configure

#!/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) 2018, 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.
#
#

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

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

	# Echo usage info.
	echo " "
	echo " ${script_name} (BLIS ${version})"
	#echo " "
	#echo " BLIS ${version}"
	echo " "
	echo " Field G. Van Zee"
	echo " "
	echo " Configure BLIS's build system for compilation using a specified"
	echo " configuration directory."
	echo " "
	echo " Usage:"
	echo " "
	echo "   ${script_name} [options] [env. vars.] confname"
	echo " "
	echo " Arguments:"
	echo " "
	echo "   confname      The name of the sub-directory inside of the 'config'"
	echo "                 directory containing the desired BLIS configuration."
	echo "                 Note that confname MUST be specified; if it is not,"
	echo "                 configure will complain. To build a completely generic"
	echo "                 implementation, use the 'generic' configuration"
	echo " "
	echo " Options:"
	echo " "
	echo "   -p PREFIX, --prefix=PREFIX"
	echo " "
	echo "                 The path to which make will install all build products."
	echo "                 If given, this option implies the following options:"
	echo "                   --libdir=PREFIX/lib"
	echo "                   --incdir=PREFIX/include"
	echo "                   --sharedir=PREFIX/share"
	echo "                 If not given, PREFIX defaults to \$(HOME)/blis. If PREFIX"
	echo "                 refers to a directory that does not exist, it will be"
	echo "                 created."
	echo " "
	echo "   --libdir=LIBDIR"
	echo " "
	echo "                 The path to which make will install libraries. If given,"
	echo "                 LIBDIR will override the corresponding directory implied"
	echo "                 by --prefix; if not not given, LIBDIR defaults to"
	echo "                 PREFIX/lib. If LIBDIR refers to a directory that does"
	echo "                 not exist, it will be created."
	echo " "
	echo "   --includedir=INCDIR"
	echo " "
	echo "                 The path to which make will install development header"
	echo "                 files. If given, INCDIR will override the corresponding"
	echo "                 directory implied by --prefix; if not given, INCDIR"
	echo "                 defaults to PREFIX/include. If INCDIR refers to a"
	echo "                 directory that does not exist, it will be created."
	echo " "
	echo "   --sharedir=SHAREDIR"
	echo " "
	echo "                 The path to which make will makefile fragments containing"
	echo "                 make variables determined by configure (e.g. CC, CFLAGS,"
	echo "                 and LDFLAGS). These files allow certain BLIS makefiles,"
	echo "                 such as those in the examples or testsuite directories, to"
	echo "                 operate on an installed copy of BLIS rather than a local"
	echo "                 (and possibly uninstalled) copy. If given, SHAREDIR will"
	echo "                 override the corresponding directory implied by --prefix;"
	echo "                 if not given, SHAREDIR defaults to PREFIX/share. If"
	echo "                 SHAREDIR refers to a directory that does not exist, it"
	echo "                 will be created."
	echo " "
	echo "   -d DEBUG, --enable-debug[=DEBUG]"
	echo " "
	echo "                 Enable debugging symbols in the library. If argument"
	echo "                 DEBUG is given as 'opt', then optimization flags are"
	echo "                 kept in the framework, otherwise optimization is"
	echo "                 turned off."
	echo " "
	echo "   --enable-verbose-make, --disable-verbose-make"
	echo " "
	echo "                 Enable (disabled by default) verbose compilation output"
	echo "                 during make."
	echo " "
	echo "   --enable-arg-max-hack --disable-arg-max-hack"
	echo " "
	echo "                 Enable (disabled by default) build system logic that"
	echo "                 will allow archiving/linking the static/shared library"
	echo "                 even if the command plus command line arguments exceeds"
	echo "                 the operating system limit (ARG_MAX)."
	echo " "
	echo "   --disable-static, --enable-static"
	echo " "
	echo "                 Disable (enabled by default) building BLIS as a static"
	echo "                 library. If the static library build is disabled, the"
	echo "                 shared library build must remain enabled."
	echo " "
	echo "   --disable-shared, --enable-shared"
	echo " "
	echo "                 Disable (enabled by default) building BLIS as a shared"
	echo "                 library. If the shared library build is disabled, the"
	echo "                 static library build must remain enabled."
	echo " "
	echo "   -t MODEL, --enable-threading[=MODEL], --disable-threading"
	echo " "
	echo "                 Enable threading in the library, using threading model"
	echo "                 MODEL={openmp,pthreads,no}. If MODEL=no or "
	echo "                 --disable-threading is specified, threading will be"
	echo "                 disabled. The default is 'no'."
	echo " "
	echo "   --disable-pba-pools, --enable-pba-pools"
	echo "   --disable-sba-pools, --enable-sba-pools"
	echo " "
	echo "                 Disable (enabled by default) use of internal memory pools"
	echo "                 within the packing block allocator (pba) and/or the small"
	echo "                 block allocator (sba). The former is used to allocate"
	echo "                 memory used to pack submatrices while the latter is used"
	echo "                 to allocate control/thread tree nodes and thread"
	echo "                 communicators. Both allocations take place in the context"
	echo "                 of level-3 operations. When the pba is disabled, the"
	echo "                 malloc()-like function specified by BLIS_MALLOC_POOL is"
	echo "                 called on-demand whenever a packing block is needed, and"
	echo "                 when the sba is disabled, the malloc()-like function"
	echo "                 specified by BLIS_MALLOC_INTL is called whenever a small"
	echo "                 block is needed, with the two allocators calling free()-"
	echo "                 like functions BLIS_FREE_POOL and BLIS_FREE_INTL,"
	echo "                 respectively when blocks are released. When enabled,"
	echo "                 either or both pools are populated via the same functions"
	echo "                 mentioned previously, and henceforth blocks are checked"
	echo "                 out and in. The library quickly reaches a state in which"
	echo "                 it no longer needs to call malloc() or free(), even"
	echo "                 across many separate level-3 operation invocations."
	echo " "
	echo "   --enable-mem-tracing, --disable-mem-tracing"
	echo " "
	echo "                 Enable (disable by default) output to stdout that traces"
	echo "                 the allocation and freeing of memory, including the names"
	echo "                 of the functions that triggered the allocation/freeing."
	echo "                 Enabling this option WILL NEGATIVELY IMPACT PERFORMANCE."
	echo "                 Please use only for informational/debugging purposes."
	echo " "
	echo "   -i SIZE, --int-size=SIZE"
	echo " "
	echo "                 Set the size (in bits) of internal BLIS integers and"
	echo "                 integer types used in native BLIS interfaces. The"
	echo "                 default inteter type size is architecture dependent."
	echo "                 (Hint: You can always find this value printed at the"
	echo "                 beginning of the testsuite output.)"
	echo " "
	echo "   -b SIZE, --blas-int-size=SIZE"
	echo " "
	echo "                 Set the size (in bits) of integer types in external"
	echo "                 BLAS and CBLAS interfaces, if enabled. The default"
	echo "                 integer type size used in BLAS/CBLAS is 32 bits."
	echo " "
	echo "   --disable-blas, --enable-blas"
	echo " "
	echo "                 Disable (enabled by default) building the BLAS"
	echo "                 compatibility layer."
	echo " "
	echo "   --enable-cblas, --disable-cblas"
	echo " "
	echo "                 Enable (disabled by default) building the CBLAS"
	echo "                 compatibility layer. This automatically enables the"
	echo "                 BLAS compatibility layer as well."
	echo " "
	echo "   --disable-mixed-dt, --enable-mixed-dt"
	echo " "
	echo "                 Disable (enabled by default) support for mixing the"
	echo "                 storage domain and/or storage precision of matrix"
	echo "                 operands for the gemm operation, as well as support"
	echo "                 for computing in a precision different from one or"
	echo "                 both of matrices A and B."
	echo " "
	echo "   --disable-mixed-dt-extra-mem, --enable-mixed-dt-extra-mem"
	echo " "
	echo "                 Disable (enabled by default) support for additional"
	echo "                 mixed datatype optimizations that require temporarily"
	echo "                 allocating extra memory--specifically, a single m x n"
	echo "                 matrix (per application thread) whose storage datatype"
	echo "                 is equal to the computation datatype. This option may"
	echo "                 only be enabled when mixed domain/precision support is"
	echo "                 enabled."
	echo " "
	echo "   -s NAME --enable-sandbox=NAME"
	echo " "
	echo "                 Enable a separate sandbox implementation of gemm. This"
	echo "                 option disables BLIS's conventional gemm implementation"
	echo "                 (which shares common infrastructure with other level-3"
	echo "                 operations) and instead compiles and uses the code in"
	echo "                 the NAME directory, which is expected to be a sub-"
	echo "                 directory of 'sandbox'. By default, no sandboxes are"
	echo "                 enabled."
	echo " "
	echo "   --with-memkind, --without-memkind"
	echo " "
	echo "                 Forcibly enable or disable the use of libmemkind's"
	echo "                 hbw_malloc() and hbw_free() as substitutes for malloc()"
	echo "                 and free(), respectively, when allocating memory for"
	echo "                 BLIS's memory pools, which are used to manage buffers"
	echo "                 into which matrices are packed. The default behavior"
	echo "                 for this option is environment-dependent; if configure"
	echo "                 detects the presence of libmemkind, libmemkind is used"
	echo "                 by default, and otherwise it is not used by default."
	echo " "
	echo "   -r METHOD, --thread-part-jrir=METHOD"
	echo " "
	echo "                 Request a method of assigning micropanels to threads in"
	echo "                 the JR and IR loops. Valid values for METHOD are 'slab'"
	echo "                 and 'rr'. Using 'slab' assigns (as much as possible)"
	echo "                 contiguous regions of micropanels to each thread while"
	echo "                 using 'rr' assigns micropanels to threads in a round-"
	echo "                 robin fashion. The chosen method also applies during"
	echo "                 the packing of A and B. The default method is 'slab'."
	echo "                 NOTE: Specifying this option constitutes a request,"
	echo "                 which may be ignored in select situations if the"
	echo "                 implementation has a good reason to do so."
	echo " "
	echo "   --force-version=STRING"
	echo " "
	echo "                 Force configure to use an arbitrary version string"
	echo "                 STRING. This option may be useful when repackaging"
	echo "                 custom versions of BLIS by outside organizations."
	echo " "
	echo "   -c, --show-config-lists"
	echo " "
	echo "                 Print the config and kernel lists, and kernel-to-config"
	echo "                 map after they are read from file. This can be useful"
	echo "                 when debugging certain configuration issues, and/or as"
	echo "                 a sanity check to make sure these lists are constituted"
	echo "                 as expected."
	echo " "
	echo "   -q, --quiet   Suppress informational output. By default, configure"
	echo "                 is verbose. (NOTE: -q is not yet implemented)"
	echo " "
	echo "   -h, --help    Output this information and quit."
	echo " "
	echo " Environment Variables:"
	echo " "
	echo "   CC            Specifies the C compiler to use."
	echo "   RANLIB        Specifies the ranlib executable to use."
	echo "   AR            Specifies the archiver to use."
	echo "   CFLAGS        Specifies additional compiler flags to use (prepended)."
	echo "   LDFLAGS       Specifies additional linker flags to use (prepended)."
	echo "   LIBPTHREAD    Pthreads library to use."
	echo "   PYTHON        Specifies the python interpreter to use."
	echo " "
	echo "   Environment variables may also be specified as command line"
	echo "   options, e.g.:"
	echo " "
	echo "     ./configure [options] CC=gcc haswell"
	echo " "
	echo "   Note that not all compilers are compatible with a given"
	echo "   configuration."
	echo " "

	# 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.
#	dlist=\$"$1"
#	ditem=\$"$2"
#
#	# Acquire the contents of $list and $item and store them in list_c
#	# and item_c, respectively.
#	list_c=$(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 "$1=\"${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 [ "x${curline}" = "x" ]; 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]}"
					clist=$(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.
					newclist=$(echo -e "${clist}" | sed -e "s/${mem}/${mems_mem}/g")
					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.
					newklist=$(echo -e "${klisttmp}" | sed -e "s/${ker}/${kers_ker}/g")
					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
}

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 [ $(is_singleton "${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()
{
	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}"
}

select_tool()
{
	local search_list CC_env the_cc cc

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

	# The environment variable associated with the compiler/tool type we
	# are searching (e.g. CC, CXX, PYTHON).
	CC_env=$2

	# If CC_env contains something, add it to the beginning of our default
	# search list.
	if [ -n "${CC_env}" ]; then
		search_list="${CC_env} ${search_list}"
	fi

	# Initialize our selected compiler/tool to empty.
	the_cc=""

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

		# See if the current compiler/tool works and/or is present.
		${cc} --version > /dev/null 2>&1

		if [ "$?" == 0 ]; then
			the_cc=${cc}
			break
		fi
	done

	# Return the selected compiler/tool.
	echo "${the_cc}"
}

auto_detect()
{
	local cc cflags config_defines detected_config rval

	# 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

	# Locate our source files.
	bli_arch_c="bli_arch.c"
	bli_cpuid_c="bli_cpuid.c"
	main_c="config_detect.c"

	bli_arch_c_filepath=$(find ${dist_path}/frame -name "${bli_arch_c}")
	bli_cpuid_c_filepath=$(find ${dist_path}/frame -name "${bli_cpuid_c}")
	main_c_filepath=$(find ${dist_path}/build -name "${main_c}")

	# Locate headers needed directly by the above files.
	bli_arch_h="bli_arch.h"
	bli_cpuid_h="bli_cpuid.h"
	bli_typed_h="bli_type_defs.h"

	bli_arch_h_filepath=$(find ${dist_path}/frame -name "${bli_arch_h}")
	bli_cpuid_h_filepath=$(find ${dist_path}/frame -name "${bli_cpuid_h}")
	bli_typed_h_filepath=$(find ${dist_path}/frame -name "${bli_typed_h}")

	bli_arch_h_path=${bli_arch_h_filepath%/${bli_arch_h}}
	bli_cpuid_h_path=${bli_cpuid_h_filepath%/${bli_cpuid_h}}
	bli_typed_h_path=${bli_typed_h_filepath%/${bli_typed_h}}

	# Locate other headers needed by bli_type_defs.h.
	bli_pthread_h="bli_pthread.h"
	bli_pthread_h_filepath=$(find ${dist_path}/frame -name "${bli_pthread_h}")
	bli_pthread_h_path=${bli_pthread_h_filepath%/${bli_pthread_h}}
	bli_malloc_h="bli_malloc.h"
	bli_malloc_h_filepath=$(find ${dist_path}/frame -name "${bli_malloc_h}")
	bli_malloc_h_path=${bli_malloc_h_filepath%/${bli_malloc_h}}

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

	# Create #defines for all of the BLIS_CONFIG_ macros in bli_cpuid.c.
	config_defines=$(grep BLIS_CONFIG_ ${bli_cpuid_c_filepath} \
	                 | sed -e 's/#ifdef /-D/g')

	# Set the linker flags. We need pthreads 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 [ $is_win = no ]; then
		ldflags="${LIBPTHREAD--lpthread}"
	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).
	${cc} ${config_defines} \
	      -DBLIS_CONFIGURETIME_CPUID \
	      -I${bli_cpuid_h_path} \
	      -I${bli_arch_h_path} \
	      -I${bli_typed_h_path} \
	      -I${bli_pthread_h_path} \
	      -I${bli_malloc_h_path} \
	      -std=c99 -D_GNU_SOURCE \
	      ${cflags} \
	      ${bli_arch_c_filepath} \
	      ${bli_cpuid_c_filepath} \
	      ${ldflags} \
	      ${main_c_filepath} \
	   -o ${autodetect_x}

	# 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.
	${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
}

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}" | egrep -o '[0-9]+\.[0-9]+\.?[0-9]*' | { read 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}" | egrep -o 'icc|gcc|clang|emcc|pnacl|IBM' | { read first rest ; echo $first ; })
	if [ "${cc_vendor}" = "icc" -o \
	     "${cc_vendor}" = "gcc" -o \
	     "${cc_vendor}" = "clang" ]; then
		cc_version=$(${cc} -dumpversion)
	else
		cc_version=$(echo "${vendor_string}" | egrep -o '[0-9]+\.[0-9]+\.?[0-9]*' | { read 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" -a ${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+, clang 3.5+
	#   haswell: any
	#   sandybridge: any
	#   penryn: any
	#
	#   zen: 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
	#
	#   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}."

	# gcc
	if [ "x${cc_vendor}" = "xgcc" ]; 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 ]; 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"
		fi
	fi

	# icc
	if [ "x${cc_vendor}" = "xicc" ]; 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
	fi

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

		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"
				blacklistcc_add "knl"
			fi
			if [ ${cc_minor} -lt 9 ]; then
				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
	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 [ "x${knows_fma4}" == "xno" ]; 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 [ "x${knows_avx}" == "xno" ]; 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 [ "x${knows_fma3}" == "xno" ]; 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 [ "$(uname -s)" == "Darwin" ]; then
		cflags="-Wa,-march=knl"
	fi

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

	if [ "x${knows_avx512f}" == "xno" ]; 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 [ "$(uname -s)" == "Darwin" ]; then
		cflags="-Wa,-march=skylake-avx512"
	fi

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

	if [ "x${knows_avx512dq}" == "xno" ]; then
		blacklistbu_add "skx"
	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.
	${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=$(cat ${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=$(cat "${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=$(cat "${version_file}")
	fi
}



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

	# 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}"

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

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

	# -- configure options --

	# The user-given install prefix and a flag indicating it was given.
	#install_prefix_def="${HOME}/blis"
	install_prefix_user=${HOME}/blis  # default to this directory.
	prefix_flag=''

	# The user-given install libdir and a flag indicating it was given.
	install_libdir_user=''
	libdir_flag=''

	# The user-given install includedir and a flag indicating it was given.
	install_incdir_user=''
	incdir_flag=''

	# The user-given install sharedir and a flag indicating it was given.
	install_sharedir_user=''
	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=''

	# The threading flag.
	threading_model='no'

	# 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_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_memkind='' # The default memkind value is determined later on.
	force_version='no'

	# 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'


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

	found=true
	while $found = true; do

		# Process our command line options.
		unset OPTIND
		while getopts ":hp:d:s:t:r:qci:b:-:" opt; do
			case $opt in
				-)
					case "$OPTARG" in
						help)
							print_usage
							;;
						quiet)
							quiet_flag=1
							;;
						prefix=*)
							prefix_flag=1
							install_prefix_user=${OPTARG#*=}
							;;
						libdir=*)
							libdir_flag=1
							install_libdir_user=${OPTARG#*=}
							;;
						includedir=*)
							incdir_flag=1
							install_incdir_user=${OPTARG#*=}
							;;
						sharedir=*)
							sharedir_flag=1
							install_sharedir_user=${OPTARG#*=}
							;;
						enable-debug)
							debug_flag=1
							debug_type=noopt
							;;
						enable-debug=*)
							debug_flag=1
							debug_type=${OPTARG#*=}
							;;
						disable-debug)
							debug_flag=0
							;;
						enable-verbose-make)
							enable_verbose='yes'
							;;
						disable-verbose-make)
							enable_verbose='no'
							;;
						enable-arg-max-hack)
							enable_arg_max_hack='yes'
							;;
						disable-arg-max-hack)
							enable_arg_max_hack='no'
							;;
						enable-static)
							enable_static='yes'
							;;
						disable-static)
							enable_static='no'
							;;
						enable-shared)
							enable_shared='yes'
							;;
						disable-shared)
							enable_shared='no'
							;;
						enable-threading=*)
							threading_model=${OPTARG#*=}
							;;
						thread-part-jrir=*)
							thread_part_jrir=${OPTARG#*=}
							;;
						disable-threading)
							threading_model='no'
							;;
						enable-pba-pools)
							enable_pba_pools='yes'
							;;
						disable-pba-pools)
							enable_pba_pools='no'
							;;
						enable-sba-pools)
							enable_sba_pools='yes'
							;;
						disable-sba-pools)
							enable_sba_pools='no'
							;;
						enable-mem-tracing)
							enable_mem_tracing='yes'
							;;
						disable-mem-tracing)
							enable_mem_tracing='no'
							;;
						enable-sandbox=*)
							sandbox_flag=1
							sandbox=${OPTARG#*=}
							;;
						disable-sandbox)
							sandbox_flag=0
							;;
						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'
							;;
						with-memkind)
							enable_memkind='yes'
							;;
						without-memkind)
							enable_memkind='no'
							;;
						force-version=*)
							force_version=${OPTARG#*=}
							;;
						show-config-list)
							show_config_list=1
							;;
						*)
							print_usage
							;;
					esac;;
				h)
					print_usage
					;;
				p)
					prefix_flag=1
					install_prefix_user=$OPTARG
					;;
				d)
					debug_flag=1
					debug_type=$OPTARG
					;;
				s)
					sandbox_flag=1
					sandbox=$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 $var=\$value
					export $var
					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 python search order. This may vary based on the os found
	# above.
	python_search_list=$(get_python_search_list)

	echo "${script_name}: python interpeter search list is: ${python_search_list}."

	# Find a working python interpreter.
	found_python=$(select_tool "${python_search_list}" "${PYTHON}")

	# If we didn't find any working python interpreters, we print an error
	# message.
	if [ -z "${found_python}" ]; then
		echo "${script_name}: *** Could not find working python interperter! Cannot continue."
		exit 1
	fi

	echo "${script_name}: using '${found_python}' python interpreter."


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

	# Check the python interpreter's version.
	get_python_version
	check_python


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

	# Acquire the compiler search order. This will vary based on the os found
	# above.
	cc_search_list=$(get_cc_search_list)

	echo "${script_name}: C compiler search list is: ${cc_search_list}."

	# Find a working C compiler.
	found_cc=$(select_tool "${cc_search_list}" "${CC}")

	# If we didn't find any working C compilers, we print an error message.
	if [ -z "${found_cc}" ]; then
		echo "${script_name}: *** Could not find working C compiler! Cannot continue."
		exit 1
	fi

	echo "${script_name}: using '${found_cc}' C compiler."


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

	# Acquire the compiler search order. This will vary based on the os
	# found above.
	cxx_search_list=$(get_cxx_search_list)

	echo "${script_name}: C++ compiler search list is: ${cxx_search_list}."

	# Find a working C++ compiler. NOTE: We can reuse the select_tool()
	# function since it is written in a way that is general-purpose.
	found_cxx=$(select_tool "${cxx_search_list}" "${CXX}")

	# If we didn't find any working C++ compilers, we print an error message.
	if [ -z "${found_cxx}" ]; then
		echo "${script_name}: Could not find working C++ compiler! C++ will not be available in sandbox."
		found_cxx="c++notfound"
	fi

	echo "${script_name}: using '${found_cxx}' C++ compiler (for sandbox only)."


	# -- 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.
	get_compiler_version
	check_compiler

	# 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

	# 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


	# -- 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 [ "x${force_version}" = "xno" ]; then
		echo "${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=$(cat ${so_version_filepath} | sed -n "1p")

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

	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)

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

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

		#echo "${script_name}: manual configuration requested."
		echo "${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.
	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 first name.
		else

			first_config=${configs%% *}
			reducedclist="${first_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 "${script_name}: 'auto-detected configuration '${conf}' is NOT registered!"
			echo "${script_name}: "
			echo "${script_name}: *** Cannot continue with unregistered configuration '${conf}'. ***"
			echo "${script_name}: "
			exit 1;

		else

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

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

	# Set initial (candidate) values for the libdir and includedir using the
	# install prefix that was determined above.
	install_libdir=${install_prefix_user}/lib
	install_incdir=${install_prefix_user}/include
	install_sharedir=${install_prefix_user}/share

	# Set the install libdir, if it was specified. Note that this will override
	# the default libdir implied by the install prefix, even if both options
	# were given.
	if [ -n "${libdir_flag}" ]; then
		echo "${script_name}: detected --libdir='${install_libdir_user}'."
		install_libdir=${install_libdir_user}
	else
		echo "${script_name}: no install libdir option given; defaulting to PREFIX/lib."
	fi

	# Set the install includedir, if it was specified. Note that this will
	# override the default includedir implied by the install prefix, even if
	# both options were given.
	if [ -n "${incdir_flag}" ]; then
		echo "${script_name}: detected --includedir='${install_incdir_user}'."
		install_incdir=${install_incdir_user}
	else
		echo "${script_name}: no install includedir option given; defaulting to PREFIX/include."
	fi

	# Set the install sharedir, if it was specified. Note that this will
	# override the default sharedir implied by the install prefix, even if
	# both options were given.
	if [ -n "${sharedir_flag}" ]; then
		echo "${script_name}: detected --sharedir='${install_sharedir_user}'."
		install_sharedir=${install_sharedir_user}
	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}:   libdir:     ${install_libdir}"
	echo "${script_name}:   includedir: ${install_incdir}"
	echo "${script_name}:   sharedir:   ${install_sharedir}"

	# 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 debug flag was specified.
	if [ -n "${debug_flag}" ]; then
		if [ "x${debug_type}" = "xopt" ]; then
			echo "${script_name}: enabling debug symbols with optimizations."
		elif [ "x${debug_type}" = "xsde" ]; then
			debug_type='sde'
			echo "${script_name}: enabling SDE processor emulation."
		else
			debug_type='noopt'
			echo "${script_name}: enabling debug symbols; optimizations disabled."
		fi
	else
		debug_type='off'
		echo "${script_name}: debug symbols disabled."
	fi

	# Check if the verbose make flag was specified.
	if [ "x${enable_verbose}" = "xyes" ]; then
		echo "${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 [ "x${enable_arg_max_hack}" = "xyes" ]; then
		echo "${script_name}: enabling ARG_MAX hack."
	else
		echo "${script_name}: disabling ARG_MAX hack."
	fi

	enable_shared_01=1
	# Check if the static lib flag was specified.
	if   [ "x${enable_static}" = "xyes" -a "x${enable_shared}" = "xyes" ]; then
		echo "${script_name}: building BLIS as both static and shared libraries."
	elif [ "x${enable_static}" = "xyes" -a "x${enable_shared}" = "xno"  ]; then
		echo "${script_name}: building BLIS as a static library (shared library disabled)."
		enable_shared_01=0
	elif [ "x${enable_static}" = "xno"  -a "x${enable_shared}" = "xyes" ]; then
		echo "${script_name}: building BLIS as a shared library (static library disabled)."
	else
		echo "${script_name}: Both static and shared libraries were disabled."
		echo "${script_name}: *** Please enable one (or both) to continue."
		exit 1
	fi

	# Check the threading model flag and standardize its value, if needed.
	# NOTE: 'omp' is deprecated but still supported; 'openmp' is preferred.
	enable_openmp='no'
	enable_openmp_01=0
	enable_pthreads='no'
	enable_pthreads_01=0
	if [ "x${threading_model}" = "xauto" ]; then
		echo "${script_name}: determining the threading model automatically."
	elif [ "x${threading_model}" = "xopenmp" ] ||
	     [ "x${threading_model}" = "xomp" ]; then
		echo "${script_name}: using OpenMP for threading."
		enable_openmp='yes'
		enable_openmp_01=1
		threading_model="openmp" # Standardize the value.
	elif [ "x${threading_model}" = "xpthreads" ] ||
	     [ "x${threading_model}" = "xpthread" ] ||
	     [ "x${threading_model}" = "xposix" ]; then
		echo "${script_name}: using POSIX threads for threading."
		enable_pthreads='yes'
		enable_pthreads_01=1
		threading_model="pthreads" # Standardize the value.
	elif [ "x${threading_model}" = "xno" ] ||
	     [ "x${threading_model}" = "xnone" ]; then
		echo "${script_name}: threading is disabled."
	else
		echo "${script_name}: *** Unsupported threading model: ${threading_model}."
		exit 1
	fi

	# Check the method of assigning micropanels to threads in the JR and IR
	# loops.
	enable_jrir_slab_01=0
	enable_jrir_rr_01=0
	if [ "x${thread_part_jrir}" = "xslab" ]; then
		echo "${script_name}: requesting slab threading in jr and ir loops."
		enable_jrir_slab_01=1
	elif [ "x${thread_part_jrir}" = "xrr" ]; then
		echo "${script_name}: requesting round-robin threading in jr and ir loops."
		enable_jrir_rr_01=1
	else
		echo "${script_name}: *** Unsupported method of thread partitioning in jr and ir loops: ${threading_model}."
		exit 1
	fi

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

		if [ "x${enable_mixed_dt_extra_mem}" = "xyes" ]; then
			echo "${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

	# Report integer sizes.
	if [ "x${int_type_size}" = "x32" ]; then
		echo "${script_name}: the BLIS API integer size is 32-bit."
	elif [ "x${int_type_size}" = "x64" ]; then
		echo "${script_name}: the BLIS API integer size is 64-bit."
	else
		echo "${script_name}: the BLIS API integer size is automatically determined."
	fi
	if [ "x${blas_int_type_size}" = "x32" ]; then
		echo "${script_name}: the BLAS/CBLAS API integer size is 32-bit."
	elif [ "x${blas_int_type_size}" = "x64" ]; 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 [ "x${blas_int_type_size}" = "x64" -a "x${int_type_size}" = "x32" ]; 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 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


	# 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')
	install_libdir_esc=$(echo   "${install_libdir}"   | sed 's/\//\\\//g')
	install_incdir_esc=$(echo   "${install_incdir}"   | sed 's/\//\\\//g')
	install_sharedir_esc=$(echo "${install_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')
	#sandbox_relpath_esc=$(echo "${sandbox_relpath}" | sed 's/\//\\\//g')

	# For RANLIB, if the variable is not set, we use a default value of
	# 'ranlib'.
	ranlib_esc=$(echo "${RANLIB:-ranlib}" | sed 's/\//\\\//g')
	# For AR, if the variable is not set, we use a default value of 'ar'.
	ar_esc=$(echo "${AR:-ar}" | 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 ]; 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


	# -- 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, bli_config.h files from templates --------------

	# Begin substituting information into the config_mk_in file, outputting
	# to config_mk_out.
	echo "${script_name}: creating ${config_mk_out_path} from ${config_mk_in_path}"
	cat "${config_mk_in_path}" \
		| sed -e "s/@version@/${version_esc}/g" \
		| sed -e "s/@so_version_major@/${so_version_major}/g" \
		| sed -e "s/@so_version_minorbuild@/${so_version_minorbuild}/g" \
		| sed -e "s/@config_name@/${config_name}/g" \
		| sed -e "s/@config_list@/${config_list}/g" \
		| sed -e "s/@kernel_list@/${kernel_list}/g" \
		| sed -e "s/@kconfig_map@/${kconfig_map}/g" \
		| sed -e "s/@os_name@/${os_name_esc}/g" \
		| sed -e "s/@is_win@/${is_win}/g" \
		| sed -e "s/@dist_path@/${dist_path_esc}/g" \
		| sed -e "s/@CC_VENDOR@/${cc_vendor}/g" \
		| sed -e "s/@CC@/${cc_esc}/g" \
		| sed -e "s/@CXX@/${cxx_esc}/g" \
		| sed -e "s/@RANLIB@/${ranlib_esc}/g" \
		| sed -e "s/@AR@/${ar_esc}/g" \
		| sed -e "s/@libpthread@/${libpthread_esc}/g" \
		| sed -e "s/@cflags_preset@/${cflags_preset_esc}/g" \
		| sed -e "s/@ldflags_preset@/${ldflags_preset_esc}/g" \
		| sed -e "s/@debug_type@/${debug_type}/g" \
		| sed -e "s/@threading_model@/${threading_model}/g" \
		| sed -e "s/@install_libdir@/${install_libdir_esc}/g" \
		| sed -e "s/@install_incdir@/${install_incdir_esc}/g" \
		| sed -e "s/@install_sharedir@/${install_sharedir_esc}/g" \
		| sed -e "s/@enable_verbose@/${enable_verbose}/g" \
		| sed -e "s/@configured_oot@/${configured_oot}/g" \
		| sed -e "s/@enable_arg_max_hack@/${enable_arg_max_hack}/g" \
		| sed -e "s/@enable_static@/${enable_static}/g" \
		| sed -e "s/@enable_shared@/${enable_shared}/g" \
		| sed -e "s/@enable_blas@/${enable_blas}/g" \
		| sed -e "s/@enable_cblas@/${enable_cblas}/g" \
		| sed -e "s/@enable_memkind@/${enable_memkind}/g" \
		| sed -e "s/@pragma_omp_simd@/${pragma_omp_simd}/g" \
		| sed -e "s/@sandbox@/${sandbox}/g" \
		> "${config_mk_out_path}"
		

	# 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 ${bli_config_h_in_path}"
	cat "${bli_config_h_in_path}" \
		| perl -pe "s/\@config_name_define\@/${config_name_define}/g" \
		| perl -pe "s/\@config_list_defines\@/${config_list_defines}/g" \
		| perl -pe "s/\@kernel_list_defines\@/${kernel_list_defines}/g" \
		| sed   -e "s/@enable_openmp@/${enable_openmp_01}/g" \
		| sed   -e "s/@enable_pthreads@/${enable_pthreads_01}/g" \
		| sed   -e "s/@enable_jrir_slab@/${enable_jrir_slab_01}/g" \
		| sed   -e "s/@enable_jrir_rr@/${enable_jrir_rr_01}/g" \
		| sed   -e "s/@enable_pba_pools@/${enable_pba_pools_01}/g" \
		| sed   -e "s/@enable_sba_pools@/${enable_sba_pools_01}/g" \
		| sed   -e "s/@enable_mem_tracing@/${enable_mem_tracing_01}/g" \
		| sed   -e "s/@int_type_size@/${int_type_size}/g" \
		| sed   -e "s/@blas_int_type_size@/${blas_int_type_size}/g" \
		| sed   -e "s/@enable_blas@/${enable_blas_01}/g" \
		| sed   -e "s/@enable_cblas@/${enable_cblas_01}/g" \
		| sed   -e "s/@enable_mixed_dt@/${enable_mixed_dt_01}/g" \
		| sed   -e "s/@enable_mixed_dt_extra_mem@/${enable_mixed_dt_extra_mem_01}/g" \
		| sed   -e "s/@enable_memkind@/${enable_memkind_01}/g" \
		| sed   -e "s/@enable_pragma_omp_simd@/${enable_pragma_omp_simd_01}/g" \
		| sed   -e "s/@enable_sandbox@/${enable_sandbox_01}/g" \
		| sed   -e "s/@enable_shared@/${enable_shared_01}/g" \
		> "${bli_config_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}"

	#echo "${script_name}: creating ${obj_config_dirpath}"
	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}"

	#echo "${script_name}: creating ${obj_kernels_dirpath}"
	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}"

	#echo "${script_name}: creating ${obj_refkern_dirpath}"
	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 "${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 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 ------------------------------------------

	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

		echo "${script_name}: creating makefile fragments in ${obj_config_dirpath}/${config_name}"
		${gen_make_frags_sh} \
				 -h -r -v0 \
				 -o ${script_name} \
				 -p 'CONFIG' \
				 ${config_dirpath}/${config_name} \
				 ${obj_config_dirpath}/${config_name} \
				 ${gen_make_frags_dirpath}/fragment.mk \
				 ${gen_make_frags_dirpath}/suffix_list \
				 ${gen_make_frags_dirpath}/ignore_list
	fi

	# Generate makefile fragments for each of the sub-configurations present
	# in the configuration list.
	for conf in ${config_list}; do

		echo "${script_name}: creating makefile fragments in ${obj_config_dirpath}/${conf}"
		${gen_make_frags_sh} \
				 -h -r -v0 \
				 -o ${script_name} \
				 -p 'CONFIG' \
				 ${config_dirpath}/${conf} \
				 ${obj_config_dirpath}/${conf} \
				 ${gen_make_frags_dirpath}/fragment.mk \
				 ${gen_make_frags_dirpath}/suffix_list \
				 ${gen_make_frags_dirpath}/ignore_list
	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

		echo "${script_name}: creating makefile fragments in ${obj_kernels_dirpath}/${kern}"
		${gen_make_frags_sh} \
				 -h -r -v0 \
				 -o ${script_name} \
				 -p 'KERNELS' \
				 ${kernels_dirpath}/${kern} \
				 ${obj_kernels_dirpath}/${kern} \
				 ${gen_make_frags_dirpath}/fragment.mk \
				 ${gen_make_frags_dirpath}/suffix_list \
				 ${gen_make_frags_dirpath}/ignore_list
	done

	# Generate makefile fragments in the reference kernels directory.
	echo "${script_name}: creating makefile fragments in ${obj_refkern_dirpath}"
	${gen_make_frags_sh} \
			 -h -r -v0 \
			 -o ${script_name} \
			 -p 'REFKERN' \
			 ${refkern_dirpath} \
			 ${obj_refkern_dirpath} \
			 ${gen_make_frags_dirpath}/fragment.mk \
			 ${gen_make_frags_dirpath}/suffix_list \
			 ${gen_make_frags_dirpath}/ignore_list

	# Generate makefile fragments in the framework directory.
	echo "${script_name}: creating makefile fragments in ${obj_frame_dirpath}"
	${gen_make_frags_sh} \
			 -h -r -v0 \
			 -o ${script_name} \
			 -p 'FRAME' \
			 ${frame_dirpath} \
			 ${obj_frame_dirpath} \
			 ${gen_make_frags_dirpath}/fragment.mk \
			 ${gen_make_frags_dirpath}/suffix_list \
			 ${gen_make_frags_dirpath}/ignore_list

	# Generate makefile fragments in the sandbox sub-directory.
	if [ -n "${sandbox_flag}" ]; then

		echo "${script_name}: creating makefile fragments in ${obj_sandbox_dirpath}/${sandbox}"
		${gen_make_frags_sh} \
				 -h -r -v0 \
				 -o ${script_name} \
				 -p 'SANDBOX' \
				 ${sandbox_dirpath}/${sandbox} \
				 ${obj_sandbox_dirpath}/${sandbox} \
				 ${gen_make_frags_dirpath}/fragment.mk \
				 ${gen_make_frags_dirpath}/suffix_list \
				 ${gen_make_frags_dirpath}/ignore_list
	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

		# If 'Makefile' 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 "./Makefile" ]; then

			echo "${script_name}: creating symbolic link to Makefile."
			ln -s "${dist_path}/Makefile"

		elif [ -h "./Makefile" ]; then
			echo "${script_name}: symbolic link to Makefile already exists; forcing creation of new link."
			ln -sf "${dist_path}/Makefile"
		else
			echo "${script_name}: Non-symbolic link file or directory 'Makefile' blocks creation of symlink."
			echo "${script_name}: *** Please remove this entity and re-run configure."
			exit 1
		fi

		# If 'common.mk' 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 "./common.mk" ]; then

			echo "${script_name}: creating symbolic link to common.mk."
			ln -s "${dist_path}/common.mk"

		elif [ -h "./common.mk" ]; then
			echo "${script_name}: symbolic link to common.mk already exists; forcing creation of new link."
			ln -sf "${dist_path}/common.mk"
		else
			echo "${script_name}: Non-symbolic link file or directory 'common.mk' blocks creation of symlink."
			echo "${script_name}: *** Please remove this entity and re-run configure."
			exit 1
		fi

		# If 'config' 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 "./config" ]; then

			echo "${script_name}: creating symbolic link to 'config' directory."
			ln -s "${dist_path}/config"

		elif [ -h "./config" ]; then
			echo "${script_name}: symbolic link to 'config' directory already exists; forcing creation of new link."
			ln -sf "${dist_path}/config"
		else
			echo "${script_name}: Non-symbolic link file or directory 'config' blocks creation of symlink."
			echo "${script_name}: *** Please remove this entity and re-run configure."
			exit 1
		fi

		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


	# Exit peacefully.
	return 0
}


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