ab-angle->ABCF D

Percentage Accurate: 82.4% → 99.7%
Time: 46.9s
Alternatives: 3
Speedup: 1.0×

Specification

?
\[-\left(\left(a \cdot a\right) \cdot b\right) \cdot b \]
(FPCore (a b)
  :precision binary64
  :pre TRUE
  (- (* (* (* a a) b) b)))
double code(double a, double b) {
	return -(((a * a) * b) * b);
}
real(8) function code(a, b)
use fmin_fmax_functions
    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(Float64(Float64(a * a) * b) * b))
end
function tmp = code(a, b)
	tmp = -(((a * a) * b) * b);
end
code[a_, b_] := (-N[(N[(N[(a * a), $MachinePrecision] * b), $MachinePrecision] * b), $MachinePrecision])
f(a, b):
	a in [-inf, +inf],
	b in [-inf, +inf]
code: THEORY
BEGIN
f(a, b: real): real =
	- (((a * a) * b) * b)
END code
-\left(\left(a \cdot a\right) \cdot b\right) \cdot b

Local Percentage Accuracy vs ?

The average percentage accuracy by input value. Horizontal axis shows value of an input variable; the variable is choosen in the title. Vertical axis is accuracy; higher is better. Red represent the original program, while blue represents Herbie's suggestion. These can be toggled with buttons below the plot. The line is an average while dots represent individual samples.

Accuracy vs Speed?

Herbie found 3 alternatives:

AlternativeAccuracySpeedup
The accuracy (vertical axis) and speed (horizontal axis) of each alternatives. Up and to the right is better. The red square shows the initial program, and each blue circle shows an alternative.The line shows the best available speed-accuracy tradeoffs.

Initial Program: 82.4% accurate, 1.0× speedup?

\[-\left(\left(a \cdot a\right) \cdot b\right) \cdot b \]
(FPCore (a b)
  :precision binary64
  :pre TRUE
  (- (* (* (* a a) b) b)))
double code(double a, double b) {
	return -(((a * a) * b) * b);
}
real(8) function code(a, b)
use fmin_fmax_functions
    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(Float64(Float64(a * a) * b) * b))
end
function tmp = code(a, b)
	tmp = -(((a * a) * b) * b);
end
code[a_, b_] := (-N[(N[(N[(a * a), $MachinePrecision] * b), $MachinePrecision] * b), $MachinePrecision])
f(a, b):
	a in [-inf, +inf],
	b in [-inf, +inf]
code: THEORY
BEGIN
f(a, b: real): real =
	- (((a * a) * b) * b)
END code
-\left(\left(a \cdot a\right) \cdot b\right) \cdot b

Alternative 1: 99.7% accurate, 1.0× speedup?

\[\left(-a \cdot b\right) \cdot \left(a \cdot b\right) \]
(FPCore (a b)
  :precision binary64
  :pre TRUE
  (* (- (* a b)) (* a b)))
double code(double a, double b) {
	return -(a * b) * (a * b);
}
real(8) function code(a, b)
use fmin_fmax_functions
    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(-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]
f(a, b):
	a in [-inf, +inf],
	b in [-inf, +inf]
code: THEORY
BEGIN
f(a, b: real): real =
	(- (a * b)) * (a * b)
END code
\left(-a \cdot b\right) \cdot \left(a \cdot b\right)
Derivation
  1. Initial program 82.4%

    \[-\left(\left(a \cdot a\right) \cdot b\right) \cdot b \]
  2. Applied rewrites99.7%

    \[\leadsto \left(-a \cdot b\right) \cdot \left(a \cdot b\right) \]
  3. Add Preprocessing

Alternative 2: 97.7% accurate, 0.3× speedup?

\[\begin{array}{l} t_0 := \mathsf{min}\left(\left|a\right|, \left|b\right|\right)\\ t_1 := \mathsf{max}\left(\left|a\right|, \left|b\right|\right)\\ t_2 := t\_0 \cdot t\_1\\ \mathbf{if}\;t\_0 \leq 6.580653175437961 \cdot 10^{-184}:\\ \;\;\;\;t\_0 \cdot \left(t\_1 \cdot \left(-t\_2\right)\right)\\ \mathbf{else}:\\ \;\;\;\;-\left(t\_0 \cdot t\_2\right) \cdot t\_1\\ \end{array} \]
(FPCore (a b)
  :precision binary64
  :pre TRUE
  (let* ((t_0 (fmin (fabs a) (fabs b)))
       (t_1 (fmax (fabs a) (fabs b)))
       (t_2 (* t_0 t_1)))
  (if (<= t_0 6.580653175437961e-184)
    (* t_0 (* t_1 (- t_2)))
    (- (* (* t_0 t_2) t_1)))))
double code(double a, double b) {
	double t_0 = fmin(fabs(a), fabs(b));
	double t_1 = fmax(fabs(a), fabs(b));
	double t_2 = t_0 * t_1;
	double tmp;
	if (t_0 <= 6.580653175437961e-184) {
		tmp = t_0 * (t_1 * -t_2);
	} else {
		tmp = -((t_0 * t_2) * t_1);
	}
	return tmp;
}
real(8) function code(a, b)
use fmin_fmax_functions
    real(8), intent (in) :: a
    real(8), intent (in) :: b
    real(8) :: t_0
    real(8) :: t_1
    real(8) :: t_2
    real(8) :: tmp
    t_0 = fmin(abs(a), abs(b))
    t_1 = fmax(abs(a), abs(b))
    t_2 = t_0 * t_1
    if (t_0 <= 6.580653175437961d-184) then
        tmp = t_0 * (t_1 * -t_2)
    else
        tmp = -((t_0 * t_2) * t_1)
    end if
    code = tmp
end function
public static double code(double a, double b) {
	double t_0 = fmin(Math.abs(a), Math.abs(b));
	double t_1 = fmax(Math.abs(a), Math.abs(b));
	double t_2 = t_0 * t_1;
	double tmp;
	if (t_0 <= 6.580653175437961e-184) {
		tmp = t_0 * (t_1 * -t_2);
	} else {
		tmp = -((t_0 * t_2) * t_1);
	}
	return tmp;
}
def code(a, b):
	t_0 = fmin(math.fabs(a), math.fabs(b))
	t_1 = fmax(math.fabs(a), math.fabs(b))
	t_2 = t_0 * t_1
	tmp = 0
	if t_0 <= 6.580653175437961e-184:
		tmp = t_0 * (t_1 * -t_2)
	else:
		tmp = -((t_0 * t_2) * t_1)
	return tmp
function code(a, b)
	t_0 = fmin(abs(a), abs(b))
	t_1 = fmax(abs(a), abs(b))
	t_2 = Float64(t_0 * t_1)
	tmp = 0.0
	if (t_0 <= 6.580653175437961e-184)
		tmp = Float64(t_0 * Float64(t_1 * Float64(-t_2)));
	else
		tmp = Float64(-Float64(Float64(t_0 * t_2) * t_1));
	end
	return tmp
end
function tmp_2 = code(a, b)
	t_0 = min(abs(a), abs(b));
	t_1 = max(abs(a), abs(b));
	t_2 = t_0 * t_1;
	tmp = 0.0;
	if (t_0 <= 6.580653175437961e-184)
		tmp = t_0 * (t_1 * -t_2);
	else
		tmp = -((t_0 * t_2) * t_1);
	end
	tmp_2 = tmp;
end
code[a_, b_] := Block[{t$95$0 = N[Min[N[Abs[a], $MachinePrecision], N[Abs[b], $MachinePrecision]], $MachinePrecision]}, Block[{t$95$1 = N[Max[N[Abs[a], $MachinePrecision], N[Abs[b], $MachinePrecision]], $MachinePrecision]}, Block[{t$95$2 = N[(t$95$0 * t$95$1), $MachinePrecision]}, If[LessEqual[t$95$0, 6.580653175437961e-184], N[(t$95$0 * N[(t$95$1 * (-t$95$2)), $MachinePrecision]), $MachinePrecision], (-N[(N[(t$95$0 * t$95$2), $MachinePrecision] * t$95$1), $MachinePrecision])]]]]
f(a, b):
	a in [-inf, +inf],
	b in [-inf, +inf]
code: THEORY
BEGIN
f(a, b: real): real =
	LET tmp = IF ((abs(a)) < (abs(b))) THEN (abs(a)) ELSE (abs(b)) ENDIF IN
	LET t_0 = tmp IN
		LET tmp_1 = IF ((abs(a)) > (abs(b))) THEN (abs(a)) ELSE (abs(b)) ENDIF IN
		LET t_1 = tmp_1 IN
			LET t_2 = (t_0 * t_1) IN
				LET tmp_2 = IF (t_0 <= (6580653175437961130972315507035316039922052352214427415602883917303577306908167843261101333977352445741999890370571693156360685975903822368447221195269477525483941385406300821766125308814118449361006089885061212554973432008766510200778526960623710544485438428125839386444199040355138899994550125162709451305605458029968780076651215964718388915448941700891493845257793716167470693081408622299581374250924692848730125573753504285561761522928281298305819291272200644016265869140625e-661)) THEN (t_0 * (t_1 * (- t_2))) ELSE (- ((t_0 * t_2) * t_1)) ENDIF IN
	tmp_2
END code
\begin{array}{l}
t_0 := \mathsf{min}\left(\left|a\right|, \left|b\right|\right)\\
t_1 := \mathsf{max}\left(\left|a\right|, \left|b\right|\right)\\
t_2 := t\_0 \cdot t\_1\\
\mathbf{if}\;t\_0 \leq 6.580653175437961 \cdot 10^{-184}:\\
\;\;\;\;t\_0 \cdot \left(t\_1 \cdot \left(-t\_2\right)\right)\\

\mathbf{else}:\\
\;\;\;\;-\left(t\_0 \cdot t\_2\right) \cdot t\_1\\


\end{array}
Derivation
  1. Split input into 2 regimes
  2. if a < 6.5806531754379611e-184

    1. Initial program 82.4%

      \[-\left(\left(a \cdot a\right) \cdot b\right) \cdot b \]
    2. Applied rewrites81.9%

      \[\leadsto a \cdot \left(\left(-a\right) \cdot \left(b \cdot b\right)\right) \]
    3. Applied rewrites94.3%

      \[\leadsto a \cdot \left(b \cdot \left(-a \cdot b\right)\right) \]

    if 6.5806531754379611e-184 < a

    1. Initial program 82.4%

      \[-\left(\left(a \cdot a\right) \cdot b\right) \cdot b \]
    2. Applied rewrites93.9%

      \[\leadsto -\left(a \cdot \left(a \cdot b\right)\right) \cdot b \]
  3. Recombined 2 regimes into one program.
  4. Add Preprocessing

Alternative 3: 94.0% accurate, 0.4× speedup?

\[\begin{array}{l} t_0 := \mathsf{min}\left(\left|a\right|, b\right)\\ t_1 := \mathsf{max}\left(\left|a\right|, b\right)\\ -\left(t\_0 \cdot \left(t\_0 \cdot t\_1\right)\right) \cdot t\_1 \end{array} \]
(FPCore (a b)
  :precision binary64
  :pre TRUE
  (let* ((t_0 (fmin (fabs a) b)) (t_1 (fmax (fabs a) b)))
  (- (* (* t_0 (* t_0 t_1)) t_1))))
double code(double a, double b) {
	double t_0 = fmin(fabs(a), b);
	double t_1 = fmax(fabs(a), b);
	return -((t_0 * (t_0 * t_1)) * t_1);
}
real(8) function code(a, b)
use fmin_fmax_functions
    real(8), intent (in) :: a
    real(8), intent (in) :: b
    real(8) :: t_0
    real(8) :: t_1
    t_0 = fmin(abs(a), b)
    t_1 = fmax(abs(a), b)
    code = -((t_0 * (t_0 * t_1)) * t_1)
end function
public static double code(double a, double b) {
	double t_0 = fmin(Math.abs(a), b);
	double t_1 = fmax(Math.abs(a), b);
	return -((t_0 * (t_0 * t_1)) * t_1);
}
def code(a, b):
	t_0 = fmin(math.fabs(a), b)
	t_1 = fmax(math.fabs(a), b)
	return -((t_0 * (t_0 * t_1)) * t_1)
function code(a, b)
	t_0 = fmin(abs(a), b)
	t_1 = fmax(abs(a), b)
	return Float64(-Float64(Float64(t_0 * Float64(t_0 * t_1)) * t_1))
end
function tmp = code(a, b)
	t_0 = min(abs(a), b);
	t_1 = max(abs(a), b);
	tmp = -((t_0 * (t_0 * t_1)) * t_1);
end
code[a_, b_] := Block[{t$95$0 = N[Min[N[Abs[a], $MachinePrecision], b], $MachinePrecision]}, Block[{t$95$1 = N[Max[N[Abs[a], $MachinePrecision], b], $MachinePrecision]}, (-N[(N[(t$95$0 * N[(t$95$0 * t$95$1), $MachinePrecision]), $MachinePrecision] * t$95$1), $MachinePrecision])]]
f(a, b):
	a in [-inf, +inf],
	b in [-inf, +inf]
code: THEORY
BEGIN
f(a, b: real): real =
	LET tmp = IF ((abs(a)) < b) THEN (abs(a)) ELSE b ENDIF IN
	LET t_0 = tmp IN
		LET tmp_1 = IF ((abs(a)) > b) THEN (abs(a)) ELSE b ENDIF IN
		LET t_1 = tmp_1 IN
	- ((t_0 * (t_0 * t_1)) * t_1)
END code
\begin{array}{l}
t_0 := \mathsf{min}\left(\left|a\right|, b\right)\\
t_1 := \mathsf{max}\left(\left|a\right|, b\right)\\
-\left(t\_0 \cdot \left(t\_0 \cdot t\_1\right)\right) \cdot t\_1
\end{array}
Derivation
  1. Initial program 82.4%

    \[-\left(\left(a \cdot a\right) \cdot b\right) \cdot b \]
  2. Applied rewrites93.9%

    \[\leadsto -\left(a \cdot \left(a \cdot b\right)\right) \cdot b \]
  3. Add Preprocessing

Reproduce

?
herbie shell --seed 2026074 +o generate:egglog
(FPCore (a b)
  :name "ab-angle->ABCF D"
  :precision binary64
  (- (* (* (* a a) b) b)))