
(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}
a_m = (fabs.f64 a) b_m = (fabs.f64 b) (FPCore (a_m b_m) :precision binary64 (if (<= (* a_m a_m) 5e+252) (fma a_m a_m (* b_m (- b_m))) (* a_m (+ a_m (* b_m -2.0)))))
a_m = fabs(a);
b_m = fabs(b);
double code(double a_m, double b_m) {
double tmp;
if ((a_m * a_m) <= 5e+252) {
tmp = fma(a_m, a_m, (b_m * -b_m));
} else {
tmp = a_m * (a_m + (b_m * -2.0));
}
return tmp;
}
a_m = abs(a) b_m = abs(b) function code(a_m, b_m) tmp = 0.0 if (Float64(a_m * a_m) <= 5e+252) tmp = fma(a_m, a_m, Float64(b_m * Float64(-b_m))); else tmp = Float64(a_m * Float64(a_m + Float64(b_m * -2.0))); end return tmp end
a_m = N[Abs[a], $MachinePrecision] b_m = N[Abs[b], $MachinePrecision] code[a$95$m_, b$95$m_] := If[LessEqual[N[(a$95$m * a$95$m), $MachinePrecision], 5e+252], N[(a$95$m * a$95$m + N[(b$95$m * (-b$95$m)), $MachinePrecision]), $MachinePrecision], N[(a$95$m * N[(a$95$m + N[(b$95$m * -2.0), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}
a_m = \left|a\right|
\\
b_m = \left|b\right|
\\
\begin{array}{l}
\mathbf{if}\;a\_m \cdot a\_m \leq 5 \cdot 10^{+252}:\\
\;\;\;\;\mathsf{fma}\left(a\_m, a\_m, b\_m \cdot \left(-b\_m\right)\right)\\
\mathbf{else}:\\
\;\;\;\;a\_m \cdot \left(a\_m + b\_m \cdot -2\right)\\
\end{array}
\end{array}
if (*.f64 a a) < 4.9999999999999997e252Initial program 100.0%
sqr-neg100.0%
cancel-sign-sub100.0%
fma-def100.0%
Simplified100.0%
if 4.9999999999999997e252 < (*.f64 a a) Initial program 76.4%
difference-of-squares100.0%
add-sqr-sqrt54.2%
sqrt-prod79.2%
sqr-neg79.2%
sqrt-unprod34.7%
add-sqr-sqrt83.3%
sub-neg83.3%
pow183.3%
pow183.3%
pow-prod-up83.3%
add-sqr-sqrt40.2%
add-sqr-sqrt25.0%
difference-of-squares25.0%
metadata-eval25.0%
unpow-prod-down25.0%
Applied egg-rr25.0%
unpow225.0%
unpow225.0%
unswap-sqr25.0%
difference-of-squares25.0%
unpow1/225.0%
unpow1/225.0%
pow-sqr25.0%
metadata-eval25.0%
unpow125.0%
unpow1/225.0%
unpow1/225.0%
pow-sqr25.0%
metadata-eval25.0%
unpow125.0%
difference-of-squares25.0%
unpow1/225.0%
unpow1/225.0%
pow-sqr48.6%
metadata-eval48.6%
unpow148.6%
Simplified83.3%
Taylor expanded in a around inf 72.2%
*-commutative72.2%
associate-*l*72.2%
unpow272.2%
distribute-lft-out88.9%
Simplified88.9%
Final simplification96.9%
a_m = (fabs.f64 a) b_m = (fabs.f64 b) (FPCore (a_m b_m) :precision binary64 (if (<= (* a_m a_m) 5e+252) (- (* a_m a_m) (* b_m b_m)) (* a_m (+ a_m (* b_m -2.0)))))
a_m = fabs(a);
b_m = fabs(b);
double code(double a_m, double b_m) {
double tmp;
if ((a_m * a_m) <= 5e+252) {
tmp = (a_m * a_m) - (b_m * b_m);
} else {
tmp = a_m * (a_m + (b_m * -2.0));
}
return tmp;
}
a_m = abs(a)
b_m = abs(b)
real(8) function code(a_m, b_m)
real(8), intent (in) :: a_m
real(8), intent (in) :: b_m
real(8) :: tmp
if ((a_m * a_m) <= 5d+252) then
tmp = (a_m * a_m) - (b_m * b_m)
else
tmp = a_m * (a_m + (b_m * (-2.0d0)))
end if
code = tmp
end function
a_m = Math.abs(a);
b_m = Math.abs(b);
public static double code(double a_m, double b_m) {
double tmp;
if ((a_m * a_m) <= 5e+252) {
tmp = (a_m * a_m) - (b_m * b_m);
} else {
tmp = a_m * (a_m + (b_m * -2.0));
}
return tmp;
}
a_m = math.fabs(a) b_m = math.fabs(b) def code(a_m, b_m): tmp = 0 if (a_m * a_m) <= 5e+252: tmp = (a_m * a_m) - (b_m * b_m) else: tmp = a_m * (a_m + (b_m * -2.0)) return tmp
a_m = abs(a) b_m = abs(b) function code(a_m, b_m) tmp = 0.0 if (Float64(a_m * a_m) <= 5e+252) tmp = Float64(Float64(a_m * a_m) - Float64(b_m * b_m)); else tmp = Float64(a_m * Float64(a_m + Float64(b_m * -2.0))); end return tmp end
a_m = abs(a); b_m = abs(b); function tmp_2 = code(a_m, b_m) tmp = 0.0; if ((a_m * a_m) <= 5e+252) tmp = (a_m * a_m) - (b_m * b_m); else tmp = a_m * (a_m + (b_m * -2.0)); end tmp_2 = tmp; end
a_m = N[Abs[a], $MachinePrecision] b_m = N[Abs[b], $MachinePrecision] code[a$95$m_, b$95$m_] := If[LessEqual[N[(a$95$m * a$95$m), $MachinePrecision], 5e+252], N[(N[(a$95$m * a$95$m), $MachinePrecision] - N[(b$95$m * b$95$m), $MachinePrecision]), $MachinePrecision], N[(a$95$m * N[(a$95$m + N[(b$95$m * -2.0), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}
a_m = \left|a\right|
\\
b_m = \left|b\right|
\\
\begin{array}{l}
\mathbf{if}\;a\_m \cdot a\_m \leq 5 \cdot 10^{+252}:\\
\;\;\;\;a\_m \cdot a\_m - b\_m \cdot b\_m\\
\mathbf{else}:\\
\;\;\;\;a\_m \cdot \left(a\_m + b\_m \cdot -2\right)\\
\end{array}
\end{array}
if (*.f64 a a) < 4.9999999999999997e252Initial program 100.0%
if 4.9999999999999997e252 < (*.f64 a a) Initial program 76.4%
difference-of-squares100.0%
add-sqr-sqrt54.2%
sqrt-prod79.2%
sqr-neg79.2%
sqrt-unprod34.7%
add-sqr-sqrt83.3%
sub-neg83.3%
pow183.3%
pow183.3%
pow-prod-up83.3%
add-sqr-sqrt40.2%
add-sqr-sqrt25.0%
difference-of-squares25.0%
metadata-eval25.0%
unpow-prod-down25.0%
Applied egg-rr25.0%
unpow225.0%
unpow225.0%
unswap-sqr25.0%
difference-of-squares25.0%
unpow1/225.0%
unpow1/225.0%
pow-sqr25.0%
metadata-eval25.0%
unpow125.0%
unpow1/225.0%
unpow1/225.0%
pow-sqr25.0%
metadata-eval25.0%
unpow125.0%
difference-of-squares25.0%
unpow1/225.0%
unpow1/225.0%
pow-sqr48.6%
metadata-eval48.6%
unpow148.6%
Simplified83.3%
Taylor expanded in a around inf 72.2%
*-commutative72.2%
associate-*l*72.2%
unpow272.2%
distribute-lft-out88.9%
Simplified88.9%
Final simplification96.9%
a_m = (fabs.f64 a) b_m = (fabs.f64 b) (FPCore (a_m b_m) :precision binary64 (* a_m (+ a_m (* b_m -2.0))))
a_m = fabs(a);
b_m = fabs(b);
double code(double a_m, double b_m) {
return a_m * (a_m + (b_m * -2.0));
}
a_m = abs(a)
b_m = abs(b)
real(8) function code(a_m, b_m)
real(8), intent (in) :: a_m
real(8), intent (in) :: b_m
code = a_m * (a_m + (b_m * (-2.0d0)))
end function
a_m = Math.abs(a);
b_m = Math.abs(b);
public static double code(double a_m, double b_m) {
return a_m * (a_m + (b_m * -2.0));
}
a_m = math.fabs(a) b_m = math.fabs(b) def code(a_m, b_m): return a_m * (a_m + (b_m * -2.0))
a_m = abs(a) b_m = abs(b) function code(a_m, b_m) return Float64(a_m * Float64(a_m + Float64(b_m * -2.0))) end
a_m = abs(a); b_m = abs(b); function tmp = code(a_m, b_m) tmp = a_m * (a_m + (b_m * -2.0)); end
a_m = N[Abs[a], $MachinePrecision] b_m = N[Abs[b], $MachinePrecision] code[a$95$m_, b$95$m_] := N[(a$95$m * N[(a$95$m + N[(b$95$m * -2.0), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
a_m = \left|a\right|
\\
b_m = \left|b\right|
\\
a\_m \cdot \left(a\_m + b\_m \cdot -2\right)
\end{array}
Initial program 93.4%
difference-of-squares100.0%
add-sqr-sqrt51.1%
sqrt-prod73.1%
sqr-neg73.1%
sqrt-unprod24.7%
add-sqr-sqrt52.2%
sub-neg52.2%
pow152.2%
pow152.2%
pow-prod-up52.2%
add-sqr-sqrt27.7%
add-sqr-sqrt15.2%
difference-of-squares15.2%
metadata-eval15.2%
unpow-prod-down15.2%
Applied egg-rr15.2%
unpow215.2%
unpow215.2%
unswap-sqr15.2%
difference-of-squares15.2%
unpow1/215.2%
unpow1/215.2%
pow-sqr15.2%
metadata-eval15.2%
unpow115.2%
unpow1/215.2%
unpow1/215.2%
pow-sqr15.2%
metadata-eval15.2%
unpow115.2%
difference-of-squares15.2%
unpow1/215.2%
unpow1/215.2%
pow-sqr27.5%
metadata-eval27.5%
unpow127.5%
Simplified52.2%
Taylor expanded in a around inf 50.7%
*-commutative50.7%
associate-*l*50.7%
unpow250.7%
distribute-lft-out55.4%
Simplified55.4%
Final simplification55.4%
a_m = (fabs.f64 a) b_m = (fabs.f64 b) (FPCore (a_m b_m) :precision binary64 (* b_m (* a_m -2.0)))
a_m = fabs(a);
b_m = fabs(b);
double code(double a_m, double b_m) {
return b_m * (a_m * -2.0);
}
a_m = abs(a)
b_m = abs(b)
real(8) function code(a_m, b_m)
real(8), intent (in) :: a_m
real(8), intent (in) :: b_m
code = b_m * (a_m * (-2.0d0))
end function
a_m = Math.abs(a);
b_m = Math.abs(b);
public static double code(double a_m, double b_m) {
return b_m * (a_m * -2.0);
}
a_m = math.fabs(a) b_m = math.fabs(b) def code(a_m, b_m): return b_m * (a_m * -2.0)
a_m = abs(a) b_m = abs(b) function code(a_m, b_m) return Float64(b_m * Float64(a_m * -2.0)) end
a_m = abs(a); b_m = abs(b); function tmp = code(a_m, b_m) tmp = b_m * (a_m * -2.0); end
a_m = N[Abs[a], $MachinePrecision] b_m = N[Abs[b], $MachinePrecision] code[a$95$m_, b$95$m_] := N[(b$95$m * N[(a$95$m * -2.0), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
a_m = \left|a\right|
\\
b_m = \left|b\right|
\\
b\_m \cdot \left(a\_m \cdot -2\right)
\end{array}
Initial program 93.4%
difference-of-squares100.0%
add-sqr-sqrt51.1%
sqrt-prod73.1%
sqr-neg73.1%
sqrt-unprod24.7%
add-sqr-sqrt52.2%
sub-neg52.2%
pow152.2%
pow152.2%
pow-prod-up52.2%
add-sqr-sqrt27.7%
add-sqr-sqrt15.2%
difference-of-squares15.2%
metadata-eval15.2%
unpow-prod-down15.2%
Applied egg-rr15.2%
unpow215.2%
unpow215.2%
unswap-sqr15.2%
difference-of-squares15.2%
unpow1/215.2%
unpow1/215.2%
pow-sqr15.2%
metadata-eval15.2%
unpow115.2%
unpow1/215.2%
unpow1/215.2%
pow-sqr15.2%
metadata-eval15.2%
unpow115.2%
difference-of-squares15.2%
unpow1/215.2%
unpow1/215.2%
pow-sqr27.5%
metadata-eval27.5%
unpow127.5%
Simplified52.2%
Taylor expanded in a around inf 50.7%
*-commutative50.7%
associate-*l*50.7%
unpow250.7%
distribute-lft-out55.4%
Simplified55.4%
Taylor expanded in a around 0 16.6%
associate-*r*16.6%
*-commutative16.6%
Simplified16.6%
Final simplification16.6%
(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 2024027
(FPCore (a b)
:name "Difference of squares"
:precision binary64
:herbie-target
(* (+ a b) (- a b))
(- (* a a) (* b b)))