Change void*-typed function pointers to void_fp.
- Updated all instances of void* variables that store function pointers
to variables of a new type, void_fp. Originally, I wanted to define
the type of void_fp as "void (*void_fp)( void )"--that is, a pointer
to a function with no return value and no arguments. However, once
I did this, I realized that gcc complains with incompatible pointer
type (-Wincompatible-pointer-types) warnings every time any such a
pointer is being assigned to its final, type-accurate function
pointer type. That is, gcc will silently typecast a void* to
another defined function pointer type (e.g. dscalv_ker_ft) during
an assignment from the former to the latter, but the same statement
will trigger a warning when typecasting from a void_fp type. I suspect
an explicit typecast is needed in order to avoid the warning, which
I'm not willing to insert at this time.
- Added a typedef to bli_type_defs.h defining void_fp as void*, along
with a commented-out version of the aborted definition described
above. (Note that POSIX requires that void* and function pointers
be interchangeable; it is the C standard that does not provide this
guarantee.)
- Comment updates to various _oapi.c files.
Details:
- Removed explicit reference to The University of Texas at Austin in the
third clause of the license comment blocks of all relevant files and
replaced it with a more all-encompassing "copyright holder(s)".
- Removed duplicate words ("derived") from a few kernels' license
comment blocks.
- Homogenized license comment block in kernels/zen/3/bli_gemm_small.c
with format of all other comment blocks.
Details:
- Consolidated the *sl.c and *rr.c level-3 macrokernels into a single
file per sl/rr pair, with those files named as they were before
c92762e. The consolidation does not take away the *option* of using
slab or round-robin assignment of micropanels to threads; it merely
*hides* the choice within the definitions of functions such as
bli_thread_range_jrir(), bli_packm_my_iter(), and bli_is_last_iter()
rather than expose that choice explicitly in the code. The choice of
slab or rr is not always hidden, however; there are some cases
involving herk and trmm, for example, that require some part of the
computation to use rr unconditionally. (The --thread-part-jrir option
controls the partitioning in all other cases.)
- Note: Originally, the sl and rr macrokernels were separated out for
clarity. However, aside from the additional binary code bloat, I later
deemed that clarity not worth the price of maintaining the additional
(mostly similar) codes.
Details:
- Implemented support for gemm where A, B, and C may have different
storage datatypes, as well as a computational precision (and implied
computation domain) that may be different from the storage precision
of either A or B. This results in 128 different combinations, all
which are implemented within this commit. (For now, the mixed-datatype
functionality is only supported via the object API.) If desired, the
mixed-datatype support may be disabled at configure-time.
- Added a memory-intensive optimization to certain mixed-datatype cases
that requires a single m-by-n matrix be allocated (temporarily) per
call to gemm. This optimization aims to avoid the overhead involved in
repeatedly updating C with general stride, or updating C after a
typecast from the computation precision. This memory optimization may
be disabled at configure-time (provided that the mixed-datatype
support is enabled in the first place).
- Added support for testing mixed-datatype combinations to testsuite.
The user may test gemm with mixed domains, precisions, both, or
neither.
- Added a standalone test driver directory for building and running
mixed-datatype performance experiments.
- Defined a new variation of castm, castnzm, which operates like castm
except that imaginary values are not touched when casting a real
operand to a complex operand. (By contrast, in these situations castm
sets the imaginary components of the destination matrix to zero.)
- Defined bli_obj_imag_is_zero() and substituted calls in lieu of all
usages of bli_obj_imag_equals() that tested against BLIS_ZERO, and
also simplified the implementation of bli_obj_imag_equals().
- Fixed bad behavior from bli_obj_is_real() and bli_obj_is_complex()
when given BLIS_CONSTANT objects.
- Disabled dt_on_output field in auxinfo_t structure as well as all
accessor functions. Also commented out all usage of accessor
functions within macrokernels. (Typecasting in the microkernel is
still feasible, though probably unrealistic for now given the
additional complexity required.)
- Use void function pointer type (instead of void*) for storing function
pointers in bli_l0_fpa.c.
- Added documentation for using gemm with mixed datatypes in
docs/MixedDatatypes.md and example code in examples/oapi/11gemm_md.c.
- Defined level-1d operation xpbyd and level-1m operation xpbym.
- Added xpbym test module to testsuite.
- Updated frame/include/bli_x86_asm_macros.h with additional macros
(courtsey of Devin Matthews).
Details:
- Updated existing macrokernel function names and definitions to
explicitly use slab assignment of micropanels to threads, then created
duplicate versions of macrokernels that explicitly use round-robin
assignment instead of slab. NOTE: As in ac18949, trsm_r macrokernels
were not substantially updated in this commit because they are
currently disabled in bli_trsm_front.c.
- Updated existing packing function (in blk_packm_blk_var1.c) to
explicitly use slab partitioning, and then duplicated for round-robin.
- Updated control tree initialization to use the appropriate macrokernel
and packm function pointers depending on which method (slab or rr) was
enabled at configure-time.
- Updated configure script to accept new --thread-part-jrir=[slab|rr]
option (-m [slab|rr] for short), which allows the user to explicitly
request either slab or round-robin assignment (partitioning) of
micropanels to threads.
- Updated sandbox/ref99 according to above changes.
- Minor updates to build/add-copyright.py.
Details:
- Adjusted the method by which micropanels are assigned to threads in
the 2nd (jr) and 1st (ir) loops around the microkernel to (mostly)
employ contiguous "slab" partitioning rather than interleaved (round
robin) partitioning. The new partitioning schemes and related details
for specific families of operations are listed below:
- gemm: slab partitioning.
- herk: slab partitioning for region corresponding to non-triangular
region of C; round robin partitioning for triangular region.
- trmm: slab partitioning for region corresponding to non-triangular
region of B; round robin partitioning for triangular region.
(NOTE: This affects both left- and right-side macrokernels:
trmm_ll, trmm_lu, trmm_rl, trmm_ru.)
- trsm: slab partitioning.
(NOTE: This only affects only left-side macrokernels trsm_ll,
trsm_lu; right-side macrokernels were not touched.)
Also note that the previous macrokernels were preserved inside of
the 'other' directory of each operation family directory (e.g.
frame/3/gemm/other, frame/3/herk/other, etc).
- Updated gemm macrokernel in sandbox/ref99 in light of above changes
and fixed a stale function pointer type in blx_gemm_int.c
(gemm_voft -> gemm_var_oft).
- Added standalone test drivers in test/3m4m for herk, trmm, and trsm
and minor changes to test/3m4m/Makefile.
- Updated the arguments and definitions of bli_*_get_next_[ab]_upanel()
and bli_trmm_?_?r_my_iter() macros defined in bli_l3_thrinfo.h.
- Renamed bli_thread_get_range*() APIs to bli_thread_range*().
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.
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.
Details:
- Applied changes to ref99 sandbox analagous to those applied to
framework code in f97a86f. This involves setting the pack schemas of
A and B objects temporarily to communicate those desired schemas to
the control tree creation function in blx_gemm_cntl.c. This allows us
to (henceforth) query the schemas from the control tree rather than
the context.
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.
Details:
- Reordered the arguments in the ref99 sandbox's call to
bli_cntx_set_thrloop_from_env() to be consistent with the updated
function signature from f97a86f. Thanks to Devangi Parikh for
reporting this issue.
Details:
- Minor edits to sandbox/ref99/README.md.
- Removed cpp guards in sandbox/ref99/thread/blx_gemm_thread.h to be
consistent with other headers in sandbox/ref99.
- Additional targets and related cleanups in test/3m4m/Makefile.
Details:
- Renamed sandbox/c99 to sandbox/ref99. I wanted to name the sandbox so
that it would be thought of as a "reference" sandbox. I kept the "99"
to differientiate it from future reference sandboxes that may be
written in another language (such as C++).
- Updates to sandbox/ref99/README.md.
Details:
- Added a c99 sandbox (in sandbox/c99) to serve as a starting point for
others looking to experiment with alternative implementations of gemm
in BLIS. Note that this sandbox implementation is a first draft and
will be refined over time.
- Minor updates to Makefile and common.mk to restrict what source files
get recompiled when sandbox files are touched.
- Added an initial draft of a README.md in sandbox/c99.
Detail:
- configure:
- add support for --enable-sandbox=NAME to configure script, where NAME
is a subdirectory of a new 'sandbox' directory that contains an
alternative implementation of gemm. (For now, only implementations of
gemm may be provided via a sandbox.);
- add support for C++ compiler. C++ compilers are handled in a manner
similar to that of C compilers, in that a default search order is
used, and that CXX is searched for first, if the variable is set. In
practice, the C++ compiler that is selected should correspond to the
selected C compiler. (Example: If gcc is selected for C, g++ should
be selected for C++.) The result of the search is output to config.mk
via build/config.mk.in. NOTE: The use of C++ in BLIS is still
hypothetical, but may eventually move to being experimental. This
support was intended only for use of C++ within a gemm sandbox.
- build/config.mk.in:
- define SANDBOX variable containing sandbox subdirectory name.
- build/bli_config.in:
- define either of the BLIS_ENABLE_SANDBOX or BLIS_DISABLE_SANDBOX
macros in bli_config.h.
- common.mk:
- include makefile fragments that were propagated into the specified
sandbox subdirectory;
- generate different CFLAGS for sandboxes, as well as a separate
CXXFLAGS variable for sandboxes when C++ source files are compiled;
- isolate into a single location lists of file suffixes for various
purposes.
- reorganized/clean up code related to identifying header files and
paths.
- Makefile:
- generate object filepaths for and compile source code files found in
sandbox sub-directory;
- remove makefile fragments placed in sandbox sub-directory (cleanmk);
- various other cleanups.
- Added .cc, .cpp, and .cxx to list of suffixes of files to recognize in
makefile fragments (via build/gen-make-frags/suffix_list).
- Updated blis.h to conditionally #include bli_sandbox.h (via a new file,
bli_sbox.h), which each sandbox is assumed to use for any type
definitions and function prototypes it wishes to export out to blis.h.
- Conditionally disable bli_gemmnat() implementation in frame/3 when
BLIS_ENABLE_SANDBOX is defined.
