Details:
- NOTE: This is a merge commit of 'master' of git://github.com/amd/blis
into 'amd-master' of flame/blis.
- Fixed a bug in the downstream value of BLIS_NUM_ARCHS, which was
inadvertantly not incremented when the Zen2 subconfiguration was
added.
- In bli_gemm_front(), added a missing conditional constraint around the
call to bli_gemm_small() that ensures that the computation precision
of C matches the storage precision of C.
- In bli_syrk_front(), reorganized and relocated the notrans/trans logic
that existed around the call to bli_syrk_small() into bli_syrk_small()
to minimize the calling code footprint and also to bring that code
into stylistic harmony with similar code in bli_gemm_front() and
bli_trsm_front(). Also, replaced direct accessing of obj_t fields with
proper accessor static functions (e.g. 'a->dim[0]' becomes
'bli_obj_length( a )').
- Added #ifdef BLIS_ENABLE_SMALL_MATRIX guard around prototypes for
bli_gemm_small(), bli_syrk_small(), and bli_trsm_small(). This is
strictly speaking unnecessary, but it serves as a useful visual cue to
those who may be reading the files.
- Removed cpp macro-protected small matrix debugging code from
bli_trsm_front.c.
- Added a GCC_OT_9_1_0 variable to build/config.mk.in to facilitate gcc
version check for availability of -march=znver2, and added appropriate
support to configure script.
- Cleanups to compiler flags common to recent AMD microarchitectures in
config/zen/amd_config.mk, including: removal of -march=znver1 et al.
from CKVECFLAGS (since the -march flag is added within make_defs.mk);
setting CRVECFLAGS similarly to CKVECFLAGS.
- Cleanups to config/zen/bli_cntx_init_zen.c.
- Cleanups, added comments to config/zen/make_defs.mk.
- Cleanups to config/zen2/make_defs.mk, including making use of newly-
added GCC_OT_9_1_0 and existing GCC_OT_6_1_0 to choose the correct
set of compiler flags based on the version of gcc being used.
- Reverted downstream changes to test/test_gemm.c.
- Various whitespace/comment changes.
Details:
- Fixed an obscure but in the bli_dgemmsup_rv_haswell_asm_5x8n() kernel
that only affected the beta == 0, column-storage output case. Thanks
to the BLAS test drivers for catching this bug.
- Previously, bli_gemmsup_ref_var1n() and _var2m() were returning if
k = 0, when the correct action would be to scale by beta (and then
return). Thanks to the BLAS test drivers to catching this bug.
- Changed the sup threshold behavior such that the sup implementation
only kicks in if a matrix dimension is strictly less than (rather than
less than or equal to) the threshold in question.
- Initialize all thresholds to zero (instead of 10) by default in
ref_kernels/bli_cntx_ref.c. This, combined with the above change to
threshold testing means that calls to BLIS or BLAS with one or more
matrix dimensions of zero will no longer trigger the sup
implementation.
- Added disabled debugging output to frame/3/bli_l3_sup.c (for future
use, perhaps).
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:
- 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:
- 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:
- Changed the void* arguments of the following static functions:
bli_is_aligned_to()
bli_is_unaligned_to()
bli_offset_past_alignment()
to siz_t, and the return type of bli_offset_past_alignment() from
guint_t to siz_t. This allows for more versatile usage of these
functions (e.g. when aligning both pointers and leading dimension).
- Updated all invocations of these functions, mostly in kernels/penryn
but also in kernels/bgq, to include explicit typecasts to siz_t when
pointer arguments are passed in.
- Thanks to Devin Matthews for pointing out this potential bug (via issue
#211).
- Deleted a few trailing spaces in various penryn kernels.
- Removed duplicate instances of the words "derived" and "THEORY" from
various kernel license headers, likely from a malformed recursive sed
performed long ago.
Details:
- Inserted missing safeguards into most microkernels to ensure that the
integers read by the microkernel's assembly instructions are of the
appropriate size. In many cases, this bug was going undetected likely
because the compiler was inserting zero padding before the integers
in the calling function, allowing the assembly code to read 64-bits
in a way that did not corrupt the "lower" 32 integer bits with garbage
in the higher bits. Thanks to Francisco Igual and Devangi Parikh for
finding this issue.
Details:
- Moved microkernels in kernels/haswell/3 to kernels/haswell/3/old. These
microkernels were no longer being used and only sowed confusion to
anyone inspecting the repository without being fully cognizant of the
build system and how it works (and sometimes even to those who wrote
the build system). Note that the haswell configuration currently
employs the zen microkernels.
Details:
- Applied the read-beyond-bounds bugfix in 34b72a3 to other haswell and
zen kernels (ie: other microtile shapes) which are not used by default.
This was done mostly in case someone decided to pick up these kernels
and start using them, not because it affects BLIS's behavior
out-of-the-box.
Details:
- Fixed an obscure bug in the bli_sgemm_haswell_asm_6x16 and
bli_sgemm_zen_asm_6x16 microkernels when the input/output matrix C
is stored with general stride (ie: both rs and cs are non-unit). The
bug was rooted in the way those microkernels read from matrix C--
namely, they used vmovlps/vmovhps instead of movss. By loading two
floats at a time, even if one of them was treated as junk, the
assembly code could be written in a more concise manner. However,
under certain conditions--if m % mr == 0 and n % nr == 0 and the
underlying matrix is not an internal "view" into a larger matrix--
this could result in the very last vmovhps of the last (bottom-right)
microkernel invocation reading beyond valid memory. Specifically, the
low 32 bits read would always be valid, but the high 32 bits could
reside beyond the bounds of the array in which the output C matrix is
contained. To remedy this situation, we now selectively use movss to
load any element that could be the last element in the matrix.
Details:
- Merged contributions made by AMD via 'amd' branch (see summary below).
Special thanks to AMD for their contributions to-date, especially with
regard to intrinsic- and assembly-based kernels.
- Added column storage output cases to microkernels in
bli_gemm_zen_asm_d6x8.c and bli_gemmtrsm_l_zen_asm_d6x8.c. Even with
the extra cost of transposing the microtile in registers, this is
much faster than using the general storage case when the underlying
matrix is column-stored.
- Added s and d assembly-based zen gemmtrsm_u microkernel (including
column storage optimization mentioned above).
- Updated zen sub-configuration to reflect presence of new native
kernels.
- Temporarily reverted zen sub-configuration's level-3 cache blocksizes
to smaller haswell values.
- Temporarily disabled small matrix handling for zen configuration
family in config/zen/bli_family_zen.h.
- Updated zen CFLAGS according to changes in 1e4365b.
- Updated haswell microkernels such that:
- only one vzeroupper instruction is called prior to returning
- movapd/movupd are used in leiu of movaps/movups for double-real
microkernels. (Note that single-real microkernels still use
movaps/movups.)
- Added kernel prototypes to kernels/zen/bli_kernels_zen.h, which is
now included via frame/include/bli_arch_config.h.
- Minor updates to bli_amaxv_ref.c (and to inlined "test" implementation
in testsuite/src/test_amaxv.c).
- Added early return for alpha == 0 in bli_dotxv_ref.c.
- Integrated changes from f07b176, including a fix for undefined
behavior when executing the 1m method under certain conditions.
- Updated config_registry; no longer need haswell kernels for zen
sub-configuration.
- Tweaked marginal and pass thresholds for dotxf.
- Reformatted level-1v, -1f, and -3 amd kernels and inserted additional
comments.
- Updated LICENSE file to explicitly mention that parts are copyright
UT-Austin and AMD.
- Added AMD copyright to header templates in build/templates.
Summary of previous changes from 'amd' branch.
- Added s and d assembly-based zen gemm microkernels (d6x8 and d8x6) and
s and d assembly-based zen gemmtrsm_l microkernels (d6x8).
- Added s and d intrinsics-based zen kernels for amaxv, axpyv, dotv, dotxv,
and scalv, with extra-unrolling variants for axpyv and scalv.
- Added a small matrix handler to bli_gemm_front(), with the handler
implemented in kernels/zen/3/bli_gemm_small_matrix.c.
- Added additional logic to sumsqv that first attempts to compute the
sum of the squares via dotv(). If there is a floating-point exception
(FE_OVERFLOW), then the previous (numerically conservative) code is
used; otherwise, the result of dotv() is square-rooted and stored as
the result. This new implementation is only enabled when FE_OVERFLOW
is #defined. If the macro is not #defined, then the previous
implementation is used.
- Added axpyv and dotv standalone test drivers to test directory.
- Added zen support to old cpuid_x86.c driver in build/auto-detect/old.
- Added thread-local and __attribute__-related macros to bli_macro_defs.h.
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.
