


Bits error versus a



Bits error versus b



Bits error versus c
if b < -4.8021396801207425e+125Initial program 50.9
rmApplied add-sqr-sqrt50.9
Applied rem-sqrt-square50.9
Simplified50.8
Taylor expanded around 0 3.4
if -4.8021396801207425e+125 < b < 3.2165368891128914e+63Initial program 9.1
rmApplied add-sqr-sqrt9.1
Applied rem-sqrt-square9.1
Simplified9.2
rmApplied add-sqr-sqrt9.3
rmApplied add-cube-cbrt9.3
Applied sqrt-prod9.3
Simplified9.3
if 3.2165368891128914e+63 < b Initial program 26.7
Taylor expanded around inf 6.9
Simplified3.4
rmApplied add-sqr-sqrt3.4
Final simplification6.9
herbie shell --seed 2019016 +o rules:numerics
(FPCore (a b c)
:name "jeff quadratic root 2"
(if (>= b 0) (/ (* 2 c) (- (- b) (sqrt (- (* b b) (* (* 4 a) c))))) (/ (+ (- b) (sqrt (- (* b b) (* (* 4 a) c)))) (* 2 a))))
Time bar (total: 28.6s)Debug log
| 378× | (pre true 80) |
| 285× | (body real 80) |
| 93× | (body nan 80) |
| 96.0ms | (if (>= b 0) (/ (* 2 c) (- (- b) (sqrt (- (* b b) (* (* 4 a) c))))) (/ (+ (- b) (sqrt (- (* b b) (* (* 4 a) c)))) (* 2 a))) |
1 alts after pruning (1 fresh and 0 done)
Merged error: 19.9b
Found 4 expressions with local error:
| 23.2b | (sqrt (- (* b b) (* (* 4 a) c))) |
| 23.2b | (sqrt (- (* b b) (* (* 4 a) c))) |
| 2.2b | (+ (- b) (sqrt (- (* b b) (* (* 4 a) c)))) |
| 1.2b | (- (- b) (sqrt (- (* b b) (* (* 4 a) c)))) |
| 28× | add-sqr-sqrt |
| 26× | *-un-lft-identity |
| 24× | prod-diff |
| 22× | add-cube-cbrt |
| 19× | sqrt-prod |
| 8× | add-log-exp |
| 8× | neg-mul-1 |
| 4× | log1p-expm1-u |
| 4× | add-exp-log |
| 4× | sqrt-div |
| 4× | fma-neg |
| 4× | add-cbrt-cube |
| 4× | fma-def |
| 4× | pow1 |
| 4× | expm1-log1p-u |
| 3× | flip-- |
| 3× | flip3-- |
| 2× | difference-of-squares |
| 2× | pow1/2 |
| 2× | rem-sqrt-square |
| 2× | neg-sub0 |
| 1× | distribute-lft-out-- |
| 1× | distribute-lft-out |
| 1× | flip-+ |
| 1× | associate-+l- |
| 1× | diff-log |
| 1× | flip3-+ |
| 1× | sub-neg |
| 1× | sum-log |
| 1× | +-commutative |
| 1× | associate--l- |
| 11.0ms | (- (- b) (sqrt (- (* b b) (* (* 4 a) c)))) |
| 6.0ms | (+ (- b) (sqrt (- (* b b) (* (* 4 a) c)))) |
| 5.0ms | (sqrt (- (* b b) (* (* 4 a) c))) |
| 3.0ms | (sqrt (- (* b b) (* (* 4 a) c))) |
| 52.0ms | (sqrt (- (* b b) (* (* 4 a) c))) |
| 49.0ms | (+ (- b) (sqrt (- (* b b) (* (* 4 a) c)))) |
| 44.0ms | (- (- b) (sqrt (- (* b b) (* (* 4 a) c)))) |
| 40.0ms | (sqrt (- (* b b) (* (* 4 a) c))) |
| 470.0ms | (sqrt (- (pow (* b b) 3) (pow (* (* 4 a) c) 3))) |
| 377.0ms | (sqrt (- (pow (* b b) 3) (pow (* (* 4 a) c) 3))) |
| 168.0ms | (- b (* 2 (/ (* a c) b))) |
| 160.0ms | (sqrt (- (* (* b b) (* b b)) (* (* (* 4 a) c) (* (* 4 a) c)))) |
| 126.0ms | (- b (* 2 (/ (* a c) b))) |
10 alts after pruning (10 fresh and 0 done)
Merged error: 6.9b
Found 4 expressions with local error:
| 23.2b | (sqrt (fma (* a -4) c (* b b))) |
| 23.2b | (sqrt (- (* b b) (* (* 4 a) c))) |
| 2.2b | (+ (- b) (fabs (sqrt (fma (* a -4) c (* b b))))) |
| 1.2b | (- (- b) (sqrt (- (* b b) (* (* 4 a) c)))) |
| 28× | add-sqr-sqrt |
| 26× | *-un-lft-identity |
| 24× | prod-diff |
| 22× | add-cube-cbrt |
| 19× | sqrt-prod |
| 8× | add-log-exp |
| 8× | neg-mul-1 |
| 4× | log1p-expm1-u |
| 4× | add-exp-log |
| 4× | fma-neg |
| 4× | add-cbrt-cube |
| 4× | fma-def |
| 4× | pow1 |
| 4× | expm1-log1p-u |
| 2× | difference-of-squares |
| 2× | flip-- |
| 2× | sqrt-div |
| 2× | pow1/2 |
| 2× | flip3-- |
| 2× | rem-sqrt-square |
| 2× | neg-sub0 |
| 1× | distribute-lft-out-- |
| 1× | distribute-lft-out |
| 1× | flip-+ |
| 1× | associate-+l- |
| 1× | diff-log |
| 1× | flip3-+ |
| 1× | sub-neg |
| 1× | sum-log |
| 1× | +-commutative |
| 1× | associate--l- |
| 14.0ms | (- (- b) (sqrt (- (* b b) (* (* 4 a) c)))) |
| 4.0ms | (+ (- b) (fabs (sqrt (fma (* a -4) c (* b b))))) |
| 3.0ms | (sqrt (- (* b b) (* (* 4 a) c))) |
| 1.0ms | (sqrt (fma (* a -4) c (* b b))) |
| 80.0ms | (sqrt (fma (* a -4) c (* b b))) |
| 57.0ms | (- (- b) (sqrt (- (* b b) (* (* 4 a) c)))) |
| 40.0ms | (sqrt (- (* b b) (* (* 4 a) c))) |
| 9.0ms | (+ (- b) (fabs (sqrt (fma (* a -4) c (* b b))))) |
| 438.0ms | (sqrt (- (pow (* b b) 3) (pow (* (* 4 a) c) 3))) |
| 163.0ms | (sqrt (- (* (* b b) (* b b)) (* (* (* 4 a) c) (* (* 4 a) c)))) |
| 121.0ms | (- b (* 2 (/ (* a c) b))) |
| 97.0ms | (fma (* (cbrt (- b)) (cbrt (- b))) (cbrt (- b)) (- (* (sqrt (cbrt (- (* b b) (* (* 4 a) c)))) (sqrt (* (cbrt (- (* b b) (* (* 4 a) c))) (cbrt (- (* b b) (* (* 4 a) c)))))))) |
| 92.0ms | (fma (sqrt (- b)) (sqrt (- b)) (- (* (sqrt (- (* b b) (* (* 4 a) c))) (sqrt 1)))) |
8 alts after pruning (8 fresh and 0 done)
Merged error: 5.2b
Found 4 expressions with local error:
| 23.2b | (sqrt (- (* b b) (* (* 4 a) c))) |
| 5.0b | (* (/ c b) a) |
| 3.8b | (/ (* 2 c) (- (- b) (fma (* (/ c b) a) -2 b))) |
| 2.2b | (+ (- b) (sqrt (- (* b b) (* (* 4 a) c)))) |
| 15× | *-un-lft-identity |
| 14× | add-sqr-sqrt |
| 9× | add-cube-cbrt |
| 6× | add-log-exp |
| 6× | add-exp-log |
| 6× | add-cbrt-cube |
| 5× | times-frac |
| 5× | associate-/r* |
| 4× | log1p-expm1-u |
| 4× | associate-*l* |
| 4× | fma-def |
| 4× | pow1 |
| 4× | expm1-log1p-u |
| 3× | sqrt-prod |
| 2× | difference-of-squares |
| 2× | distribute-lft-out-- |
| 2× | flip-- |
| 2× | div-inv |
| 2× | associate-/r/ |
| 2× | sqrt-div |
| 2× | flip3-- |
| 1× | associate-/l* |
| 1× | distribute-lft-out |
| 1× | flip-+ |
| 1× | associate-+l- |
| 1× | *-commutative |
| 1× | associate-*l/ |
| 1× | div-exp |
| 1× | pow1/2 |
| 1× | flip3-+ |
| 1× | frac-2neg |
| 1× | sum-log |
| 1× | neg-mul-1 |
| 1× | clear-num |
| 1× | rem-sqrt-square |
| 1× | +-commutative |
| 1× | cbrt-undiv |
| 1× | neg-sub0 |
| 7.0ms | (/ (* 2 c) (- (- b) (fma (* (/ c b) a) -2 b))) |
| 6.0ms | (+ (- b) (sqrt (- (* b b) (* (* 4 a) c)))) |
| 3.0ms | (sqrt (- (* b b) (* (* 4 a) c))) |
| 2.0ms | (* (/ c b) a) |
| 77.0ms | (/ (* 2 c) (- (- b) (fma (* (/ c b) a) -2 b))) |
| 48.0ms | (sqrt (- (* b b) (* (* 4 a) c))) |
| 45.0ms | (+ (- b) (sqrt (- (* b b) (* (* 4 a) c)))) |
| 23.0ms | (* (/ c b) a) |
| 363.0ms | (sqrt (- (pow (* b b) 3) (pow (* (* 4 a) c) 3))) |
| 271.0ms | (+ (* (- b) (- b)) (+ (* (fma (* (/ c b) a) -2 b) (fma (* (/ c b) a) -2 b)) (* (- b) (fma (* (/ c b) a) -2 b)))) |
| 209.0ms | (sqrt (- (* (* b b) (* b b)) (* (* (* 4 a) c) (* (* 4 a) c)))) |
| 165.0ms | (- b (* 2 (/ (* a c) b))) |
| 142.0ms | (sqrt (- (- b) (fma (* (/ c b) a) -2 b))) |
10 alts after pruning (10 fresh and 0 done)
Merged error: 5.2b
Found 4 expressions with local error:
| 23.2b | (sqrt (fma (* a -4) c (* b b))) |
| 23.2b | (sqrt (- (* b b) (* (* 4 a) c))) |
| 23.2b | (sqrt (- (* b b) (* (* 4 a) c))) |
| 9.3b | (- (- b) (* (sqrt (sqrt (- (* b b) (* (* 4 a) c)))) (sqrt (sqrt (- (* b b) (* (* 4 a) c)))))) |
| 13× | add-sqr-sqrt |
| 9× | sqrt-prod |
| 9× | add-cube-cbrt |
| 9× | *-un-lft-identity |
| 6× | add-log-exp |
| 4× | log1p-expm1-u |
| 4× | add-exp-log |
| 4× | prod-diff |
| 4× | sqrt-div |
| 4× | fma-neg |
| 4× | add-cbrt-cube |
| 4× | pow1 |
| 4× | expm1-log1p-u |
| 3× | flip-- |
| 3× | pow1/2 |
| 3× | flip3-- |
| 3× | rem-sqrt-square |
| 2× | neg-mul-1 |
| 1× | difference-of-squares |
| 1× | diff-log |
| 1× | sub-neg |
| 1× | neg-sub0 |
| 1× | associate--l- |
| 4.0ms | (- (- b) (* (sqrt (sqrt (- (* b b) (* (* 4 a) c)))) (sqrt (sqrt (- (* b b) (* (* 4 a) c)))))) |
| 3.0ms | (sqrt (- (* b b) (* (* 4 a) c))) |
| 3.0ms | (sqrt (- (* b b) (* (* 4 a) c))) |
| 1.0ms | (sqrt (fma (* a -4) c (* b b))) |
| 75.0ms | (sqrt (- (* b b) (* (* 4 a) c))) |
| 70.0ms | (sqrt (- (* b b) (* (* 4 a) c))) |
| 67.0ms | (sqrt (fma (* a -4) c (* b b))) |
| 56.0ms | (- (- b) (* (sqrt (sqrt (- (* b b) (* (* 4 a) c)))) (sqrt (sqrt (- (* b b) (* (* 4 a) c)))))) |
| 377.0ms | (sqrt (- (pow (* b b) 3) (pow (* (* 4 a) c) 3))) |
| 366.0ms | (sqrt (- (pow (* b b) 3) (pow (* (* 4 a) c) 3))) |
| 192.0ms | (sqrt (- (* (* b b) (* b b)) (* (* (* 4 a) c) (* (* 4 a) c)))) |
| 139.0ms | (sqrt (- (* (* b b) (* b b)) (* (* (* 4 a) c) (* (* 4 a) c)))) |
| 134.0ms | (- b (* 2 (/ (* a c) b))) |
10 alts after pruning (10 fresh and 0 done)
Merged error: 5.2b
91.9% (1.1b remaining)
Error of 6.9b against oracle of 5.8b and baseline of 19.7b
| 11500× | (pre true 80) |
| 8754× | (body real 80) |
| 2746× | (body nan 80) |