
(FPCore (a b) :precision binary64 (- (* a a) (* b b)))
double code(double a, double b) {
return (a * a) - (b * b);
}
real(8) function code(a, b)
real(8), intent (in) :: a
real(8), intent (in) :: b
code = (a * a) - (b * b)
end function
public static double code(double a, double b) {
return (a * a) - (b * b);
}
def code(a, b): return (a * a) - (b * b)
function code(a, b) return Float64(Float64(a * a) - Float64(b * b)) end
function tmp = code(a, b) tmp = (a * a) - (b * b); end
code[a_, b_] := N[(N[(a * a), $MachinePrecision] - N[(b * b), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
a \cdot a - b \cdot b
\end{array}
Sampling outcomes in binary64 precision:
Herbie found 4 alternatives:
| Alternative | Accuracy | Speedup |
|---|
(FPCore (a b) :precision binary64 (- (* a a) (* b b)))
double code(double a, double b) {
return (a * a) - (b * b);
}
real(8) function code(a, b)
real(8), intent (in) :: a
real(8), intent (in) :: b
code = (a * a) - (b * b)
end function
public static double code(double a, double b) {
return (a * a) - (b * b);
}
def code(a, b): return (a * a) - (b * b)
function code(a, b) return Float64(Float64(a * a) - Float64(b * b)) end
function tmp = code(a, b) tmp = (a * a) - (b * b); end
code[a_, b_] := N[(N[(a * a), $MachinePrecision] - N[(b * b), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
a \cdot a - b \cdot b
\end{array}
(FPCore (a b) :precision binary64 (* (- a b) (+ a b)))
double code(double a, double b) {
return (a - b) * (a + b);
}
real(8) function code(a, b)
real(8), intent (in) :: a
real(8), intent (in) :: b
code = (a - b) * (a + b)
end function
public static double code(double a, double b) {
return (a - b) * (a + b);
}
def code(a, b): return (a - b) * (a + b)
function code(a, b) return Float64(Float64(a - b) * Float64(a + b)) end
function tmp = code(a, b) tmp = (a - b) * (a + b); end
code[a_, b_] := N[(N[(a - b), $MachinePrecision] * N[(a + b), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\left(a - b\right) \cdot \left(a + b\right)
\end{array}
Initial program 94.1%
difference-of-squares100.0%
sub-neg100.0%
add-sqr-sqrt48.3%
sqrt-unprod75.5%
sqr-neg75.5%
sqrt-prod28.2%
add-sqr-sqrt55.2%
Applied egg-rr55.2%
add-sqr-sqrt28.2%
sqrt-prod75.5%
add-sqr-sqrt28.2%
add-sqr-sqrt28.2%
sqr-neg28.2%
swap-sqr28.2%
sqrt-unprod0.0%
add-sqr-sqrt51.4%
distribute-rgt-neg-out51.4%
add-sqr-sqrt100.0%
sub-neg100.0%
Applied egg-rr100.0%
(FPCore (a b)
:precision binary64
(if (<= (* b b) 2e-185)
(* a a)
(if (<= (* b b) 2e-133)
(* b (- b))
(if (<= (* b b) 2e-61) (* a a) (* b (- a b))))))
double code(double a, double b) {
double tmp;
if ((b * b) <= 2e-185) {
tmp = a * a;
} else if ((b * b) <= 2e-133) {
tmp = b * -b;
} else if ((b * b) <= 2e-61) {
tmp = a * a;
} else {
tmp = b * (a - b);
}
return tmp;
}
real(8) function code(a, b)
real(8), intent (in) :: a
real(8), intent (in) :: b
real(8) :: tmp
if ((b * b) <= 2d-185) then
tmp = a * a
else if ((b * b) <= 2d-133) then
tmp = b * -b
else if ((b * b) <= 2d-61) then
tmp = a * a
else
tmp = b * (a - b)
end if
code = tmp
end function
public static double code(double a, double b) {
double tmp;
if ((b * b) <= 2e-185) {
tmp = a * a;
} else if ((b * b) <= 2e-133) {
tmp = b * -b;
} else if ((b * b) <= 2e-61) {
tmp = a * a;
} else {
tmp = b * (a - b);
}
return tmp;
}
def code(a, b): tmp = 0 if (b * b) <= 2e-185: tmp = a * a elif (b * b) <= 2e-133: tmp = b * -b elif (b * b) <= 2e-61: tmp = a * a else: tmp = b * (a - b) return tmp
function code(a, b) tmp = 0.0 if (Float64(b * b) <= 2e-185) tmp = Float64(a * a); elseif (Float64(b * b) <= 2e-133) tmp = Float64(b * Float64(-b)); elseif (Float64(b * b) <= 2e-61) tmp = Float64(a * a); else tmp = Float64(b * Float64(a - b)); end return tmp end
function tmp_2 = code(a, b) tmp = 0.0; if ((b * b) <= 2e-185) tmp = a * a; elseif ((b * b) <= 2e-133) tmp = b * -b; elseif ((b * b) <= 2e-61) tmp = a * a; else tmp = b * (a - b); end tmp_2 = tmp; end
code[a_, b_] := If[LessEqual[N[(b * b), $MachinePrecision], 2e-185], N[(a * a), $MachinePrecision], If[LessEqual[N[(b * b), $MachinePrecision], 2e-133], N[(b * (-b)), $MachinePrecision], If[LessEqual[N[(b * b), $MachinePrecision], 2e-61], N[(a * a), $MachinePrecision], N[(b * N[(a - b), $MachinePrecision]), $MachinePrecision]]]]
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;b \cdot b \leq 2 \cdot 10^{-185}:\\
\;\;\;\;a \cdot a\\
\mathbf{elif}\;b \cdot b \leq 2 \cdot 10^{-133}:\\
\;\;\;\;b \cdot \left(-b\right)\\
\mathbf{elif}\;b \cdot b \leq 2 \cdot 10^{-61}:\\
\;\;\;\;a \cdot a\\
\mathbf{else}:\\
\;\;\;\;b \cdot \left(a - b\right)\\
\end{array}
\end{array}
if (*.f64 b b) < 2e-185 or 2.0000000000000001e-133 < (*.f64 b b) < 2.0000000000000001e-61Initial program 100.0%
difference-of-squares100.0%
sub-neg100.0%
add-sqr-sqrt45.1%
sqrt-unprod93.7%
sqr-neg93.7%
sqrt-prod48.6%
add-sqr-sqrt91.2%
Applied egg-rr91.2%
Taylor expanded in a around inf 91.4%
Taylor expanded in a around inf 91.9%
if 2e-185 < (*.f64 b b) < 2.0000000000000001e-133Initial program 99.9%
difference-of-squares100.0%
sub-neg100.0%
add-sqr-sqrt43.4%
sqrt-unprod57.7%
sqr-neg57.7%
sqrt-prod13.9%
add-sqr-sqrt27.4%
Applied egg-rr27.4%
add-sqr-sqrt13.9%
sqrt-prod57.7%
add-sqr-sqrt13.9%
add-sqr-sqrt13.9%
sqr-neg13.9%
swap-sqr13.9%
sqrt-unprod0.0%
add-sqr-sqrt55.8%
distribute-rgt-neg-out55.8%
add-sqr-sqrt100.0%
sub-neg100.0%
Applied egg-rr100.0%
Taylor expanded in a around 0 72.5%
Taylor expanded in a around 0 74.2%
neg-mul-174.2%
Simplified74.2%
if 2.0000000000000001e-61 < (*.f64 b b) Initial program 88.2%
difference-of-squares100.0%
sub-neg100.0%
add-sqr-sqrt51.8%
sqrt-unprod61.5%
sqr-neg61.5%
sqrt-prod11.9%
add-sqr-sqrt26.8%
Applied egg-rr26.8%
add-sqr-sqrt11.9%
sqrt-prod61.5%
add-sqr-sqrt11.9%
add-sqr-sqrt11.9%
sqr-neg11.9%
swap-sqr11.9%
sqrt-unprod0.0%
add-sqr-sqrt47.9%
distribute-rgt-neg-out47.9%
add-sqr-sqrt100.0%
sub-neg100.0%
Applied egg-rr100.0%
Taylor expanded in a around 0 78.8%
Final simplification84.3%
(FPCore (a b)
:precision binary64
(if (or (<= (* a a) 6e-72)
(and (not (<= (* a a) 1.5e+61)) (<= (* a a) 1e+167)))
(* b (- b))
(* a a)))
double code(double a, double b) {
double tmp;
if (((a * a) <= 6e-72) || (!((a * a) <= 1.5e+61) && ((a * a) <= 1e+167))) {
tmp = b * -b;
} else {
tmp = a * a;
}
return tmp;
}
real(8) function code(a, b)
real(8), intent (in) :: a
real(8), intent (in) :: b
real(8) :: tmp
if (((a * a) <= 6d-72) .or. (.not. ((a * a) <= 1.5d+61)) .and. ((a * a) <= 1d+167)) then
tmp = b * -b
else
tmp = a * a
end if
code = tmp
end function
public static double code(double a, double b) {
double tmp;
if (((a * a) <= 6e-72) || (!((a * a) <= 1.5e+61) && ((a * a) <= 1e+167))) {
tmp = b * -b;
} else {
tmp = a * a;
}
return tmp;
}
def code(a, b): tmp = 0 if ((a * a) <= 6e-72) or (not ((a * a) <= 1.5e+61) and ((a * a) <= 1e+167)): tmp = b * -b else: tmp = a * a return tmp
function code(a, b) tmp = 0.0 if ((Float64(a * a) <= 6e-72) || (!(Float64(a * a) <= 1.5e+61) && (Float64(a * a) <= 1e+167))) tmp = Float64(b * Float64(-b)); else tmp = Float64(a * a); end return tmp end
function tmp_2 = code(a, b) tmp = 0.0; if (((a * a) <= 6e-72) || (~(((a * a) <= 1.5e+61)) && ((a * a) <= 1e+167))) tmp = b * -b; else tmp = a * a; end tmp_2 = tmp; end
code[a_, b_] := If[Or[LessEqual[N[(a * a), $MachinePrecision], 6e-72], And[N[Not[LessEqual[N[(a * a), $MachinePrecision], 1.5e+61]], $MachinePrecision], LessEqual[N[(a * a), $MachinePrecision], 1e+167]]], N[(b * (-b)), $MachinePrecision], N[(a * a), $MachinePrecision]]
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;a \cdot a \leq 6 \cdot 10^{-72} \lor \neg \left(a \cdot a \leq 1.5 \cdot 10^{+61}\right) \land a \cdot a \leq 10^{+167}:\\
\;\;\;\;b \cdot \left(-b\right)\\
\mathbf{else}:\\
\;\;\;\;a \cdot a\\
\end{array}
\end{array}
if (*.f64 a a) < 6e-72 or 1.5e61 < (*.f64 a a) < 1e167Initial program 100.0%
difference-of-squares100.0%
sub-neg100.0%
add-sqr-sqrt46.1%
sqrt-unprod65.1%
sqr-neg65.1%
sqrt-prod18.8%
add-sqr-sqrt29.9%
Applied egg-rr29.9%
add-sqr-sqrt18.8%
sqrt-prod65.1%
add-sqr-sqrt18.8%
add-sqr-sqrt18.8%
sqr-neg18.8%
swap-sqr18.8%
sqrt-unprod0.0%
add-sqr-sqrt53.5%
distribute-rgt-neg-out53.5%
add-sqr-sqrt100.0%
sub-neg100.0%
Applied egg-rr100.0%
Taylor expanded in a around 0 83.2%
Taylor expanded in a around 0 83.7%
neg-mul-183.7%
Simplified83.7%
if 6e-72 < (*.f64 a a) < 1.5e61 or 1e167 < (*.f64 a a) Initial program 87.7%
difference-of-squares100.0%
sub-neg100.0%
add-sqr-sqrt50.8%
sqrt-unprod86.9%
sqr-neg86.9%
sqrt-prod38.5%
add-sqr-sqrt83.0%
Applied egg-rr83.0%
Taylor expanded in a around inf 89.2%
Taylor expanded in a around inf 83.7%
Final simplification83.7%
(FPCore (a b) :precision binary64 (* a a))
double code(double a, double b) {
return a * a;
}
real(8) function code(a, b)
real(8), intent (in) :: a
real(8), intent (in) :: b
code = a * a
end function
public static double code(double a, double b) {
return a * a;
}
def code(a, b): return a * a
function code(a, b) return Float64(a * a) end
function tmp = code(a, b) tmp = a * a; end
code[a_, b_] := N[(a * a), $MachinePrecision]
\begin{array}{l}
\\
a \cdot a
\end{array}
Initial program 94.1%
difference-of-squares100.0%
sub-neg100.0%
add-sqr-sqrt48.3%
sqrt-unprod75.5%
sqr-neg75.5%
sqrt-prod28.2%
add-sqr-sqrt55.2%
Applied egg-rr55.2%
Taylor expanded in a around inf 59.1%
Taylor expanded in a around inf 56.1%
(FPCore (a b) :precision binary64 (* (+ a b) (- a b)))
double code(double a, double b) {
return (a + b) * (a - b);
}
real(8) function code(a, b)
real(8), intent (in) :: a
real(8), intent (in) :: b
code = (a + b) * (a - b)
end function
public static double code(double a, double b) {
return (a + b) * (a - b);
}
def code(a, b): return (a + b) * (a - b)
function code(a, b) return Float64(Float64(a + b) * Float64(a - b)) end
function tmp = code(a, b) tmp = (a + b) * (a - b); end
code[a_, b_] := N[(N[(a + b), $MachinePrecision] * N[(a - b), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\left(a + b\right) \cdot \left(a - b\right)
\end{array}
herbie shell --seed 2024110
(FPCore (a b)
:name "Difference of squares"
:precision binary64
:alt
(* (+ a b) (- a b))
(- (* a a) (* b b)))