\left(a + \left(b + \left(c + d\right)\right)\right) \cdot 2
\left(\left(a + d\right) + \left(b + c\right)\right) \cdot 2
(FPCore (a b c d) :precision binary64 (* (+ a (+ b (+ c d))) 2.0))
(FPCore (a b c d) :precision binary64 (* (+ (+ a d) (+ b c)) 2.0))
double code(double a, double b, double c, double d) {
return (a + (b + (c + d))) * 2.0;
}
double code(double a, double b, double c, double d) {
return ((a + d) + (b + c)) * 2.0;
}




Bits error versus a




Bits error versus b




Bits error versus c




Bits error versus d
Results
| Original | 3.7 |
|---|---|
| Target | 3.8 |
| Herbie | 0 |
Initial program 3.7
rmApplied associate-+r+_binary642.8
rmApplied add-cbrt-cube_binary642.9
Simplified2.9
rmApplied associate-+r+_binary640.6
rmApplied rem-cbrt-cube_binary640
Final simplification0
herbie shell --seed 2020232
(FPCore (a b c d)
:name "Expression, p6"
:precision binary64
:pre (and (<= -14.0 a -13.0) (<= -3.0 b -2.0) (<= 3.0 c 3.5) (<= 12.5 d 13.5))
:herbie-target
(+ (* (+ a b) 2.0) (* (+ c d) 2.0))
(* (+ a (+ b (+ c d))) 2.0))