COMP: Remove dead vendored netlib LAPACK; cherry-pick lsame into blas

[hjmjohnson]

Removes the vendored netlib LAPACK tree from VNL (~248 files, −56k LOC). No VNL class calls any LAPACK routine — vnl uses the older linpack (SVD/QR/Cholesky) and eispack (eigensystems) paths. The single LAPACK symbol reached from retained code, lsame_, is cherry-picked into blas/. Advances the VNL pruning direction (#6403).

What lsame provides for BLAS (why it's kept)

lsame_(ca, cb) is a case-insensitive single-character equality test — the helper BLAS level-2/3 routines use to parse their option flags (TRANS∈{N,T,C}, UPLO∈{U,L}, DIAG, SIDE), so a caller may pass either case. blas/dgemm.c, dgemv.c, dtrmm.c, dtrsv.c, … call it ~99×. It is portable across character encodings (ASCII / EBCDIC / CDC), which is why it's ~120 lines rather than a one-liner. It has no dependencies of its own. Reference-LAPACK ships lsame as part of the BLAS reference, so relocating it into blas/ is the natural home; it merely lived under lapack/util/ in netlib's f2c packaging.

Why the rest of LAPACK is dead (verification)

• No VNL class references a LAPACK driver — confirmed across core/vnl/** (the one apparent hit, vnl_real_eigensystem, only mentions dgeev in a comment; it calls eispack rg_).
• No retained netlib subdir (blas/linpack/opt/eispack/sparse/linalg) calls any of the 82 LAPACK driver routines; only lsame_ is reached (by BLAS).
• The lone direct LAPACK consumer was the test test_qsvd (sggsvd_, a generalized SVD that no VNL class exposes) — dropped.
• ieeeck/ilaenv/izmax1 (LAPACK util) had zero retained callers — removed.
• Build links and all 23 vnl_algo tests pass without the removed files — the linker is the proof the drivers were dead.

Change scope

• git mv lapack/util/lsame.{c,h} → blas/ (provenance comment added to both).
• Delete v3p/netlib/lapack/ (82 drivers + 3 util + headers).
• CMakeLists.txt: drop V3P_NETLIB_lapack_SOURCES group + reference; add lsame to V3P_NETLIB_blas_SOURCES.
• v3p_netlib_prototypes.h: drop the LAPACK include block; add blas/lsame.h.
• v3p_netlib_mangle.h/unmangle.h: prune 82 LAPACK symbol entries (keep lsame_).
• v3p_netlib_init.c: drop slartg/dlartg per-routine init calls.
• Drop test_qsvd (source + driver DECLARE/REGISTER + add_test).

[greptile-apps]

Greptile Summary

Removes the vendored netlib LAPACK tree (~248 files, −56k LOC) from the VNL third-party layer, cherry-picking only lsame_ into blas/ because it is the sole LAPACK symbol still reached from the retained BLAS code. The accompanying test_qsvd test (the only VNL test that called a LAPACK driver) is dropped alongside the sources.

• CMakeLists.txt, mangle/unmangle headers, and the prototypes header are all updated consistently: 82 LAPACK driver symbols are pruned and lsame_ is re-homed under blas/.
• v3p_netlib_init.c drops the slartg/dlartg per-routine init calls that belonged to the removed tree.
• The new blas/lsame.c and blas/lsame.h carry multi-line in-source comments that exceed the repo's prose-budget cap and contain forbidden "deleted behavior" references, which is a style-guide violation for this repository.

Confidence Score: 4/5

The LAPACK removal is mechanically complete: CMakeLists, mangle/unmangle headers, prototype header, and init file are all updated consistently, and the lone retained symbol lsame_ is correctly re-homed under blas/.

All build-wiring changes are internally consistent and the lsame_ symbol path is intact. The two new files carry multi-line comments that breach the repo's in-source prose-budget rule, but this does not affect runtime behavior.

blas/lsame.c and blas/lsame.h — prose-budget violations in the added comments.

Important Files Changed

Filename	Overview
Modules/ThirdParty/VNL/src/vxl/v3p/netlib/blas/lsame.c	New file: correct f2c translation of lsame_, but the 3-line provenance comment violates the 1-line/100-char in-source cap and contains a forbidden "deleted behavior" reference.
Modules/ThirdParty/VNL/src/vxl/v3p/netlib/blas/lsame.h	New file: prototype matches old lapack/util/lsame.h correctly, but the 2-line comment violates the in-source prose cap and references deleted behavior.
Modules/ThirdParty/VNL/src/vxl/v3p/netlib/CMakeLists.txt	Removes V3P_NETLIB_lapack_SOURCES group and its reference; adds lsame.c/lsame.h to V3P_NETLIB_blas_SOURCES. Mechanically correct.
Modules/ThirdParty/VNL/src/vxl/v3p/netlib/v3p_netlib_mangle.h	Removes 82 LAPACK symbol defines; correctly retains lsame_ → v3p_netlib_lsame_ mapping.
Modules/ThirdParty/VNL/src/vxl/v3p/netlib/v3p_netlib_unmangle.h	Symmetric removal of 82 LAPACK #undef entries; retains lsame_ unmangle correctly.
Modules/ThirdParty/VNL/src/vxl/v3p/netlib/v3p_netlib_prototypes.h	Swaps lapack includes for blas/lsame.h; insertion at the top of the blas block is correct.
Modules/ThirdParty/VNL/src/vxl/v3p/netlib/v3p_netlib_init.c	Drops slartg/dlartg init calls that belonged to removed LAPACK sources; remaining slamch/dlamch inits are unaffected.
Modules/ThirdParty/VNL/src/vxl/core/vnl/algo/tests/CMakeLists.txt	Removes test_qsvd.cxx source and its add_test entry; consistent with dropping the sggsvd_ caller.
Modules/ThirdParty/VNL/src/vxl/core/vnl/algo/tests/test_driver.cxx	Removes DECLARE/REGISTER for test_qsvd; remaining registration list is consistent.

Flowchart

%%{init: {'theme': 'neutral'}}%%
flowchart TD
    subgraph Before
        B_BLAS[blas/]
        B_LAPACK[lapack/double + single + util/]
        B_LAPACK_LSAME[lapack/util/lsame.c]
        B_TEST[test_qsvd → sggsvd_]
        B_LAPACK --> B_LAPACK_LSAME
        B_BLAS -->|calls lsame_| B_LAPACK_LSAME
        B_TEST -->|calls sggsvd_| B_LAPACK
    end

    subgraph After
        A_BLAS[blas/]
        A_BLAS_LSAME[blas/lsame.c cherry-picked]
        A_BLAS -->|calls lsame_| A_BLAS_LSAME
    end

    B_LAPACK -->|82 drivers + 3 util removed| X[deleted]
    B_TEST -->|test dropped| X

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flowchart TD
    subgraph Before
        B_BLAS[blas/]
        B_LAPACK[lapack/double + single + util/]
        B_LAPACK_LSAME[lapack/util/lsame.c]
        B_TEST[test_qsvd → sggsvd_]
        B_LAPACK --> B_LAPACK_LSAME
        B_BLAS -->|calls lsame_| B_LAPACK_LSAME
        B_TEST -->|calls sggsvd_| B_LAPACK
    end

    subgraph After
        A_BLAS[blas/]
        A_BLAS_LSAME[blas/lsame.c cherry-picked]
        A_BLAS -->|calls lsame_| A_BLAS_LSAME
    end

    B_LAPACK -->|82 drivers + 3 util removed| X[deleted]
    B_TEST -->|test dropped| X

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