Improve convergence of DLAED4/SLAED4 (Reference-LAPACK PR655)

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Martin Kroeker 2022-11-21 21:18:39 +01:00 committed by GitHub
parent 880a3fb20f
commit afcd7e88b6
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2 changed files with 10 additions and 4 deletions

View File

@ -328,9 +328,12 @@
IF( C.LT.ZERO )
$ C = ABS( C )
IF( C.EQ.ZERO ) THEN
* ETA = B/A
* ETA = B/A
* ETA = RHO - TAU
ETA = DLTUB - TAU
* ETA = DLTUB - TAU
*
* Update proposed by Li, Ren-Cang:
ETA = -W / ( DPSI+DPHI )
ELSE IF( A.GE.ZERO ) THEN
ETA = ( A+SQRT( ABS( A*A-FOUR*B*C ) ) ) / ( TWO*C )
ELSE

View File

@ -328,9 +328,12 @@
IF( C.LT.ZERO )
$ C = ABS( C )
IF( C.EQ.ZERO ) THEN
* ETA = B/A
* ETA = B/A
* ETA = RHO - TAU
ETA = DLTUB - TAU
* ETA = DLTUB - TAU
*
* Update proposed by Li, Ren-Cang:
ETA = -W / ( DPSI+DPHI )
ELSE IF( A.GE.ZERO ) THEN
ETA = ( A+SQRT( ABS( A*A-FOUR*B*C ) ) ) / ( TWO*C )
ELSE