DSB2ST_KERNELS(3)

💅 DSB2ST_KERNELS(3) 💅

Okay so welcome to the Library Functions Manual, bestie — this page is all about DSB2ST_KERNELS(3), and it’s giving internal LAPACK routine energy. Grab a lil snack 🍓, because we’re gonna keep every single detail exactly where it belongs.

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✨ NAME ✨

The NAME section is literally just this path — no extra lore, no hidden meaning, just the file:

/home/abuild/rpmbuild/BUILD/lapack-static-3.12.0-build/lapack-3.12.0/SRC/dsb2st_kernels.f

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✨ SYNOPSIS ✨

Functions/Subroutines

       subroutine DSB2ST_KERNELS (uplo, wantz, ttype, st, ed, sweep, n, nb, ib,
           a, lda, v, tau, ldvt, work)
           DSB2ST_KERNELS

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🦋 FUNCTION/SUBROUTINE DOCUMENTATION 🦋

Here’s the full typed-out signature, copied exactly because we do not play with source code:

   subroutine DSB2ST_KERNELS (character uplo, logical wantz, integer ttype,
       integer st, integer ed, integer sweep, integer n, integer nb, integer
       ib, double precision, dimension( lda, * ) a, integer lda, double
       precision, dimension( * ) v, double precision, dimension( * ) tau,
       integer ldvt, double precision, dimension( * ) work)
       DSB2ST_KERNELS

🎀 PURPOSE 🎀

DSB2ST_KERNELS is an internal routine used by the DSYTRD_SB2ST subroutine. That’s the whole purpose, and honestly? iconic minimalism. ✨

🍓 PARAMETERS 🍓

• UPLO — UPLO is CHARACTER*1. That’s literally all the original gives us here, bestie.
• WANTZ — WANTZ is LOGICAL, and it indicates if eigenvalues are requested, or both eigenvalues/eigenvectors.
• TTYPE — TTYPE is INTEGER.
• ST — ST is INTEGER, and it’s an internal parameter for indices.
• ED — ED is INTEGER, and it’s an internal parameter for indices.
• SWEEP — SWEEP is INTEGER, and it’s an internal parameter for indices.
• N — N is INTEGER. It’s the order of the matrix A.
• NB — NB is INTEGER. It’s the size of the band.
• IB — IB is INTEGER.
• A — A is a DOUBLE PRECISION array. It’s a pointer to the matrix A.
• LDA — LDA is INTEGER. It’s the leading dimension of the matrix A.
• V — V is a DOUBLE PRECISION array, dimension 2*n if eigenvalues only are requested or to be queried for vectors.
• TAU — TAU is a DOUBLE PRECISION array, dimension (2*n). The scalar factors of the Householder reflectors are stored in this array.
• LDVT — LDVT is INTEGER.
• WORK — WORK is a DOUBLE PRECISION array. Workspace of size nb.

💜 FURTHER DETAILS 💜

Implemented by Azzam Haidar. 💖

All details are available on technical report, SC11, SC13 papers.

• Azzam Haidar, Hatem Ltaief, and Jack Dongarra. “Parallel reduction to condensed forms for symmetric eigenvalue problems using aggregated fine-grained and memory-aware kernels.” In Proceedings of 2011 International Conference for High Performance Computing, Networking, Storage and Analysis (SC '11), New York, NY, USA, Article 8 , 11 pages. http://doi.acm.org/10.1145/2063384.2063394
• A. Haidar, J. Kurzak, P. Luszczek, 2013. “An improved parallel singular value algorithm and its implementation for multicore hardware, In Proceedings of 2013 International Conference for High Performance Computing, Networking, Storage and Analysis (SC '13). Denver, Colorado, USA, 2013. Article 90, 12 pages.” http://doi.acm.org/10.1145/2503210.2503292
• A. Haidar, R. Solca, S. Tomov, T. Schulthess and J. Dongarra. “A novel hybrid CPU-GPU generalized eigensolver for electronic structure calculations based on fine-grained memory aware tasks.” International Journal of High Performance Computing Applications. Volume 28 Issue 2, Pages 196-209, May 2014. http://hpc.sagepub.com/content/28/2/196

Definition at line 169 of file dsb2st_kernels.f.

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👑 AUTHOR 👑

Generated automatically by Doxygen for LAPACK from the source code. 🫶

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Sign-off time, bestie: this cutie is LAPACK Version 3.12.0, and the page footer points to /home/abui...t_kernels.f(3). Stay shiny, and remember: internal routines deserve love too. 💖✨🎀