmp = code(c_p, c_n, t, s) tmp = 1.0; end
code[c$95$p_, c$95$n_, t_, s_] := 1.0
\begin{array}{l}
\\
1
\end{array}
Initial program 92.3%
Taylor expanded in c_n around 0
lower-/.f64N/A
lower-pow.f64N/A
lower-/.f64N/A
lower-+.f64N/A
lower-exp.f64N/A
lower-neg.f64N/A
lower-pow.f64N/A
lower-/.f64N/A
lower-+.f64N/A
lower-exp.f64N/A
lower-neg.f6494.5
Applied rewrites94.5%
Taylor expanded in c_p around 0
Applied rewrites95.8%
(FPCore (c_p c_n t s) :precision binary64 (* (pow (/ (+ 1.0 (exp (- t))) (+ 1.0 (exp (- s)))) c_p) (pow (/ (+ 1.0 (exp t)) (+ 1.0 (exp s))) c_n)))
double code(double c_p, double c_n, double t, double s) {
return pow(((1.0 + exp(-t)) / (1.0 + exp(-s))), c_p) * pow(((1.0 + exp(t)) / (1.0 + exp(s))), c_n);
}
real(8) function code(c_p, c_n, t, s)
real(8), intent (in) :: c_p
real(8), intent (in) :: c_n
real(8), intent (in) :: t
real(8), intent (in) :: s
code = (((1.0d0 + exp(-t)) / (1.0d0 + exp(-s))) ** c_p) * (((1.0d0 + exp(t)) / (1.0d0 + exp(s))) ** c_n)
end function
public static double code(double c_p, double c_n, double t, double s) {
return Math.pow(((1.0 + Math.exp(-t)) / (1.0 + Math.exp(-s))), c_p) * Math.pow(((1.0 + Math.exp(t)) / (1.0 + Math.exp(s))), c_n);
}
def code(c_p, c_n, t, s): return math.pow(((1.0 + math.exp(-t)) / (1.0 + math.exp(-s))), c_p) * math.pow(((1.0 + math.exp(t)) / (1.0 + math.exp(s))), c_n)
function code(c_p, c_n, t, s) return Float64((Float64(Float64(1.0 + exp(Float64(-t))) / Float64(1.0 + exp(Float64(-s)))) ^ c_p) * (Float64(Float64(1.0 + exp(t)) / Float64(1.0 + exp(s))) ^ c_n)) end
function tmp = code(c_p, c_n, t, s) tmp = (((1.0 + exp(-t)) / (1.0 + exp(-s))) ^ c_p) * (((1.0 + exp(t)) / (1.0 + exp(s))) ^ c_n); end
code[c$95$p_, c$95$n_, t_, s_] := N[(N[Power[N[(N[(1.0 + N[Exp[(-t)], $MachinePrecision]), $MachinePrecision] / N[(1.0 + N[Exp[(-s)], $MachinePrecision]), $MachinePrecision]), $MachinePrecision], c$95$p], $MachinePrecision] * N[Power[N[(N[(1.0 + N[Exp[t], $MachinePrecision]), $MachinePrecision] / N[(1.0 + N[Exp[s], $MachinePrecision]), $MachinePrecision]), $MachinePrecision], c$95$n], $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
{\left(\frac{1 + e^{-t}}{1 + e^{-s}}\right)}^{c\_p} \cdot {\left(\frac{1 + e^{t}}{1 + e^{s}}\right)}^{c\_n}
\end{array}
herbie shell --seed 2024231
(FPCore (c_p c_n t s)
:name "Harley's example"
:precision binary64
:pre (and (< 0.0 c_p) (< 0.0 c_n))
:alt
(! :herbie-platform default (* (pow (/ (+ 1 (exp (- t))) (+ 1 (exp (- s)))) c_p) (pow (/ (+ 1 (exp t)) (+ 1 (exp s))) c_n)))
(/ (* (pow (/ 1.0 (+ 1.0 (exp (- s)))) c_p) (pow (- 1.0 (/ 1.0 (+ 1.0 (exp (- s))))) c_n)) (* (pow (/ 1.0 (+ 1.0 (exp (- t)))) c_p) (pow (- 1.0 (/ 1.0 (+ 1.0 (exp (- t))))) c_n))))