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#!/usr/bin/env bash
#
#  BLIS
#  An object-based framework for developing high-performance BLAS-like
#  libraries.
#
#  Copyright (C) 2014, The University of Texas at Austin
#  Copyright (C) 2020-2022, Advanced Micro Devices, Inc.
#
#  Redistribution and use in source and binary forms, with or without
#  modification, are permitted provided that the following conditions are
#  met:
#   - Redistributions of source code must retain the above copyright
#     notice, this list of conditions and the following disclaimer.
#   - Redistributions in binary form must reproduce the above copyright
#     notice, this list of conditions and the following disclaimer in the
#     documentation and/or other materials provided with the distribution.
#   - Neither the name(s) of the copyright holder(s) nor the names of its
#     contributors may be used to endorse or promote products derived
#     from this software without specific prior written permission.
#
#  THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
#  "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
#  LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
#  A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
#  HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
#  SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
#  LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
#  DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
#  THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
#  (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
#  OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
#
#
# shellcheck disable=2001,2249,2034,2154,2181,2312,2250,2292

#
# -- Helper functions ----------------------------------------------------------
#

print_usage()
{
	# Use the version string in the 'version' file since we don't have
	# the patched version string yet.
	if [ -z "${version}" ]; then
		version=$(<"${version_filepath}")
	fi

	# Echo usage info.
	cat <<EOF

 ${script_name} (BLIS ${version})

 Configure BLIS's build system for compilation using a specified
 configuration directory.

 Usage:

   ${script_name} [options] [env. vars.] confname

 Arguments:

   confname      The name of the sub-directory inside of the 'config'
                 directory containing the desired BLIS configuration.
                 Note that confname MUST be specified; if it is not,
                 configure will complain. To build a completely generic
                 implementation, use the 'generic' configuration

 Options:

   -p PREFIX, --prefix=PREFIX

                 The common installation prefix for all files. If given,
                 this option effectively implies:
                   --libdir=EXECPREFIX/lib
                   --includedir=PREFIX/include
                   --sharedir=PREFIX/share
                 where EXECPREFIX defaults to PREFIX. If this option is
                 not given, PREFIX defaults to '${prefix_def}'. If PREFIX
                 refers to a directory that does not exist, it will be
                 created.

   --exec-prefix=EXECPREFIX

                 The installation prefix for libraries. Specifically, if
                 given, this option effectively implies:
                   --libdir=EXECPREFIX/lib
                 If not given, EXECPREFIX defaults to PREFIX, which may be
                 modified by the --prefix option. If EXECPREFIX refers to
                 a directory that does not exist, it will be created.

   --libdir=LIBDIR

                 The path to which make will install libraries. If not
                 given, LIBDIR defaults to PREFIX/lib. If LIBDIR refers to
                 a directory that does not exist, it will be created.

   --includedir=INCDIR

                 The path to which make will install development header
                 files. If not given, INCDIR defaults to PREFIX/include.
                 If INCDIR refers to a directory that does not exist, it
                 will be created.

   --sharedir=SHAREDIR

                 The path to which make will makefile fragments containing
                 make variables determined by configure (e.g. CC, CFLAGS,
                 and LDFLAGS). These files allow certain BLIS makefiles,
                 such as those in the examples or testsuite directories, to
                 operate on an installed copy of BLIS rather than a local
                 (and possibly uninstalled) copy. If not given, SHAREDIR
                 defaults to PREFIX/share. If SHAREDIR refers to a
                 directory that does not exist, it will be created.

   --enable-verbose-make, --disable-verbose-make

                 Enable (disabled by default) verbose compilation output
                 during make.

   --enable-arg-max-hack --disable-arg-max-hack

                 Enable (disabled by default) build system logic that
                 will allow archiving/linking the static/shared library
                 even if the command plus command line arguments exceeds
                 the operating system limit (ARG_MAX).

   -d DEBUG, --enable-debug[=DEBUG]

                 Enable debugging symbols in the library. If argument
                 DEBUG is given as 'opt', then optimization flags are
                 kept in the framework, otherwise optimization is
                 turned off.

   --disable-static, --enable-static

                 Disable (enabled by default) building BLIS as a static
                 library. If the static library build is disabled, the
                 shared library build must remain enabled.

   --disable-shared, --enable-shared

                 Disable (enabled by default) building BLIS as a shared
                 library. If the shared library build is disabled, the
                 static library build must remain enabled.

   --enable-rpath, --disable-rpath

                 Enable (disabled by default) setting an install_name for
                 dynamic libraries on macOS which starts with @rpath rather
                 than the absolute install path.

   -e SYMBOLS, --export-shared[=SYMBOLS]

                 Specify the subset of library symbols that are exported
                 within a shared library. Valid values for SYMBOLS are:
                 'public' (the default) and 'all'. By default, only
                 functions and variables that belong to public APIs are
                 exported in shared libraries. However, the user may
                 instead export all symbols in BLIS, even those that were
                 intended for internal use only. Note that the public APIs
                 encompass all functions that almost any user would ever
                 want to call, including the BLAS/CBLAS compatibility APIs
                 as well as the basic and expert interfaces to the typed
                 and object APIs that are unique to BLIS. Also note that
                 changing this option to 'all' will have no effect in some
                 environments, such as when compiling with clang on
                 Windows.

   -t MODEL, --enable-threading[=MODEL], --disable-threading

                 Enable threading in the library, using threading model(s)
                 MODEL={single,openmp,pthreads,hpx,auto}. If multiple values
                 are specified within MODEL, they will all be compiled into
                 BLIS, and the choice of which to use will be determined at
                 runtime. If the user does not express a preference (by
                 setting the BLIS_THREAD_IMPL environment variable to
                 'single', 'openmp', 'pthreads', or 'hpx'; by calling the
                 global runtime API bli_thread_set_thread_impl(); or by
                 encoding a choice on a per-call basis within a rntm_t
                 passed into the expert API), then the first model listed
                 in MODEL will be used by default. Note that 'single' is
                 silently appended to whatever the user specifies in MODEL,
                 meaning that single-threaded functionality will always be
                 available, even if it is not requested and even if it is
                 not enabled by default. Even --disable-threading is
                 actually shorthand for --enable-threading=single (which is
                 the default when the option is not specified).

   --enable-system, --disable-system

                 Enable conventional operating system support, such as
                 pthreads for thread-safety. The default state is enabled.
                 However, in rare circumstances you may wish to configure
                 BLIS for use with a minimal or nonexistent operating
                 system (e.g. hardware simulators). In these situations,
                 --disable-system may be used to jettison all compile-time
                 and link-time dependencies outside of the standard C
                 library. When disabled, this option also forces the use
                 of --disable-threading.

   --enable-tls, --disable-tls

                 Enable thread-local storage (TLS) for static variables
                 in BLIS. The default state is enabled. However, like with
                 --disable-system, there may be rare situations, such as
                 when --disable-system is appropriate, where thread-local
                 storage is unsupported by the compiler. In those cases,
                 disabling TLS may be a suitable workaround.
		         WARNING: DISABLING TLS IS DANGEROUS AND MAY CAUSE RACE
                 CONDITIONS! Please try combining --disable-tls with
                 --disable-threading if you suspect any correctness or
                 deadlock issues.

   --disable-pba-pools, --enable-pba-pools
   --disable-sba-pools, --enable-sba-pools

                 Disable (enabled by default) use of internal memory pools
                 within the packing block allocator (pba) and/or the small
                 block allocator (sba). The former is used to allocate
                 memory used to pack submatrices while the latter is used
                 to allocate control/thread tree nodes and thread
                 communicators. Both allocations take place in the context
                 of level-3 operations. When the pba is disabled, the
                 malloc()-like function specified by BLIS_MALLOC_POOL is
                 called on-demand whenever a packing block is needed, and
                 when the sba is disabled, the malloc()-like function
                 specified by BLIS_MALLOC_INTL is called whenever a small
                 block is needed, with the two allocators calling free()-
                 like functions BLIS_FREE_POOL and BLIS_FREE_INTL,
                 respectively when blocks are released. When enabled,
                 either or both pools are populated via the same functions
                 mentioned previously, and henceforth blocks are checked
                 out and in. The library quickly reaches a state in which
                 it no longer needs to call malloc() or free(), even
                 across many separate level-3 operation invocations.

   --enable-mem-tracing, --disable-mem-tracing

                 Enable (disabled by default) output to stdout that traces
                 the allocation and freeing of memory, including the names
                 of the functions that triggered the allocation/freeing.
                 Enabling this option WILL NEGATIVELY IMPACT PERFORMANCE.
                 Please use only for informational/debugging purposes.

   --enable-asan, --disable-asan

                 Enable (disabled by default) compiling and linking BLIS
                 framework code with the AddressSanitizer (ASan) library.
                 Optimized kernels are NOT compiled with ASan support due
                 to limitations of register assignment in inline assembly.
                 WARNING: ENABLING THIS OPTION WILL NEGATIVELY IMPACT
                 PERFORMANCE. Please use only for informational/debugging
                 purposes.

   -i SIZE, --int-size=SIZE

                 Set the size (in bits) of internal BLIS integers and
                 integer types used in native BLIS interfaces. The
                 default integer type size is architecture dependent.
                 (Hint: You can always find this value printed at the
                 beginning of the testsuite output.)

   -b SIZE, --blas-int-size=SIZE

                 Set the size (in bits) of integer types in external
                 BLAS and CBLAS interfaces, if enabled. The default
                 integer type size used in BLAS/CBLAS is 32 bits.

   --disable-blas, --enable-blas

                 Disable (enabled by default) building the BLAS
                 compatibility layer.

   --enable-cblas, --disable-cblas

                 Enable (disabled by default) building the CBLAS
                 compatibility layer. This automatically enables the
                 BLAS compatibility layer as well.

   --disable-mixed-dt, --enable-mixed-dt

                 Disable (enabled by default) support for mixing the
                 storage domain and/or storage precision of matrix
                 operands for the gemm operation, as well as support
                 for computing in a precision different from one or
                 both of matrices A and B.

   --disable-mixed-dt-extra-mem, --enable-mixed-dt-extra-mem

                 Disable (enabled by default) support for additional
                 mixed datatype optimizations that require temporarily
                 allocating extra memory--specifically, a single m x n
                 matrix (per application thread) whose storage datatype
                 is equal to the computation datatype. This option may
                 only be enabled when mixed domain/precision support is
                 enabled.

   --disable-sup-handling, --enable-sup-handling

                 Disable (enabled by default) handling of small/skinny
                 matrix problems via separate code branches. When disabled,
                 these small/skinny level-3 operations will be performed by
                 the conventional implementation, which is optimized for
                 medium and large problems. Note that what qualifies as
                 "small" depends on thresholds that may vary by sub-
                 configuration.

   --enable-amd-frame-tweaks, --disable-amd-frame-tweaks

                 Enable building with certain framework files that have
                 been customized by AMD for Zen-based microarchitectures.
                 The default counterparts of these files must be portable,
                 and so these customized files may provide some (typically
                 modest) performance improvement for some select operations
                 and/or APIs, though there may a few (tiny dimension) cases
                 where the improvement is more pronounced. Note that the
                 target configuration must be Zen-based (or 'amd64') for
                 this option to have any effect. (Also note that this
                 option is NOT to be confused with enabling AMD *kernels*,
                 which are determined by the BLIS subconfiguration used at
                 runtime.) By default, these customized files are disabled.

   --enable-scalapack-compat, --disable-scalapack-compat

                 Enable strict compatibility with ScaLAPACK, which may
                 requiring disabling certain conflicting functionality
                 available through the BLAS and/or CBLAS interfaces.

   -a NAME --enable-addon=NAME

                 Enable the code provided by an addon. An addon consists
                 of a separate directory of code that provides additional
                 APIs, implementations, and/or operations that would
                 otherwise not be present within a build of BLIS. This
                 option may be used multiple times to specify the inclusion
                 of multiple addons. By default, no addons are enabled.

   -s NAME --enable-sandbox=NAME

                 Enable a separate sandbox implementation of gemm. This
                 option disables BLIS's conventional gemm implementation
                 (which shares common infrastructure with other level-3
                 operations) and instead compiles and uses the code in
                 the NAME directory, which is expected to be a sub-
                 directory of 'sandbox'. By default, no sandboxes are
                 enabled.

   --with-memkind, --without-memkind

                 Forcibly enable or disable the use of libmemkind's
                 hbw_malloc() and hbw_free() as substitutes for malloc()
                 and free(), respectively, when allocating memory for
                 BLIS's memory pools, which are used to manage buffers
                 into which matrices are packed. The default behavior
                 for this option is environment-dependent; if configure
                 detects the presence of libmemkind, libmemkind is used
                 by default, and otherwise it is not used by default.

   -r METHOD, --thread-part-jrir=METHOD

                 Select a strategy for partitioning computation in JR and
                 IR loops and assigning that computation to threads. Valid
                 values for METHOD are 'rr', 'slab', and 'tlb':
                  'rr':   Assign the computation associated with whole
                          columns of microtiles to threads in a round-
                          robin fashion. When selected, round-robin
                          assignment is also employed during packing.
                  'slab': Partition the computation into N contiguous
                          regions, where each region contains a whole
                          number of microtile columns, and assign one
                          region to each thread. For some operations, the
                          number of microtile columns contained within a
                          given region may differ from that of other
                          regions, depending on how much work is implied
                          by each region. When selected, slab assignment
                          is also employed during packing.
                  'tlb':  Tile-level load balancing is similar to slab,
                          except that regions will be divided at a more
                          granular level (individual microtiles instead
                          of whole columns of microtiles) to ensure more
                          equitable assignment of work to threads. When
                          selected, tlb will only be employed for level-3
                          operations except trsm; due to practical and
                          algorithmic limitations, slab partitioning will
                          be used instead during packing and for trsm.
                 The default strategy is 'slab'. NOTE: Specifying this
                 option constitutes a request, which may be ignored in
                 select situations if implementation has a good reason to
                 do so. (See description of 'tlb' above for an example of
                 this.)

   --disable-trsm-preinversion, --enable-trsm-preinversion

                 Disable (enabled by default) pre-inversion of triangular
                 matrix diagonals when performing trsm. When pre-inversion
                 is enabled, diagonal elements are inverted outside of the
                 microkernel (e.g. during packing) so that the microkernel
                 can use multiply instructions. When disabled, division
                 instructions are used within the microkernel. Executing
                 these division instructions within the microkernel will
                 incur a performance penalty, but numerical robustness will
                 improve for certain cases involving denormal numbers that
                 would otherwise result in overflow in the pre-inverted
                 values.

   --force-version=STRING

                 Force configure to use an arbitrary version string
                 STRING. This option may be useful when repackaging
                 custom versions of BLIS by outside organizations.

   -c, --show-config-lists

                 Print the config and kernel lists, and kernel-to-config
                 map after they are read from file. This can be useful
                 when debugging certain configuration issues, and/or as
                 a sanity check to make sure these lists are constituted
                 as expected.

   --complex-return=gnu|intel

                 Specify the way in which complex numbers are returned
                 from Fortran functions, either "gnu" (return in
                 registers) or "intel" (return via hidden argument).
                 If not specified and the environment variable FC is set,
                 attempt to determine the return type from the compiler.
                 Otherwise, the default is "gnu".

   -q, --quiet   Suppress informational output. By default, configure
                 is verbose. (NOTE: -q is not yet implemented)

   -h, --help    Output this information and quit.

 Environment Variables:

   CC            Specifies the C compiler to use.
   CXX           Specifies the C++ compiler to use (sandbox only).
   FC            Specifies the Fortran compiler to use (only to determine --complex-return).
   AR            Specifies the static library archiver to use.
   RANLIB        Specifies the ranlib (library indexer) executable to use.
   PYTHON        Specifies the python interpreter to use.
   CFLAGS        Specifies additional compiler flags to use (prepended).
   LDFLAGS       Specifies additional linker flags to use (prepended).
   LIBPTHREAD    Pthreads library to use.

   Environment variables are traditionally set prior to running configure:

     CC=gcc ./configure [options] haswell

   However, they may also be specified as command line options, e.g.:

     ./configure [options] CC=gcc haswell

   Note that not all compilers are compatible with a given
   configuration.

EOF

	# Exit with non-zero exit status
	exit 1
}

query_array()
{
	local arr key var_name

	arr="$1"
	key="$2"

	var_name="${arr}_${key}"

	echo "${!var_name}"
}

assign_key_value()
{
	local arr key val

	arr="$1"
	key="$2"
	val="$3"

	printf -v "${arr}_${key}" %s "${val}"
}

#
# FGVZ: This commented-out function is being kept as an example how how
# to effectively "pass by reference" in bash. That is, pass the name of
# a variable, instead of its conents, and then let the function use the
# variable by prepending a $, at which time it can evaluate the string
# as if it were a literal variable occurance.
#
#filteradd_to_list()
#{
#	local dlist ditem list_c item_c is_blacklisted
#
#	# Add $1 to the list identified by $2, but only if $1 is not
#	# found in a blacklist.
#
#	# Note: $2 can actually be a list of items.
#	ditem=\$"$1"
#	dlist=\$"$2"
#
#	# Acquire the contents of $dlist and $ditem and store them in list_c
#	# and item_c, respectively.
#	list_c=$(eval "expr \"$dlist\" ")
#	item_c=$(eval "expr \"$ditem\" ")
#
#	# Iterate over $item_c in case it is actually multiple items.
#	for cur_item in $item_c; do
#
#		is_blacklisted=$(is_in_list "${cur_item}" "${config_blist}")
#		if [ ${is_blacklisted} == "false" ]; then
#
#			# If cur_item is not blacklisted, add it to list_c.
#			list_c="${list_c} ${cur_item}"
#		fi
#	done
#
#	# Update the argument.
#	eval "$2=\"${list_c}\""
#}

pass_config_kernel_registries()
{
	local filename passnum
	local all_blist
	local curline list item config kernels
	local cname clist klist

	# Read function arguments:
	# first argument: the file containing the configuration registry.
	# second argument: the pass number: 0 or 1. Pass 0 builds the
	# indirect config blacklist (indirect_blist) ONLY. Pass 1 actually
	# begins populating the config and kernel registries, and assumes
	# the indirect_blist has already been created.
	filename="$1"
	passnum="$2"

	# Initialize a list of indirect blacklisted configurations for the
	# current iteration. These are configurations that are invalidated by
	# the removal of blacklisted configurations. For example, if haswell
	# is registered as needing the 'haswell' and 'zen' kernel sets:
	#
	#    haswell: haswell/haswell/zen
	#
	# and 'zen' was blacklisted because of the compiler version, then the
	# 'haswell' configuration must be omitted from the registry, as it no
	# longer has all of the kernel sets it was expecting.
	if [ "${passnum}" == "0" ]; then
		indirect_blist=""
	fi

	# For convenience, merge the original and indirect blacklists.
	# NOTE: During pass 0, all_blist is equal to config_blist, since
	# indirect_blist is still empty.
	all_blist="${config_blist} ${indirect_blist}"

	# Disable support for indirect blacklisting by returning early during
	# pass 0. See issue #214 for details [1]. Basically, I realized that
	# indirect blacklisting is not needed in the use case that I envisioned
	# in the real-life example above. If a subconfiguration such as haswell
	# is defined to require the zen kernel set, it implies that the zen
	# kernels can be compiled with haswell compiler flags. That is, just
	# because the zen subconfig (and its compiler flags) is blacklisted
	# does not mean that the haswell subconfig cannot compile the zen
	# kernels with haswell-specific flags.
	#
	# [1] https://github.com/flame/blis/issues/214
	#
	if [ "${passnum}" == "0" ]; then
		return
	fi

	while read -r line
	do
		curline="${line}"

		# Remove everything after comment character '#'.
		curline=${curline%%#*}

		# We've stripped out leading whitespace and trailing comments. If
		# the line is now empty, then we can skip it altogether.
		if [[ -z ${curline} ]]; then
			continue;
		fi

		# Read the config name and config list for the current line.
		cname=${curline%%:*}
		list=${curline##*:}

		# If we encounter a slash, it means the name of the configuration
		# and the kernel set needed by that configuration are different.
		if [[ ${list} = */* ]]; then

			#echo "Slash found."
			klist=""
			clist=""

			for item in ${list}; do

				# The sub-configuration name is always the first sub-word in
				# the slash-separated compound word.
				config=${item%%/*}

				# Delete the sub-configuration name from the front of the
				# string, leaving the slash-separated kernel names (or just
				# the kernel name, if there is only one).
				kernels=${list#*/}

				# Replace the slashes with spaces to transform the string
				# into a space-separated list of kernel names.
				kernels=$(echo -e "${kernels}" | sed -e "s/\// /g")

				clist="${clist} ${config}"
				klist="${klist} ${kernels}"
			done
		else

			#echo "Slash not found."
			clist=${list}
			klist=${list}
		fi

		# Strip out whitespace from the config name and config/kernel list
		# on each line.
		cname=$(canonicalize_ws "${cname}")
		clist=$(canonicalize_ws "${clist}")
		klist=$(canonicalize_ws "${klist}")

		# Next, we prepare to:
		# - pass 0: inspect klist for blacklisted configurations, which may
		#   reveal configurations as needing to be indirectly blacklisted.
		# - pass 1: compare cname to the blacklists and commit clist/klist
		#   to their respective registries, as appropriate.

		# Handle singleton and umbrella configuration entries separately.
		if [[ $(is_singleton_family "${cname}" "${clist}") == "true" ]]; then

			# Singleton configurations/families.
			# Note: for singleton families, clist contains one item, which
			# always equals cname, but klist could contain more than one
			# item.

			# Only consider updating the indirect blacklist (pass 0) or
			# committing clist and klist to the registries (pass 1) if the
			# configuration name (cname) is not blacklisted.
			if [[ $(is_in_list "${cname}" "${all_blist}") == "false" ]]; then

				if [ "${passnum}" == "0" ]; then
					# Even if the cname isn't blacklisted, one of the requisite
					# kernels might be, so we need to check klist for blacklisted
					# items. If we find one, we must assume that the entire entry
					# must be thrown out. (Ideally, we would simply fall back to
					# reference code for the blacklisted kernels, but that is not
					# at all straightforward under the current configuration
					# system architecture.) Thus, we add cname to the indirect
					# blacklist.
					for item in ${klist}; do
						if [[ $(is_in_list "${item}" "${config_blist}") == "true" ]]; then
							indirect_blist="${indirect_blist} ${cname}"
							break
						fi
					done
				fi

				if [ "${passnum}" == "1" ]; then
					# Store the clist to the cname key of the config registry.
					#config_registry[${cname}]=${clist}
					#printf -v "config_registry_${cname}" %s "${clist}"
					assign_key_value "config_registry" "${cname}" "${clist}"
				fi
			fi

			if [ "${passnum}" == "1" ]; then
				# Store the klist to the cname key of the kernel registry.
				#kernel_registry[${cname}]=${klist}
				#printf -v "kernel_registry_${cname}" %s "${klist}"
				assign_key_value "kernel_registry" "${cname}" "${klist}"
			fi

		else
			# Umbrella configurations/families.

			# First we check cname, which should generally not be blacklisted
			# for umbrella families, but we check anyway just to be safe.
			if [[ $(is_in_list "${cname}" "${all_blist}") == "false" ]]; then

				if [ "${passnum}" == "1" ]; then

					# Check each item in the clist and klist. (At this point,
					# clist == klist.) If any sub-config is blacklisted, we
					# omit it from clist and klist.
					for item in ${clist}; do

						if [[ $(is_in_list "${item}" "${all_blist}") == "true" ]]; then
							clist=$(remove_from_list "${item}" "${clist}")
							klist=$(remove_from_list "${item}" "${klist}")
						fi
					done

					# Store the config and kernel lists to entries that
					# corresponds to the config name.
					#config_registry[${cname}]=${clist}
					#kernel_registry[${cname}]=${klist}
					#printf -v "config_registry_${cname}" %s "${clist}"
					#printf -v "kernel_registry_${cname}" %s "${klist}"
					assign_key_value "config_registry" "${cname}" "${clist}"
					assign_key_value "kernel_registry" "${cname}" "${klist}"
				fi
			fi
		fi

	done < "${filename}"

	if [ "${passnum}" == "0" ]; then
		# Assign the final indirect blacklist (with whitespace removed).
		indirect_blist=$(canonicalize_ws "${indirect_blist}")
	fi
}

read_registry_file()
{
	local filename
	local clist klist
	local iterate_again config
	local cr_var mem mems_mem newclist
	local kr_var ker kers_ker newklist

	filename="$1"

	# Execute an initial pass through the config_registry file so that
	# we can accumulate a list of indirectly blacklisted configurations,
	# if any.
	pass_config_kernel_registries "${filename}" "0"

	# Now that the indirect_blist has been created, make a second pass
	# through the 'config_registry' file, this time creating the actual
	# config and kernel registry data structures.
	pass_config_kernel_registries "${filename}" "1"

	# Now we must go back through the config_registry and subsitute any
	# configuration families with their constituents' members. Each time
	# one of these substitutions occurs, we set a flag that causes us to
	# make one more pass. (Subsituting a singleton definition does not
	# prompt additional iterations.) This process stops when a full pass
	# does not result in any subsitution.

	iterate_again="1"
	while [ "${iterate_again}" == "1" ]; do

		iterate_again="0"

		#for config in "${!config_registry[@]}"; do
		for cr_var in ${!config_registry_*}; do

			config=${cr_var##config_registry_}

			clist=$(query_array "config_registry" "${config}")

			# The entries that define singleton families should never need
			# any substitution.
			if [[ $(is_singleton_family "${config}" "${clist}") == "true" ]]; then
				continue
			fi

			#for mem in ${config_registry[$config]}; do
			#for mem in ${!cr_var}; do
			for mem in ${clist}; do

				#mems_mem="${config_registry[${mem}]}"
				mems_mem=$(query_array "config_registry" "${mem}")

				# If mems_mem is empty string, then mem was not found as a key
				# in the config list associative array. In that case, we continue
				# and will echo an error later in the script.
				if [ "${mems_mem}" == "" ]; then
					#echo "  config for ${mem} is empty string! no entry in config list."
					continue;
				fi

				if [ "${mem}" != "${mems_mem}" ]; then

					#clist="${config_registry[$config]}"
					clisttmp=$(query_array "config_registry" "${config}")

					# Replace the current config with its constituent config set,
					# canonicalize whitespace, and then remove duplicate config
					# set names, if they exist. Finally, update the config registry
					# with the new config list.
					# NOTE: WE must use substitute_words() rather than a simple sed
					# expression because we need to avoid matching partial strings.
					# For example, if clist above contains "foo bar barsk" and we use
					# sed to substitute "bee boo" as the members of "bar", the
					# result would (incorrectly) be "foo bee boo bee boosk",
					# which would then get reduced, via rm_duplicate_words(), to
					# "foo bee boo boosk".
					#newclist=$(echo -e "${clist}" | sed -e "s/${mem}/${mems_mem}/g")
					newclist=$(substitute_words "${mem}" "${mems_mem}" "${clisttmp}")
					newclist=$(canonicalize_ws "${newclist}")
					newclist=$(rm_duplicate_words "${newclist}")

					#config_registry[${config}]=${newclist}
					#printf -v "config_registry_${config}" %s "${newclist}"
					assign_key_value "config_registry" "${config}" "${newclist}"

					# Since we performed a substitution and changed the config
					# list, mark the iteration flag to continue another round,
					# but only if the config (mem) value is NOT present
					# in the list of sub-configs. If it is present, then further
					# substitution may not necessarily be needed this round.
					if [[ $(is_in_list "${mem}" "${mems_mem}") == "false" ]]; then
						iterate_again="1"
					fi
				fi
			done
		done
	done

	# Similar to what we just did for the config_registry, we now iterate
	# through the kernel_registry and substitute any configuration families
	# in the kernel list (right side of ':') with the members of that
	# family's kernel set. This process continues iteratively, as before,
	# until all families have been replaced with singleton configurations'
	# kernel sets.

	iterate_again="1"
	while [ "${iterate_again}" == "1" ]; do

		iterate_again="0"

		#for config in "${!kernel_registry[@]}"; do
		for kr_var in ${!kernel_registry_*}; do

			config=${kr_var##kernel_registry_}

			klist=$(query_array "kernel_registry" "${config}")

			# The entries that define singleton families should never need
			# any substitution. In the kernel registry, we know it's a
			# singleton entry when the cname occurs somewhere in the klist.
			# (This is slightly different than the same test in the config
			# registry, where we test that clist is one word and that
			# clist == cname.)
			if [[ $(is_in_list "${config}" "${klist}") == "true" ]]; then
				#echo "debug: '${config}' not found in '${klist}'; skipping."
				continue
			fi

			#for ker in ${kernel_registry[$config]}; do
			#for ker in ${!kr_var}; do
			for ker in ${klist}; do

				#kers_ker="${kernel_registry[${ker}]}"
				kers_ker=$(query_array "kernel_registry" "${ker}")

				# If kers_ker is empty string, then ker was not found as a key
				# in the kernel registry. While not common, this can happen
				# when ker identifies a kernel set that does not correspond to
				# any configuration. (Example: armv7a and armv8a kernel sets are
				# used by cortexa* configurations, but do not corresond to their
				# own configurations.)
				if [ "${kers_ker}" == "" ]; then
					#echo "debug: ${ker} not found in kernel registry."
					continue
				fi

				# If the current config/kernel (ker) differs from its singleton kernel
				# entry (kers_ker), then that singleton entry was specified to use
				# a different configuration's kernel set. Thus, we need to replace the
				# occurrence in the current config/kernel name with that of the kernel
				# set it needs.
				if [ "${ker}" != "${kers_ker}" ]; then

					#klisttmp="${kernel_registry[$config]}"
					klisttmp=$(query_array "kernel_registry" "${config}")

					# Replace the current config with its requisite kernels,
					# canonicalize whitespace, and then remove duplicate kernel
					# set names, if they exist. Finally, update the kernel registry
					# with the new kernel list.
					# NOTE: WE must use substitute_words() rather than a simple sed
					# expression because we need to avoid matching partial strings.
					# For example, if klist above contains "foo bar barsk" and we use
					# sed to substitute "bee boo" as the members of "bar", the
					# result would (incorrectly) be "foo bee boo bee boosk",
					# which would then get reduced, via rm_duplicate_words(), to
					# "foo bee boo boosk".
					#newklist=$(echo -e "${klisttmp}" | sed -e "s/${ker}/${kers_ker}/g")
					newklist=$(substitute_words "${ker}" "${kers_ker}" "${klisttmp}")
					newklist=$(canonicalize_ws "${newklist}")
					newklist=$(rm_duplicate_words "${newklist}")

					#kernel_registry[${config}]=${newklist}
					#printf -v "kernel_registry_${config}" %s "${newklist}"
					assign_key_value "kernel_registry" "${config}" "${newklist}"

					# Since we performed a substitution and changed the kernel
					# list, mark the iteration flag to continue another round,
					# unless we just substituted using a singleton family
					# definition, in which case we don't necessarily need to
					# iterate further this round.
					if [[ $(is_in_list "${ker}" "${kers_ker}") == "false" ]]; then
						iterate_again="1"
					fi
				fi
			done
		done
	done
}

substitute_words()
{
	local word new_words list newlist

	word="$1"
	new_words="$2"
	list="$3"

	for str in ${list}; do

		if [ "${str}" == "${word}" ]; then
			newlist="${newlist} ${new_words}"
		else
			newlist="${newlist} ${str}"
		fi
	done

	echo "${newlist}"
}

build_kconfig_registry()
{
	local familyname clist config kernels kernel cur_configs newvalue

	familyname="$1"

	#clist="${config_registry[${familyname}]}"
	clist=$(query_array "config_registry" "${familyname}")

	for config in ${clist}; do

		# Look up the kernels for the current sub-configuration.
		#kernels="${kernel_registry[${config}]}"
		kernels=$(query_array "kernel_registry" "${config}")

		for kernel in ${kernels}; do

			# Add the sub-configuration to the list associated with the
			# kernel.

			# Query the current sub-configs for the current ${kernel}.
			#cur_configs="${kconfig_registry[${kernel}]}"
			cur_configs=$(query_array "kconfig_registry" "${kernel}")

			# Add the current sub-configuration to the list of sub-configs
			# we just queried.
			newvalue=$(canonicalize_ws "${cur_configs} ${config}")

			# Update the array.
			#kconfig_registry[${kernel}]="${newvalue}"
			#printf -v "kconfig_registry_${kernel}" %s "${newvalue}"
			assign_key_value "kconfig_registry" "${kernel}" "${newvalue}"

		done

	done
}

is_in_list()
{
	local word list rval item

	word="$1"
	list="$2"
	rval="false"

	for item in ${list}; do

		if [ "${item}" == "${word}" ]; then
			rval="true"
			break
		fi
	done

	echo "${rval}"
}

is_singleton()
{
	local list rval count_str item

	list="$1"
	rval="false"

	count_str=""
	for item in ${list}; do

		count_str="${count_str}x"
	done

	if [ "${count_str}" == "x" ]; then
		rval="true"
	fi

	echo "${rval}"
}

is_singleton_family()
{
	local familyname memberlist rval

	familyname="$1"
	memberlist="$2"

	rval="false"

	if [[ -n $(is_singleton "${memberlist}") ]]; then

		if [ "${memberlist}" == "${familyname}" ]; then
			rval="true"
		fi
	fi

	echo "${rval}"
}

remove_from_list()
{
	local strike_list list flist item

	strike_words="$1"
	list="$2"
	flist=""

	for item in ${list}; do

		# Filter out any list item that matches any of the strike words.
		if [[ $(is_in_list "${item}" "${strike_words}") == "false" ]]; then
			flist="${flist} ${item}"
		fi
	done

	flist=$(canonicalize_ws "${flist}")

	# Return the filtered list.
	echo "${flist}"
}

canonicalize_ws()
{
	local str

	str="$1"

	# Remove leading and trailing whitespace.
	str=$(echo -e "${str}" | sed -e 's/^[[:space:]]*//' -e 's/[[:space:]]*$//')

	# Remove duplicate spaces between words.
	str=$(echo -e "${str}" | tr -s " ")

	# Update the input argument.
	echo "${str}"
}

rm_duplicate_words_simple()
{
	local str revstr revres res

	str="$1"

	# Remote duplicates, keeping the first occurrence.
	res=$(echo "${str}" | awk '{for (i=1;i<=NF;i++) if (!a[$i]++) printf("%s%s",$i,FS)}{printf("\n")}')

	echo "${res}"
}

rm_duplicate_words()
{
	local str revstr revres res

	str="$1"

	# We reverse the initial string, THEN remove duplicates, then reverse
	# the de-duplicated result so that only the last instance is kept after
	# removing duplicates (rather than keeping only the first). This is
	# totally unnecessary but works well for the kinds of duplicates that
	# show up in certain use cases of the config and kernel registries.
	# For example, these gymnastics allow us to keep only the last instance
	# of the 'generic' configuration in a configuration family that
	# includes it twice or more.
	revstr=$(echo "${str}" | awk '{ for (i=NF; i>1; i--) printf("%s ",$i); print $1; }')
	revres=$(echo "${revstr}" | awk '{for (i=1;i<=NF;i++) if (!a[$i]++) printf("%s%s",$i,FS)}{printf("\n")}')
	res=$(echo "${revres}" | awk '{ for (i=NF; i>1; i--) printf("%s ",$i); print $1; }')

	echo "${res}"
}

get_cc_search_list()
{
	local list

	# For Linux, Darwin (OS X), and generic OSes, prioritize gcc.
	list="gcc clang cc"

	# For OpenBSD and FreeBSD, prioritize cc and clang over gcc.
	if   [ "${os_name}" = "OpenBSD" ]; then
		list="cc clang gcc"
	elif [ "${os_name}" = "FreeBSD" ]; then
		list="cc clang gcc"
	fi

	echo "${list}"
}

get_cxx_search_list()
{
	local list

	# For Linux, Darwin (OS X), and generic OSes, prioritize g++.
	list="g++ clang++ c++"

	# For OpenBSD and FreeBSD, prioritize cc and clang over gcc.
	if   [ "${os_name}" = "OpenBSD" ]; then
		list="c++ clang++ g++"
	elif [ "${os_name}" = "FreeBSD" ]; then
		list="c++ clang++ g++"
	fi

	echo "${list}"
}

get_fc_search_list()
{
	local list

	list="gfortran ifort"

	echo "${list}"
}

get_ar_search_list()
{
	local list

	list="ar"

	echo "${list}"
}

get_ranlib_search_list()
{
	local list

	list="ranlib"

	echo "${list}"
}

auto_detect()
{
	local cc cflags config_defines detected_config rval cmd

	# Use the same compiler that was found earlier.
	cc="${found_cc}"

	# For debugging: reveal what compiler was chosen for auto-detection.
	#touch "${cc}.txt"

	# Tweak the flags we use based on the compiler. This is mostly just
	# an opportunity to turn off annoying warnings that some compilers
	# may throw off.
	if [ "${cc}" == "clang" ]; then
		cflags="-Wno-tautological-compare"
	else
		cflags=
	fi

	# Accumulate a list of source files we'll need to compile along with
	# the top-level (root) directory in which they are located.
	c_src_pairs=""
	c_src_pairs="${c_src_pairs} frame:bli_arch.c"
	c_src_pairs="${c_src_pairs} frame:bli_cpuid.c"
	c_src_pairs="${c_src_pairs} frame:bli_env.c"
	c_src_pairs="${c_src_pairs} build:config_detect.c"

	# Accumulate a list of full filepaths to the source files listed above.
	c_src_filepaths=""
	for pair in ${c_src_pairs}; do

		filename=${pair#*:}
		rootdir=${pair%:*}

		filepath=$(find "${dist_path}/${rootdir}" -name "${filename}")
		c_src_filepaths="${c_src_filepaths} ${filepath}"
	done

	# Accumulate a list of header files we'll need to locate along with
	# the top-level (root) directory in which they are located.
	c_hdr_pairs=""
	c_hdr_pairs="${c_hdr_pairs} frame:bli_system.h"
	c_hdr_pairs="${c_hdr_pairs} frame:bli_type_defs.h"
	c_hdr_pairs="${c_hdr_pairs} frame:bli_arch.h"
	c_hdr_pairs="${c_hdr_pairs} frame:bli_cpuid.h"
	c_hdr_pairs="${c_hdr_pairs} frame:bli_env.h"
	# NOTE: These headers are needed by bli_type_defs.h.
	c_hdr_pairs="${c_hdr_pairs} frame:bli_malloc.h"
	c_hdr_pairs="${c_hdr_pairs} frame:bli_pthread.h"

	# Accumulate a list of full paths to the header files listed above.
	# While we are at it, we include the "-I" compiler option to indicate
	# adding the path to the list of directories to search when encountering
	# #include directives.
	c_hdr_paths=""
	for pair in ${c_hdr_pairs}; do

		filename=${pair#*:}
		rootdir=${pair%:*}

		filepath=$(find "${dist_path}/${rootdir}" -name "${filename}")
		path=${filepath%/*}
		c_hdr_paths="${c_hdr_paths} -I${path}"
	done

	# Define the executable name.
	autodetect_x="auto-detect.x"

	# Create #defines for all of the BLIS_CONFIG_ macros in bli_cpuid.c.
	bli_cpuid_c_filepath=$(find "${dist_path}/frame" -name "bli_cpuid.c")
	config_defines=$(grep BLIS_CONFIG_ "${bli_cpuid_c_filepath}" \
	                 | sed -Ee 's/#ifdef[[:space:]]+/-D/g')

	# Set the linker flags. We typically need pthreads (or BLIS's homerolled
	# equiavlent) because it is needed for parts of bli_arch.c unrelated to
	# bli_arch_string(), which is called by the main() function in ${main_c}.
	if [[ "$is_msvc" == "no" ]]; then
		ldflags="${LIBPTHREAD--lpthread}"
	fi

	# However, if --disable-system was given, we override the choice made above
	# and do not use any pthread link flags.
	if [[ "$enable_system" == "no" ]]; then
		ldflags=
	fi

	# Compile the auto-detect program using source code inside the
	# framework.
	# NOTE: -D_GNU_SOURCE is needed to enable POSIX extensions to
	# pthreads (i.e., barriers).

	cmd="${cc} \
	      -DBLIS_CONFIGURETIME_CPUID \
	      ${c_hdr_paths} \
	      -std=c99 -D_GNU_SOURCE \
	      ${cflags}"

	# Special case for RISC-V, whose architecture can be detected with
	# preprocessor macros alone. This avoids having to run RISC-V binaries
	# on a cross-compiler host. Returns "generic" if RISC-V not detected.
	riscv_config=$(${cmd} -E "${dist_path}/build/detect/riscv/bli_riscv_cpuid.h" |
	               grep '^[^#]')
	if [[ $riscv_config != *generic* ]]; then
		echo "${riscv_config}"
		return
	fi

	# Finish command for building executable
	cmd="${cmd} ${config_defines} ${c_src_filepaths} ${ldflags} \
	     -o ${autodetect_x}"

	if [ "${debug_auto_detect}" == "no" ]; then

		# Execute the compilation command.
		# shellcheck disable=2086
		eval ${cmd}

	else

		# Debugging stuff. Instead of executing ${cmd}, join the lines together
		# with tr and trim excess whitespace via awk.
		cmd=$(echo "${cmd}" | tr '\n' ' ' | awk '{$1=$1;print}')
		echo "${cmd}"
		return
	fi

	# Run the auto-detect program.
	detected_config=$("./${autodetect_x}")

	# Remove the executable file.
	rm -f "./${autodetect_x}"

	# Return the detected sub-configuration name.
	echo "${detected_config}"
}

has_libmemkind()
{
	local main_c main_c_filepath LDFLAGS_mk binname rval

	# Path to libmemkind detection source file.
	main_c="libmemkind_detect.c"
	main_c_filepath=$(find "${dist_path}/build" -name "${main_c}")

	# Add libmemkind to LDFLAGS.
	LDFLAGS_mk="${LDFLAGS} -lmemkind"

	# Binary executable filename.
	binname="libmemkind-detect.x"

	# Attempt to compile a simple main() program that contains a call
	# to hbw_malloc() and that links to libmemkind.
	# shellcheck disable=2086
	"${found_cc}" -o "${binname}" "${main_c_filepath}" ${LDFLAGS_mk} 2> /dev/null

	# Depending on the return code from the compile step above, we set
	# enable_memkind accordingly.
	if [ "$?" == 0 ]; then
		rval='yes'
	else
		rval='no'
	fi

	# Remove the executable generated above.
	rm -f "./${binname}"

	echo "${rval}"
}

has_pragma_omp_simd()
{
	local main_c main_c_filepath binname rval

	# Path to omp-simd detection source file.
	main_c="omp_simd_detect.c"
	main_c_filepath=$(find "${dist_path}/build" -name "${main_c}")

	# Binary executable filename.
	binname="omp_simd-detect.x"

	# Attempt to compile a simple main() program that contains a
	# #pragma omp simd.
	"${found_cc}" -std=c99 -O3 -march=native -fopenmp-simd \
	            -o "${binname}" "${main_c_filepath}" 2> /dev/null

	# Depending on the return code from the compile step above, we set
	# enable_memkind accordingly.
	if [ "$?" == 0 ]; then
		rval='yes'
	else
		rval='no'
	fi

	# Remove the executable generated above.
	rm -f "./${binname}"

	echo "${rval}"
}

echoerr()
{
	printf "${script_name}: error: %s\n" "$*" #>&2;
}

echowarn()
{
	printf "${script_name}: warning: %s\n" "$*" #>&2;
}

blacklistcc_add()
{
	# Check whether we've already blacklisted the given sub-config so
	# we don't output redundant messages.
	if [[ $(is_in_list "$1" "${config_blist}") == "false" ]]; then

		echowarn "${cc_vendor} ${cc_version} does not support '$1'; adding to blacklist."
		config_blist="${config_blist} $1"
	fi
}

blacklistbu_add()
{
	# Check whether we've already blacklisted the given sub-config so
	# we don't output redundant messages.
	if [[ $(is_in_list "$1" "${config_blist}") == "false" ]]; then

		echowarn "assembler ('as' ${bu_version}) does not support '$1'; adding to blacklist."
		config_blist="${config_blist} $1"
	fi
}

blacklistos_add()
{
	# Check whether we've already blacklisted the given sub-config so
	# we don't output redundant messages.
	if [[ $(is_in_list "$1" "${config_blist}") == "false" ]]; then

		echowarn "The operating system does not support building '$1'; adding to blacklist."
		config_blist="${config_blist} $1"
	fi
}

blacklist_init()
{
	config_blist=""
}

blacklist_cleanup()
{
	# Remove duplicates and whitespace from the blacklist.
	config_blist=$(rm_duplicate_words "${config_blist}")
	config_blist=$(canonicalize_ws "${config_blist}")
}

echoerr_unsupportedcc()
{
	echoerr "${script_name}: *** Unsupported compiler version: ${cc_vendor} ${cc_version}."
	exit 1
}

echoerr_unsupportedpython()
{
	echoerr "${script_name}: *** Unsupported python version: ${python_version}."
	exit 1
}

get_binutils_version()
{
	binutil=${AS:-as}

	# Query the full binutils version string output. This includes the
	# version string along with (potentially) a bunch of other textual
	# clutter.
	if [ "$(uname -s)" == "Darwin" ]; then
		# The default OS X assembler uses a trifecta of brain-dead
		# conventions: responding only to '-v', hanging indefinitely if
		# not given an argument, and outputing the result to stderr.
		# (And if you still weren't convinced, it creates an 'a.out'
		# by default. So yeah.)
		bu_string=$(${binutil} -v /dev/null -o /dev/null 2>&1)
	else
		bu_string=$(${binutil} --version 2>/dev/null)
	fi

	# Query the binutils version number.
	# The last part ({ read first rest ; echo $first ; }) is a workaround
	# to OS X's egrep only returning the first match.
	bu_version=$(echo "${bu_string}" | grep -oE '[0-9]+\.[0-9]+\.?[0-9]*' |
	             { read -r first rest ; echo "${first}"; })

	# Parse the version number into its major, minor, and revision
	# components.
	bu_major=$(echo "${bu_version}" | cut -d. -f1)
	bu_minor=$(echo "${bu_version}" | cut -d. -f2)
	bu_revision=$(echo "${bu_version}" | cut -d. -f3)

	echo "${script_name}: found assembler ('as') version ${bu_version} (maj: ${bu_major}, min: ${bu_minor}, rev: ${bu_revision})."
}

get_python_search_list()
{
	local list

	# For Linux, Darwin (OS X), and generic OSes, prioritize 'python'.
	list="python python3 python2"

	echo "${list}"
}

get_python_version()
{
	local python vendor_string

	python="${found_python}"

	# Query the python version. This includes the version number along
	# with other text, such as "Python ".
	# NOTE: Python seems to echo its version info to stderr, not
	# stdout, and thus we redirect stderr to stdout and capture that.
	vendor_string="$(${python} --version 2>&1)"

	# Drop any preceding text and save only the first numbers and what
	# comes after.
	python_version=$(echo "${vendor_string}" | sed -e "s/[a-zA-Z_ ]* \([0-9]*\..*\)/\1/g")
	# Parse the version number into its major, minor, and revision
	# components.
	python_major=$(echo "${python_version}" | cut -d. -f1)
	python_minor=$(echo "${python_version}" | cut -d. -f2)
	python_revision=$(echo "${python_version}" | cut -d. -f3)

	echo "${script_name}: found python version ${python_version} (maj: ${python_major}, min: ${python_minor}, rev: ${python_revision})."
}

check_python()
{
	local python

	python="${found_python}"

	#
	# Python requirements
	#
	# python1: no versions supported
	# python2: 2.7+
	# python3: 3.4+
	#
	# NOTE: It's actually unclear whether python 3.0 through 3.3.x would work.
	# Python 3.5 is the oldest python3 that I have available to test with, and
	# I only know that 3.4 will work thanks to feedback from Dave Love. So it's
	# quite possible that some of those "unsupported" python3 versions are
	# sufficient. -FGVZ
	#

	# Python 1.x is unsupported.
	if [[ ${python_major} -eq 1 ]]; then
		echoerr_unsupportedpython
	fi

	# Python 2.6.x or older is unsupported.
	if [[ ${python_major} -eq 2 ]]; then
		if [[ ${python_minor} -lt 7 ]]; then
			echoerr_unsupportedpython
		fi
	fi

	# Python 3.3.x or older is unsupported.
	if [[ ${python_major} -eq 3 ]]; then
		if [[ ${python_minor} -lt 4 ]]; then
			echoerr_unsupportedpython
		fi
	fi

	echo "${script_name}: python ${python_version} appears to be supported."
}

get_compiler_version()
{
	local cc vendor_string

	cc="${found_cc}"

	# Query the full vendor version string output. This includes the
	# version number along with (potentially) a bunch of other textual
	# clutter.
	# NOTE: This maybe should use merged stdout/stderr rather than only
	# stdout. But it works for now.
	vendor_string="$(${cc} --version 2>/dev/null)"

	# Query the compiler "vendor" (ie: the compiler's simple name) and
	# isolate the version number.
	# The last part ({ read first rest ; echo $first ; }) is a workaround
	# to OS X's egrep only returning the first match.
	cc_vendor=$(echo "${vendor_string}" |
	            grep -oE 'icc|gcc|clang|nvc|emcc|pnacl|IBM|oneAPI|crosstool-NG|GCC' |
	            { read -r first rest ; echo "${first}"; })

	# AOCC version strings contain both "clang" and "AOCC" substrings, and
	# so we have perform a follow-up check to make sure cc_vendor gets set
	# correctly.
	if [[ ${vendor_string} = *AOCC* ]]; then
		cc_vendor="aocc"
	fi

	# Detect armclang, which doesn't have a nice, unambiguous, one-word tag
	if [[ ${vendor_string} = *'Arm C/C++/Fortran Compiler'* ]]; then
		cc_vendor="armclang"
	fi

	# Begin parsing cc_vendor for the version string.

	if [ "${cc_vendor}" = "GCC" ]; then
		# Conda gcc sometimes has GCC (all caps) in the version string
		cc_vendor="gcc"
	fi
	if [ "${cc_vendor}" = "crosstool-NG" ]; then
		# Treat compilers built by crosstool-NG (for eg: conda) as gcc.
		cc_vendor="gcc"
	fi
	if [[ ${cc_vendor} = icc || ${cc_vendor} = gcc ]]; then

		cc_version=$(${cc} -dumpversion)

	elif [ "${cc_vendor}" = "armclang" ]; then

		# Treat armclang as regular clang.
		cc_vendor="clang"
		cc_version=$(echo "${vendor_string}" \
		             | grep -oE 'based on LLVM [0-9]+\.[0-9]+\.?[0-9]*' \
		             | grep -oE               '[0-9]+\.[0-9]+\.?[0-9]*')

	elif [ "${cc_vendor}" = "clang" ]; then

		cc_version=$(echo "${vendor_string}" \
		             | grep -oE '(clang|LLVM) version [0-9]+\.[0-9]+\.?[0-9]*' \
		             | grep -oE                      '[0-9]+\.[0-9]+\.?[0-9]*')

	elif [ "${cc_vendor}" = "aocc" ]; then

		# Versions 2.0 and 2.1 had different version string formats from
		# 2.2 and later, so we have to handle them separately.
		# Examples:
		# AOCC.LLVM.2.0.0.B191.2019_07_19 clang version 8.0.0 (CLANG: Jenkins AOCC_2_0_0-Build#191) (based on LLVM AOCC.LLVM.2.0.0.B191.2019_07_19)
		# AOCC.LLVM.2.1.0.B1030.2019_11_12 clang version 9.0.0 (CLANG: Build#1030) (based on LLVM AOCC.LLVM.2.1.0.B1030.2019_11_12)
		# AMD clang version 10.0.0 (CLANG: AOCC_2.2.0-Build#93 2020_06_25) (based on LLVM Mirror.Version.10.0.0)
		# AMD clang version 11.0.0 (CLANG: AOCC_2.3.0-Build#85 2020_11_10) (based on LLVM Mirror.Version.11.0.0)
		# AMD clang version 12.0.0 (CLANG: AOCC_3.0.0-Build#2 2020_11_05) (based on LLVM Mirror.Version.12.0.0)

		if [[ ${vendor_string} = *AOCC.LLVM.2* ]]; then

			# Grep for the AOCC.LLVM.x.y.z substring first, and then isolate the
			# version number. Also, the string may contain multiple instances of
			# the version number, so only use the first occurrence.
			cc_version=$(echo "${vendor_string}" \
			             | grep -oE 'AOCC.LLVM.[0-9]+\.[0-9]+\.?[0-9]*' \
			             | grep -oE           '[0-9]+\.[0-9]+\.?[0-9]*' \
			             | { read -r first rest ; echo "${first}"; })
		else

			# Grep for the AOCC_x.y.z substring first, and then isolate the
			# version number. As of this writing, these version strings don't
			# include multiple instances of the version, but we nonetheless
			# take only the first occurrence as a future-oriented safety
			# measure.
			cc_version=$(echo "${vendor_string}" \
			             | grep -oE 'AOCC_[0-9]+\.[0-9]+\.?[0-9]*' \
			             | grep -oE      '[0-9]+\.[0-9]+\.?[0-9]*' \
			             | { read -r first rest ; echo "${first}"; })
		fi

	elif [ "${cc_vendor}" = "oneAPI" ]; then

		# Treat Intel oneAPI's clang as clang, not icc.
		cc_vendor="clang"
		cc_version=$(echo "${vendor_string}" \
		             | grep -oE '[0-9]+\.[0-9]+\.[0-9]+\.?[0-9]*' \
		             | { read -r first rest ; echo "${first}"; })

	else

		cc_version=$(echo "${vendor_string}" \
		             | grep -oE '[0-9]+\.[0-9]+\.?[0-9]*' \
		             | { read -r first rest ; echo "${first}"; })
	fi

	# Parse the version number into its major, minor, and revision
	# components.
	cc_major=$(echo "${cc_version}" | cut -d. -f1)
	cc_minor=$(echo "${cc_version}" | cut -d. -f2)
	cc_revision=$(echo "${cc_version}" | cut -d. -f3)

	# gcc 7 introduced new behavior to -dumpversion whereby only the major
	# version component is output. However, as part of this change, gcc 7
	# also introduced a new option, -dumpfullversion, which is guaranteed to
	# always output the major, minor, and revision numbers. Thus, if we're
	# using gcc and its version is 7 or later, we re-query and re-parse the
	# version string.
	if [[ ${cc_vendor} = "gcc" && ${cc_major} -ge 7 ]]; then

		# Re-query the version number using -dumpfullversion.
		cc_version=$(${cc} -dumpfullversion)

		# And parse the result.
		cc_major=$(echo "${cc_version}" | cut -d. -f1)
		cc_minor=$(echo "${cc_version}" | cut -d. -f2)
		cc_revision=$(echo "${cc_version}" | cut -d. -f3)
	fi

	echo "${script_name}: found ${cc_vendor} version ${cc_version} (maj: ${cc_major}, min: ${cc_minor}, rev: ${cc_revision})."
}

check_compiler()
{
	local cc

	cc="${found_cc}"

	#
	# Compiler requirements
	#
	# General:
	#
	#   icc 15+, gcc 4.7+, clang 3.3+
	#
	# Specific:
	#
	#   skx: icc 15.0.1+, gcc 6.0+, clang 3.9+
	#   knl: icc 14.0.1+, gcc 5.0-14, clang 3.9+
	#   haswell: any
	#   sandybridge: any
	#   penryn: any
	#
	#   zen: gcc 6.0+[1], clang 4.0+
	#   zen2: gcc 6.0+[1], clang 4.0+
	#   zen3: gcc 6.0+[1], clang 4.0+
	#   excavator: gcc 4.9+, clang 3.5+
	#   steamroller: any
	#   piledriver: any
	#   bulldozer: any
	#
	#   cortexa57: any
	#   cortexa15: any
	#   cortexa9: any
	#
	#   armsve: clang11+, gcc10+
	#
	#   generic: any
	#
	# Note: These compiler requirements were originally modeled after similar
	# requirements encoded into TBLIS's configure.ac [2].
	#
	# [1] While gcc 6.0 or newer is needed for zen support (-march=znver1),
	#     we relax this compiler version constraint a bit by targeting bdver4
	#     and then disabling the instruction sets that were removed in the
	#     transition from bdver4 to znver1. (See config/zen/make_defs.mk for
	#     the specific compiler flags used.)
	# [2] https://github.com/devinamatthews/tblis/
	#

	echo "${script_name}: checking for blacklisted configurations due to ${cc} ${cc_version}."

	# Fixme: check on a64fx, neoverse, and others

	# gcc
	if [[ ${cc_vendor} = gcc ]]; then

		if [[ ${cc_major} -lt 4 ]]; then
			echoerr_unsupportedcc
		fi
		if [[ ${cc_major} -eq 4 ]]; then
			blacklistcc_add "knl"
			if [[ ${cc_minor} -lt 7 ]]; then
				echoerr_unsupportedcc
			fi
			if [[ ${cc_minor} -lt 9 ]]; then
				blacklistcc_add "excavator"
				blacklistcc_add "zen"
			fi
		fi
		if [[ ${cc_major} -lt 5 ]] || [[ ${cc_major} -gt 14 ]]; then
			blacklistcc_add "knl"
		fi
		if [[ ${cc_major} -lt 6 ]]; then
			# Normally, zen would be blacklisted for gcc prior to 6.0.
			# However, we have a workaround in place in the zen
			# configuration's make_defs.mk file that starts with bdver4
			# and disables the instructions that were removed in znver1.
			# Thus, this "blacklistcc_add" statement has been moved above.
			#blacklistcc_add "zen"
			blacklistcc_add "skx"
			# gcc 5.x may support POWER9 but it is unverified.
			blacklistcc_add "power9"
		fi
		if [[ ${cc_major} -lt 10 ]]; then
			blacklistcc_add "armsve"
		fi
	fi

	# icc
	if [[ ${cc_vendor} = icc ]]; then

		if [[ ${cc_major} -lt 15 ]]; then
			echoerr_unsupportedcc
		fi
		if [[ ${cc_major} -eq 15 ]]; then
			if [[ ${cc_revision} -lt 1 ]]; then
				blacklistcc_add "skx"
			fi
		fi
		if [[ ${cc_major} -eq 18 ]]; then
			echo "${script_name}: ${cc} ${cc_version} is known to cause erroneous results. See https://github.com/flame/blis/issues/371 for details."
			blacklistcc_add "knl"
			blacklistcc_add "skx"
		fi
		if [[ ${cc_major} -ge 19 ]]; then
			echo "${script_name}: ${cc} ${cc_version} is known to cause erroneous results. See https://github.com/flame/blis/issues/371 for details."
			echoerr_unsupportedcc
		fi
	fi

	# clang
	if [[ ${cc_vendor} = clang ]]; then
		if [[ ${vendor_string} = *Apple* ]]; then
			if [[ ${cc_major} -lt 5 ]]; then
				echoerr_unsupportedcc
			fi
			# See https://en.wikipedia.org/wiki/Xcode#Toolchain_versions
			if [[ ${cc_major} -eq 5 ]]; then
				# Apple clang 5.0 is clang 3.4svn
				blacklistcc_add "excavator"
				blacklistcc_add "zen"
			fi
			if [[ ${cc_major} -lt 7 ]]; then
				blacklistcc_add "knl"
				blacklistcc_add "skx"
			fi
		else
			if [[ ${cc_major} -lt 3 ]]; then
				echoerr_unsupportedcc
			fi
			if [[ ${cc_major} -eq 3 ]]; then
				if [[ ${cc_minor} -lt 3 ]]; then
					echoerr_unsupportedcc
				fi
				if [[ ${cc_minor} -lt 5 ]]; then
					blacklistcc_add "excavator"
					blacklistcc_add "zen"
				fi
				if [[ ${cc_minor} -lt 9 ]]; then
					blacklistcc_add "knl"
					blacklistcc_add "skx"
				fi
			fi
			if [[ ${cc_major} -lt 4 ]]; then
				# See comment above regarding zen support.
				#blacklistcc_add "zen"
				: # explicit no-op since bash can't handle empty loop bodies.
			fi
			if [[ ${cc_major} -lt 11 ]]; then
				blacklistcc_add "armsve"
			fi
		fi
	fi
}

check_compiler_version_ranges()
{
	local cc

	cc="${found_cc}"

	#
	# We check for various compiler version ranges that may cause us
	# issues in properly supporting those compiler versions within the
	# BLIS build system.
	#
	# range: gcc < 4.9.0 (ie: 4.8.5 or older)
	# variable: gcc_older_than_4_9_0
	# comments:
	#   These older versions of gcc may support microarchitectures such as
	#   sandybridge, but the '-march=' flag uses a different label syntax.
	#   In newer versions, '-march=sandybridge' is the preferred syntax [1].
	#   However, in older versions, the syntax for the same compiler option
	#   is '-march=corei7-avx' [2].
	#
	#   [1] https://gcc.gnu.org/onlinedocs/gcc-4.9.0/gcc/i386-and-x86-64-Options.html#i386-and-x86-64-Options
	#   [2] https://gcc.gnu.org/onlinedocs/gcc-4.8.5/gcc/i386-and-x86-64-Options.html#i386-and-x86-64-Options
	#
	# range: gcc < 6.1 (ie: 5.5 or older)
	# variable: gcc_older_than_6_1_0
	# comments:
	#   These older versions of gcc do not explicitly support the Zen (Zen1)
	#   microarchitecture; the newest microarchitectural value understood by
	#   these versions is '-march=bdver4' [3]. However, basic support for these
	#   older versions can be attained in a roundabout way by starting with the
	#   instruction sets enabled by '-march=bdver4' and then disabling the
	#   instruction sets that were removed in the transition from Excavator to
	#   Zen, namely: FMA4, TBM, XOP, and LWP. Newer versions of gcc support Zen
	#   via the '-march=znver1' option [4].
	#
	#   [3] https://gcc.gnu.org/onlinedocs/gcc-5.5.0/gcc/x86-Options.html#x86-Options
	#   [4] https://gcc.gnu.org/onlinedocs/gcc-6.1.0/gcc/x86-Options.html#x86-Options
	#
	# range: gcc < 9.1 (ie: 8.3 or older)
	# variable: gcc_older_than_9_1_0
	# comments:
	#   These older versions of gcc do not explicitly support the Zen2
	#   microarchitecture; the newest microarchitectural value understood by
	#   these versions is either '-march=znver1' (if !gcc_older_than_6_1_0) [5]
	#   or '-march=bdver4' (if gcc_older_than_6_1_0) [3]. If gcc is 6.1 or
	#   newer, '-march=znver1' may be used (since the instruction sets it
	#   enables are a subset of those enabled by '-march=znver2'); otherwise,
	#   '-march=bdver4' must be used in conjuction with disabling the
	#   instruction sets that were removed in the transition from Excavator to
	#   Zen, as described in the section above for gcc_older_than_6_1_0.
	#   Newer versions of gcc support Zen2 via the '-march=znver2' option [6].
	#
	#   [5] https://gcc.gnu.org/onlinedocs/gcc-8.3.0/gcc/x86-Options.html#x86-Options
	#   [6] https://gcc.gnu.org/onlinedocs/gcc-9.4.0/gcc/x86-Options.html#x86-Options
	#
	# range: gcc < 10.3 (ie: 9.4 or older)
	# variable: gcc_older_than_10_3_0
	# comments:
	#   These older versions of gcc do not explicitly support the Zen3
	#   microarchitecture; the newest microarchitectural value understood by
	#   these versions is '-march=znver2' (if !gcc_older_than_9_1_0) [7].
	#   Newer versions of gcc support Zen3 via the '-march=znver3' option [8].
	#
	#   [7] https://gcc.gnu.org/onlinedocs/gcc-9.4.0/gcc/x86-Options.html#x86-Options
	#   [8] https://gcc.gnu.org/onlinedocs/gcc-10.3.0/gcc/x86-Options.html#x86-Options
	#

	gcc_older_than_4_9_0='no'
	gcc_older_than_6_1_0='no'
	gcc_older_than_9_1_0='no'
	gcc_older_than_10_3_0='no'

	clang_older_than_9_0_0='no'
	clang_older_than_12_0_0='no'

	aocc_older_than_2_0_0='no'
	aocc_older_than_3_0_0='no'

	echo "${script_name}: checking ${cc} ${cc_version} against known consequential version ranges."

	# gcc
	if [[ ${cc_vendor} = gcc ]]; then

		# Check for gcc < 4.9.0 (ie: 4.8.5 or older).
		if [[ ${cc_major} -eq 4 ]]; then
			if [[ ${cc_minor} -lt 9 ]]; then
				echo "${script_name}: note: found ${cc} version older than 4.9.0."
				gcc_older_than_4_9_0='yes'
			fi
		fi

		# Check for gcc < 6.1.0 (ie: 5.5 or older).
		if [[ ${cc_major} -lt 6 ]]; then
			echo "${script_name}: note: found ${cc} version older than 6.1."
			gcc_older_than_6_1_0='yes'
		fi

		# Check for gcc < 9.1.0 (ie: 8.3 or older).
		if [[ ${cc_major} -lt 9 ]]; then
			echo "${script_name}: note: found ${cc} version older than 9.1."
			gcc_older_than_9_1_0='yes'
		fi

		# Check for gcc < 10.3.0 (ie: 10.2 or older).
		if [[ ( ${cc_major} -lt 10 ) || ( ${cc_major} -eq 10 && ${cc_minor} -lt 3 ) ]]; then
			echo "${script_name}: note: found ${cc} version older than 10.3."
			gcc_older_than_10_3_0='yes'
		fi
	fi

	# icc
	if [[ ${cc_vendor} = icc ]]; then
		:
	fi

	# clang
	if [[ ${cc_vendor} = clang ]]; then

		# Check for clang < 9.0.0.
		if [[ ${cc_major} -lt 9 ]]; then
			echo "${script_name}: note: found ${cc} version older than 9.0."
			clang_older_than_9_0_0='yes'
		fi

		# Check for clang < 12.0.0.
		if [[ ${cc_major} -lt 12 ]]; then
			echo "${script_name}: note: found ${cc} version older than 12.0."
			clang_older_than_12_0_0='yes'
		fi
	fi

	# aocc
	if [[ ${cc_vendor} = aocc ]]; then

		# Check for aocc < 2.0.0.
		if [[ ${cc_major} -lt 2 ]]; then
			echo "${script_name}: note: found ${cc} version older than 2.0."
			aocc_older_than_2_0_0='yes'
		fi

		# Check for aocc < 3.0.0.
		if [[ ${cc_major} -lt 3 ]]; then
			echo "${script_name}: note: found ${cc} version older than 3.0."
			aocc_older_than_3_0_0='yes'
		fi
	fi
}

check_assembler()
{
	local cc asm_dir cflags asm_fp

	cc="${found_cc}"

	# The directory where the assembly files will be.
	asm_dir="${dist_path}/build"

	# Most of the time, we won't need any additional compiler flags.
	cflags=""

	echo "${script_name}: checking for blacklisted configurations due to as ${bu_version}."

	#
	# Check support for FMA4 (amd: bulldozer).
	#
	asm_fp=$(find "${asm_dir}" -name "fma4.s")
	knows_fma4=$(try_assemble "${cc}" "${cflags}" "${asm_fp}")

	if [[ ${knows_fma4} = no ]]; then
		blacklistbu_add "bulldozer"
	fi

	#
	# Check support for AVX (intel: sandybridge+, amd: piledriver+).
	#
	asm_fp=$(find "${asm_dir}" -name "avx.s")
	knows_avx=$(try_assemble "${cc}" "${cflags}" "${asm_fp}")

	if [[ ${knows_avx} = no ]]; then
		blacklistbu_add "sandybridge"
	fi

	#
	# Check support for FMA3 (intel: haswell+, amd: piledriver+).
	#
	asm_fp=$(find "${asm_dir}" -name "fma3.s")
	knows_fma3=$(try_assemble "${cc}" "${cflags}" "${asm_fp}")

	if [[ ${knows_fma3} = no ]]; then
		blacklistbu_add "haswell"
		blacklistbu_add "piledriver"
		blacklistbu_add "steamroller"
		blacklistbu_add "excavator"
		blacklistbu_add "skx"
	fi

	#
	# Check support for AVX-512f (knl, skx).
	#

	# The assembler on OS X won't recognize AVX-512 without help.
	if [ "${cc_vendor}" == "clang" ]; then
		cflags="-march=knl"
	fi

	asm_fp=$(find "${asm_dir}" -name "avx512f.s")
	knows_avx512f=$(try_assemble "${cc}" "${cflags}" "${asm_fp}")

	if [[ ${knows_avx512f} = no ]]; then
		blacklistbu_add "knl"
		blacklistbu_add "skx"
	fi

	#
	# Check support for AVX-512dq (skx).
	#

	# The assembler on OS X won't recognize AVX-512 without help.
	if [ "${cc_vendor}" == "clang" ]; then
		cflags="-march=skylake-avx512"
	fi

	asm_fp=$(find "${asm_dir}" -name "avx512dq.s")
	knows_avx512dq=$(try_assemble "${cc}" "${cflags}" "${asm_fp}")

	if [[ ${knows_avx512dq} = no ]]; then
		blacklistbu_add "skx"
	fi
}

check_os()
{
	if [[ "$(uname -s)" == "Darwin" && "$(uname -m)" == "arm64" ]]; then
		blacklistos_add "armsve"
	fi
}

try_assemble()
{
	local cc cflags asm_src asm_base asm_bin rval

	cc="$1"
	cflags="$2"
	asm_src="$3"

	# Construct the filename to the .o file corresponding to asm_src.
	# (Strip the filepath, then the file extension, and then add ".o".)
	asm_base=${asm_src##*/}
	asm_base=${asm_base%.*}
	asm_bin="${asm_base}.o"

	# Try to assemble the file.
	# shellcheck disable=2086
	"${cc}" ${cflags} -c "${asm_src}" -o "${asm_bin}" > /dev/null 2>&1

	if [ "$?" == 0 ]; then
		rval='yes'
	else
		rval='no'
	fi

	# Remove the object file.
	rm -f "${asm_bin}"

	# Return the result.
	echo "${rval}"
}

set_default_version()
{
	local gitdir version_file gd_stderr git_describe_str git_error new_version_str

	gitdir='.git'

	# The path to the version file.
	version_file=$1

	echo "${script_name}: determining default version string."

	# Check if the .git dir exists; if it does not, we do nothing.
	if [ -d "${dist_path}/${gitdir}" ]; then

		echo "${script_name}: found '${gitdir}' directory; assuming git clone."

		echo "${script_name}: executing: git describe --tags."

		gd_stderr="git_describe_stderr.txt"

		# Query git for the version string, which is simply the current tag,
		# followed by a number signifying how many commits have transpired
		# since the tag, followed by a 'g' and a shortened hash tab. Capture
		# stderr to a file.
		git_describe_str=$(git -C "${dist_path}" describe --tags 2> "${gd_stderr}")

		# Pull in whatever error message was generated, if any, and delete
		# the file.
		git_error=$(<"${gd_stderr}")

		# Remove the stderr file.
		rm -f "${gd_stderr}"

		# If git returned an error, don't do anything.
		if [ -n "${git_error}" ]; then

			echo "${script_name}: git returned an error: '${git_error}'."
			echo "${script_name}: using string from unmodified version file."

			# Use what's in the version file as-is.
			version=$(<"${version_file}")
		else

			echo "${script_name}: got back ${git_describe_str}."

			# Strip off the commit hash label.
			new_version_str=$(echo "${git_describe_str}" | cut -d- -f-2)

			echo "${script_name}: truncating to ${new_version_str}."

			# Write the new version string to the version file.
			#echo "${new_version_str}" > ${version_file}

			# Set the version variable.
			version="${new_version_str}"
		fi
	else

		echo "${script_name}: could not find '${gitdir}' directory; using unmodified version file."

		# Use what's in the version file as-is.
		version=$(<"${version_file}")
	fi
}

select_tool_w_env()
{
	local search_list env_var env_str tool_str found_var
	local _the_tool

	# Example calling sequence:
	#
	#  select_tool_w_env "${cc_search_list}" "${CC}" "CC" "C compiler" "yes" found_cc
	#

	search_list="$1" # the tool's default search list.
	env_var="$2"     # the value of the environment variable for this tool.
	env_str="$3"     # a string naming the source of env_var.
	tool_str="$4"    # a human-readable string identifying the tool.
	is_required="$5" # is it fatal if env_var doesn't exist/work? (yes or no)
	found_var="$6"   # the variable into which to save the selected tool.

	# If the environment variable contains something, verify that it exists. If
	# it is unset or empty, we proceed with the default search list.
	if [ -n "${env_var}" ]; then

		echo "${script_name}: user specified a ${tool_str} via ${env_str} (${env_var})."

		# See if the binary specified by env_var exists.
		_the_tool=$(select_tool "${env_var}" "${env_str}")

		# Copy the result into the variable specified by found_var.
		eval "${found_var}=\"${_the_tool}\""

		# If the tool specified by env_var doesn't exist, throw a tantrum.
		if [ -z "${_the_tool}" ]; then

			echo "${script_name}: *** Could not find the ${tool_str} specified via ${env_str} ('${env_var}')."

			# Whether the tantrum is fatal depends on the is_required argument.
			if [ "${is_required}" == "yes" ]; then
				echo "${script_name}: *** A working ${tool_str} is required. Please set ${env_str}"
				echo "${script_name}: *** to a ${tool_str} that exists (or unset ${env_str})."
				exit 1
			else
				echo "${script_name}: *** Note that a ${tool_str} will not be available."

				# Set the found_var variable to *something* so that the output
				# makefile fragment contains a record that the tool wasn't found.
				eval "${found_var}=\"${env_str}\"-not-found"
			fi
		else
			# The user-specified tool was found.
			echo "${script_name}: ${_the_tool} exists and appears to work."
			echo "${script_name}: using '${_the_tool}' as ${tool_str}."
		fi

	else

		echo "${script_name}: ${tool_str} search list is: ${search_list}."

		# Search for a working tool from the search list.
		_the_tool=$(select_tool "${search_list}" "${env_str}")

		# Copy the result into the variable specified by found_var.
		eval "${found_var}=\"${_the_tool}\""

		# If we didn't find a working tool from the search list, throw a tantrum.
		if [ -z "${_the_tool}" ]; then

			echo "${script_name}: *** Could not find a ${tool_str} from the search list."

			# Whether the tantrum is fatal depends on the is_required argument.
			if [ "${is_required}" == "yes" ]; then
				echo "${script_name}: *** A working ${tool_str} is required. Cannot continue."
				exit 1
			else
				echo "${script_name}: *** Note that a ${tool_str} will not be available."

				# Set the found_var variable to *something* so that the output
				# makefile fragment contains a record that the tool wasn't found.
				eval "${found_var}=\"${env_str}-not-found\""
			fi
		else
			# A tool from the search list was found.
			echo "${script_name}: found '${_the_tool}'."
			echo "${script_name}: using '${_the_tool}' as ${tool_str}."
		fi
	fi
}

select_tool()
{
	local search_list env_str
	local the_tool tool the_flags rval

	# This is the list of tools to search for, and the order in which
	# to search for them.
	search_list="$1"

	# This is the name of the environment variable associated with the tool. For
	# example, if search_list is a list of C compilers, env_str will be "CC".
	env_str="$2"

	# Initialize our selected tool to empty.
	the_tool=""

	# Try each tool in the list and select the first one we find that works.
	for tool in ${search_list}; do

		# Map each tool (via its canonical environment variable form) to the set
		# of options we should use to check that it is working and available.
		the_flags=$(get_tool_checkflags "${env_str}")

		# Check that the tool works with at least one of the flags in the_flags
		# the_flags (or, if the_flags is empty, check that the tool exists).
		rval=$(check_tool "${tool}" "${the_flags}")

		# If check_tool() returns 0, we're done.
		if [ "${rval}" == "0" ]; then
			the_tool=${tool}
			break
		fi
	done

	# Return the selected tool.
	echo "${the_tool}"
}

get_tool_checkflags()
{
	local env_str
	local allflags flaglist

	# The tool for which we will determine the flag/option to pass in
	# when testing that the tool works. Notice that it's not actually
	# the tool but rather its equivalent environment variable.
	env_str="${1}"

	# The default list of flags to use in most circumstances.
	allflags="--version -V -h"

	if [ "${os_name}" = "Linux" ]; then

		# If we are on Linux, it is very likely that all the tools will respond
		# to at least one of the usual flags.
		flaglist="${allflags}"

	else

		# If we are on Darwin/OSX/BSD or something else, we sometimes skip flag
		# checks. (Note that when the list of flags to check is empty, we end
		# up testing for the existence of the tool instead.)
		if   [[ ${env_str} = AR || ${env_str} = RANLIB ]]; then

			# AR, RANLIB may not respond to the normal flags on Darwin/OSX/BSD,
			# so all we can really do is check for their existence.
			flaglist=""
		else
			# Even on Darwin/OSX/BSD, we expect that CC, CXX, FC, PYTHON will
			# respond to the typical flag checklist.
			flaglist="${allflags}"
		fi
	fi

	echo "${flaglist}"
}

check_tool()
{
	local tool the_flags
	local rval opt toolpath

	# This is the name, or filepath, of the tool to check for.
	tool="$1"

	# Some command line options to try to determine that the tool works.
	the_flags="$2"

	# Start with the assuming that the tool doesn't work/exist.
	rval=1

	if [ -n "${the_flags}" ]; then

		# If the list of flags to check non-empty, we will iterate through the
		# list in search of a flag that works. Failure to find one that works
		# means the tool doesn't work (or, if the user specified the tool via
		# its environment variable, failure might mean that the tool doesn't
		# even exist).

		# Try each flag in the list of flags.
		for opt in ${the_flags}; do

			# See if the tool responds to the current flag.
			"${tool}" "${opt}" > /dev/null 2>&1

			# If the tool responded to the flag with a nominal error code of
			# 0, we found one that works and set rval accoringly.
			if [ "$?" == 0 ]; then
				rval=0
				break
			fi
		done
	else

		# If the list of flags to check is empty, we interpret this as a
		# request to instead check for the existence of the tool.

		# Use 'which' to determine if the tool exists.
		toolpath="$(command -v "${tool}" 2> /dev/null)"

		# If the tool doesn't exist, we set rval accordingly.
		if [ -n "${toolpath}" ]; then
			rval=0
		fi
	fi

	# Return the error code.
	echo "${rval}"
}



#
# -- main function -------------------------------------------------------------
#

main()
{
	#declare -A config_registry
	#declare -A kernel_registry
	#declare -A kconfig_registry

	# -- Basic names and paths --

	# The name of the script, stripped of any preceeding path.
	script_name=${0##*/}

	# The path to the script. We need this to find the top-level directory
	# of the source distribution in the event that the user has chosen to
	# build elsewhere.
	dist_path=${0%"/${script_name}"}

	# The path to the directory in which we are building. We do this to
	# make explicit that we distinguish between the top-level directory
	# of the distribution and the directory in which we are building.
	cur_dirpath="."

	# The name of and path to the directory named "build" in the top-level
	# directory of the source distribution.
	build_dir='build'
	build_dirpath="${dist_path}/${build_dir}"

	# The name/path to the registry (master list) of supported configurations.
	registry_file="config_registry"
	registry_filepath=${dist_path}/${registry_file}

	# The names/paths for the template config.mk.in and its instantiated
	# counterpart.
	config_mk_in='config.mk.in'
	config_mk_out='config.mk'
	config_mk_in_path="${build_dirpath}/${config_mk_in}"
	config_mk_out_path="${cur_dirpath}/${config_mk_out}"

	# The names/paths for the template bli_config.h.in and its instantiated
	# counterpart.
	bli_config_h_in='bli_config.h.in'
	bli_config_h_out='bli_config.h'
	bli_config_h_in_path="${build_dirpath}/${bli_config_h_in}"
	bli_config_h_out_path="${cur_dirpath}/${bli_config_h_out}"

	# The names/paths for the template bli_addon.h.in and its instantiated
	# counterpart.
	bli_addon_h_in='bli_addon.h.in'
	bli_addon_h_out='bli_addon.h'
	bli_addon_h_in_path="${build_dirpath}/${bli_addon_h_in}"
	bli_addon_h_out_path="${cur_dirpath}/${bli_addon_h_out}"

	# Path to 'mirror-tree.sh' script.
	mirror_tree_sh="${build_dirpath}/mirror-tree.sh"

	# Path to 'gen-make-frags.sh' script and directory.
	gen_make_frags_dirpath="${build_dirpath}/gen-make-frags"
	gen_make_frags_sh="${gen_make_frags_dirpath}/gen-make-frag.sh"

	# The name of the (top-level) configuration directory.
	config_dir='config'
	config_dirpath="${dist_path}/${config_dir}"

	# The name of the (top-level) kernels directory.
	kernels_dir='kernels'
	kernels_dirpath="${dist_path}/${kernels_dir}"

	# The name of the (top-level) reference kernels directory.
	refkern_dir='ref_kernels'
	refkern_dirpath="${dist_path}/${refkern_dir}"

	# The root directory of the BLIS framework.
	frame_dir='frame'
	frame_dirpath="${dist_path}/${frame_dir}"

	# The names of the addons.
	addon_dir='addon'
	addon_dirpath="${dist_path}/${addon_dir}"

	# The name of the sandbox directory.
	sandbox_dir='sandbox'
	sandbox_dirpath="${dist_path}/${sandbox_dir}"

	# The name of the directory in which object files will be kept.
	obj_dir='obj'
	obj_dirpath="${cur_dirpath}/${obj_dir}"

	# The name of the directory in which libraries will be kept.
	lib_dir='lib'
	lib_dirpath="${cur_dirpath}/${lib_dir}"

	# The name of the directory in which headers will be kept.
	include_dir='include'
	include_dirpath="${cur_dirpath}/${include_dir}"

	# The name of the directory in which the BLAS test suite is kept.
	blastest_dir='blastest'

	# The name of the directory in which the BLIS test suite is kept.
	testsuite_dir='testsuite'

	# -- Version-related --

	# The file in which the version string is kept.
	version_file="version"
	version_filepath="${build_dirpath}/${version_file}"

	# The shared library (.so) version file.
	so_version_file='so_version'
	so_version_filepath="${build_dirpath}/${so_version_file}"

	# The major and minor/build .so version numbers.
	so_version_major=''
	so_version_minorbuild=''

	# -- configure options --

	# Define the default prefix so that the print_usage() function can
	# output it in the --help text.
	prefix_def='/usr/local'

	# The installation prefix, assigned its default value, and a flag to
	# track whether or not it was given by the user.
	prefix=${prefix_def}
	prefix_flag=''

	# The installation exec_prefix, assigned its default value, and a flag to
	# track whether or not it was given by the user.
	# shellcheck disable=2016
	exec_prefix='${prefix}'
	exec_prefix_flag=''

	# The installation libdir, assigned its default value, and a flag to
	# track whether or not it was given by the user.
	# shellcheck disable=2016
	libdir='${exec_prefix}/lib'
	libdir_flag=''

	# The installation includedir, assigned its default value, and a flag to
	# track whether or not it was given by the user.
	# shellcheck disable=2016
	includedir='${prefix}/include'
	includedir_flag=''

	# The installation sharedir, assigned its default value, and a flag to
	# track whether or not it was given by the user.
	# shellcheck disable=2016
	sharedir='${prefix}/share'
	sharedir_flag=''

	# The preset value of CFLAGS and LDFLAGS (ie: compiler and linker flags
	# to use in addition to those determined by the build system).
	cflags_preset=''
	ldflags_preset=''

	# The user-given debug type and a flag indicating it was given.
	debug_type=''
	debug_flag=''
	enable_debug='no'

	# A flag indicating whether AddressSanitizer should be used.
	enable_asan='no'

	# The system flag.
	enable_system='yes'

	# The thread-local storage flag.
	enable_tls='yes'

	# The threading flag.
	threading_model='off'

	# The method of assigning micropanels to threads in the JR and JR loops.
	thread_part_jrir='slab'

	# Option variables.
	quiet_flag=''
	show_config_list=''

	# Additional flags.
	enable_verbose='no'
	enable_arg_max_hack='no'
	enable_static='yes'
	enable_shared='yes'
	enable_rpath='no'
	export_shared='public'
	enable_pba_pools='yes'
	enable_sba_pools='yes'
	enable_mem_tracing='no'
	int_type_size=0
	blas_int_type_size=32
	enable_blas='yes'
	enable_cblas='no'
	enable_mixed_dt='yes'
	enable_mixed_dt_extra_mem='yes'
	enable_sup_handling='yes'
	enable_amd_frame_tweaks='no'
	enable_memkind='' # The default memkind value is determined later on.
	enable_trsm_preinversion='yes'
	enable_scalapack_compat='no'
	force_version='no'
	complex_return='default'

	# The addon flag and names.
	addon_flag=''
	addon_list=''

	# The sandbox flag and name.
	sandbox_flag=''
	sandbox=''

	# -- Configuration registry --

	# The name of the chosen configuration (the configuration "family").
	config_name=''

	# The list of sub-configurations associated with config_name.
	config_list=''

	# The list of kernel sets that will be needed by the sub-configurations
	# in config_list..
	kernel_list=''

	# The list of kernel:sub-configuration pairs for all kernels contained
	# in kernel_list.
	kconfig_map=''

	# -- Out-of-tree --

	# Whether we are building out-of-tree.
	configured_oot="no"

	# Dummy file. Used to check whether the cwd is the same as the top-level
	# source distribution directory.
	dummy_file='_blis_dir_detect.tmp'

	# -- Debugging --

	# A global flag to help debug the compilation command for the executable
	# that configure builds on-the-fly to perform hardware auto-detection.
	debug_auto_detect="no"



	# -- Command line option/argument parsing ----------------------------------

	found=true
	while [[ $found = true ]]; do

		# Process our command line options.
		unset OPTIND
		while getopts ":hp:d:e:a:s:t:r:qci:b:-:" opt; do
			case $opt in
				-)
					case "$OPTARG" in

						help)
							print_usage
							;;

						quiet)
							quiet_flag=1
							;;

						prefix=*)
							prefix_flag=1
							prefix=${OPTARG#*=}
							;;
						exec-prefix=*)
							exec_prefix_flag=1
							exec_prefix=${OPTARG#*=}
							;;
						libdir=*)
							libdir_flag=1
							libdir=${OPTARG#*=}
							;;
						includedir=*)
							includedir_flag=1
							includedir=${OPTARG#*=}
							;;
						sharedir=*)
							sharedir_flag=1
							sharedir=${OPTARG#*=}
							;;

						enable-debug)
							debug_flag=1
							debug_type=noopt
							;;
						enable-debug=*)
							debug_flag=1
							debug_type=${OPTARG#*=}
							;;
						disable-debug)
							debug_flag=0
							;;

						enable-asan)
							enable_asan='yes'
							;;
						disable-asan)
							enable_asan='no'
							;;

						enable-verbose-make)
							enable_verbose='yes'
							;;
						disable-verbose-make)
							enable_verbose='no'
							;;

						enable-arg-max-hack)
							enable_arg_max_hack='yes'
							;;
						disable-arg-max-hack)
							enable_arg_max_hack='no'
							;;

						enable-static)
							enable_static='yes'
							;;
						disable-static)
							enable_static='no'
							;;

						enable-shared)
							enable_shared='yes'
							;;
						disable-shared)
							enable_shared='no'
							;;

						enable-rpath)
							enable_rpath='yes'
							;;
						disable-rpath)
							enable_rpath='no'
							;;

						export-shared=*)
							export_shared=${OPTARG#*=}
							;;

						enable-system)
							enable_system='yes'
							;;
						disable-system)
							enable_system='no'
							;;

						enable-tls)
							enable_tls='yes'
							;;
						disable-tls)
							enable_tls='no'
							;;

						enable-threading=*)
							threading_model=${OPTARG#*=}
							;;
						disable-threading)
							threading_model='single'
							;;

						thread-part-jrir=*)
							thread_part_jrir=${OPTARG#*=}
							;;

						enable-pba-pools)
							enable_pba_pools='yes'
							;;
						disable-pba-pools)
							enable_pba_pools='no'
							;;

						enable-sba-pools)
							enable_sba_pools='yes'
							;;
						disable-sba-pools)
							enable_sba_pools='no'
							;;

						enable-mem-tracing)
							enable_mem_tracing='yes'
							;;
						disable-mem-tracing)
							enable_mem_tracing='no'
							;;

						enable-addon=*)
							addon_flag=1
							addon_name=${OPTARG#*=}
							# Append the addon name to the list.
							addon_list="${addon_list} ${addon_name}"
							;;
						disable-addon)
							addon_flag=''
							;;

						enable-sandbox=*)
							sandbox_flag=1
							sandbox=${OPTARG#*=}
							;;
						disable-sandbox)
							sandbox_flag=''
							;;

						int-size=*)
							int_type_size=${OPTARG#*=}
							;;

						blas-int-size=*)
							blas_int_type_size=${OPTARG#*=}
							;;

						enable-blas)
							enable_blas='yes'
							;;
						disable-blas)
							enable_blas='no'
							;;

						enable-cblas)
							enable_cblas='yes'
							;;
						disable-cblas)
							enable_cblas='no'
							;;

						enable-mixed-dt)
							enable_mixed_dt='yes'
							;;
						disable-mixed-dt)
							enable_mixed_dt='no'
							;;

						enable-mixed-dt-extra-mem)
							enable_mixed_dt_extra_mem='yes'
							;;
						disable-mixed-dt-extra-mem)
							enable_mixed_dt_extra_mem='no'
							;;

						sup)
							enable_sup_handling='yes'
							;;
						enable-sup-handling)
							enable_sup_handling='yes'
							;;
						nosup)
							enable_sup_handling='no'
							;;
						disable-sup-handling)
							enable_sup_handling='no'
							;;

						enable-amd-frame-tweaks)
							enable_amd_frame_tweaks='yes'
							;;
						disable-amd-frame-tweaks)
							enable_amd_frame_tweaks='no'
							;;

						enable-scalapack-compat)
							enable_scalapack_compat='yes'
							;;
						disable-scalapack-compat)
							enable_scalapack_compat='no'
							;;

						with-memkind)
							enable_memkind='yes'
							;;
						without-memkind)
							enable_memkind='no'
							;;

						enable-trsm-preinversion)
							enable_trsm_preinversion='yes'
							;;
						disable-trsm-preinversion)
							enable_trsm_preinversion='no'
							;;

						force-version=*)
							force_version=${OPTARG#*=}
							;;

						show-config-list)
							show_config_list=1
							;;

						complex-return=*)
							complex_return=${OPTARG#*=}
							;;

						*)
							print_usage
							;;
					esac;;
				h)
					print_usage
					;;
				p)
					prefix_flag=1
					prefix=$OPTARG
					;;
				d)
					debug_flag=1
					debug_type=$OPTARG
					;;
				e)
					export_shared=$OPTARG
					;;
				a)
					addon_flag=1
					addon_name=$OPTARG
					# Append the addon name to the list.
					addon_list="${addon_list} ${addon_name}"
					;;
				s)
					sandbox_flag=1
					sandbox=$OPTARG
					;;
				q)
					quiet_flag=1
					;;
				t)
					threading_model=$OPTARG
					;;
				r)
					thread_part_jrir=$OPTARG
					;;
				i)
					int_type_size=$OPTARG
					;;
				b)
					blas_int_type_size=$OPTARG
					;;
				c)
					show_config_list=1
					;;
				\?)
					print_usage
					;;
			esac
		done
		shift $((OPTIND - 1))

		# Parse environment variables
		found=false
		while [ $# -gt 0 ]; do
			case $1 in
				*=*)
					var=$(expr "$1" : '\([^=]*\)=')
					value=$(expr "$1" : '[^=]*=\(.*\)')
					eval "export $var=\$value"
					shift
					found=true
					;;
				*)
					break
					;;
			esac
		done
	done


	# -- Check the operating system --------------------------------------------

	os_name=$(uname -s)
	os_vers=$(uname -r)
	echo "${script_name}: detected ${os_name} kernel version ${os_vers}."

	# Define a single variable off of which we can branch to tell if we are
	# building for Windows.
	is_win=no
	if [[ $os_name == MSYS* ]] || \
	   [[ $os_name == MINGW* ]]  || \
	   [[ $os_name == CYGWIN* ]] ; then
		is_win=yes
	fi


	# -- Find a python interpreter ---------------------------------------------

	# Acquire the default python search order.
	python_search_list=$(get_python_search_list)

	# Select a python interpreter from the default list, or from PYTHON if it
	# refers to a valid binary.
	# shellcheck disable=2153
	select_tool_w_env "${python_search_list}" "${PYTHON}" "PYTHON" \
	                  "python interpreter" "yes" found_python

	# -- Check the python version ----------------------------------------------

	# Check the python interpreter's version.
	get_python_version
	check_python


	# -- Find a C compiler -----------------------------------------------------

	# Acquire the default compiler search order. This will vary based on os_name.
	cc_search_list=$(get_cc_search_list)

	# Select a C compiler from the default list, or from CC if it refers to a
	# valid binary.
	select_tool_w_env "${cc_search_list}" "${CC}" "CC" \
	                  "C compiler" "yes" found_cc

	# Also check the compiler to see if we are (cross-)compiling for Windows
	if "${found_cc}" -dM -E - < /dev/null 2> /dev/null | grep -q _WIN32; then
		is_win=yes
	fi
	is_msvc=no
	if "${found_cc}" -dM -E - < /dev/null 2> /dev/null | grep -q _MSC_VER; then
		is_msvc=yes
	fi


	# -- Check the compiler version --------------------------------------------

	# Initialize the blacklist to empty.
	blacklist_init

	# Check the compiler's version. Certain versions of certain compilers
	# will preclude building certain sub-configurations, which are added
	# to a blacklist. We also make note of certain version ranges that
	# will be useful to know about later.
	get_compiler_version
	check_compiler
	check_compiler_version_ranges

	# Now check the assembler's ability to assemble code. Older versions
	# of binutils may not be aware of certain instruction sets. Those
	# sub-configurations employing kernels that use such instruction sets
	# will also be blacklisted.
	get_binutils_version
	check_assembler

	# Check if there is any incompatibility due to the operating system.
	check_os

	# Remove duplicates and whitespace from the blacklist.
	blacklist_cleanup

	if [ -n "${config_blist}" ]; then

		echo "${script_name}: configuration blacklist:"
		echo "${script_name}:   ${config_blist}"
	fi


	# -- Find a C++ compiler ---------------------------------------------------

	# Acquire the default C++ compiler search order. This will vary based on
	# os_name.
	cxx_search_list=$(get_cxx_search_list)

	# Select a C compiler from the default list, or from CC if it refers to a
	# valid binary.
	select_tool_w_env "${cxx_search_list}" "${CXX}" "CXX" \
	                  "C++ compiler" "no" found_cxx


	# -- Find a Fortran compiler -----------------------------------------------

	# Acquire the default Fortran compiler search order.
	fc_search_list=$(get_fc_search_list)

	# Select a Fortran compiler from the default list, or from FC if it refers
	# to a valid binary.
	# NOTE: A Fortran compiler is not necessary for building BLIS. The only
	# reason we might want to query it is to detect the style of returning
	# complex values from functions. The 'gnu' style returns complex values
	# from functions normally, via the C language return statement, while the
	# 'intel' style returns them in a "hidden" parameter (inserted by the
	# compiler) that precedes all other function parameters.
	select_tool_w_env "${fc_search_list}" "${FC}" "FC" \
	                  "Fortran compiler" "no" found_fc


	# -- Find a static library archiver ----------------------------------------

	# Acquire the default archiver search order.
	ar_search_list=$(get_ar_search_list)

	# Select an archiver from the default list, or from AR if it refers
	# to a valid binary.
	select_tool_w_env "${ar_search_list}" "${AR}" "AR" \
	                  "library archiver" "yes" found_ar


	# -- Find an archive indexer -----------------------------------------------

	# Acquire the default archive indexer search order.
	ranlib_search_list=$(get_ranlib_search_list)

	# Select an archive indexer from the default list, or from RANLIB if it
	# refers to a valid binary.
	select_tool_w_env "${ranlib_search_list}" "${RANLIB}" "RANLIB" \
	                  "archive indexer" "yes" found_ranlib


	# -- Read the configuration registry ---------------------------------------

	# Make sure the config registry file exists and can be opened.
	if [ ! -f "${registry_filepath}" ]; then

		echo "${script_name}: could not open '${registry_file}' file; cannot continue."
		echo "${script_name}: BLIS distribution appears to be incomplete."
		echo "${script_name}: *** Please verify source distribution."

		exit 1
	fi

	# Read the registered configuration names and lists into associative
	# arrays.
	echo -n "${script_name}: reading configuration registry..."
	read_registry_file "${registry_filepath}"
	echo "done."

	# Report if additional configurations needed to be blacklisted.
	# NOTE: This branch should never execute so long as indirect blacklisting
	# is disabled. See comment regarding issue #214 in the definition of
	# pass_config_kernel_registries().
	if [ -n "${indirect_blist}" ]; then
		echo "${script_name}: needed to indirectly blacklist additional configurations:"
		echo "${script_name}:   ${indirect_blist}"
	fi


	# -- Acquire the BLIS version ----------------------------------------------

	# Set the 'version' variable to the default value (the 'git describe'
	# augmented instance of whatever is in the 'version' file if this is a git
	# clone, or whatever is in the 'version' file unmodified if it is a bare
	# source release).
	set_default_version "${version_filepath}"

	# Initial message.
	echo "${script_name}: starting configuration of BLIS ${version}."

	# Check if the user requested a custom version string.
	if [[ ${force_version} = no ]]; then
		echo "${script_name}: configuring with official version string."
	else
		echo "${script_name}: configuring with custom version string '${force_version}'."
		version="${force_version}"
	fi


	# -- Acquire the shared library (.so) versions -----------------------------

	# The first line of the 'so_version' file contains the .so major version.
	so_version_major=$(sed -n "1p" < "${so_version_filepath}")

	# The second line contains the minor and build .so version numbers
	# (separated by a '.').
	so_version_minorbuild=$(sed -n "2p" < "${so_version_filepath}")

	echo "${script_name}: found shared library .so version '${so_version_major}.${so_version_minorbuild}'."
	echo "${script_name}:   .so major version: ${so_version_major}"
	echo "${script_name}:   .so minor.build version: ${so_version_minorbuild}"


	# -- Various pre-configuration checks --------------------------------------

	# Set config_name based on the number of arguments leftover (after command
	# line option processing).
	if [ $# = "0" ]; then

		#configs_avail="auto "$(ls ${config_dirpath})

		echo "${script_name}: "
		echo "${script_name}: *** No configuration given! ***"
		echo "${script_name}: "
		echo "${script_name}: Default configuration behavior is not implemented (for your"
		echo "${script_name}: own safety). Please re-run '${script_name}' and specify one"
		echo "${script_name}: of the existing configurations in the source distribution's"
		echo "${script_name}  '${registry_file}' file:"
		echo "${script_name}: "
		#for k in "${!config_registry[@]}"; do
		for cr_var in ${!config_registry_*}; do

			#v=${config_registry[$k]}
			k=${cr_var##config_registry_}; v=${!cr_var}

			echo "${script_name}:   $k (${v})"
		done
		echo "${script_name}: "

		exit 1

	elif [ $# != "1" ]; then   # more than one configuration argument given.

		print_usage

	fi

	if [[ $1 = auto ]]; then

		echo "${script_name}: automatic configuration requested."

		# Call the auto_detect() function and save the returned string in
		# config_name.
		config_name=$(auto_detect)

		# Debugging stuff. When confirming the behavior of auto_detect(),
		# it is useful to output ${config_name}, which in theory could be
		# set temoprarily to something other than the config_name, such as
		# the compilation command.
		if [ "${debug_auto_detect}" = "yes" ]; then
			echo "auto-detect program compilation command: ${config_name}"
			exit 1
		fi

		echo "${script_name}: hardware detection driver returned '${config_name}'."

		# If the auto-detect code returned the "generic" string, it means we
		# were unable to automatically detect the user's hardware type. While
		# this is going to be a rare event, it will likely lead the user to
		# experience much lower performance than expected, and thus we will
		# warn them about it at the end of the configure output (to increase
		# the chances that they see it).
		if [ "${config_name}" = "generic" ]; then

			warn_user_generic=1
		else
			warn_user_generic=0
		fi
	else

		# Use the command line argument as the configuration name.
		config_name=$1

		echo "${script_name}: manual configuration requested; configuring with '${config_name}'."

	fi

	# Use the selected config name to look up the list of configurations
	# and kernels associated with that name.
	#config_list=${config_registry[${config_name}]}
	#kernel_list=${kernel_registry[${config_name}]}
	config_list=$(query_array "config_registry" "${config_name}")
	kernel_list=$(query_array "kernel_registry" "${config_name}")

	# Use the config_registry and kernel_registry to build a kconfig_registry
	# for the selected config_name.
	build_kconfig_registry "${config_name}"

	# Print the configuration list and kernel list, if requested.
	if [ "${show_config_list}" == "1" ]; then

		echo "${script_name}: configuration list:"
		#for k in "${!config_registry[@]}"; do
		for cr_var in ${!config_registry_*}; do

			#v=${config_registry[$k]}
			k=${cr_var##config_registry_}; v=${!cr_var}

			echo "${script_name}:   $k: ${v}"
		done

		echo "${script_name}: kernel list:"
		#for k in "${!kernel_registry[@]}"; do
		for kr_var in ${!kernel_registry_*}; do

			#v=${kernel_registry[$k]}
			k=${kr_var##kernel_registry_}; v=${!kr_var}

			echo "${script_name}:   $k: ${v}"
		done

		echo "${script_name}: kernel-to-config map for '${config_name}':"
		#for k in "${!kconfig_registry[@]}"; do
		for kc_var in ${!kconfig_registry_*}; do

			#v=${kconfig_registry[$k]}
			k=${kc_var##kconfig_registry_}; v=${!kc_var}

			echo "${script_name}:   $k: ${v}"
		done
	fi

	# For each kernel in the kernel list, reduce the list of associated
	# sub-configurations (in the kconfig_registry) to a singleton using
	# the following rules:
	# 1. If the list is a singleton, use that name.
	# 2. If the list contains a sub-configuration name that matches the
	#    kernel name, use that name.
	# 3. Otherwise, use the first name in the list.
	# We use the chosen singleton to ceate a "kernel:subconfig" pair, which
	# we accumulate into a list. This list is the kernel-to-config map, or
	# kconfig_map.

	# We use a sorted version of kernel_list so that it ends up matching the
	# display order of the kconfig_registry above.
	# shellcheck disable=2086
	kernel_list_sort=$(echo ${kernel_list} | xargs -n1 | sort -u)

	kconfig_map=""
	for kernel in ${kernel_list_sort}; do

		#configs="${kconfig_registry[$kernel]}"
		configs=$(query_array "kconfig_registry" "${kernel}")

		has_one_kernel=$(is_singleton "${configs}")
		contains_kernel=$(is_in_list "${kernel}" "${configs}")

		# Check if the list is a singleton.
		if [ "${has_one_kernel}" == "true" ]; then

			reducedclist="${configs}"

		# Check if the list contains a sub-config name that matches the kernel.
		elif [ "${contains_kernel}" == "true" ]; then

			reducedclist="${kernel}"

		# Otherwise, use the last name.
		else

			last_config=${configs##* }
			reducedclist="${last_config}"
		fi

		# Create a new "kernel:subconfig" pair and add it to the kconfig_map
		# list, removing whitespace.
		new_pair="${kernel}:${reducedclist}"
		kconfig_map=$(canonicalize_ws "${kconfig_map} ${new_pair}")
	done

	if [ "${show_config_list}" == "1" ]; then

		echo "${script_name}: kernel-to-config map for '${config_name}' (chosen pairs):"
		for k in ${kconfig_map}; do
			echo "${script_name}:   $k"
		done
	fi


	echo "${script_name}: checking configuration against contents of '${registry_file}'."

	# First, ensure that the config name is registered (ie: it is present
	# in the config_registry file).
	if [ -z "${config_list}" ]; then

		# NOTE: This branch should never execute when using auto-detection,
		# but we have it here just in case.
		if [[ $1 = auto ]]; then

			echo "${script_name}: 'auto-detected configuration '${config_name}' is NOT registered!"
			echo "${script_name}: "
			echo "${script_name}: *** Cannot continue with unregistered configuration '${config_name}'. ***"
			echo "${script_name}: "
			exit 1;

		else

			# At this point, we know: (a) config_list is empty; and (b) the user
			# requested manual configuration. If the config_name given by the
			# user is present in the configuration blacklist (config_blist),
			# then we can deduce why the config_list is empty: because the only
			# subconfig implied by config_name is blacklisted. Thus, we cannot
			# proceed.

			if [[ $(is_in_list "${config_name}" "${config_blist}") = true ]]; then

				echo "${script_name}: 'user-specified configuration '${config_name}' is blacklisted!"
				echo "${script_name}: "
				echo "${script_name}: *** Cannot continue with blacklisted configuration '${config_name}'. ***"
				echo "${script_name}: *** Try updating your compiler and/or assembler (binutils) versions. ***"
				echo "${script_name}: "
				exit 1;
			else

				# If config_name is NOT present in config_blist, then we know
				# that config_list is empty simply because config_name is
				# unregistered.

				echo "${script_name}: 'user-specified configuration '${config_name}' is NOT registered!"
				echo "${script_name}: "
				echo "${script_name}: *** Cannot continue with unregistered configuration '${config_name}'. ***"
				echo "${script_name}: "
				exit 1;
			fi
		fi
	else

		# This branch executes when the configuration is found to be present
		# (i.e. registered) in the config_registry file.

		echo "${script_name}: configuration '${config_name}' is registered."
		echo "${script_name}: '${config_name}' is defined as having the following sub-configurations:"
		echo "${script_name}:    ${config_list}"
		echo "${script_name}: which collectively require the following kernels:"
		echo "${script_name}:    ${kernel_list}"

	fi


	echo "${script_name}: checking sub-configurations:"

	# Now, verify that the constituent configurations associated with the
	# config name are all valid.
	for conf in ${config_list}; do

		# First confirm that the current configuration is registered.
		#this_clist=${config_registry[${conf}]}
		this_clist=$(query_array "config_registry" "${conf}")

		# If the config_list associated with conf is empty, then it was
		# never entered into the config_registry to begin with. Thus,
		# conf must be unregistered.
		if [ -z "${this_clist}" ]; then
			echo "${script_name}: '${conf}' is NOT registered!"
			echo "${script_name}: "
			echo "${script_name}: *** Cannot continue with unregistered configuration '${conf}'. ***"
			echo "${script_name}: "
			exit 1;
		else
			echo -n "${script_name}:   '${conf}' is registered."
		fi

		# Then confirm that the current sub-configuration directory exists.
		if [ ! -d "${config_dirpath}/${conf}" ]; then
			echo "..but does NOT exist!"
			echo "${script_name}: "
			echo "${script_name}: *** Cannot continue with nonexistent configuration '${conf}'. ***"
			echo "${script_name}: "
			exit 1;
		else
			echo "..and exists."
		fi
	done


	echo "${script_name}: checking sub-configurations' requisite kernels:"

	# Also, let's verify that the requisite kernel sets associated with
	# the config name all correspond to directories that exist.
	for kernel in ${kernel_list}; do

		echo -n "${script_name}:   '${kernel}' kernels..."

		# Confirm that the current kernel sub-directory exists.
		if [ ! -d "${kernels_dirpath}/${kernel}" ]; then
			echo "do NOT exist!"
			echo "${script_name}: "
			echo "${script_name}: *** Cannot continue with nonexistent kernel '${kernel}'. ***"
			echo "${script_name}: "
			exit 1;
		else
			echo "exist."
		fi
	done

	# In order to determine the default behavior of the --with[out]-memkind
	# option, we try to detect whether libmemkind is available. If it is,
	# the default implied option will be --with-memkind; otherwise, will be
	# --without-memkind.
	has_memkind=$(has_libmemkind)

	# Try to determine whether the chosen compiler supports #pragma omp simd.
	pragma_omp_simd=$(has_pragma_omp_simd)


	# -- Prepare variables for subsitution into template files -----------------

	# Parse the status of the prefix option and echo feedback.
	if [ -n "${prefix_flag}" ]; then
		echo "${script_name}: detected --prefix='${prefix}'."
	else
		echo "${script_name}: no install prefix option given; defaulting to '${prefix}'."
	fi

	# Parse the status of the exec_prefix option and echo feedback.
	if [ -n "${exec_prefix_flag}" ]; then
		echo "${script_name}: detected --exec-prefix='${exec_prefix}'."
	else
		echo "${script_name}: no install exec_prefix option given; defaulting to PREFIX."
	fi

	# Parse the status of the libdir option and echo feedback.
	if [ -n "${libdir_flag}" ]; then
		echo "${script_name}: detected --libdir='${libdir}'."
	else
		echo "${script_name}: no install libdir option given; defaulting to EXECPREFIX/lib."
	fi

	# Parse the status of the includedir option and echo feedback.
	if [ -n "${includedir_flag}" ]; then
		echo "${script_name}: detected --includedir='${includedir}'."
	else
		echo "${script_name}: no install includedir option given; defaulting to PREFIX/include."
	fi

	# Parse the status of the sharedir option and echo feedback.
	if [ -n "${sharedir_flag}" ]; then
		echo "${script_name}: detected --sharedir='${sharedir}'."
	else
		echo "${script_name}: no install sharedir option given; defaulting to PREFIX/share."
	fi

	# Echo the installation directories that we settled on.
	echo "${script_name}: final installation directories:"
	echo "${script_name}:   prefix:      $(eval echo "${prefix}")"
	echo "${script_name}:   exec_prefix: $(eval echo "${exec_prefix}")"
	echo "${script_name}:   libdir:      $(eval echo "$(eval echo "${libdir}")")"
	echo "${script_name}:   includedir:  $(eval echo "${includedir}")"
	echo "${script_name}:   sharedir:    $(eval echo "${sharedir}")"
	echo "${script_name}: NOTE: the variables above can be overridden when running make."

	# Check if CFLAGS is non-empty.
	if [ -n "${CFLAGS}" ]; then
		cflags_preset="${CFLAGS}"
		echo "${script_name}: detected preset CFLAGS; prepending:"
		echo "${script_name}:   ${cflags_preset}"
	else
		cflags_preset=''
		echo "${script_name}: no preset CFLAGS detected."
	fi

	# Check if LDFLAGS is non-empty.
	if [ -n "${LDFLAGS}" ]; then
		ldflags_preset="${LDFLAGS}"
		echo "${script_name}: detected preset LDFLAGS; prepending:"
		echo "${script_name}:   ${ldflags_preset}"
	else
		ldflags_preset=''
		echo "${script_name}: no preset LDFLAGS detected."
	fi

	# Check if the verbose make flag was specified.
	if [[ ${enable_verbose} = yes ]]; then
		echo "${script_name}: enabling verbose make output. (disable with 'make V=0'.)"
	else
		echo "${script_name}: disabling verbose make output. (enable with 'make V=1'.)"
	fi

	# Check if the ARG_MAX hack was requested.
	if [[ ${enable_arg_max_hack} = yes ]]; then
		echo "${script_name}: enabling ARG_MAX hack."
	else
		echo "${script_name}: disabling ARG_MAX hack."
	fi

	# Check if the debug flag was specified.
	if [[ -n ${debug_flag} ]]; then
		if [[ ${debug_type} = opt ]]; then
			echo "${script_name}: enabling debug symbols with optimizations."
		elif [[ ${debug_type} = sde ]]; then
			debug_type='sde'
			echo "${script_name}: enabling SDE processor emulation."
		else
			debug_type='noopt'
			echo "${script_name}: enabling debug symbols; optimizations disabled."
		fi
		enable_debug='yes'
	else
		debug_type='off'
		enable_debug='no'
		echo "${script_name}: debug symbols disabled."
	fi

	# Check if the AddressSanitizer flag was specified.
	if [[ ${enable_asan} = yes ]]; then
		echo "${script_name}: enabling AddressSanitizer support (except for optimized kernels)."
	else
		enable_asan='no'
		echo "${script_name}: AddressSanitizer support disabled."
	fi

	# Check if the static lib flag was specified.
	if   [[ ${enable_static} = yes && ${enable_shared} = yes ]]; then
		echo "${script_name}: building BLIS as both static and shared libraries."
		enable_shared_01=1
	elif [[ ${enable_static} = no && ${enable_shared} = yes ]]; then
		echo "${script_name}: building BLIS as a shared library (static library disabled)."
		enable_shared_01=1
	elif [[ ${enable_static} = yes && ${enable_shared} = no ]]; then
		echo "${script_name}: building BLIS as a static library (shared library disabled)."
		enable_shared_01=0
	else
		echo "${script_name}: Both static and shared libraries were disabled."
		echo "${script_name}: *** Please enable one (or both) to continue."
		exit 1
	fi

	# Check if the "export shared" flag was specified.
	if [[ ${export_shared} = all ]]; then
		if [[ ${enable_shared} = yes ]]; then
			echo "${script_name}: exporting all symbols within shared library."
		else
			echo "${script_name}: ignoring request to export all symbols within shared library."
		fi
	elif [[ ${export_shared} = public ]]; then
		if [[ ${enable_shared} = yes ]]; then
			echo "${script_name}: exporting only public symbols within shared library."
		fi
	else
		echo "${script_name}: *** Invalid argument '${export_shared}' to --export-shared option given."
		echo "${script_name}: *** Please use 'public' or 'all'."
		exit 1
	fi

	# Check if we are building with or without operating system support.
	if [[ ${enable_system} = yes ]]; then
		echo "${script_name}: enabling operating system support."
		enable_system_01=1
	else
		echo "${script_name}: disabling operating system support."
		echo "${script_name}: WARNING: disabling OS support forcibly disables all threading!"
		enable_system_01=0

		# Force threading to be disabled.
		threading_model='off'
	fi

	# Check if we are building with or without thread-local storage support.
	if [[ ${enable_tls} = yes ]]; then
		echo "${script_name}: enabling thread-local storage (TLS) support."
		enable_tls_01=1
	else
		echo "${script_name}: disabling thread-local storage (TLS) support."
		echo "${script_name}: WARNING: THIS IS DANGEROUS! Disabling TLS may cause race conditions!"
		echo "${script_name}: WARNING: Please try --disable-threading if you suspect any correctness"
		echo "${script_name}: WARNING: or deadlock issues."
		enable_tls_01=0
	fi

	# Check the threading model flag and standardize its value, if needed.
	# Note that single-threaded mode will always be enabled, but not necessarily
	# by default.
	enable_single='yes'
	enable_openmp='no'
	enable_pthreads='no'
	enable_hpx='no'
	enable_single_01=1
	enable_openmp_01=0
	enable_pthreads_01=0
	enable_hpx_01=0
	parsed_tm=''
	first_tm=''
	enable_single_as_def_01=0
	enable_openmp_as_def_01=0
	enable_pthreads_as_def_01=0
	enable_hpx_as_def_01=0

	# Convert whatever reasonable separator the user may have used into a space.
	threading_model_list=$(echo "${threading_model}" | sed -e "s/[,+]/ /g")

	# Search for all recognized values and standardize them to one of four
	# strings: 'single', 'openmp', 'pthreads', 'auto'. Notice that we keep
	# the strings in the same order as they originally appeared.
	for word in ${threading_model_list}; do

		if [[ ${word} = single ]] ||
		   [[ ${word} = none   ]] ||
		   [[ ${word} = off    ]] ||
		   [[ ${word} = no     ]]; then

			parsed_tm="${parsed_tm} single"

		elif [[ ${word} = openmp ]] ||
			 [[ ${word} = omp    ]]; then

			parsed_tm="${parsed_tm} openmp"

		elif [[ ${word} = pthreads ]] ||
			 [[ ${word} = pthread  ]] ||
			 [[ ${word} = posix    ]]; then

			parsed_tm="${parsed_tm} pthreads"

		elif [[ ${word} = hpx ]]; then

			parsed_tm="${parsed_tm} hpx"

		elif [[ ${word} = auto ]]; then

			parsed_tm="${parsed_tm} auto"

		else

			echo "${script_name}: *** Unsupported threading model: ${word}."
			exit 1
		fi
	done

	# Always enable single-threaded behavior. If the user explicitly
	# requested 'single' as well as other modes, the first occurrence will
	# be kept when duplicates are removed, which will preserve the order
	# for purposes of determining which mode will be the default (absent
	# any explicit choice at runtime).
	parsed_tm="${parsed_tm} single"

	# Remove duplicates, if they exist.
	parsed_tm=$(rm_duplicate_words_simple "${parsed_tm}")

	#echo "parsed_tm0: _${parsed_tm}_"

	# If parsed_tm contains 'auto', substitute in the automatic choice
	# based on which compiler family is being used.
	if [ "$(is_in_list "auto" "${parsed_tm}")" = "true" ]; then

		# If 'auto' was found in the threading model string, we ignore any
		# other choice that may have been expressed and leave everything
		# disabled. (The Makefile will automatically choose a model based
		# on information such as the compiler.)
		echo "${script_name}: determining the threading model automatically."

		# Use OpenMP for gcc and icc, but pthreads for clang.
		if   [ "${cc_vendor}" = "gcc" ]; then

			selected_tm="openmp"
			echo "${script_name}:   automatically selected OpenMP."

		elif [ "${cc_vendor}" = "icc" ]; then

			selected_tm="openmp"
			echo "${script_name}:   automatically selected OpenMP."

		elif [ "${cc_vendor}" = "clang" ]; then

			selected_tm="pthreads"
			echo "${script_name}:   automatically selected pthreads."
		fi

		# Substitute the selected threading model for 'auto' in parsed_tm.
		parsed_tm=$(substitute_words "auto" "${selected_tm}" "${parsed_tm}")
	fi

	#echo "parsed_tm1: _${parsed_tm}_"

	# Remove any extra whitespace.
	parsed_tm=$(canonicalize_ws "${parsed_tm}")

	#echo "parsed_tm2: _${parsed_tm}_"

	# Find the first word. This will be the default threading model.
	first_tm=${parsed_tm%% *}

	#echo "first_tm0:  _${first_tm}_"

	# Now that we've standardized the list, removed duplicates, and handled
	# the possibility of 'auto' being among the listed threading models, we can
	# proceed to formally processing each threading model to enable. Since
	# 'auto' has been converted to 'openmp' or 'pthreads', we only need to
	# handle the remaining three options (openmp, pthreads, and single) going
	# forward.
	for word in ${parsed_tm}; do

		if [[ ${word} = single ]]; then

			echo "${script_name}: enabling support for single-threading."
			enable_single='yes'
			enable_single_01=1

		elif [[ ${word} = openmp ]]; then

			echo "${script_name}: enabling support for threading via OpenMP."
			enable_openmp='yes'
			enable_openmp_01=1

		elif [[ ${word} = pthreads ]]; then

			echo "${script_name}: enabling support for threading via pthreads."
			enable_pthreads='yes'
			enable_pthreads_01=1

		elif [[ ${word} = hpx ]]; then

			echo "${script_name}: enabling support for threading via HPX."
			enable_hpx='yes'
			enable_hpx_01=1

		fi

	done

	# Define boolean variables that can easily be interpreted with #ifdef
	# directives.
	if [[ ${first_tm} = single ]]; then

		enable_single_as_def_01=1
		enable_openmp_as_def_01=0
		enable_pthreads_as_def_01=0
		enable_hpx_as_def_01=0

	elif [[ ${first_tm} = openmp ]]; then

		enable_single_as_def_01=0
		enable_openmp_as_def_01=1
		enable_pthreads_as_def_01=0
		enable_hpx_as_def_01=0

	elif [[ ${first_tm} = pthreads ]]; then

		enable_single_as_def_01=0
		enable_openmp_as_def_01=0
		enable_pthreads_as_def_01=1
		enable_hpx_as_def_01=0

	elif [[ ${first_tm} = hpx ]]; then

		enable_single_as_def_01=0
		enable_openmp_as_def_01=0
		enable_pthreads_as_def_01=0
		enable_hpx_as_def_01=1

	fi

	# If OpenMP, pthreads, or HPX was enabled, given that single-threaded mode is
	# also always enabled, remind the user which one will serve as the default
	# (that is, absent any explicit choice at runtime).
	if [[ ${enable_openmp}   = yes ]] ||
	   [[ ${enable_pthreads} = yes ]] ||
	   [[ ${enable_hpx}      = yes ]]; then

		if   [[ ${first_tm}   = single ]]; then
			echo "${script_name}: threading will default to single-threaded."
		elif [[ ${first_tm}   = openmp ]]; then
			echo "${script_name}: threading will default to OpenMP."
		elif [[ ${first_tm}   = pthreads ]]; then
			echo "${script_name}: threading will default to pthreads."
		elif [[ ${first_tm}   = hpx ]]; then
			echo "${script_name}: threading will default to HPX."
		fi
	fi

	# Copy the final parsed threading model list back to the original variable.
	threading_model="${parsed_tm}"

	#echo "parsed_tm: _${parsed_tm}_"
	#echo "first_tm:  _${first_tm}_"

	# Check the method of assigning micropanels to threads in the JR and IR
	# loops.
	enable_jrir_rr_01=0
	enable_jrir_slab_01=0
	enable_jrir_tlb_01=0
	if   [[ ${thread_part_jrir} = rr ]]; then
		echo "${script_name}: requesting round-robin (rr) work partitioning in jr and/or ir loops."
		enable_jrir_rr_01=1
	elif [[ ${thread_part_jrir} = slab ]]; then
		echo "${script_name}: requesting slab work partitioning in jr and/or ir loops."
		enable_jrir_slab_01=1
	elif [[ ${thread_part_jrir} = tlb ]]; then
		echo "${script_name}: requesting tile-level load balancing (tlb) in unified jr+ir loop."
		enable_jrir_tlb_01=1
	else
		echo "${script_name}: *** Unsupported method of work partitioning in jr/ir loops: ${thread_part_jrir}."
		exit 1
	fi

	# Convert 'yes' and 'no' flags to booleans.
	if [[ ${enable_pba_pools} = yes ]]; then
		echo "${script_name}: internal memory pools for packing blocks are enabled."
		enable_pba_pools_01=1
	else
		echo "${script_name}: internal memory pools for packing blocks are disabled."
		enable_pba_pools_01=0
	fi
	if [[ ${enable_sba_pools} = yes ]]; then
		echo "${script_name}: internal memory pools for small blocks are enabled."
		enable_sba_pools_01=1
	else
		echo "${script_name}: internal memory pools for small blocks are disabled."
		enable_sba_pools_01=0
	fi
	if [[ ${enable_mem_tracing} = yes ]]; then
		echo "${script_name}: memory tracing output is enabled."
		enable_mem_tracing_01=1
	else
		echo "${script_name}: memory tracing output is disabled."
		enable_mem_tracing_01=0
	fi
	if [[ ${enable_scalapack_compat} = yes ]]; then
		echo "${script_name}: ScaLAPACK compatibility is enabled."
		enable_scalapack_compat_01=1
	else
		echo "${script_name}: ScaLAPACK compatibility is disabled."
		enable_scalapack_compat_01=0
	fi
	if [[ ${has_memkind} = yes ]]; then
		if [[ -z ${enable_memkind} ]]; then
			# If no explicit option was given for libmemkind one way or the other,
			# we use the value returned previously by has_libmemkind(), in this
			# case "yes", to determine the default.
			echo "${script_name}: libmemkind found; default is to enable use."
			enable_memkind="yes"
			enable_memkind_01=1
		else
			if [[ ${enable_memkind} = yes ]]; then
				echo "${script_name}: received explicit request to enable libmemkind."
				enable_memkind="yes"
				enable_memkind_01=1
			else
				echo "${script_name}: received explicit request to disable libmemkind."
				enable_memkind="no"
				enable_memkind_01=0
			fi
		fi
	else
		echo "${script_name}: libmemkind not found; disabling."
		if [[ ${enable_memkind} = yes ]]; then
			echo "${script_name}: cannot honor explicit request to enable libmemkind."
		fi
		enable_memkind="no"
		enable_memkind_01=0
	fi
	if [[ ${pragma_omp_simd} = yes ]]; then
		echo "${script_name}: compiler appears to support #pragma omp simd."
		enable_pragma_omp_simd_01=1
	else
		echo "${script_name}: compiler appears to not support #pragma omp simd."
		enable_pragma_omp_simd_01=0
	fi
	if [[ ${enable_blas} = yes ]]; then
		echo "${script_name}: the BLAS compatibility layer is enabled."
		enable_blas_01=1
	else
		echo "${script_name}: the BLAS compatibility layer is disabled."
		enable_blas_01=0
	fi
	if [[ ${enable_cblas} = yes ]]; then
		echo "${script_name}: the CBLAS compatibility layer is enabled."
		enable_cblas_01=1
		# Force BLAS layer when CBLAS is enabled
		enable_blas='yes'
	else
		echo "${script_name}: the CBLAS compatibility layer is disabled."
		enable_cblas_01=0
	fi
	if [[ ${enable_mixed_dt} = yes ]]; then
		echo "${script_name}: mixed datatype support is enabled."

		if [[ ${enable_mixed_dt_extra_mem} = yes ]]; then
			echo "${script_name}: mixed datatype optimizations requiring extra memory are enabled."
			enable_mixed_dt_extra_mem_01=1
		else
			echo "${script_name}: mixed datatype optimizations requiring extra memory are disabled."
			enable_mixed_dt_extra_mem_01=0
		fi

		enable_mixed_dt_01=1
	else
		echo "${script_name}: mixed datatype support is disabled."

		enable_mixed_dt_extra_mem_01=0
		enable_mixed_dt_01=0
	fi
	if [[ ${enable_sup_handling} = yes ]]; then
		echo "${script_name}: sup (skinny/unpacked) matrix handling is enabled."
		enable_sup_handling_01=1
	else
		echo "${script_name}: sup (skinny/unpacked) matrix handling is disabled."
		enable_sup_handling_01=0
	fi
	if [[ ${enable_trsm_preinversion} = yes ]]; then
		echo "${script_name}: trsm diagonal element pre-inversion is enabled."
		enable_trsm_preinversion_01=1
	else
		echo "${script_name}: trsm diagonal element pre-inversion is disabled."
		enable_trsm_preinversion_01=0
	fi

	# Report integer sizes.
	if [[ ${int_type_size} = 32 ]]; then
		echo "${script_name}: the BLIS API integer size is 32-bit."
	elif [[ ${int_type_size} = 64 ]]; then
		echo "${script_name}: the BLIS API integer size is 64-bit."
	else
		echo "${script_name}: the BLIS API integer size is automatically determined."
	fi
	if [[ ${blas_int_type_size} = 32 ]]; then
		echo "${script_name}: the BLAS/CBLAS API integer size is 32-bit."
	elif [[ ${blas_int_type_size} = 64 ]]; then
		echo "${script_name}: the BLAS/CBLAS API integer size is 64-bit."
	else
		echo "${script_name}: the BLAS/CBLAS API integer size is automatically determined."
	fi

	# Disallow the simultaneous use of 64-bit integers in the BLAS and
	# 32-bit integers in BLIS.
	if [[ ${blas_int_type_size} = 64 && ${int_type_size} = 32 ]]; then
		echo "${script_name}: *** To avoid the possibility of truncation, we do not allow use of 64-bit integers in the BLAS API with 32-bit integers in BLIS. Please use a different configuration of integers."
		exit 1
	fi

	# Check whether we should use AMD-customized versions of certain framework
	# files.
	if [[ ${enable_amd_frame_tweaks} = yes ]]; then

		echo "${script_name}: AMD-specific framework files will be considered."
		echo "${script_name}:   checking eligibility of target configuration."

		# Make sure we are targeting either one of the zen subconfigs or the
		# amd64 umbrella family.
		if [[ ${config_name} != *zen* && ${config_name} != *amd64* ]]; then
			echo "${script_name}:   target configuration '${config_name}' is not eligible."
			echo "${script_name}:   disabling AMD-specific framework files."
			enable_amd_frame_tweaks='no'
		else
			echo "${script_name}:   target configuration '${config_name}' is eligible."
			echo "${script_name}:   enabling AMD-specific framework files."
		fi
	else
		echo "${script_name}: AMD-specific framework files will not be considered."
	fi

	# Check if addons were given.
	if [ -n "${addon_flag}" ]; then

		# Remove duplicates in the addon list, if they exist.
		addon_list=$(rm_duplicate_words_simple "${addon_list}")

		echo "${script_name}: configuring with addons:"

		for addon in ${addon_list}; do

			echo "${script_name}:   ${addon_dir}/${addon}"

			addon_fullpath="${addon_dirpath}/${addon}"

			if [ ! -d "${addon_fullpath}" ]; then
				echo "${script_name}: requested addon sub-directory does not exist! Cannot continue."
				echo "${script_name}: *** Please verify addon existence and name."
				exit 1
			fi
		done

		enable_addons_01=1
	else
		echo "${script_name}: configuring with no addons."

		enable_addons_01=0
	fi

	# Check if a sandbox was given.
	if [ -n "${sandbox_flag}" ]; then

		#sandbox_relpath="${sandbox_dir}/${sandbox}"

		echo "${script_name}: configuring for alternate gemm implementation:"
		echo "${script_name}:   ${sandbox_dir}/${sandbox}"

		sandbox_fullpath="${sandbox_dirpath}/${sandbox}"

		if [ ! -d "${sandbox_fullpath}" ]; then
			echo "${script_name}: requested sandbox sub-directory does not exist! Cannot continue."
			echo "${script_name}: *** Please verify sandbox existence and name."
			exit 1
		fi

		enable_sandbox_01=1
	else
		echo "${script_name}: configuring for conventional gemm implementation."

		enable_sandbox_01=0
	fi

	# Check the method used for returning complex numbers.
	if [[ ${complex_return} = default ]]; then

		# If we prevoiusly found a Fortran compiler, let's query it to see what
		# kind of complex return type it uses (gnu or intel). The 'gnu' style
		# returns complex values from functions normally, via the C language
		# return statement, while the 'intel' style returns them in a "hidden"
		# parameter (inserted by the compiler) that precedes all other function
		# parameters.
		if [ -n "${found_fc}" ]; then

			# Query the full vendor version string output. This includes the
			# version number along with (potentially) a bunch of other textual
			# clutter.
			# NOTE: This maybe should use merged stdout/stderr rather than only
			# stdout. But it works for now.
			vendor_string="$(${found_fc} --version 2>/dev/null || :)"

			# Query the compiler "vendor" (ie: the compiler's simple name).
			# The last part ({ read first rest ; echo $first ; }) is a workaround
			# to OS X's egrep only returning the first match.
			fc_vendor=$(echo "${vendor_string}" | grep -oE 'IFORT|GNU' |
			            { read -r first rest ; echo "${first}"; })

			if [[ ${fc_vendor} = IFORT ]]; then
				complex_return='intel'
			elif [[ ${fc_vendor} = GNU ]]; then
				complex_return='gnu'
			else
				echo "${script_name}: unable to determine Fortran compiler vendor!"
				complex_return='gnu'
			fi
		else
			complex_return='gnu'
		fi
	fi

	if [[ ${complex_return} = gnu ]]; then
		complex_return_intel01='0'
	elif [[ ${complex_return} = intel ]]; then
		complex_return_intel01='1'
	else
		echo "${script_name}: unknown complex return type \"${complex_return}\"! Cannot continue."
		echo "${script_name}: *** Acceptable values are \"gnu\" and \"intel\"."
		exit 1
	fi

	echo "${script_name}: configuring complex return type as \"${complex_return}\"."

	# Variables that may contain forward slashes, such as paths, need extra
	# escaping when used in sed commands. We insert those extra escape
	# characters here so that the sed commands below do the right thing.
	os_name_esc=$(echo     "${os_name}"      | sed 's/\//\\\//g')
	prefix_esc=$(echo      "${prefix}"       | sed 's/\//\\\//g')
	exec_prefix_esc=$(echo "${exec_prefix}"  | sed 's/\//\\\//g')
	libdir_esc=$(echo      "${libdir}"       | sed 's/\//\\\//g')
	includedir_esc=$(echo  "${includedir}"   | sed 's/\//\\\//g')
	sharedir_esc=$(echo    "${sharedir}"     | sed 's/\//\\\//g')
	dist_path_esc=$(echo   "${dist_path}"    | sed 's/\//\\\//g')
	cc_esc=$(echo          "${found_cc}"     | sed 's/\//\\\//g')
	cxx_esc=$(echo         "${found_cxx}"    | sed 's/\//\\\//g')
	ar_esc=$(echo          "${found_ar}"     | sed 's/\//\\\//g')
	ranlib_esc=$(echo      "${found_ranlib}" | sed 's/\//\\\//g')
	python_esc=$(echo      "${found_python}" | sed 's/\//\\\//g')

	libpthread_esc=$(echo "${LIBPTHREAD--lpthread}" | sed 's/\//\\\//g')
	cflags_preset_esc=$(echo "${cflags_preset}" | sed 's/\//\\\//g')
	ldflags_preset_esc=$(echo "${ldflags_preset}" | sed 's/\//\\\//g')

	# For Windows builds, clear the libpthread_esc variable so that
	# no pthreads library is substituted into config.mk. (Windows builds
	# employ an implementation of pthreads that is internal to BLIS.)
	if [[ "$is_win" == "yes" && "$cc_vendor" == "clang" ]]; then
		libpthread_esc=
	fi

	# We also clear the libpthread_esc variable for systemless builds
	# (--disable-system).
	if [[ "$enable_system" == "no" ]]; then
		libpthread_esc=
	fi

	# Typically, there are no slashes in the version variable. However,
	# downstream maintainers (such as those for Debian) may create custom
	# tags in their local clones such as "upstream/0.4.1", which obviously
	# contain slashes. This line, and subsequent use of the escaped variable
	# for the version string, accommodates those use cases.
	version_esc=$(echo "${version}" | sed 's/\//\\\//g')

	# Create a #define for the configuration family (config_name).
	uconf=$(echo "${config_name}" | tr '[:lower:]' '[:upper:]')
	config_name_define="#define BLIS_FAMILY_${uconf}\n"

	# Create a list of #defines, one for each configuration in config_list.
	config_list_defines=""
	for conf in ${config_list}; do

		# Convert the current config name to uppercase.
		uconf=$(echo "${conf}" | tr '[:lower:]' '[:upper:]')

		# Create a #define and add it to the running list.
		config_define="BLIS_CONFIG_${uconf}"
		config_list_defines="${config_list_defines}#define ${config_define}\n"
	done

	# Create a list of #defines, one for each kernel set in kernel_list.
	kernel_list_defines=""
	for kern in ${kernel_list}; do

		# Convert the current config name to uppercase.
		uconf=$(echo "${kern}" | tr '[:lower:]' '[:upper:]')

		# Create a #define and add it to the running list.
		kernel_define="BLIS_KERNELS_${uconf}"
		kernel_list_defines="${kernel_list_defines}#define ${kernel_define}\n"
	done

	# Create a list of #includes, one for each addon in addon_list.
	addon_list_includes=""
	for addon in ${addon_list}; do

		# Create a #define and add it to the running list.
		addon_header="\"${addon}.h\""
		addon_list_includes="${addon_list_includes}#include ${addon_header}\n"
	done


	# -- Determine whether we are performing an out-of-tree build --------------

	if [ "${dist_path}" != "./" ]; then

		# At this point, we know the user did not run "./configure". But we
		# have not yet ruled out "<fullpath>/configure" or some # equivalent
		# that uses relative paths. To further rule out these possibilities,
		# we create a dummy file in the current build directory.
		touch "./${dummy_file}"

		# If the dummy file we just created in the current directory does not
		# appear in the source distribution path, then we are in a different
		# directory and thus we must create a symbolic link.
		if [ ! -f "${dist_path}/${dummy_file}" ]; then
			configured_oot="yes"
			#echo "${script_name}: detected out-of-tree build directory."
		else
			configured_oot="no"
			#echo "${script_name}: detected in-tree build directory."
		fi

		# Remove the dummy file.
		rm -f "./${dummy_file}"
	fi


	# -- Instantiate config.mk file from template ------------------------------

	# Begin substituting information into the config_mk_in file, outputting
	# to config_mk_out.
	echo "${script_name}: creating ${config_mk_out_path} from ${config_mk_in_path}"
	sed <"${config_mk_in_path}" >"${config_mk_out_path}"          \
	-e "s/@version@/${version_esc}/g"                             \
	-e "s/@so_version_major@/${so_version_major}/g"               \
	-e "s/@so_version_minorbuild@/${so_version_minorbuild}/g"     \
	-e "s/@config_name@/${config_name}/g"                         \
	-e "s/@config_list@/${config_list}/g"                         \
	-e "s/@kernel_list@/${kernel_list}/g"                         \
	-e "s/@kconfig_map@/${kconfig_map}/g"                         \
	-e "s/@os_name@/${os_name_esc}/g"                             \
	-e "s/@is_win@/${is_win}/g"                                   \
	-e "s/@is_msvc@/${is_msvc}/g"                                 \
	-e "s/@dist_path@/${dist_path_esc}/g"                         \
	-e "s/@CC_VENDOR@/${cc_vendor}/g"                             \
	-e "s/@gcc_older_than_4_9_0@/${gcc_older_than_4_9_0}/g"       \
	-e "s/@gcc_older_than_6_1_0@/${gcc_older_than_6_1_0}/g"       \
	-e "s/@gcc_older_than_9_1_0@/${gcc_older_than_9_1_0}/g"       \
	-e "s/@gcc_older_than_10_3_0@/${gcc_older_than_10_3_0}/g"     \
	-e "s/@clang_older_than_9_0_0@/${clang_older_than_9_0_0}/g"   \
	-e "s/@clang_older_than_12_0_0@/${clang_older_than_12_0_0}/g" \
	-e "s/@aocc_older_than_2_0_0@/${aocc_older_than_2_0_0}/g"     \
	-e "s/@aocc_older_than_3_0_0@/${aocc_older_than_3_0_0}/g"     \
	-e "s/@CC@/${cc_esc}/g"                                       \
	-e "s/@CXX@/${cxx_esc}/g"                                     \
	-e "s/@AR@/${ar_esc}/g"                                       \
	-e "s/@RANLIB@/${ranlib_esc}/g"                               \
	-e "s/@PYTHON@/${python_esc}/g"                               \
	-e "s/@libpthread@/${libpthread_esc}/g"                       \
	-e "s/@cflags_preset@/${cflags_preset_esc}/g"                 \
	-e "s/@ldflags_preset@/${ldflags_preset_esc}/g"               \
	-e "s/@enable_asan@/${enable_asan}/g"                         \
	-e "s/@debug_type@/${debug_type}/g"                           \
	-e "s/@enable_debug@/${enable_debug}/g"                       \
	-e "s/@enable_system@/${enable_system}/g"                     \
	-e "s/@threading_model@/${threading_model}/g"                 \
	-e "s/@prefix@/${prefix_esc}/g"                               \
	-e "s/@exec_prefix@/${exec_prefix_esc}/g"                     \
	-e "s/@libdir@/${libdir_esc}/g"                               \
	-e "s/@includedir@/${includedir_esc}/g"                       \
	-e "s/@sharedir@/${sharedir_esc}/g"                           \
	-e "s/@enable_verbose@/${enable_verbose}/g"                   \
	-e "s/@configured_oot@/${configured_oot}/g"                   \
	-e "s/@enable_arg_max_hack@/${enable_arg_max_hack}/g"         \
	-e "s/@enable_static@/${enable_static}/g"                     \
	-e "s/@enable_shared@/${enable_shared}/g"                     \
	-e "s/@enable_rpath@/${enable_rpath}/g"                       \
	-e "s/@export_shared@/${export_shared}/g"                     \
	-e "s/@enable_blas@/${enable_blas}/g"                         \
	-e "s/@enable_cblas@/${enable_cblas}/g"                       \
	-e "s/@enable_amd_frame_tweaks@/${enable_amd_frame_tweaks}/g" \
	-e "s/@enable_memkind@/${enable_memkind}/g"                   \
	-e "s/@pragma_omp_simd@/${pragma_omp_simd}/g"                 \
	-e "s/@addon_list@/${addon_list}/g"                           \
	-e "s/@sandbox@/${sandbox}/g"

	# -- Instantiate bli_config.h file from template ---------------------------

	# Begin substituting information into the bli_config_h_in file, outputting
	# to bli_config_h_out. NOTE: We use perl instead of sed because the version
	# of sed used on OS X is old and does not handle the '\n' character
	# intuitively, which was used when constructing ${config_name_define},
	# ${config_list_defines}, and ${kernel_list_defines}.
	echo "${script_name}: creating ${bli_config_h_out_path} from ${bli_config_h_in_path}"
	<"${bli_config_h_in_path}" perl -p                                   \
	-e "s/\@config_name_define\@/${config_name_define}/g;"               \
	-e "s/\@config_list_defines\@/${config_list_defines}/g;"             \
	-e "s/\@kernel_list_defines\@/${kernel_list_defines}/g;"             \
	| sed >"${bli_config_h_out_path}"                                    \
	-e "s/@version@/${version_esc}/g"                                    \
	-e "s/@enable_system@/${enable_system_01}/g"                         \
	-e "s/@enable_tls@/${enable_tls_01}/g"                               \
	-e "s/@enable_openmp@/${enable_openmp_01}/g"                         \
	-e "s/@enable_openmp_as_def@/${enable_openmp_as_def_01}/g"           \
	-e "s/@enable_pthreads@/${enable_pthreads_01}/g"                     \
	-e "s/@enable_pthreads_as_def@/${enable_pthreads_as_def_01}/g"       \
	-e "s/@enable_hpx@/${enable_hpx_01}/g"                               \
	-e "s/@enable_hpx_as_def@/${enable_hpx_as_def_01}/g"                 \
	-e "s/@enable_jrir_rr@/${enable_jrir_rr_01}/g"                       \
	-e "s/@enable_jrir_slab@/${enable_jrir_slab_01}/g"                   \
	-e "s/@enable_jrir_tlb@/${enable_jrir_tlb_01}/g"                     \
	-e "s/@enable_pba_pools@/${enable_pba_pools_01}/g"                   \
	-e "s/@enable_sba_pools@/${enable_sba_pools_01}/g"                   \
	-e "s/@enable_mem_tracing@/${enable_mem_tracing_01}/g"               \
	-e "s/@int_type_size@/${int_type_size}/g"                            \
	-e "s/@blas_int_type_size@/${blas_int_type_size}/g"                  \
	-e "s/@enable_blas@/${enable_blas_01}/g"                             \
	-e "s/@enable_cblas@/${enable_cblas_01}/g"                           \
	-e "s/@enable_mixed_dt@/${enable_mixed_dt_01}/g"                     \
	-e "s/@enable_mixed_dt_extra_mem@/${enable_mixed_dt_extra_mem_01}/g" \
	-e "s/@enable_sup_handling@/${enable_sup_handling_01}/g"             \
	-e "s/@enable_memkind@/${enable_memkind_01}/g"                       \
	-e "s/@enable_trsm_preinversion@/${enable_trsm_preinversion_01}/g"   \
	-e "s/@enable_pragma_omp_simd@/${enable_pragma_omp_simd_01}/g"       \
	-e "s/@enable_sandbox@/${enable_sandbox_01}/g"                       \
	-e "s/@enable_shared@/${enable_shared_01}/g"                         \
	-e "s/@enable_scalapack_compat@/${enable_scalapack_compat_01}/g"     \
	-e "s/@complex_return_intel@/${complex_return_intel01}/g"

	# -- Instantiate bli_addon.h file from template ----------------------------

	# Begin substituting information into the bli_addon_h_in file, outputting
	# to bli_addon_h_out. NOTE: We use perl instead of sed because the version
	# of sed used on OS X is old and does not handle the '\n' character
	# intuitively, which was used when constructing ${addon_list_includes}.
	echo "${script_name}: creating ${bli_addon_h_out_path} from ${bli_addon_h_in_path}"
	perl -pe "s/\@addon_list_includes\@/${addon_list_includes}/g" "${bli_addon_h_in_path}" \
	| sed -e "s/@enable_addons@/${enable_addons_01}/g" > "${bli_addon_h_out_path}"

	# -- Create top-level object directories -----------------------------------

	# Create obj sub-directories (if they do not already exist).
	base_obj_dirpath="${obj_dirpath}/${config_name}"

	echo "${script_name}: creating ${base_obj_dirpath}"
	mkdir -p "${base_obj_dirpath}"


	obj_config_dirpath="${base_obj_dirpath}/${config_dir}"

	mkdir -p "${obj_config_dirpath}"
	for conf in ${config_list}; do
		echo "${script_name}: creating ${obj_config_dirpath}/${conf}"
		mkdir -p "${obj_config_dirpath}/${conf}"
	done


	obj_kernels_dirpath="${base_obj_dirpath}/${kernels_dir}"

	mkdir -p "${obj_kernels_dirpath}"
	for kern in ${kernel_list}; do
		echo "${script_name}: creating ${obj_kernels_dirpath}/${kern}"
		mkdir -p "${obj_kernels_dirpath}/${kern}"
	done


	obj_refkern_dirpath="${base_obj_dirpath}/${refkern_dir}"

	mkdir -p "${obj_refkern_dirpath}"
	for conf in ${config_list}; do
		echo "${script_name}: creating ${obj_refkern_dirpath}/${conf}"
		mkdir -p "${obj_refkern_dirpath}/${conf}"
	done


	obj_frame_dirpath="${base_obj_dirpath}/${frame_dir}"

	echo "${script_name}: creating ${obj_frame_dirpath}"
	mkdir -p "${obj_frame_dirpath}"


	if [ -n "${addon_flag}" ]; then

		obj_addon_dirpath="${base_obj_dirpath}/${addon_dir}"

		for addon in ${addon_list}; do
			echo "${script_name}: creating ${obj_addon_dirpath}/${addon}"
			mkdir -p "${obj_addon_dirpath}/${addon}"
		done
	fi


	if [ -n "${sandbox_flag}" ]; then

		obj_sandbox_dirpath="${base_obj_dirpath}/${sandbox_dir}"

		echo "${script_name}: creating ${obj_sandbox_dirpath}/${sandbox}"
		mkdir -p "${obj_sandbox_dirpath}/${sandbox}"
	fi


	obj_blastest_dirpath="${base_obj_dirpath}/${blastest_dir}"

	echo "${script_name}: creating ${obj_blastest_dirpath}"
	mkdir -p "${obj_blastest_dirpath}"


	obj_testsuite_dirpath="${base_obj_dirpath}/${testsuite_dir}"

	echo "${script_name}: creating ${obj_testsuite_dirpath}"
	mkdir -p "${obj_testsuite_dirpath}"


	# Create lib directory (if it does not already exist).
	base_lib_dirpath="${lib_dirpath}/${config_name}"

	echo "${script_name}: creating ${base_lib_dirpath}"
	mkdir -p "${base_lib_dirpath}"


	# Create include directory (if it does not already exist).
	base_include_dirpath="${include_dirpath}/${config_name}"

	echo "${script_name}: creating ${base_include_dirpath}"
	mkdir -p "${base_include_dirpath}"


	# -- Mirror source directory hierarchies to object directories -------------

	# Combine the config_list with the config_name and then remove duplicates.
	config_list_plus_name=$(rm_duplicate_words "${config_list} ${config_name}")

	# Mirror each of the sub-configuration directories to the object directory.
	for conf in ${config_list_plus_name}; do

		echo "${script_name}: mirroring ${config_dirpath}/${conf} to ${obj_config_dirpath}/${conf}"
		"${mirror_tree_sh}" "${config_dirpath}/${conf}" "${obj_config_dirpath}/${conf}"
	done

	# Mirror optimized kernels source tree to its object sub-directory.
	# We perform the mirroring on each configuration/kernel sub-directory
	# within 'kernels'.
	for kern in ${kernel_list}; do

		# Only mirror the optimized kernels source directory if it exists.
		# There are occasions where one of the sub-configurations in the
		# config_list does not correspond to a kernels sub-directory, such
		# as when architecture B is so close to architecture A that B can
		# use A's kernel source code unmodified (though perhaps with
		# different blocksizes).
		#if [ -d "${kernels_dirpath}/${conf}" ]; then

		echo "${script_name}: mirroring ${kernels_dirpath}/${kern} to ${obj_kernels_dirpath}/${kern}"
		${mirror_tree_sh} "${kernels_dirpath}/${kern}" "${obj_kernels_dirpath}/${kern}"
		#else
		#	echo "${script_name}: mirroring ${kernels_dirpath}/${conf} skipped... directory does not exist"
		#fi
	done

	# Mirror reference kernel source tree to its object sub-directory.
	echo "${script_name}: mirroring ${refkern_dirpath} to ${obj_refkern_dirpath}"
	"${mirror_tree_sh}" "${refkern_dirpath}" "${obj_refkern_dirpath}"

	# Mirror reference kernels source tree to its object sub-directory.
	for conf in ${config_list}; do

		echo "${script_name}: mirroring ${refkern_dirpath} to ${obj_refkern_dirpath}/${conf}"
		"${mirror_tree_sh}" "${refkern_dirpath}" "${obj_refkern_dirpath}/${conf}"
	done

	# Mirror framework source tree to its object sub-directory.
	echo "${script_name}: mirroring ${frame_dirpath} to ${obj_frame_dirpath}"
	"${mirror_tree_sh}" "${frame_dirpath}" "${obj_frame_dirpath}"

	# Mirror the chosen addon source tree to its object sub-directory.
	if [[ -n ${addon_flag} ]]; then

		for addon in ${addon_list}; do

			echo "${script_name}: mirroring ${addon_dirpath}/${addon} to ${obj_addon_dirpath}/${addon}"
			"${mirror_tree_sh}" "${addon_dirpath}/${addon}" "${obj_addon_dirpath}/${addon}"
		done
	fi

	# Mirror the chosen sandbox source tree to its object sub-directory.
	if [[ -n ${sandbox_flag} ]]; then

		echo "${script_name}: mirroring ${sandbox_dirpath}/${sandbox} to ${obj_sandbox_dirpath}/${sandbox}"
		"${mirror_tree_sh}" "${sandbox_dirpath}/${sandbox}" "${obj_sandbox_dirpath}/${sandbox}"
	fi


	# -- Generate makefile fragements ------------------------------------------

	create_makefile_fragment() {
		echo "${script_name}: creating makefile fragments in $3"
		"${gen_make_frags_sh}"                           \
			-h -r -v0                                \
			-o "${script_name}"                      \
			-p "$1" "$2" "$3"                        \
			"${gen_make_frags_dirpath}/fragment.mk"  \
			"${gen_make_frags_dirpath}/suffix_list"  \
			"${gen_make_frags_dirpath}/ignore_list"
	}

	clist_contains_cname=$(is_in_list "${config_name}" "${config_list}")

	# If the config_list does not already contain the config_name (i.e.,
	# if config_name is an umbrella family), generate makefiles in that
	# directory. (In the next step, we will loop over the actual sub-
	# configurations and create fragments there as well.)
	if [[ ${clist_contains_cname} = false ]]; then
		create_makefile_fragment CONFIG "${config_dirpath}/${config_name}" \
		                         "${obj_config_dirpath}/${config_name}"
	fi

	# Generate makefile fragments for each of the sub-configurations present
	# in the configuration list.
	for conf in ${config_list}; do
		create_makefile_fragment CONFIG "${config_dirpath}/${conf}" \
		                         "${obj_config_dirpath}/${conf}"
	done

	# Generate makefile fragments for each of the kernel sets required by
	# the configuration list (in the kernel list).
	for kern in ${kernel_list}; do
		create_makefile_fragment KERNELS "${kernels_dirpath}/${kern}" \
		                         "${obj_kernels_dirpath}/${kern}"
	done

	# Generate makefile fragments in the reference kernels directory.
	create_makefile_fragment REFKERN "${refkern_dirpath}" \
	                         "${obj_refkern_dirpath}"

	# Generate makefile fragments in the framework directory.
	create_makefile_fragment FRAME "${frame_dirpath}" \
	                         "${obj_frame_dirpath}"

	# Generate makefile fragments in the addon sub-directory.
	if [[ -n ${addon_flag} ]]; then
		for addon in ${addon_list}; do
			create_makefile_fragment ADDON "${addon_dirpath}/${addon}" \
			                         "${obj_addon_dirpath}/${addon}"
		done
	fi

	# Generate makefile fragments in the sandbox sub-directory.
	if [[ -n ${sandbox_flag} ]]; then
		create_makefile_fragment SANDBOX "${sandbox_dirpath}/${sandbox}" \
		                         "${obj_sandbox_dirpath}/${sandbox}"
	fi


	# -- Handle out-of-tree builds ---------------------------------------------

	# Under some circumstances, we need to create some symbolic links to
	# properly handle out-of-tree builds.
	if [[ ${configured_oot} = yes ]]; then
		for file in Makefile blis.pc.in common.mk config; do
			# If symlink does not already exist in the current
			# directory, create a symbolic link to it. If one does exist, we
			# use -f to force creation of a new link.
			if [[ ! -e ${file} ]]; then
				echo "${script_name}: creating symbolic link to ${file}."
				ln -s "${dist_path}/${file}" .
			elif [[ -h ${file} ]]; then
				echo "${script_name}: symbolic link to ${file} already exists; forcing creation of new link."
				ln -sf "${dist_path}/${file}" .
			else
				echo "${script_name}: Non-symbolic link file or directory '${file}' blocks creation of symlink."
				echo "${script_name}: *** Please remove this entity and re-run configure."
				exit 1
			fi
		done

		echo "${script_name}: configured to build outside of source distribution."
	else

		echo "${script_name}: configured to build within top-level directory of source distribution."
	fi

	if [ "${warn_user_generic}" = "1" ]; then

		echo "${script_name}: "
		echo "${script_name}: *** Unable to automatically detect hardware type! ***"
		echo "${script_name}: "
		echo "${script_name}: NOTE: configure was unable to identify a subconfiguration"
		echo "${script_name}: optimized for your hardware. As a result, the 'generic'"
		echo "${script_name}: subconfiguration (with low-performance reference kernels)"
		echo "${script_name}: will be used. For support, please open an issue on GitHub"
		echo "${script_name}: at https://github.com/flame/blis/issues."
		echo "${script_name}: "
	fi

	# Exit peacefully.
	return 0
}


# The script's main entry point, passing all parameters given.
main "$@"