Average Error: 39.6 → 0.3
Time: 3.6s
Precision: binary64
\[\]
↓
\[\]
↓
double code(double x) {
	return ((double) log(((double) (1.0 + x))));
}

↓
double code(double x) {
	double VAR;
	if ((((double) (1.0 + x)) <= 1.0000054502705635)) {
		VAR = ((double) (((double) (1.0 * x)) + ((double) (((double) log(1.0)) + ((double) (((double) (((double) (-0.5 / ((double) (1.0 * 1.0)))) * ((double) (2.0 * ((double) (x * ((double) log(((double) cbrt(((double) exp(x)))))))))))) + ((double) (x * ((double) (((double) (-0.5 / ((double) (1.0 * 1.0)))) * ((double) (x * 0.3333333333333333))))))))))));
	} else {
		VAR = ((double) log(((double) (1.0 + x))));
	}
	return VAR;
}

Error
Bits error versus x
Try it out
Your Program's Arguments
Results
Enter valid numbers for all inputs
Target
Original39.6
Target0.2
Herbie0.3
\[\]
Derivation
  1. Split input into 2 regimes
  2. if  (+ 1.0 x)  < 1.00000545027056353
    1. Initial program 59.1
      \[\]
    2. Taylor expanded around 0 0.3
      \[\leadsto \]
    3. Simplified0.3
      \[\leadsto \]
    4. Using strategy rm
    5. Applied add-log-exp0.7
      \[\leadsto \]
    6. Simplified0.7
      \[\leadsto \]
    7. Using strategy rm
    8. Applied add-cube-cbrt0.7
      \[\leadsto \]
    9. Applied unpow-prod-down0.7
      \[\leadsto \]
    10. Applied unpow-prod-down0.7
      \[\leadsto \]
    11. Applied log-prod0.7
      \[\leadsto \]
    12. Simplified0.7
      \[\leadsto \]
    13. Simplified0.3
      \[\leadsto \]
    14. Using strategy rm
    15. Applied pow1/30.3
      \[\leadsto \]
    16. Applied log-pow0.3
      \[\leadsto \]
    17. Simplified0.3
      \[\leadsto \]
    if 1.00000545027056353 <  (+ 1.0 x) 
    1. Initial program 0.1
      \[\]
  3. Recombined 2 regimes into one program.
  4. Final simplification0.3
    \[\leadsto \]
Reproduce
herbie shell --seed 2020190 
(FPCore (x)
  :name "ln(1 + x)"
  :precision binary64

  :herbie-target
  (if (== (+ 1.0 x) 1.0) x (/ (* x (log (+ 1.0 x))) (- (+ 1.0 x) 1.0)))

  (log (+ 1.0 x)))