BLIS 1.2

This release contains several new features and optimizations related to threaded execution, as well as internal changes that improve maintainability and lay the groundwork for future refactoring. The build system and kernel sets saw lots of new code and tweaks to old code, and of course there were many bugfixes.

Improvements present in 1.2 (June 25, 2025):

Compatibility:

• gemmtr aliases for the gemmt BLAS and CBLAS compatibility functions have been added to support recent versions of LAPACK. (Mo Zhou)

Kernels:

• Fixed bug affecting reference kernels with clang 14.
• Fixed an incompatibility between the haswell gemmsup kernels and gcc 15. (Dave Love, Christopher Hillenbrand)

Build system:

• Disabled armsve on Windows due to build failures. (Hernan Martinez, Atsushi Tatsuma)
• Moved #include <omp.h> from blis.h to the relevant source files. (Melven Roehrig-Zoellner)
• Disable building KNL with gcc 15. (Dave Love)

Testing:

• CI testing infrastructure has moved to CircleCI.

Documentation:

• Widened print format in code examples to avoid misinterpretation of results. (Minh Quan Ho, Mason McBride)

Improvements present in 1.1 (January 15, 2025):

Compatibility:

• Added a ScaLAPACK compatibility mode which disables some conflicting BLAS definitions.
• Fixed issues with improperly escaped strings in python scripts for compatibility with python 3.12+. (@AngryLoki)

Kernels:

• Fixed an out-of-bounds read bug in the haswell gemmsup kernels. (John Mather)
• Fixed a bug in the complex-domain gemm kernels for piledriver. (@rmast)

Improvements present in 1.0 (May 6, 2024):

Framework:

• Initialize/finalize BLIS via a new bli_pthread_switch_t API. (Field Van Zee, Devin Matthews)
• Revamped bli_init() to use TLS where feasible. (Field Van Zee, Edward Smyth, Minh Quan Ho)
• Implemented support for fat multithreading.
• Implemented tile-level load balancing (tlb), or tile-level partitioning, in jr/ir loops for gemm, gemmt, and trmm macrokernels. (Field Van Zee, Devin Matthews, Leick Robinson, Minh Quan Ho)
• Added padding to thrcomm_t fields to avoid false sharing of cache lines. (Leick Robinson)
• Rewrote/fixed broken tree barrier implementation. (Leick Robinson)
• Refactored some rntm_t management code. (Field Van Zee, Devin Matthews)
• Initialize rntm_t nt/ways fields with 1 (not -1). (Field Van Zee, Jeff Diamond, Leick Robinson, Devin Matthews)
• Defined invscalv, invscalm, invscald operations.
• Added consistent NaN/Inf handling in sumsqv. (Devin Matthews)
• Implemented support for HPX as a threading backend option. (Christopher Taylor, Srinivas Yadav)
• Relocated the pba, sba pool (from the rntm_t), and mem_t (from the cntl_t) to the thrinfo_t object.
• Modified which communicator is associated with a given node of the thrinfo_t tree. (Devin Matthews)
• Refactored level-3 thread decorator into two parts: a thread launcher and a function to pass operands. (Devin Matthews)
• Refactored structure awareness in bli_packm_blk_var1.c. (Devin Matthews)
• Reimplemented bli_l3_determine_kc(). (Devin Matthews)
• Implemented cntx_t pointer caching in gks. (Field Van Zee, Harihara Sudhan S)
• Added const keyword to pointers in kernel APIs. (Field Van Zee, Nisanth M P)
• Migrated all kernel APIs to use void* pointers.
• Defined new global scalar constants: BLIS_ONE_I, BLIS_MINUS_ONE_I, BLIS_NAN. (Devin Matthews)
• Disabled modification of KC in the gemmsup kernels. (Devin Matthews)
• Defined lt, lte, gt, gte operations and other miscellaneous updates.
• Consolidated INSERT_ macro sets via variadic macros. (Devin Matthews)
• De-templatized macrokernels for gemmt, trmm, and trsm to match that of gemm. (Devin Matthews)
• De-templatized bli_l3_sup_var1n2m.c and unified _sup_packm_a/b(). (Devin Matthews)
• Fixed 1m enablement for herk/her2k/syrk/syr2k. (Devin Matthews)
• Fixed trmm[3]/trsm performance bug introduced in cf7d616. (Field Van Zee, Leick Robinson)
• Fixed a 1m optimization bug in right-sided hemm/symm. (Field Van Zee, Nisanth M P)
• Fixed a bug in sup threshold registration. (Devin Matthews, Field Van Zee)
• Fixed brokenness in the small block allocator (sba) when the sba is disabled. (Field Van Zee, John Mather)
• Fixed type bug in bli_cntx_set_ukr_prefs(). (Field Van Zee, Leick Robinson, Devin Matthews, Jeff Diamond)
• Fixed incorrect sizeof(type) in edge case macros. (@moon-chilled)
• Fixed bugs and added sanity check in bli_pool.c. (Devin Matthews)
• Fixed a typo in the macro definition for VEXTRACTF64X2 in bli_x86_asm_macros.h. (Harsh Dave)
• Fixed a typo in bli_type_defs.h where BLIS_BLAS_INT_TYPE_SIZE was misspelled. (Devin Matthews)
• Typecast printf() args in bli_thread_range_tlb.c to avoid compiler warnings. (Lee Killough)
• Minor tweaks to bli_l3_check.c.
• Partial addition of const to all interfaces above the (micro)kernels. (Devin Matthews)
• Fixed a harmless misspelling of xpbys in gemm macrokernel.
• Various internal API renaming/reorganization.
• Various other fixes.

Compatibility:

• Implemented [cz]symv_(), [cz]syr_(), [cz]rot_(). (Field Van Zee, James Foster)
• Fixed compilation errors when BLIS_DISABLE_BLAS_DEFS is defined. (Field Van Zee, Edward Smyth, Devin Matthews)
• Include bli_config.h before bli_system.h in cblas.h so that BLIS_ENABLE_SYSTEM is defined in time for proper OS detection. (Edward Smyth)

Kernels:

• Updated ARMv8a kernels to fix two prefetching issues and re-enable general stride IO. (Jeff Diamond)
• Restored general storage case to armsve kernels. (RuQing Xu)
• Added arm64 dgemmsup with extended MR and NR. (RuQing Xu)
• Reorganized the way packm kernels are stored within the cntx_t so that BLIS only stores two packm kernels per datatype: one for MRxk upanels and one for kxNR upanels. (Devin Matthews)
• Fixed bugs in scal2v reference kernel when alpha == 1.
• Fixed out-of-bounds read in haswell gemmsup kernels. (Daniël de Kok, Bhaskar Nallani, Madeesh Kannan)
• Fixed k = 0 edge case in power10 microkernels. (Nisanth M P)
• Disabled power10 kernels other than sgemm, dgemm. (Nisanth M P)
• Fixed bli_gemm_small() prototype mismatch. (Jeff Diamond)

Extras:

• Use the conventional level-3 sup thread decorator within the gemmlike sandbox.
• Fixed type-mismatch errors in power10 sandbox. (Nisanth M P)
• Fixed gemmlike sandbox bug that stems from reuse of bli_thrinfo_sup_grow().

Build system:

• Added two arm64 subconfigs: altra and altramax. (Jeff Diamond, Leick Robinson)
• Added support for RISC-V configuration targets. (Angelika Schwarz, Lee Killough)
• Auto-detect the RISC-V ABI of the compiler and use -mabi= during RISC-V builds. (Lee Killough)
• Added sifive_x280 subconfig and kernel set. (Aaron Hutchinson, Lee Killough, Devin Matthews, and Angelika Schwarz)
• Added AddressSanitizer (--enable-asan) option to configure. (Devin Matthews)
• Added option to disable thread-local storage via --disable-tls. (Field Van Zee, Nick Knight)
• Exclude -lrt on Android with Bionic libraries. (Lee Killough)
• Omit -fPIC option when shared library build is disabled. (Field Van Zee, Nick Knight)
• Move -fPIC option insertion to subconfigs' make_defs.mk files. (Field Van Zee, Nick Knight)
• Install one-line helper headers to INCDIR prefix so that user can #include "blis.h" instead of #include <blis/blis.h> and/or "cblas.h" instead of <blis/cblas.h> if CBLAS is enabled). (Field Van Zee, Jed Brown, Devin Matthews, Mo Zhou)
• Enhanced detection of Fortran compiler when checking the version string for the purposes of determining a default return convention for complex domain values. (Bart Oldeman)
• Added detection of the NVIDIA nvhpc compiler (nvc) in configure. (Ajay Panyala)
• Updated zen3 subconfig to support NVHPC compilers. (Abhishek Bagusetty)
• Use kernel CFLAGS for kernels subdirs in addons. (AMD, Mithun Mohan)
• Created power umbrella configuration family (which currently includes power9 and power10 subconfigs). (Nisanth M P)
• Defined BLIS_VERSION_STRING in blis.h instead of via command line argument during compilation. (Field Van Zee, Mohsen Aznaveh, Tim Davis)
• Rewrote regen-symbols.sh as gen-libblis-symbols.sh. (Field Van Zee)
• Support clang targetting MinGW. (Isuru Fernando)
• Added autodetection (via /proc/cpuinfo) for POWER7, POWER9 and POWER10 microarchitectures. (Alexander Grund)
• Added #line directives to flattened blis.h to facilitate easier debugging. (Devin Matthews)
• Added --nosup and --sup shorthand options to configure.
• Use here-document syntax for configure --help output. (Lee Killough)
• Updated configure to pass all shellcheck checks. (Lee Killough)
• Tweaks to .dir-locals.el to enhance emacs formatting of C files. (Lee Killough)
• Removed buggy cruft from power10 subconfig. (Field Van Zee, Nicholai Tukanov)
• Added missing #include <io.h> for Windows. (@h-vetinari)
• Fixed hardware auto-detection for firestorm (Apple M1) subconfig. (Devin Matthews)
• Fixed bug in detection of Fortran compiler vendor. (Devin Matthews)
• Fixed version check for znver3, which needs gcc >= 10.3. (Jed Brown)
• Fixed typo in configure --help text. (Lee Killough)
• Fixed warning about regular expressions with stray backslashes as the result of recent changes to grep.
• Added output.testsuite to .gitignore.
• Minor changes to .gitignore and LICENSE files. (Jeff Diamond)
• Minor decluttering of top-level directory.
• Very minor tweaks to common.mk.

Testing:

• Rewrote test/3 drivers to take parameters via command line arguments. (Field Van Zee, Jeff Diamond, Leick Robinson)
• Added arm64 entry to .travis.yml so that Travis CI will compile/test ARM builds. (Field Van Zee, RuQing Xu)
• Test the gemmlike sandbox via AppVeyor. (Jeff Diamond)
• Added -q quiet mode option to testsuite.
• Fixed non-deterministic segfault in standalone test/3 drivers. (Field Van Zee, Leick Robinson)
• Fixed a crash that occurs when either cblat1 or zblat1 are linked with a build of BLIS that was compiled with --complex-return=intel. (Bart Oldeman)
• Other minor fixes/tweaks.

Documentation:

• Added Discord documentation (docs/Discord.md) and logo to README.md.
• Added the mm_algorithm files (for bp and pb) to docs/diagrams.
• Added mention of Wilkinson Prize to README.md.
• Minor fixes and improvements to docs/Multithreading.md.
• Fix typos in docs + example code comments. (Igor Zhuravlov)