
(FPCore (a b eps) :precision binary64 (/ (* eps (- (exp (* (+ a b) eps)) 1.0)) (* (- (exp (* a eps)) 1.0) (- (exp (* b eps)) 1.0))))
double code(double a, double b, double eps) {
return (eps * (exp(((a + b) * eps)) - 1.0)) / ((exp((a * eps)) - 1.0) * (exp((b * eps)) - 1.0));
}
real(8) function code(a, b, eps)
real(8), intent (in) :: a
real(8), intent (in) :: b
real(8), intent (in) :: eps
code = (eps * (exp(((a + b) * eps)) - 1.0d0)) / ((exp((a * eps)) - 1.0d0) * (exp((b * eps)) - 1.0d0))
end function
public static double code(double a, double b, double eps) {
return (eps * (Math.exp(((a + b) * eps)) - 1.0)) / ((Math.exp((a * eps)) - 1.0) * (Math.exp((b * eps)) - 1.0));
}
def code(a, b, eps): return (eps * (math.exp(((a + b) * eps)) - 1.0)) / ((math.exp((a * eps)) - 1.0) * (math.exp((b * eps)) - 1.0))
function code(a, b, eps) return Float64(Float64(eps * Float64(exp(Float64(Float64(a + b) * eps)) - 1.0)) / Float64(Float64(exp(Float64(a * eps)) - 1.0) * Float64(exp(Float64(b * eps)) - 1.0))) end
function tmp = code(a, b, eps) tmp = (eps * (exp(((a + b) * eps)) - 1.0)) / ((exp((a * eps)) - 1.0) * (exp((b * eps)) - 1.0)); end
code[a_, b_, eps_] := N[(N[(eps * N[(N[Exp[N[(N[(a + b), $MachinePrecision] * eps), $MachinePrecision]], $MachinePrecision] - 1.0), $MachinePrecision]), $MachinePrecision] / N[(N[(N[Exp[N[(a * eps), $MachinePrecision]], $MachinePrecision] - 1.0), $MachinePrecision] * N[(N[Exp[N[(b * eps), $MachinePrecision]], $MachinePrecision] - 1.0), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\frac{\varepsilon \cdot \left(e^{\left(a + b\right) \cdot \varepsilon} - 1\right)}{\left(e^{a \cdot \varepsilon} - 1\right) \cdot \left(e^{b \cdot \varepsilon} - 1\right)}
\end{array}
Sampling outcomes in binary64 precision:
Herbie found 5 alternatives:
| Alternative | Accuracy | Speedup |
|---|
(FPCore (a b eps) :precision binary64 (/ (* eps (- (exp (* (+ a b) eps)) 1.0)) (* (- (exp (* a eps)) 1.0) (- (exp (* b eps)) 1.0))))
double code(double a, double b, double eps) {
return (eps * (exp(((a + b) * eps)) - 1.0)) / ((exp((a * eps)) - 1.0) * (exp((b * eps)) - 1.0));
}
real(8) function code(a, b, eps)
real(8), intent (in) :: a
real(8), intent (in) :: b
real(8), intent (in) :: eps
code = (eps * (exp(((a + b) * eps)) - 1.0d0)) / ((exp((a * eps)) - 1.0d0) * (exp((b * eps)) - 1.0d0))
end function
public static double code(double a, double b, double eps) {
return (eps * (Math.exp(((a + b) * eps)) - 1.0)) / ((Math.exp((a * eps)) - 1.0) * (Math.exp((b * eps)) - 1.0));
}
def code(a, b, eps): return (eps * (math.exp(((a + b) * eps)) - 1.0)) / ((math.exp((a * eps)) - 1.0) * (math.exp((b * eps)) - 1.0))
function code(a, b, eps) return Float64(Float64(eps * Float64(exp(Float64(Float64(a + b) * eps)) - 1.0)) / Float64(Float64(exp(Float64(a * eps)) - 1.0) * Float64(exp(Float64(b * eps)) - 1.0))) end
function tmp = code(a, b, eps) tmp = (eps * (exp(((a + b) * eps)) - 1.0)) / ((exp((a * eps)) - 1.0) * (exp((b * eps)) - 1.0)); end
code[a_, b_, eps_] := N[(N[(eps * N[(N[Exp[N[(N[(a + b), $MachinePrecision] * eps), $MachinePrecision]], $MachinePrecision] - 1.0), $MachinePrecision]), $MachinePrecision] / N[(N[(N[Exp[N[(a * eps), $MachinePrecision]], $MachinePrecision] - 1.0), $MachinePrecision] * N[(N[Exp[N[(b * eps), $MachinePrecision]], $MachinePrecision] - 1.0), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\frac{\varepsilon \cdot \left(e^{\left(a + b\right) \cdot \varepsilon} - 1\right)}{\left(e^{a \cdot \varepsilon} - 1\right) \cdot \left(e^{b \cdot \varepsilon} - 1\right)}
\end{array}
(FPCore (a b eps) :precision binary64 (+ (/ 1.0 b) (/ 1.0 a)))
double code(double a, double b, double eps) {
return (1.0 / b) + (1.0 / a);
}
real(8) function code(a, b, eps)
real(8), intent (in) :: a
real(8), intent (in) :: b
real(8), intent (in) :: eps
code = (1.0d0 / b) + (1.0d0 / a)
end function
public static double code(double a, double b, double eps) {
return (1.0 / b) + (1.0 / a);
}
def code(a, b, eps): return (1.0 / b) + (1.0 / a)
function code(a, b, eps) return Float64(Float64(1.0 / b) + Float64(1.0 / a)) end
function tmp = code(a, b, eps) tmp = (1.0 / b) + (1.0 / a); end
code[a_, b_, eps_] := N[(N[(1.0 / b), $MachinePrecision] + N[(1.0 / a), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\frac{1}{b} + \frac{1}{a}
\end{array}
Initial program 0.0%
Taylor expanded in eps around 0
/-lowering-/.f64N/A
+-commutativeN/A
+-lowering-+.f64N/A
*-commutativeN/A
*-lowering-*.f6459.4
Simplified59.4%
+-commutativeN/A
*-rgt-identityN/A
*-commutativeN/A
*-lft-identityN/A
*-commutativeN/A
frac-addN/A
+-lowering-+.f64N/A
/-lowering-/.f64N/A
/-lowering-/.f64100.0
Applied egg-rr100.0%
(FPCore (a b eps)
:precision binary64
(if (<= b 2.05e-190)
(/ 1.0 b)
(if (<= b 1.7e-148)
(/ 1.0 a)
(if (<= b 5.8e-117) (* (/ 1.0 (* b a)) (+ b a)) (/ 1.0 a)))))
double code(double a, double b, double eps) {
double tmp;
if (b <= 2.05e-190) {
tmp = 1.0 / b;
} else if (b <= 1.7e-148) {
tmp = 1.0 / a;
} else if (b <= 5.8e-117) {
tmp = (1.0 / (b * a)) * (b + a);
} else {
tmp = 1.0 / a;
}
return tmp;
}
real(8) function code(a, b, eps)
real(8), intent (in) :: a
real(8), intent (in) :: b
real(8), intent (in) :: eps
real(8) :: tmp
if (b <= 2.05d-190) then
tmp = 1.0d0 / b
else if (b <= 1.7d-148) then
tmp = 1.0d0 / a
else if (b <= 5.8d-117) then
tmp = (1.0d0 / (b * a)) * (b + a)
else
tmp = 1.0d0 / a
end if
code = tmp
end function
public static double code(double a, double b, double eps) {
double tmp;
if (b <= 2.05e-190) {
tmp = 1.0 / b;
} else if (b <= 1.7e-148) {
tmp = 1.0 / a;
} else if (b <= 5.8e-117) {
tmp = (1.0 / (b * a)) * (b + a);
} else {
tmp = 1.0 / a;
}
return tmp;
}
def code(a, b, eps): tmp = 0 if b <= 2.05e-190: tmp = 1.0 / b elif b <= 1.7e-148: tmp = 1.0 / a elif b <= 5.8e-117: tmp = (1.0 / (b * a)) * (b + a) else: tmp = 1.0 / a return tmp
function code(a, b, eps) tmp = 0.0 if (b <= 2.05e-190) tmp = Float64(1.0 / b); elseif (b <= 1.7e-148) tmp = Float64(1.0 / a); elseif (b <= 5.8e-117) tmp = Float64(Float64(1.0 / Float64(b * a)) * Float64(b + a)); else tmp = Float64(1.0 / a); end return tmp end
function tmp_2 = code(a, b, eps) tmp = 0.0; if (b <= 2.05e-190) tmp = 1.0 / b; elseif (b <= 1.7e-148) tmp = 1.0 / a; elseif (b <= 5.8e-117) tmp = (1.0 / (b * a)) * (b + a); else tmp = 1.0 / a; end tmp_2 = tmp; end
code[a_, b_, eps_] := If[LessEqual[b, 2.05e-190], N[(1.0 / b), $MachinePrecision], If[LessEqual[b, 1.7e-148], N[(1.0 / a), $MachinePrecision], If[LessEqual[b, 5.8e-117], N[(N[(1.0 / N[(b * a), $MachinePrecision]), $MachinePrecision] * N[(b + a), $MachinePrecision]), $MachinePrecision], N[(1.0 / a), $MachinePrecision]]]]
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;b \leq 2.05 \cdot 10^{-190}:\\
\;\;\;\;\frac{1}{b}\\
\mathbf{elif}\;b \leq 1.7 \cdot 10^{-148}:\\
\;\;\;\;\frac{1}{a}\\
\mathbf{elif}\;b \leq 5.8 \cdot 10^{-117}:\\
\;\;\;\;\frac{1}{b \cdot a} \cdot \left(b + a\right)\\
\mathbf{else}:\\
\;\;\;\;\frac{1}{a}\\
\end{array}
\end{array}
if b < 2.0500000000000001e-190Initial program 0.0%
Taylor expanded in b around 0
/-lowering-/.f6464.3
Simplified64.3%
if 2.0500000000000001e-190 < b < 1.7000000000000001e-148 or 5.8000000000000001e-117 < b Initial program 0.0%
Taylor expanded in a around 0
/-lowering-/.f6475.5
Simplified75.5%
if 1.7000000000000001e-148 < b < 5.8000000000000001e-117Initial program 0.0%
Taylor expanded in eps around 0
/-lowering-/.f64N/A
+-commutativeN/A
+-lowering-+.f64N/A
*-commutativeN/A
*-lowering-*.f6479.0
Simplified79.0%
clear-numN/A
associate-/r/N/A
*-lowering-*.f64N/A
/-lowering-/.f64N/A
*-lowering-*.f64N/A
+-lowering-+.f6479.0
Applied egg-rr79.0%
(FPCore (a b eps)
:precision binary64
(if (<= b 8e-190)
(/ 1.0 b)
(if (<= b 1.8e-148)
(/ 1.0 a)
(if (<= b 1.6e-116) (/ (+ b a) (* b a)) (/ 1.0 a)))))
double code(double a, double b, double eps) {
double tmp;
if (b <= 8e-190) {
tmp = 1.0 / b;
} else if (b <= 1.8e-148) {
tmp = 1.0 / a;
} else if (b <= 1.6e-116) {
tmp = (b + a) / (b * a);
} else {
tmp = 1.0 / a;
}
return tmp;
}
real(8) function code(a, b, eps)
real(8), intent (in) :: a
real(8), intent (in) :: b
real(8), intent (in) :: eps
real(8) :: tmp
if (b <= 8d-190) then
tmp = 1.0d0 / b
else if (b <= 1.8d-148) then
tmp = 1.0d0 / a
else if (b <= 1.6d-116) then
tmp = (b + a) / (b * a)
else
tmp = 1.0d0 / a
end if
code = tmp
end function
public static double code(double a, double b, double eps) {
double tmp;
if (b <= 8e-190) {
tmp = 1.0 / b;
} else if (b <= 1.8e-148) {
tmp = 1.0 / a;
} else if (b <= 1.6e-116) {
tmp = (b + a) / (b * a);
} else {
tmp = 1.0 / a;
}
return tmp;
}
def code(a, b, eps): tmp = 0 if b <= 8e-190: tmp = 1.0 / b elif b <= 1.8e-148: tmp = 1.0 / a elif b <= 1.6e-116: tmp = (b + a) / (b * a) else: tmp = 1.0 / a return tmp
function code(a, b, eps) tmp = 0.0 if (b <= 8e-190) tmp = Float64(1.0 / b); elseif (b <= 1.8e-148) tmp = Float64(1.0 / a); elseif (b <= 1.6e-116) tmp = Float64(Float64(b + a) / Float64(b * a)); else tmp = Float64(1.0 / a); end return tmp end
function tmp_2 = code(a, b, eps) tmp = 0.0; if (b <= 8e-190) tmp = 1.0 / b; elseif (b <= 1.8e-148) tmp = 1.0 / a; elseif (b <= 1.6e-116) tmp = (b + a) / (b * a); else tmp = 1.0 / a; end tmp_2 = tmp; end
code[a_, b_, eps_] := If[LessEqual[b, 8e-190], N[(1.0 / b), $MachinePrecision], If[LessEqual[b, 1.8e-148], N[(1.0 / a), $MachinePrecision], If[LessEqual[b, 1.6e-116], N[(N[(b + a), $MachinePrecision] / N[(b * a), $MachinePrecision]), $MachinePrecision], N[(1.0 / a), $MachinePrecision]]]]
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;b \leq 8 \cdot 10^{-190}:\\
\;\;\;\;\frac{1}{b}\\
\mathbf{elif}\;b \leq 1.8 \cdot 10^{-148}:\\
\;\;\;\;\frac{1}{a}\\
\mathbf{elif}\;b \leq 1.6 \cdot 10^{-116}:\\
\;\;\;\;\frac{b + a}{b \cdot a}\\
\mathbf{else}:\\
\;\;\;\;\frac{1}{a}\\
\end{array}
\end{array}
if b < 8.0000000000000002e-190Initial program 0.0%
Taylor expanded in b around 0
/-lowering-/.f6464.3
Simplified64.3%
if 8.0000000000000002e-190 < b < 1.7999999999999999e-148 or 1.60000000000000005e-116 < b Initial program 0.0%
Taylor expanded in a around 0
/-lowering-/.f6475.5
Simplified75.5%
if 1.7999999999999999e-148 < b < 1.60000000000000005e-116Initial program 0.0%
Taylor expanded in eps around 0
/-lowering-/.f64N/A
+-commutativeN/A
+-lowering-+.f64N/A
*-commutativeN/A
*-lowering-*.f6479.0
Simplified79.0%
(FPCore (a b eps) :precision binary64 (if (<= b 8e-190) (/ 1.0 b) (/ 1.0 a)))
double code(double a, double b, double eps) {
double tmp;
if (b <= 8e-190) {
tmp = 1.0 / b;
} else {
tmp = 1.0 / a;
}
return tmp;
}
real(8) function code(a, b, eps)
real(8), intent (in) :: a
real(8), intent (in) :: b
real(8), intent (in) :: eps
real(8) :: tmp
if (b <= 8d-190) then
tmp = 1.0d0 / b
else
tmp = 1.0d0 / a
end if
code = tmp
end function
public static double code(double a, double b, double eps) {
double tmp;
if (b <= 8e-190) {
tmp = 1.0 / b;
} else {
tmp = 1.0 / a;
}
return tmp;
}
def code(a, b, eps): tmp = 0 if b <= 8e-190: tmp = 1.0 / b else: tmp = 1.0 / a return tmp
function code(a, b, eps) tmp = 0.0 if (b <= 8e-190) tmp = Float64(1.0 / b); else tmp = Float64(1.0 / a); end return tmp end
function tmp_2 = code(a, b, eps) tmp = 0.0; if (b <= 8e-190) tmp = 1.0 / b; else tmp = 1.0 / a; end tmp_2 = tmp; end
code[a_, b_, eps_] := If[LessEqual[b, 8e-190], N[(1.0 / b), $MachinePrecision], N[(1.0 / a), $MachinePrecision]]
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;b \leq 8 \cdot 10^{-190}:\\
\;\;\;\;\frac{1}{b}\\
\mathbf{else}:\\
\;\;\;\;\frac{1}{a}\\
\end{array}
\end{array}
if b < 8.0000000000000002e-190Initial program 0.0%
Taylor expanded in b around 0
/-lowering-/.f6464.3
Simplified64.3%
if 8.0000000000000002e-190 < b Initial program 0.0%
Taylor expanded in a around 0
/-lowering-/.f6470.2
Simplified70.2%
(FPCore (a b eps) :precision binary64 (/ 1.0 a))
double code(double a, double b, double eps) {
return 1.0 / a;
}
real(8) function code(a, b, eps)
real(8), intent (in) :: a
real(8), intent (in) :: b
real(8), intent (in) :: eps
code = 1.0d0 / a
end function
public static double code(double a, double b, double eps) {
return 1.0 / a;
}
def code(a, b, eps): return 1.0 / a
function code(a, b, eps) return Float64(1.0 / a) end
function tmp = code(a, b, eps) tmp = 1.0 / a; end
code[a_, b_, eps_] := N[(1.0 / a), $MachinePrecision]
\begin{array}{l}
\\
\frac{1}{a}
\end{array}
Initial program 0.0%
Taylor expanded in a around 0
/-lowering-/.f6446.4
Simplified46.4%
(FPCore (a b eps) :precision binary64 (+ (/ 1.0 a) (/ 1.0 b)))
double code(double a, double b, double eps) {
return (1.0 / a) + (1.0 / b);
}
real(8) function code(a, b, eps)
real(8), intent (in) :: a
real(8), intent (in) :: b
real(8), intent (in) :: eps
code = (1.0d0 / a) + (1.0d0 / b)
end function
public static double code(double a, double b, double eps) {
return (1.0 / a) + (1.0 / b);
}
def code(a, b, eps): return (1.0 / a) + (1.0 / b)
function code(a, b, eps) return Float64(Float64(1.0 / a) + Float64(1.0 / b)) end
function tmp = code(a, b, eps) tmp = (1.0 / a) + (1.0 / b); end
code[a_, b_, eps_] := N[(N[(1.0 / a), $MachinePrecision] + N[(1.0 / b), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\frac{1}{a} + \frac{1}{b}
\end{array}
herbie shell --seed 2024194
(FPCore (a b eps)
:name "expq3 (problem 3.4.2)"
:precision binary64
:pre (and (and (<= (fabs a) 710.0) (<= (fabs b) 710.0)) (and (<= (* 1e-27 (fmin (fabs a) (fabs b))) eps) (<= eps (fmin (fabs a) (fabs b)))))
:alt
(! :herbie-platform default (+ (/ 1 a) (/ 1 b)))
(/ (* eps (- (exp (* (+ a b) eps)) 1.0)) (* (- (exp (* a eps)) 1.0) (- (exp (* b eps)) 1.0))))