
(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+266) (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+266) {
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+266) 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+266], 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^{+266}:\\
\;\;\;\;\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) < 4.9999999999999999e266Initial program 100.0%
sqr-neg100.0%
cancel-sign-sub100.0%
fma-def100.0%
Simplified100.0%
if 4.9999999999999999e266 < (*.f64 a a) Initial program 70.0%
difference-of-squares100.0%
add-sqr-sqrt42.5%
sqrt-prod81.3%
sqr-neg81.3%
sqrt-unprod42.5%
add-sqr-sqrt76.3%
sub-neg76.3%
pow176.3%
pow176.3%
pow-prod-up76.3%
metadata-eval76.3%
add-sqr-sqrt41.2%
add-sqr-sqrt22.4%
difference-of-squares22.4%
unpow-prod-down22.4%
Applied egg-rr22.4%
unpow222.4%
unpow222.4%
unswap-sqr22.4%
difference-of-squares22.4%
unpow1/222.4%
unpow1/222.4%
pow-sqr22.5%
metadata-eval22.5%
unpow122.5%
unpow1/222.5%
unpow1/222.5%
pow-sqr22.5%
metadata-eval22.5%
unpow122.5%
difference-of-squares22.5%
unpow1/222.5%
unpow1/222.5%
pow-sqr33.8%
metadata-eval33.8%
unpow133.8%
Simplified76.3%
Taylor expanded in a around inf 63.8%
*-commutative63.8%
associate-*l*63.8%
unpow263.8%
distribute-lft-out87.5%
Simplified87.5%
Final simplification96.1%
a_m = (fabs.f64 a) b_m = (fabs.f64 b) (FPCore (a_m b_m) :precision binary64 (if (<= (* a_m a_m) 5e+266) (- (* 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+266) {
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+266) 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+266) {
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+266: 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+266) 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+266) 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+266], 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^{+266}:\\
\;\;\;\;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) < 4.9999999999999999e266Initial program 100.0%
if 4.9999999999999999e266 < (*.f64 a a) Initial program 70.0%
difference-of-squares100.0%
add-sqr-sqrt42.5%
sqrt-prod81.3%
sqr-neg81.3%
sqrt-unprod42.5%
add-sqr-sqrt76.3%
sub-neg76.3%
pow176.3%
pow176.3%
pow-prod-up76.3%
metadata-eval76.3%
add-sqr-sqrt41.2%
add-sqr-sqrt22.4%
difference-of-squares22.4%
unpow-prod-down22.4%
Applied egg-rr22.4%
unpow222.4%
unpow222.4%
unswap-sqr22.4%
difference-of-squares22.4%
unpow1/222.4%
unpow1/222.4%
pow-sqr22.5%
metadata-eval22.5%
unpow122.5%
unpow1/222.5%
unpow1/222.5%
pow-sqr22.5%
metadata-eval22.5%
unpow122.5%
difference-of-squares22.5%
unpow1/222.5%
unpow1/222.5%
pow-sqr33.8%
metadata-eval33.8%
unpow133.8%
Simplified76.3%
Taylor expanded in a around inf 63.8%
*-commutative63.8%
associate-*l*63.8%
unpow263.8%
distribute-lft-out87.5%
Simplified87.5%
Final simplification96.1%
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 90.6%
difference-of-squares100.0%
add-sqr-sqrt46.4%
sqrt-prod72.0%
sqr-neg72.0%
sqrt-unprod26.7%
add-sqr-sqrt52.4%
sub-neg52.4%
pow152.4%
pow152.4%
pow-prod-up52.4%
metadata-eval52.4%
add-sqr-sqrt27.5%
add-sqr-sqrt14.6%
difference-of-squares14.6%
unpow-prod-down14.6%
Applied egg-rr14.6%
unpow214.6%
unpow214.6%
unswap-sqr14.6%
difference-of-squares14.6%
unpow1/214.6%
unpow1/214.6%
pow-sqr14.6%
metadata-eval14.6%
unpow114.6%
unpow1/214.6%
unpow1/214.6%
pow-sqr14.6%
metadata-eval14.6%
unpow114.6%
difference-of-squares14.6%
unpow1/214.6%
unpow1/214.6%
pow-sqr25.7%
metadata-eval25.7%
unpow125.7%
Simplified52.4%
Taylor expanded in a around inf 49.8%
*-commutative49.8%
associate-*l*49.8%
unpow249.8%
distribute-lft-out57.2%
Simplified57.2%
Final simplification57.2%
a_m = (fabs.f64 a) b_m = (fabs.f64 b) (FPCore (a_m b_m) :precision binary64 (* -2.0 (* a_m b_m)))
a_m = fabs(a);
b_m = fabs(b);
double code(double a_m, double b_m) {
return -2.0 * (a_m * b_m);
}
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 = (-2.0d0) * (a_m * b_m)
end function
a_m = Math.abs(a);
b_m = Math.abs(b);
public static double code(double a_m, double b_m) {
return -2.0 * (a_m * b_m);
}
a_m = math.fabs(a) b_m = math.fabs(b) def code(a_m, b_m): return -2.0 * (a_m * b_m)
a_m = abs(a) b_m = abs(b) function code(a_m, b_m) return Float64(-2.0 * Float64(a_m * b_m)) end
a_m = abs(a); b_m = abs(b); function tmp = code(a_m, b_m) tmp = -2.0 * (a_m * b_m); end
a_m = N[Abs[a], $MachinePrecision] b_m = N[Abs[b], $MachinePrecision] code[a$95$m_, b$95$m_] := N[(-2.0 * N[(a$95$m * b$95$m), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
a_m = \left|a\right|
\\
b_m = \left|b\right|
\\
-2 \cdot \left(a_m \cdot b_m\right)
\end{array}
Initial program 90.6%
difference-of-squares100.0%
add-sqr-sqrt46.4%
sqrt-prod72.0%
sqr-neg72.0%
sqrt-unprod26.7%
add-sqr-sqrt52.4%
sub-neg52.4%
pow152.4%
pow152.4%
pow-prod-up52.4%
metadata-eval52.4%
add-sqr-sqrt27.5%
add-sqr-sqrt14.6%
difference-of-squares14.6%
unpow-prod-down14.6%
Applied egg-rr14.6%
unpow214.6%
unpow214.6%
unswap-sqr14.6%
difference-of-squares14.6%
unpow1/214.6%
unpow1/214.6%
pow-sqr14.6%
metadata-eval14.6%
unpow114.6%
unpow1/214.6%
unpow1/214.6%
pow-sqr14.6%
metadata-eval14.6%
unpow114.6%
difference-of-squares14.6%
unpow1/214.6%
unpow1/214.6%
pow-sqr25.7%
metadata-eval25.7%
unpow125.7%
Simplified52.4%
Taylor expanded in a around inf 49.8%
*-commutative49.8%
associate-*l*49.8%
unpow249.8%
distribute-lft-out57.2%
Simplified57.2%
Taylor expanded in a around 0 13.7%
Final simplification13.7%
(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 2023319
(FPCore (a b)
:name "Difference of squares"
:precision binary64
:herbie-target
(* (+ a b) (- a b))
(- (* a a) (* b b)))