7 Commits

Author	SHA1	Message	Date
Field G. Van Zee	4fa4cb0734	Trivial comment header updates. ... Details: - Removed four trailing spaces after "BLIS" that occurs in most files' commented-out license headers. - Added UT copyright lines to some files. (These files previously had only AMD copyright lines but were contributed to by both UT and AMD.) - In some files' copyright lines, expanded 'The University of Texas' to 'The University of Texas at Austin'. - Fixed various typos/misspellings in some license headers.	2018-08-29 18:06:41 -05:00
Field G. Van Zee	ecbebe7c2e	Defined rntm_t to relocate cntx_t.thrloop (#235). ... Details: - Defined a new struct datatype, rntm_t (runtime), to house the thrloop field of the cntx_t (context). The thrloop array holds the number of ways of parallelism (thread "splits") to extract per level-3 algorithmic loop until those values can be used to create a corresponding node in the thread control tree (thrinfo_t structure), which (for any given level-3 invocation) usually happens by the time the macrokernel is called for the first time. - Relocating the thrloop from the cntx_t remedies a thread-safety issue when invoking level-3 operations from two or more application threads. The race condition existed because the cntx_t, a pointer to which is usually queried from the global kernel structure (gks), is supposed to be a read-only. However, the previous code would write to the cntx_t's thrloop field *after* it had been queried, thus violating its read-only status. In practice, this would not cause a problem when a sequential application made a multithreaded call to BLIS, nor when two or more application threads used the same parallelization scheme when calling BLIS, because in either case all application theads would be using the same ways of parallelism for each loop. The true effects of the race condition were limited to situations where two or more application theads used *different* parallelization schemes for any given level-3 call. - In remedying the above race condition, the application or calling library can now specify the parallelization scheme on a per-call basis. All that is required is that the thread encode its request for parallelism into the rntm_t struct prior to passing the address of the rntm_t to one of the expert interfaces of either the typed or object APIs. This allows, for example, one application thread to extract 4-way parallelism from a call to gemm while another application thread requests 2-way parallelism. Or, two threads could each request 4-way parallelism, but from different loops. - A rntm_t* parameter has been added to the function signatures of most of the level-3 implementation stack (with the most notable exception being packm) as well as all level-1v, -1d, -1f, -1m, and -2 expert APIs. (A few internal functions gained the rntm_t* parameter even though they currently have no use for it, such as bli_l3_packm().) This required some internal calls to some of those functions to be updated since BLIS was already using those operations internally via the expert interfaces. For situations where a rntm_t object is not available, such as within packm/unpackm implementations, NULL is passed in to the relevant expert interfaces. This is acceptable for now since parallelism is not obtained for non-level-3 operations. - Revamped how global parallelism is encoded. First, the conventional environment variables such as BLIS_NUM_THREADS and BLIS_*_NT are only read once, at library initialization. (Thanks to Nathaniel Smith for suggesting this to avoid repeated calls getenv(), which can be slow.) Those values are recorded to a global rntm_t object. Public APIs, in bli_thread.c, are still available to get/set these values from the global rntm_t, though now the "set" functions have additional logic to ensure that the values are set in a synchronous manner via a mutex. If/when NULL is passed into an expert API (meaning the user opted to not provide a custom rntm_t), the values from the global rntm_t are copied to a local rntm_t, which is then passed down the function stack. Calling a basic API is equivalent to calling the expert APIs with NULL for the cntx and rntm parameters, which means the semantic behavior of these basic APIs (vis-a-vis multithreading) is unchanged from before. - Renamed bli_cntx_set_thrloop_from_env() to bli_rntm_set_ways_for_op() and reimplemented, with the function now being able to treat the incoming rntm_t in a manner agnostic to its origin--whether it came from the application or is an internal copy of the global rntm_t. - Removed various global runtime APIs for setting the number of ways of parallelism for individual loops (e.g. bli_thread_set_*_nt()) as well as the corresponding "get" functions. The new model simplifies these interfaces so that one must either set the total number of threads, OR set all of the ways of parallelism for each loop simultaneously (in a single function call). - Updated sandbox/ref99 according to above changes. - Rewrote/augmented docs/Multithreading.md to document the three methods (and two specific ways within each method) of requesting parallelism in BLIS. - Removed old, disabled code from bli_l3_thrinfo.c. - Whitespace changes to code (e.g. bli_obj.c) and docs/BuildSystem.md.	2018-07-17 18:37:32 -05:00
Field G. Van Zee	87db5c048e	Changed usage of virtual microkernel slots in cntx. ... Details: - Changed the way virtual microkernels are handled in the context. Previously, there were query routines such as bli_cntx_get_l3_ukr_dt() which returned the native ukernel for a datatype if the method was equal to BLIS_NAT, or the virtual ukernel for that datatype if the method was some other value. Going forward, the context native and virtual ukernel slots will both be initialized to native ukernel function pointers for native execution, and for non-native execution the virtual ukernel pointer will be something else. This allows us to always query the virtual ukernel slot (from within, say, the macrokernel) without needing any logic in the query routine to decide which function pointer (native or virtual) to return. (Essentially, the logic has been shifted to init-time instead of compute-time.) This scheme will also allow generalized virtual ukernels as a way to insert extra logic in between the macrokernel and the native microkernel. - Initialize native contexts (in bli_cntx_ref.c) with native ukernel function addresses stored to the virtual ukernel slots pursuant to the above policy change. - Renamed all static functions that were native/virtual-ambiguous, such as bli_cntx_get_l3_ukr_dt() or bli_cntx_l3_ukr_prefers_cols_dt() pursuant to the above polilcy change. Those routines now use the substring "get_l3_vir_ukr" in their name instead of "get_l3_ukr". All of these functions were static functions defined in bli_cntx.h, and most uses were in level-3 front-ends and macrokernels. - Deprecated anti_pref bool_t in context, along with related functions such as bli_cntx_l3_ukr_eff_dislikes_storage_of(), now that 1m's panel-block execution is disabled.	2018-06-12 19:38:37 -05:00
Field G. Van Zee	2610fff0b0	Renamed 1m packm kernels from _1e to _1er. ... Details: - Renamed the reference packm kernels used by 1m. Previously, they used a _1e suffix, which was confusing since they packed to both 1e and 1r schemas. This was likely an artifact of the time when there were separate kernels for each schema before I decided to combine them into a single function (per datatype and panel dimension), and the 1e functions were the ones to inherit the 1r functionality. The kernels have now been renamed to use a _1er suffix.	2018-06-11 12:32:54 -05:00
Field G. Van Zee	f07b176c84	Fixed an obscure bug in the 1m implementation. ... Details: - Fixed a bug in the way the bli_gemm1m_cntx_ref() function (defined in ref_kernels/bli_cntx_ref.c) initializes its context for 1m execution. Previously, the function probed the context that was in the process of being updated for use with 1m--this context being previously initialized/copied from a native context--for its storage preference to determine which "variant" (row- or column-oriented) of 1m would be needed. However, the _cntx_ref() function was not updating the method field of the context until AFTER this query, and the conditional which depended on it, had taken place, meaning the storage preference query function would mistakenly think the context was for native execution, since the context's method field would still be set to BLIS_NAT. This would lead it to incorrectly grab the storage preference of the complex domain microkernel rather than the corresponding real domain microkernel, which could cause the storage preference predicate to evaluate to the wrong value, which would lead to the _cntx_ref() function choosing the wrong variant. This could lead to undefined behavior at runtime. The method is now explicitly set within the context prior to calling the storage preference query function. - Updated comments in frame/ind/oapi/bli_l3_3m4m1m_oapi.c. - Fixed a typo in the commented-out CFLAGS in config/zen/make_defs.mk, which are appropriate for gcc 6.x and newer. (Mistakenly used -march=bdver4 instead of -march=znver1.)	2018-02-15 18:36:54 -06:00
Field G. Van Zee	513ef4d040	Various typecasting fixes, mis-typed enums, etc. ... Details: - Fixed implicit typecasting of conj_t to trans_t in bli_[un]packm_cxk.c. - Properly typecast integer arguments to match format specifier in various calls to printf() in bli_l3_thrinfo.c, bli_cntx.c, bli_pool.c, and bli_util_oapi.c. - Fixed "unsigned less-than-comparison with zero" checks in bli_check.c, bli_cntx.h. - Fixed mis-typed enums in bli_cntx.c (e.g., l1mkr_t that should have been l1fkr_t or l1vkr_t). - Fixed instances of opid_t value BLIS_GEMM that should have been l3ukr_t value BLIS_GEMM_UKR in bli_cntx_ref.c. - NOTE: These issues were identified via compiler warnings when building BLIS with clang on a rather old installation of OS X: $ clang --version Apple LLVM version 5.0 (clang-500.2.79) (based on LLVM 3.3svn) Target: x86_64-apple-darwin15.2.0 Thread model: posix	2017-12-11 12:35:59 -06:00
Field G. Van Zee	453deb2906	Implemented runtime kernel management. ... Details: - Reworked the build system around a configuration registry file, named config_registry', that identifies valid configuration targets, their constituent sub-configurations, and the kernel sets that are needed by those sub-configurations. The build system now facilitates the building of a single library that can contains kernels and cache/register blocksizes for multiple configurations (microarchitectures). Reference kernels are also built on a per-configuration basis. - Updated the Makefile to use new variables set by configure via the config.mk.in template, such as CONFIG_LIST, KERNEL_LIST, and KCONFIG_MAP, in determining which sub-configurations (CONFIG_LIST) and kernel sets (KERNEL_LIST) are included in the library, and which make_defs.mk files' CFLAGS (KCONFIG_MAP) are used when compiling kernels. - Reorganized 'kernels' directory into a "flat" structure. Renamed kernel functions into a standard format that includes the kernel set name (e.g. 'haswell'). Created a "bli_kernels_<kernelset>.h" file in each kernels sub-directory. These files exist to provide prototypes for the kernels present in those directories. - Reorganized reference kernels into a top-level 'ref_kernels' directory. This directory includes a new source file, bli_cntx_ref.c (compiled on a per-configuration basis), that defines the code needed to initialize a reference context and a context for induced methods for the microarchitecture in question. - Rewrote make_defs.mk files in each configuration so that the compiler variables (e.g. CFLAGS) are "stored" (renamed) on a per-configuration basis. - Modified bli_config.h.in template so that bli_config.h is generated with #defines for the config (family) name, the sub-configurations that are associated with the family, and the kernel sets needed by those sub-configurations. - Deprecated all kernel-related information in bli_kernel.h and transferred what remains to new header files named "bli_arch_<configname>.h", which are conditionally #included from a new header bli_arch.h. These files are still needed to set library-wide parameters such as custom malloc()/free() functions or SIMD alignment values. - Added bli_cntx_init_<configname>.c files to each configuration directory. The files contain a function, named the same as the file, that initializes a "native" context for a particular configuration (microarchitecture). The idea is that optimized kernels, if available, will be initialized into these contexts. Other fields will retain pointers to reference functions, which will be compiled on a per-configuration basis. These bli_cntx_init_*() functions will be called during the initialization of the global kernel structure. They are thought of as initializing for "native" execution, but they also form the basis for contexts that use induced methods. These functions are prototyped, along with their _ref() and _ind() brethren, by prototype-generating macros in bli_arch.h. - Added a new typedef enum in bli_type_defs.h to define an arch_t, which identifies the various sub-configurations. - Redesigned the global kernel structure (gks) around a 2D array of cntx_t structures (pointers to cntx_t, actually). The first dimension is indexed over arch_t and the inner dimension is the ind_t (induced method) for each microarchitecture. When a microarchitecture (configuration) is "registered" at init-time, the inner array for that configuration in the 2D array is initialized (and allocated, if it hasn't been already). The cntx_t slot for BLIS_NAT is initialized immediately and those for other induced method types are initialized and cached on-demand, as needed. At cntx_t registration, we also store function pointers to cntx_init functions that will initialize (a) "reference" contexts and (b) contexts for use with induced methods. We don't cache the full contexts for reference contexts since they are rarely needed. The functions that initialize these two kinds of contexts are generated automatically for each targeted sub-configuration from cpp-templatized code at compile-time. Induced method contexts that need "stage" adjustments can still obtain them via functions in bli_cntx_ind_stage.c. - Added new functions and functionality to bli_cntx.c, such as for setting the level-1f, level-1v, and packm kernels, and for converting a native context into one for executing an induced method. - Moved the checking of register/cache blocksize consistency from being cpp macros in bli_kernel_macro_defs.h to being runtime checks defined in bli_check.c and called from bli_gks_register_cntx() at the time that the global kernel structure's internal context is initialized for a given microarchitecture/configuration. - Deprecated all of the old per-operation bli_*_cntx.c files and removed the previous operation-level cntx_t_init()/_finalize() invocations. Instead, we now query the gks for a suitable context, usually via bli_gks_query_cntx(). - Deprecated support for the 3m2 and 3m3 induced methods. (They required hackery that I was no longer willing to support.) - Consolidated the 1e and 1r packm kernels for any given register blocksize into a single kernel that will branch on the schema and support packing to both formats. - Added the cntx_t* argument to all packm kernel signatures. - Deprecated the local function pointer array in all bli_packm_cxk*.c files and instead obtain the packm kernel from the cntx_t. - Added bli_calloc_intl(), which serves as the calloc-equivalent to to bli_malloc_intl(). Useful when we wish to allocate and initialize to zero/NULL. - Converted existing cpp macro functions defined in bli_blksz.h, bli_func.h, bli_cntx.h into static functions.	2017-10-18 13:29:32 -05:00