Details:
- This commit adds a new BLIS sandbox that (1) provides implementations
based on low-precision gemm kernels, and (2) extends the BLIS typed
API for those new implementations. Currently, these new kernels can
only be used for the POWER10 microarchitecture; however, they may
provide a template for developing similar kernels for other
microarchitectures (even those beyond POWER), as changes would likely
be limited to select places in the microkernel and possibly the
packing routines. The new low-precision operations that are now
supported include: shgemm, sbgemm, i16gemm, i8gemm, i4gemm. For more
information, refer to the POWER10.md document that is included in
'sandbox/power10'.
Details:
- Fixed incorrect definition and prototype of bli_?gemmt() in
frame/3/bli_l3_tapi.c and .h, respectively. gemmt was previously
defined identically to gemm, which was wrong because it did not
take into account the uplo property of C.
- Fixed incorrect API documentation for her2k/syr2k in BLISTypedAPI.md.
Specifically, the document erroneously listed only a single transab
parameter instead of transa and transb.
Details:
- In exampls/tapi/00level1v.c, pointer 'z' was being freed twice and
pointer 'a' was not being freed at all. This commit correctly frees
each pointer exactly once.
Details:
- Implemented assembly-based packm kernels for single- and double-
precision complex domain (c and z) and housed them in the 'haswell'
kernel set. This means c3xk, c8xk, z3xk, and z4xk are now all
optimized.
- Registered the aforementioned packm kernels in the haswell, zen,
and zen2 subconfigs.
- Minor modifications to the corresponding s and d packm kernels that
were introduced in 426ad67.
- Thanks to AMD, who originally contributed the double-precision real
packm kernels (d6xk and d8xk), upon which these complex kernels are
partially based.
Details:
- Implemented assembly-based packm kernels for single- and double-
precision real domain (s and d) and housed them in the 'haswell'
kernel set. This means s6xk, s16xk, d6xk, and d8xk are now all
optimized.
- Registered the aforementioned packm kernels in the haswell, zen,
and zen2 subconfigs.
- Thanks to AMD, who originally contributed the double-precision real
packm kernels (d6xk and d8xk), which I have now tweaked and used to
create comparable single-precision real kernels (s6xk and s16xk).
Choose last sub-config in the kernel-to-config map if the config list doesn't contain the name of the kernel set. E.g. for "zen: skx knl haswell" pick "haswell" instead of "skx" which was chosen previously. Fixes#470.
Details:
- Expanded support for disabling trsm diagonal pre-inversion to other
microkernel types, including the reference microkernel as well as the
kernel implementations for 1m and the pre-broadcast B (bb) format used
by the power9 subconfig. This builds on the 'haswell' and 'penryn'
kernel support added in 7038bba. Thanks to Bhaskar Nallani for
reminding me, in #461 (post-closure), that 1m support was missing from
that commit.
- Removed cpp branch of ref_kernels/3/bli_trsm_ref.c that contained the
omp simd implementation after making a stripped-down copy in 'old'.
This code has been disabled for some time and it seemed better suited
to rot away out of sight rather than clutter up a file that is already
cluttered by the presence of lower and upper versions.
- Minor comment update to bli_ind_init().
Details:
- Previously, BLIS would automatically enable use of the 1m method
for a given precision if the complex domain microkernel was a
reference kernel. This commit adds an additional constraint so that
1m is only enabled if the corresponding real domain microkernel is
NOT reference. That is, BLIS now forgos use of 1m if both the real and
complex domain kernels are reference implementations. Note that this
does not prevent 1m from being enabled manually under those
conditions; it only means that 1m will not be enabled automatically
at initialization-time.
Details:
- Reduced a code segment that appears in all of the bli_*_front()
functions except for bli_gemm_front(). Previously, the code looked
like this (taken from bli_herk_front()):
if ( bli_cntx_method( cntx ) == BLIS_NAT )
{
bli_obj_set_pack_schema( BLIS_PACKED_ROW_PANELS, &a_local );
bli_obj_set_pack_schema( BLIS_PACKED_COL_PANELS, &ah_local );
}
else // if ( bli_cntx_method( cntx ) != BLIS_NAT )
{
pack_t schema_a = bli_cntx_schema_a_block( cntx );
pack_t schema_b = bli_cntx_schema_b_panel( cntx );
bli_obj_set_pack_schema( schema_a, &a_local );
bli_obj_set_pack_schema( schema_b, &ah_local );
}
This code segment is part of a sort-of-hack that allows us to
communicate the pack schemas into the level-3 thread decorator, which
needs them so that they can be passed into bli_l3_cntl_create_if(),
where the control tree is created. However, the first conditional case
above is unnecessary because the second case is fully generalized.
That is, even in the native case, the context contains correct,
queryable schemas. Thus, these code segments were reduced to something
like:
pack_t schema_a = bli_cntx_schema_a_block( cntx );
pack_t schema_b = bli_cntx_schema_b_panel( cntx );
bli_obj_set_pack_schema( schema_a, &a_local );
bli_obj_set_pack_schema( schema_b, &ah_local );
There's always a small chance that the seemingly unnecessary code
in the first branch case has some special use that is not apparent to
me, but the testsuite's default input parameters seem to think this
commit will be fine.
Details:
- Implemented a configure-time option, --disable-trsm-preinversion, that
optionally disables the pre-inversion of diagonal elements of the
triangular matrix in the trsm operation and instead uses division
instructions within the gemmtrsm microkernels. Pre-inversion is
enabled by default. When it is disabled, performance may suffer
slightly, but numerical robustness should improve for certain
pathological cases involving denormal (subnormal) numbers that would
otherwise result in overflow in the pre-inverted value. Thanks to
Bhaskar Nallani for reporting this issue via #461.
- Added preprocessor macro guards to bli_trsm_cntl.c as well as the
gemmtrsm microkernels for 'haswell' and 'penryn' kernel sets pursuant
to the aforementioned feature.
- Added macros to frame/include/bli_x86_asm_macros.h related to division
instructions.
Details:
- Exit early from libblis_test_amaxv_check() when the vector dimension
(length) of x is 0. This allows the module to run when the testsuite
driver passes in a problem size of 0. Thanks to Meghana Vankadari for
alerting us to this issue via #459.
- Note: All other testsuite modules appear to work with problem sizes
of 0, except for the microkernel modules. I chose not to "fix" those
modules because a failure (or segmentation fault, as happens in this
case) is actually meaningful in that it alerts the developer that some
microkernels cannot be used with k = 0. Specifically, the 'haswell'
kernel set contains microkernels that preload elements of B. Those
microkernels would need to be restructured to avoid preloading in
order to support usage when k = 0.
Details:
- Fixed a bug in the gemmt testsuite module that only manifested when
testing of gemmt is enabled but testing of gemv is disabled. The bug
was due to a copy-paste error dating back to the introduction of gemmt
in 88ad841.
Details:
- Fixed bugs in two sup kernels, bli_dgemmsup_rv_haswell_asm_1x6() and
bli_dgemmsup_rd_haswell_asm_1x4(), which involved extraneous assembly
instructions that were left over from when the kernels were first
written. These instructions would cause segmentation faults in some
situations where extra memory was not allocated beyond the end of
the matrix buffers. Thanks to Kiran Varaganti for reporting these
bugs and to Bhaskar Nallani for identifying the cause and solution.
Details:
- Reorganized logic of bli_thread_partition_2x2() so that the primary
guts were factored out into "fast" and "slow" variants. Then added
logic to the "fast" variant that allows for more optimal thread
factorizations in some situations where there is at least one factor
of 2.
- Changed BLIS_THREAD_RATIO_M from 2 to 1 in bli_kernel_macro_defs.h and
added comments to that file describing BLIS_THREAD_RATIO_? and
BLIS_THREAD_MAX_?R.
- In bli_family_zen.h and bli_family_zen2.h, preprocessed out several
macros not used in vanilla BLIS and removed the unused macro
BLIS_ENABLE_ZEN_BLOCK_SIZES from the former file.
- Disabled AMD's small matrix handling entry points in bli_syrk_front.c
and bli_trsm_front.c. (These branches of small matrix handling have
not been reviewed by vanilla BLIS developers.)
- Added commented-out calls printf() to bli_rntm.c.
- Whitespace changes to bli_thread.c.
Details:
- When requesting multithreaded parallelism by specifying the total
number of threads (whether it be via environment variable, globally at
runtime, or locally at runtime), reduce the number of threads actually
used by one if the original value (a) is prime and (b) exceeds a
minimum threshold defined by the macro BLIS_NT_MAX_PRIME, which is set
to 11 by default. If, when specifying the total number of threads (and
not the individual ways of parallelism for each loop), prime numbers
of threads are desired, this feature may be overridden by defining the
BLIS_ENABLE_AUTO_PRIME_NUM_THREADS macro in the bli_family_*.h that
corresponds to the configuration family targeted at configure-time.
(For now, there is no configure option(s) to control this feature.)
Thanks to Jeff Diamond for suggesting this change.
- Defined a new function in bli_thread.c, bli_is_prime(), that returns a
bool that determines whether an integer is prime. This function is
implemented in terms of existing functions in bli_thread.c.
- Updated docs/Multithreading.md to document the above feature, along
with unrelated minor edits.
Details:
- Added a configure option, --[enable|disable]-system, which determines
whether the modest operating system dependencies in BLIS are included.
The most notable example of this on Linux and BSD/OSX is the use of
POSIX threads to ensure thread safety for when application-level
threads call BLIS. When --disable-system is given, the bli_pthreads
implementation is dummied out entirely, allowing the calling code
within BLIS to remain unchanged. Why would anyone want to build BLIS
like this? The motivating example was submitted via #454 in which a
user wanted to build BLIS for a simulator such as gem5 where thread
safety may not be a concern (and where the operating system is largely
absent anyway). Thanks to Stepan Nassyr for suggesting this feature.
- Another, more minor side effect of the --disable-system option is that
the implementation of bli_clock() unconditionally returns 0.0 instead
of the time elapsed since some fixed point in the past. The reasoning
for this is that if the operating system is truly minimal, the system
function call upon which bli_clock() would normally be implemented
(e.g. clock_gettime()) may not be available.
- Refactored preprocess-guarded code in bli_pthread.c and bli_pthread.h
to remove redundancies.
- Removed old comments and commented #include of "bli_pthread_wrap.h"
from bli_system.h.
- Documented bli_clock() and bli_clock_min_diff() in BLISObjectAPI.md
and BLISTypedAPI.md, with a note that both are non-functional when
BLIS is configured with --disable-system.
Merged contributions from AMD's AOCL BLIS (#448).
Details:
- Added support for level-3 operation gemmt, which performs a gemm on
only the lower or upper triangle of a square matrix C. For now, only
the conventional/large code path will be supported (in vanilla BLIS).
This was accomplished by leveraging the existing variant logic for
herk. However, some of the infrastructure to support a gemmtsup is
included in this commit, including
- A bli_gemmtsup() front-end, similar to bli_gemmsup().
- A bli_gemmtsup_ref() reference handler function.
- A bli_gemmtsup_int() variant chooser function (with variant calls
commented out).
- Added support for inducing complex domain gemmt via the 1m method.
- Added gemmt APIs to the BLAS and CBLAS compatiblity layers.
- Added gemmt test module to testsuite.
- Added standalone gemmt test driver to 'test' directory.
- Documented gemmt APIs in BLISObjectAPI.md and BLISTypedAPI.md.
- Added a C++ template header (blis.hh) containing a BLAS-inspired
wrapper to a set of polymorphic CBLAS-like function wrappers defined
in another header (cblas.hh). These two headers are installed if
running the 'install' target with INSTALL_HH is set to 'yes'. (Also
added a set of unit tests that exercise blis.hh, although they are
disabled for now because they aren't compatible with out-of-tree
builds.) These files now live in the 'vendor' top-level directory.
- Various updates to 'zen' and 'zen2' subconfigurations, particularly
within the context initialization functions.
- Added s and d copyv, setv, and swapv kernels to kernels/zen/1, and
various minor updates to dotv and scalv kernels. Also added various
sup kernels contributed by AMD to kernels/zen/3. However, these
kernels are (for now) not yet used, in part because they caused
AppVeyor clang failures, and also because I have not found time to
review and vet them.
- Output the python found during configure into the definition of PYTHON
in build/config.mk (via build/config.mk.in).
- Added early-return checks (A, B, or C with zero dimension; alpha = 0)
to bli_gemm_front.c.
- Implemented explicit beta = 0 handling in for the sgemm ukernel in
bli_gemm_armv7a_int_d4x4.c, which was previously missing. This latent
bug surfaced because the gemmt module verifies its computation using
gemm with its beta parameter set to zero, which, on a cortexa15 system
caused the gemm kernel code to unconditionally multiply the
uninitialized C data by beta. The C matrix likely contained
non-numeric values such as NaN, which then would have resulted in a
false failure.
- Fixed a bug whereby the implementation for bli_herk_determine_kc(),
in bli_l3_blocksize.c, was inadvertantly being defined in terms of
helper functions meant for trmm. This bug was probably harmless since
the trmm code should have also done the right thing for herk.
- Used cpp macros to neutralize the various AOCL_DTL_TRACE_ macros in
kernels/zen/3/bli_gemm_small.c since those macros are not used in
vanilla BLIS.
- Added cpp guard to definition of bli_mem_clear() in bli_mem.h to
accommodate C++'s stricter type checking.
- Added cpp guard to test/*.c drivers that facilitate compilation on
Windows systems.
- Various whitespace changes.
Details:
- Increased the test thresholds used by the dotxaxpyf testsuite module
by a factor of five in order to avoid residuals that unnecessarily
fall in the MARGINAL range. This commit should fix#455. Thanks to
@nagsingh for reporting this issue.
Details:
- Moved the "Operation index" section of both the BLISObjectAPI.md and
BLISTypedAPI.md docs to appear immediately after the table of contents
of each document. This allows the reader to quickly jump to the
documentation for any operation without having to scroll through much
of the document (when rendered via a web browser).
- Fixed a mistake in the BLISObjectAPI.md for the setd operation, which
does *not* observe the diag property of its matrix argument. Thanks to
Jeff Diamond for reporting this.
Details:
- Implemented support for the user manually overriding the automatic
subconfiguration selection that happens at runtime. This override
can be requested by setting the BLIS_ARCH_TYPE environment variable.
The variable must be set to the arch_t id (as enumerated in
bli_type_defs.h) corresponding to the desired subconfiguration. If a
value outside this enumerated range is given, BLIS will abort with an
error message. If the value is in the valid range but corresponds to a
subconfiguration that was not activated at configure-time/compile-time,
BLIS will abort with a (different) error message. Thanks to decandia50
for suggesting this feature via issue #451.
- Defined a new function bli_gks_lookup_id to return the address of an
internal data structure within the gks. If this address is NULL, then
it indicates that the subconfig corresponding to the arch_t id passed
into the function was not compiled into BLIS. This function is used
in the second of the two abort scenarios described above.
- Defined the enumerated error code BLIS_UNINITIALIZED_GKS_CNTX, which
is returned for the latter of the two abort scenarios mentioned above,
along with a corresponding error message and a function to perform
the error check.
- Added cpp macro branching to bli_env.c to support compilation of the
auto-detect.x executable during configure-time. This cpp branch is
similar to the cpp code already found in bli_arch.c and bli_cpuid.c.
- Cleaned up the auto_detect() function to facilitate easier maintenance
going forward. Also added a convenient debug switch that outputs the
compilation command for the auto-detect.x executable and exits.
Details:
- Added single-threaded and multithreaded sup performance results to
docs/PerformanceSmall.md for both sgemm and dgemm. These results were
gathered on an Epyc 7742 "Rome" server featuring AMD's Zen2
microarchitecture. Special thanks to Jeff Diamond for facilitating
access to the system via the Oracle Cloud.
- Updates to octave scripts in test/sup/octave for use with Octave 5.2
and for use with subplot_tight().
- Minor updates to octave scripts in test/3/octave.
- Renamed files containing the previous Zen performance results for
consistency with the new results.
- Decreased line thickness slightly in large/conventional Zen2 graphs.
I'm done tweaking those this time. Really.
- Added missing line regarding eigen header installation for each
microarchitecture section.
Details:
- Registered full suite of sgemm and dgemm sup millikernels, blocksizes,
and crossover thresholds in bli_cntx_init_zen2.c.
- Minor updates to test/sup/runme.sh for running on Zen2 Epyc 7742
system.
Details:
- Added a frequently asked question to docs/FAQ.md regarding the
difference between upstream (vanilla) BLIS and AMD BLIS.
- Updated the name of ICES in the README.md to reflect the Oden
rebranding.
