
(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 3 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 (/ 1.0 (pow (/ (+ 1.0 (exp (- s))) 2.0) c_p)))
double code(double c_p, double c_n, double t, double s) {
return 1.0 / pow(((1.0 + exp(-s)) / 2.0), c_p);
}
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 / (((1.0d0 + exp(-s)) / 2.0d0) ** c_p)
end function
public static double code(double c_p, double c_n, double t, double s) {
return 1.0 / Math.pow(((1.0 + Math.exp(-s)) / 2.0), c_p);
}
def code(c_p, c_n, t, s): return 1.0 / math.pow(((1.0 + math.exp(-s)) / 2.0), c_p)
function code(c_p, c_n, t, s) return Float64(1.0 / (Float64(Float64(1.0 + exp(Float64(-s))) / 2.0) ^ c_p)) end
function tmp = code(c_p, c_n, t, s) tmp = 1.0 / (((1.0 + exp(-s)) / 2.0) ^ c_p); end
code[c$95$p_, c$95$n_, t_, s_] := N[(1.0 / N[Power[N[(N[(1.0 + N[Exp[(-s)], $MachinePrecision]), $MachinePrecision] / 2.0), $MachinePrecision], c$95$p], $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\frac{1}{{\left(\frac{1 + e^{-s}}{2}\right)}^{c\_p}}
\end{array}
Initial program 91.5%
associate-/l*91.5%
Simplified91.5%
Taylor expanded in c_n around 0 94.0%
div-inv94.0%
inv-pow94.0%
pow-pow94.0%
pow-flip94.0%
Applied egg-rr94.0%
neg-mul-194.0%
Simplified94.0%
pow-prod-down97.5%
pow-neg97.5%
add-exp-log97.5%
add-exp-log97.5%
prod-exp97.5%
log1p-define97.5%
log-rec97.5%
log1p-define97.5%
Applied egg-rr97.5%
log1p-define97.5%
log1p-undefine97.5%
log-rec97.5%
exp-sum97.5%
rem-exp-log97.5%
rem-exp-log97.5%
associate-*r/97.5%
*-commutative97.5%
*-lft-identity97.5%
Simplified97.5%
Taylor expanded in t around 0 97.6%
Final simplification97.6%
(FPCore (c_p c_n t s) :precision binary64 (+ 1.0 (* -0.5 (* c_p t))))
double code(double c_p, double c_n, double t, double s) {
return 1.0 + (-0.5 * (c_p * t));
}
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 + ((-0.5d0) * (c_p * t))
end function
public static double code(double c_p, double c_n, double t, double s) {
return 1.0 + (-0.5 * (c_p * t));
}
def code(c_p, c_n, t, s): return 1.0 + (-0.5 * (c_p * t))
function code(c_p, c_n, t, s) return Float64(1.0 + Float64(-0.5 * Float64(c_p * t))) end
function tmp = code(c_p, c_n, t, s) tmp = 1.0 + (-0.5 * (c_p * t)); end
code[c$95$p_, c$95$n_, t_, s_] := N[(1.0 + N[(-0.5 * N[(c$95$p * t), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
1 + -0.5 \cdot \left(c\_p \cdot t\right)
\end{array}
Initial program 91.5%
associate-/l*91.5%
Simplified91.5%
Taylor expanded in c_n around 0 94.0%
Taylor expanded in s around 0 92.1%
Taylor expanded in t around 0 95.0%
*-commutative95.0%
Simplified95.0%
Final simplification95.0%
(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 91.5%
associate-/l*91.5%
Simplified91.5%
Taylor expanded in c_n around 0 94.0%
Taylor expanded in c_p around 0 94.9%
Final simplification94.9%
(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 2024046
(FPCore (c_p c_n t s)
:name "Harley's example"
:precision binary64
:pre (and (< 0.0 c_p) (< 0.0 c_n))
:herbie-target
(* (pow (/ (+ 1.0 (exp (- t))) (+ 1.0 (exp (- s)))) c_p) (pow (/ (+ 1.0 (exp t)) (+ 1.0 (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))))