Details:
- Fine-tuned the double-precision real MT threshold (which controls
whether the sup implementation kicks for smaller m dimension values)
from 180 to 201 for haswell and 180 to 256 for zen.
- Updated octave scripts in test/sup/octave to include a seventh column
to display performance for m = n = k.
Details:
- Increased the double-precision real MT threshold (which controls
whether the sup implementation kicks for smaller m dimension values)
from 80 to 180, and this change was made for both haswell and zen
subconfigurations. This is less about the m dimension in particular
and more about facilitating a smoother performance transition when
m = n = k.
Details:
- Removed already limited use of the BLIS_ENABLE_SUP_MR_EXT and
BLIS_ENABLE_SUP_NR_EXT macros in bli_gemmsup_ref_var1n() and
bli_gemmsup_ref_var2m(). Their purpose was merely to avoid a long
conditional that would determine whether to allow the last iteration
to be merged with the second-to-last iteration. Functionally, the
macros were not needed, and they ended up causing problems when
building configuration families such as intel64 and x86_64.
Details:
- Implemented a new sub-framework within BLIS to support the management
of code and kernels that specifically target matrix problems for which
at least one dimension is deemed to be small, which can result in long
and skinny matrix operands that are ill-suited for the conventional
level-3 implementations in BLIS. The new framework tackles the problem
in two ways. First the stripped-down algorithmic loops forgo the
packing that is famously performed in the classic code path. That is,
the computation is performed by a new family of kernels tailored
specifically for operating on the source matrices as-is (unpacked).
Second, these new kernels will typically (and in the case of haswell
and zen, do in fact) include separate assembly sub-kernels for
handling of edge cases, which helps smooth performance when performing
problems whose m and n dimension are not naturally multiples of the
register blocksizes. In a reference to the sub-framework's purpose of
supporting skinny/unpacked level-3 operations, the "sup" operation
suffix (e.g. gemmsup) is typically used to denote a separate namespace
for related code and kernels. NOTE: Since the sup framework does not
perform any packing, it targets row- and column-stored matrices A, B,
and C. For now, if any matrix has non-unit strides in both dimensions,
the problem is computed by the conventional implementation.
- Implemented the default sup handler as a front-end to two variants.
bli_gemmsup_ref_var2() provides a block-panel variant (in which the
2nd loop around the microkernel iterates over n and the 1st loop
iterates over m), while bli_gemmsup_ref_var1() provides a panel-block
variant (2nd loop over m and 1st loop over n). However, these variants
are not used by default and provided for reference only. Instead, the
default sup handler calls _var2m() and _var1n(), which are similar
to _var2() and _var1(), respectively, except that they defer to the
sup kernel itself to iterate over the m and n dimension, respectively.
In other words, these variants rely not on microkernels, but on
so-called "millikernels" that iterate along m and k, or n and k.
The benefit of using millikernels is a reduction of function call
and related (local integer typecast) overhead as well as the ability
for the kernel to know which micropanel (A or B) will change during
the next iteration of the 1st loop, which allows it to focus its
prefetching on that micropanel. (In _var2m()'s millikernel, the upanel
of A changes while the same upanel of B is reused. In _var1n()'s, the
upanel of B changes while the upanel of A is reused.)
- Added a new configure option, --[en|dis]able-sup-handling, which is
enabled by default. However, the default thresholds at which the
default sup handler is activated are set to zero for each of the m, n,
and k dimensions, which effectively disables the implementation. (The
default sup handler only accepts the problem if at least one dimension
is smaller than or equal to its corresponding threshold. If all
dimensions are larger than their thresholds, the problem is rejected
by the sup front-end and control is passed back to the conventional
implementation, which proceeds normally.)
- Added support to the cntx_t structure to track new fields related to
the sup framework, most notably:
- sup thresholds: the thresholds at which the sup handler is called.
- sup handlers: the address of the function to call to implement
the level-3 skinny/unpacked matrix implementation.
- sup blocksizes: the register and cache blocksizes used by the sup
implementation (which may be the same or different from those used
by the conventional packm-based approach).
- sup kernels: the kernels that the handler will use in implementing
the sup functionality.
- sup kernel prefs: the IO preference of the sup kernels, which may
differ from the preferences of the conventional gemm microkernels'
IO preferences.
- Added a bool_t to the rntm_t structure that indicates whether sup
handling should be enabled/disabled. This allows per-call control
of whether the sup implementation is used, which is useful for test
drivers that wish to switch between the conventional and sup codes
without having to link to different copies of BLIS. The corresponding
accessor functions for this new bool_t are defined in bli_rntm.h.
- Implemented several row-preferential gemmsup kernels in a new
directory, kernels/haswell/3/sup. These kernels include two general
implementation types--'rd' and 'rv'--for the 6x8 base shape, with
two specialized millikernels that embed the 1st loop within the kernel
itself.
- Added ref_kernels/3/bli_gemmsup_ref.c, which provides reference
gemmsup microkernels. NOTE: These microkernels, unlike the current
crop of conventional (pack-based) microkernels, do not use constant
loop bounds. Additionally, their inner loop iterates over the k
dimension.
- Defined new typedef enums:
- stor3_t: captures the effective storage combination of the level-3
problem. Valid values are BLIS_RRR, BLIS_RRC, BLIS_RCR, etc. A
special value of BLIS_XXX is used to denote an arbitrary combination
which, in practice, means that at least one of the operands is
stored according to general stride.
- threshid_t: captures each of the three dimension thresholds.
- Changed bli_adjust_strides() in bli_obj.c so that bli_obj_create()
can be passed "-1, -1" as a lazy request for row storage. (Note that
"0, 0" is still accepted as a lazy request for column storage.)
- Added support for various instructions to bli_x86_asm_macros.h,
including imul, vhaddps/pd, and other instructions related to integer
vectors.
- Disabled the older small matrix handling code inserted by AMD in
bli_gemm_front.c, since the sup framework introduced in this commit
is intended to provide a more generalized solution.
- Added test/sup directory, which contains standalone performance test
drivers, a Makefile, a runme.sh script, and an 'octave' directory
containing scripts compatible with GNU Octave. (They also may work
with matlab, but if not, they are probably close to working.)
- Reinterpret the storage combination string (sc_str) in the various
level-3 testsuite modules (e.g. src/test_gemm.c) so that the order
of each matrix storage char is "cab" rather than "abc".
- Comment updates in level-3 BLAS API wrappers in frame/compat.
Details:
- Adjusted the zen sub-configuration's cache blocksizes for float,
scomplex, and dcomplex based on the existing values for double.
(The previous values were taken directly from the haswell subconfig,
which targets Intel Haswell/Broadwell/Skylake systems.)
Details:
- Changed -funsafe-loop-optimizations (re-)introduced in 7690855 for
make_defs.mk files' CRVECFLAGS to -funsafe-math-optimizations (to
account for a miscommunication in issue #300). Thanks to Dave Love
for this suggestion and Jeff Hammond for his feedback on the topic.
Details:
- Restored use of -funsafe-loop-optimizations in the definitions of
CRVECFLAGS (when using gcc), but only for sub-configurations (and
not configuration families such as amd64, intel64, and x86_64).
This more or less reverts 5190d05 and 6cf1550.
Details:
- Added -mno-tbm -mno-xop -mno-lwp to CKVECFLAGS in bulldozer,
piledriver, steamroller, and excavator configurations to explicitly
disable AMD's bulldozer-era TBM, XOP, and LWP instruction sets in an
attempt to fix the invalid instruction error that has plagued Travis
CI builds since 6a014a3. Thanks to Devin Matthews for pointing out
that the offending instruction was part of TBM (issue #300).
- Restored -O3 to piledriver configuration's COPTFLAGS.
Details:
- Removed -funsafe-loop-optimizations from the configuration families
affected by 6a014a3, specifically: intel64, amd64, and x86_64.
This is part of an attempt to debug why the sde, as executed by
Travis CI, is crashing via the following error:
TID 0 SDE-ERROR: Executed instruction not valid for specified chip
(ICELAKE): 0x9172a5: bextr_xop rax, rcx, 0x103
Details:
- Per Dave Love's recommendation in issue #300, this commit defines
COPTFLAGS := -03
and
CRVECFLAGS := $(CKVECFLAGS) -funsafe-loop-optimizations
in the make_defs.mk for all Intel- and AMD-based configurations.
Formally registered power9 sub-configuration.
Details:
- Added and registered power9 sub-configuration into the build system.
Thanks to Nicholai Tukanov and Devangi Parikh for these contributions.
- Note: The sub-configuration does not yet have a corresponding
architecture-specific kernel set registered, and so for now the
sub-config is using the generic kernel set.
Details:
- Fixed code in the skx subconfiguration that became a bug after
committing bdd46f9. Specifically, the bli_cntx_init_skx() function
was overwriting default blocksizes for the scomplex and dcomplex
microkernels despite the fact that only single and double real
microkernels were being registered. This was not a problem prior to
bdd46f9 since all microkernels used dynamically-queried (at runtime)
register blocksizes for loop bounds. However, post-bdd46f9, this
became a bug because the reference ukernels for scomplex and dcomplex
were written with their register blocksizes hard-coded as constant
loop bounds, which conflicted the the erroneous scomplex and dcomplex
values that bli_cntx_init_skx() was setting in the context. The
lesson here is that going forward, all subconfigurations must not set
any blocksizes for datatypes corresponding to default/reference
microkernels. (Note that a blocksize is left unchanged by the
bli_cntx_set_blkszs() function if it was set to -1.)
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:
- Renamed the microkernels in kernels/zen/3 to kernels/haswell/3 and
then updated the file contents to use the 'haswell' infix.
- Updated bli_cntx_init_zen.c and bli_cntx_init_haswell.c according to
above function renames.
- Moved/updated the corresponding prototypes in bli_kernels_zen.h to
bli_kernels_haswell.h.
- Updated config_registry according to above changes.
- NOTE: This rename reflects the fact that haswell microkernels are
specifically written to overcome the floating-point latency for FMA
instructions on Intel Haswell-like architectures, which can issue two
FMA instructions per cycle. These ukernels happen to work fine on AMD
Zen-based architectures. However, Zen only issues one FMA per cycle,
which, while halving its floating-point throughput, gives it extra
flexibility in the design of its microkernels--namely, mr and nr can
be smaller and still overcome the floating-point latency for those
single-issue cores. A smaller value of mr and nr allows for a larger
value of kc, which may be useful in some situations. In the future,
we may write such Zen-specific microkernels to take advantage of this
additional flexibility.
Details:
- Renamed the following C preprocessor macros whose fallback/default
values are specified within frame/include/bli_kernel_macro_defs.h:
BLIS_DEFAULT_MR_THREAD_MAX -> BLIS_THREAD_MAX_IR
BLIS_DEFAULT_NR_THREAD_MAX -> BLIS_THREAD_MAX_JR
BLIS_DEFAULT_M_THREAD_RATIO -> BLIS_THREAD_RATIO_M
BLIS_DEFAULT_N_THREAD_RATIO -> BLIS_THREAD_RATIO_N
- Renamed the above cpp macro overrides within the knl, skx, and zen
sub-configurations, as well as invocations of those macros in
bli_rntm.c.
- Moved config/zen/bli_kernel.h to an 'old' directory as it is no longer
used by any code within BLIS.
Details:
- Added the new bli_dgemm_skx_asm_16x14.c microkernel from the skx-redux
branch, along with appropriate blocksizes in bli_cntx_init_skx.c and
a prototype in bli_kernels_skx.h. (Devin has not yet written the
sgemm analague, so for now we will continue using the older sgemm
ukernel.)
- Updated frame/include/bli_x86_asm_macros.h with a minor change that
was present within the skx-redux branch.
Details:
- Added a new sub-configuration 'cortexa53', which is a mirror image
of cortexa57 except that it will use slightly different compiler
flags. Thanks to Mathieu Poumeyrol for making this suggestion after
discovering that the compiler flags being used by cortexa57 were
not working properly in certain OS X environments (the fix to which
is currently pending in pull request #245).
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.
* Add appveyor file
* Build script
* Remove fPIC for now
* copy as
* set CC and CXX
* Change the order of immintrin.h
* Fix testsuite header
* Move testsuite defs to .c
* Fix appveyor file
* Remove fPIC again and fix strerror_r missing bug
* Remove appveyor script
* cd to blis directory
* Fix sleep implementation
* Add f2c_types_win.h
* Fix f2c compilation
* Remove rdp and rename appveyor.yml
* Remove setenv declaration in test header
* set CPICFLAGS to empty
* Fix another immintrin.h issue
* Escape CFLAGS and LDFLAGS
* Fix more ?mmintrin.h issues
* Build x86_64 in appveyor
* override LIBM LIBPTHREAD AR AS
* override pthreads in configure
* Move windows definitions to bli_winsys.h
* Fix LIBPTHREAD default value
* Build intel64 in appveyor for now
Details:
- Added two presently-disabled cpp blocks in bli_cntx_init_haswell.c to
easily allow one to switch to a set of column-preferential gemm
microkernels (in the haswell subconfiguration). The second column-
preferring block sets the the register blocksizes to their appropriate
values. However, cache blocksizes are left unchanged, and therefore are
likely suboptimal. This should be addressed later.
Details:
- Disabled small matrix handling in config/zen/bli_family_zen.h due to
what appears to be a bug that manifests as failures in the single and
double precision real level-3 BLAS test drivers (visible via
out.sblat3 and out.dblat3). Thanks to Robin Christ for reporting this
issue.
Details:
- Fixed erroneous calls to bli_cntx_init_piledriver_ref() in
bli_cntx_init_steamroller() and bli_cntx_init_excavator(), which
should have been to their respectively-named bli_cntx_init_*()
functions instead. Thanks to qnerd for bringing these bugs to our
attention.
* Add custom SDE cpuid files.
* Set up testing of all x86_64 architectures (except bulldozer) using SDE.
* Update .travis.yml
[ci skip]
* Update do_testsuite.sh
[ci skip]
* Updated .travis.yml with my secret token.
Details:
- Replaced Devin's temporary secret token with my own, which is used by
Travis when accessing the Intel SDE via Dropbox.
* Work around CPUID dispatch in glibc/libm by patching ld.so.
* Detect path of loader at runtime.
* Attempt to make SDE run on Travis
* Allow unpatched ld.so if we don't know how to patch it.
I *think* this only happens for older glibc without the multi-arch stuff (e.g. Ubuntu 14.04 on Travis), but who knows?
* Upgrade Travis to gcc-6 and binutils-2.26.
* Try to get Travis to use the right assembler.
* Apparently you need ld-2.26 too.
* Try to also patch ld.so from Ubuntu 14.04.
* Take the nuclear option.
* Account for non-absolute dependencies in ldd output.
* String manipulation fail.
* Update patch-ld-so.py
* Add Zen to SDE testing.
* Removed dead variable from travis/do_testsuite.sh.
Details:
- Removed 'BLIS_ENABLE_TEST_OUTPUT=yes' from make invocations in
travis/do_testsuite.sh. This variable is no longer present in the
BLIS build system (if it ever was?), and therefore has no effect.
Details:
- Historically, the compiler selection has happened statically in the
various make_defs.mk and would only be overriden by setting CC (either
prior to running configure or as a configure argument). However, in
the last couple months, configure has evolved to contain rather
sophisticated compiler detection logic for the purposes of blacklisting
sub-configurations. It only makes sense that configure now fully take
over the responsibility of selecting a compiler from the GNU make side
of the build system. Thanks to Alex Arslan for his help exposing this
issue.
- Substitute found_cc into CC in config.mk via configure.
- Set a new variable, CC_VENDOR, in config.mk via substitution from
configure, and disable the corresponding CC_VENDOR code in common.mk.
- Disabled default compiler selection (usually gcc) in the sub-configs'
various make_def.mk files.
Details:
- Added a brief README.md file to the config directory to redirect those
who may be exploring the source tree to the ConfigurationHowTo wiki.
(Included is a very brief explanation of configurations for those who
don't have time to read the wiki.) Thanks to Nico Schlömer for this
suggestion.
Details:
- Renamed the following variables in config.mk (via build/config.mk.in):
BLIS_ENABLE_VERBOSE_MAKE_OUTPUT -> ENABLE_VERBOSE
BLIS_ENABLE_STATIC_BUILD -> MK_ENABLE_STATIC
BLIS_ENABLE_SHARED_BUILD -> MK_ENABLE_SHARED
BLIS_ENABLE_BLAS2BLIS -> MK_ENABLE_BLAS
BLIS_ENABLE_CBLAS -> MK_ENABLE_CBLAS
BLIS_ENABLE_MEMKIND -> MK_ENABLE_MEMKIND
and also renamed all uses of these variables in makefiles and makefile
fragments. Notice that we use the "MK_" prefix so that those variables
can be easily differentiated (such as via grep) from their "BLIS_" C
preprocessor macro counterparts.
- Other whitespace changes to build/config.mk.in.
- Renamed the following C preprocessor macros in bli_config.h (via
build/bli_config.h.in):
BLIS_ENABLE_BLAS2BLIS -> BLIS_ENABLE_BLAS
BLIS_DISABLE_BLAS2BLIS -> BLIS_DISABLE_BLAS
BLIS_BLAS2BLIS_INT_TYPE_SIZE -> BLIS_BLAS_INT_TYPE_SIZE
and also renamed all relevant uses of these macros in BLIS source
files.
- Renamed "blas2blis" variable occurrences in configure to "blas", as
was done in build/config.mk.in and build/bli_config.h.in.
- Renamed the following functions in frame/base/bli_info.c:
bli_info_get_enable_blas2blis() -> bli_info_get_enable_blas()
bli_info_get_blas2blis_int_type_size()
-> bli_info_get_blas_int_type_size()
- Remove bli_config.h during 'make cleanh' target of top-level Makefile.
Details:
- Converted most C preprocessor macros in bli_param_macro_defs.h and
bli_obj_macro_defs.h to static functions.
- Reshuffled some functions/macros to bli_misc_macro_defs.h and also
between bli_param_macro_defs.h and bli_obj_macro_defs.h.
- Changed obj_t-initializing macros in bli_type_defs.h to static
functions.
- Removed some old references to BLIS_TWO and BLIS_MINUS_TWO from
bli_constants.h.
- Whitespace changes in select files (four spaces to single tab).
Re-enabled AMD-specific optimizations for zen.
Details:
- Re-enabled Zen-specific cache blocksizes for 'zen' sub-configuration.
- Re-enabled small matrix gemm optimization for 'zen'.
- These were both temporarily disabled during a previous merge simply due to lack of Zen hardware for testing.
Details:
- Imported the 24x16 knl sgemm microkernel (and its corresonding spackm
kernel) from TBLIS and enabled its use in the knl sub-config. Also
Added sgemm microkernel prototype to bli_kernels_knl.h.
- Updated dgemm and dpackm microkernels from TBLIS, which included an
important change regarding the offsets array (changed from extern
declaration to static declaration/definition).
- Activated use of level-1v and -1f zen kernels in skx and knl
sub-configs.
- Removed some old macros no longer needed in bli_family_skx.h now that
libmemkind support exists in configure.
- Moved bli_avx512_macros.h to frame/include and adjusted #includes in
skx and knl kernels accordingly.
- Moved unused kernels in kernels/knl/3 to kernels/knl/3/other
directory.
- Fixed a minor bug in the 'make' output per compile when verboseness
is not turned on. The rule-generating function 'make-kernel-rule' was
previously passing in the name of the config, rather than the name of
the kernel set returned by get-config-for-kset, which could give
misleading information to the user when the kconfig_map mapped a
kernel set to a sub-configuration that did not share the same name.
(This didn't affect the CFLAGS that were actually used.)
- Updated test/3m4m/Makefile, removing acml targets and renaming the
remaining targets.
Details:
- Removed some old conditional code in config/knl/make_defs.mk that
added -lmemkind to LDFLAGS if DEBUG_TYPE was not 'sde' and inserted
code into common.mk that affirmatively filters out -lmemkind from
LDFLAGS if DEBUG_TYPE is 'sde'. (Thanks to Dave Love for reporting
this issue.) Other minor cleanups to neighboring code in common.mk.
- Updated CRVECFLAGS in knl/make_defs.mk to be based on -march=knl,
and then AVX-512 functionality is manually removed via various
-mno-avx512* flags. Also, make the setting of CRVECFLAGS conditional
on CC_VENDOR. Similar change to skx/make_defs.mk.
- Comment/whitespace updates.
Details:
- Renamed CVECFLAGS variables in sub-configurations' make_defs.mk files
to CKVECFLAGS.
- Added default defintions of two new make variables to most sub-
configurations' make_defs.mk files--CROPTFLAGS and CRVECFLAGS--
which correspond to reference kernel analogues of the CKOPTFLAGS
and CKVECFLAGS, which track optimization and vectorization flags for
optimized kernels. Currently, two sub-configurations (knl and skx)
explicitly set CRVECFLAGS to non-default values (using AVX2 instead of
AVX-512 for reference kernels. Thanks to Jeff Hammond, whose feedback
prompted me to make this change (issue #187).
- Changed common.mk so that the get-refkern-cflags-for function returns
the flags associated with the given sub-configuration's CROPTFLAGS
and CRVECFLAGS (instead of CKOPTFLAGS and CKVECFLAGS).
Details:
- Added 'skx' and 'knl' sub-configurations to the 'x86_64' configuration
family in the config_registry file.
- Added logic to configure that avoids committing certain sub-configs to
the configuration/kernel registries if those sub-configs cannot be
handled properly by the chosen compiler. (This was modeled after
similar logic in TBLIS's configure; thanks to Devin Matthews for
pointing this out.) First, the compiler and its version are inspected
and, based on the results, certain configurations are added to a
"blacklist". Then, as the configuration registries are being created,
configurations and/or kernels that match items in the blacklist are
skipped over and not commited to the registries. Under certain
circumstances, omitting a blacklisted configuration will indirectly
invalidate other configurations due to the loss of availability of
the original blacklisted configuration's kernel set. This additional
indirect blacklist is also accounted for.
- Added output to the beginning of configure that echos information
about the chosen compiler as well as the configurations that are
blacklisted and must be stripped from the registries.
- Various other cleanups in configure, especially with respect to
explicitly declaring local variables in functions.
- Comment updates to config/zen/make_defs.mk regarding choice of -march
flags based on compiler version.
Details:
- Fixed a bug in the zen (also used by haswell) dotxf kernels whereby a
vzeroupper instruction destoryed part of the intermediate result
stored by the vdpps instructions that came right before. (The
vzeroupper instrinsic was removed.)
- Removed remaining vzeroupper instrinsics from other zen kernels.
Previously, the vzeroupper instructions were included because BLIS is
typically compiled with -mfpmath=sse. But it was brought to my
attention that inserting these vzeroupper instructions is unnecessary
for our purposes, since (a) -mfpmath=sse results in VEX-encoded scalar
code rather than literal SSE instructions, and (b) compilers already
(likely) insert vzeroupper instructions where necessary. Thanks to
Devin Matthews for zeroing in on the dotxf bug.
- Removed -malign-double from bulldozer make_defs.mk. This alignment
was already happening by default since bulldozer is an x86_64 system.
Details:
- Added support for libmemkind to configure. configure attempts to
detect the presence of libmemkind by compiling a small program
containing #include <hbwmalloc.h> and a call to hbw_malloc(). If
successful, it is assumed that libmemkind is present and available.
If present, use of libmemkind is enabled by default, and otherwise
use is disabled by default. If libmemkind is present, the user may
explicitly disable use of the library by running configure with the
--without-memkind option. Furthermore, a configuration may disable
libmemkind, perhaps conditional on some aspect of the build system,
by including -DBLIS_DISABLE_MEMKIND in the configuration's CPPROCFLAGS
make variable and setting the BLIS_ENABLE_MEMKIND makefile variable,
set in config.mk, to 'no'. (The knl configuration makes use of this
latter feature; see below.)
- If enabled at configure-time, bli_system.h will #include <hbwmalloc.h>
and bli_kernel_macro_defs.h will define BLIS_MALLOC_POOL and
BLIS_FREE_POOL to use hbw_malloc() and hbw_free(), respectively.
- Deprecated explicit use of BLIS_NO_HBWMALLOC in
config/knl/bli_family.knl.h and replaced use of -DBLIS_NO_HBWMALLOC in
config/knl/make_defs.mk with -DBLIS_DISABLE_MEMKIND, which overrides
(#undefs) the definition of BLIS_ENABLE_MEMKIND in bli_system.h, if it
would otherwise be defined. Also, set the BLIS_ENABLE_MEMKIND makefile
variable to 'no'.
- common.mk now adds libmemkind to LDFLAGS if libmemkind is enabled.
