
usage: ./configure [ variable=value ]...

This configure script generates the file 'makefile' and the file
'../include/NTL/config.h', based upon the values assigned to the
variables on the command line.

Note that all of these configuration options can also be set 
by editing these two (well documented) files by hand.

This command is intended only to provide a slightly more convenient
and (perhaps more importantly) non-interactive way to do this.
This script does not perform any 'magic', like finding out what
the local C compiler is called, etc.  If the defaults are not
correct for your platform, you have to set an appropriate variable.


########### Here are the most important variables, and their default values.

CXX=g++              # The C++ compiler

CXXFLAGS=-g -O2      # C++ complilation flags

NATIVE=on            # compiles code targeted to current hardware

DEF_PREFIX=/usr/local# Default software directory

PREFIX=$(DEF_PREFIX) # Directory in which to install NTL library components
SHARED=off           # Generate a shared library (as well as static)

NTL_THREADS=off      # compile in thread-safe mode
NTL_THREAD_BOOST=off # compile with thread boosting enabled
NTL_EXCEPTIONS=off   # compile in exception-safe mode

NTL_GMP_LIP=on       # Switch to enable the use of GMP as primary 
                     #   long integer package

GMP_PREFIX=$(DEF_PREFIX) # Directory in which GMP components are installed


NTL_GF2X_LIB=off     # Switch to enable the use of the gf2x package
                     #   for faster arithmetic over GF(2)[X]

GF2X_PREFIX=$(DEF_PREFIX) # Directory in which gf2x components are installed


########## Here are more detailed description of these variables.

########## Basic compilation variables:

CXX=g++

# A C++ compiler, e.g., g++, CC, xlC
# Note that NTL appends a ".c" siffix to both C and C++ files,
# so you must, for example, use g++ (rather than gcc) as your C++ 
# compiler.



CXXFLAGS=-g -O2

# Flags for the C++ compiler. 


NATIVE=on

# Flag to target code to current hardware.



########## Installation path:

DEF_PREFIX=/usr/local

# Default software directory

PREFIX=$(DEF_PREFIX)

# Set this to the directory in which you want NTL components to be
# installed.  When 'make install' is executed, the header
# files are copied into $(PREFIX)/include/NTL, the library itself is
# copied to $(PREFIX)/lib/libntl.a, and the documentation files
# are copied into $(PREFIX)/share/doc/NTL.
# Unless you have root permissions when running 'make install',
# you will have to override the default PREFIX value with the
# name of your own local directory.
# If you want finer-grained control over where the different
# library components are installed, set the variables 
# INCLUDEDIR, LIBDIR, and DOCDIR (see below).

########## Shared library switch:

SHARED=off

# Set this to 'on' if you want to generate a shared library, in addition to
# a static library.   Shared libraries have many advantages, but
# unfortunately, their use is rather less portable than that of good,
# old-fashioned static libraries.  If you set SHARED=on, then the makefile
# attempts to make use of the GNU libtool program, which is meant to work
# around these portability issues.  You may also want to set the
# configuration variable LIBTOOL (see below), to point to another version of
# libtool.  For example, on Mac OSX, the built-in command libtool is not
# actually the GNU libtool program; in this case, you will want to set
# LIBTOOL=glibtool.  On other systems, it may be necssary to downlaod and
# install a fresh copy of the libtool program (which can be obtained from
# http://www.gnu.org/software/libtool). Note that if SHARED=on, then 
# in addition to using the libtool program, the makefile relies on
# features specific to GNU make.


########## thread safety

NTL_THREADS=off

# Set to 'on' if you want to compile NTL in thread-safe mode.
# This requires several C++11 features, including atomic types,
# mutexes, and thread_local storage.  Your compiler may not
# yet support these features.

# Note that this option is currently only supported with
# NTL_GMP_LIP=on.

########## thread boosting

NTL_THREAD_BOOST=off

# Set to 'on' if you want to compile NTL so that is does
# certain internal computations using multiple threads.
# Setting this flag automatically sets the NTL_THREADS flag.
# This feature is a work in progress.  See documentation in
# BasicThreadPool.txt for more details.

########## exceptions

NTL_EXCEPTIONS=off

# Set to 'on' if you want to compile NTL with exceptions enabled.
# This requires several C++11 features, including lambdas
# and the new rules for exception specifications.
# Your compiler may not yet support these feautures.

########## GMP variables:

NTL_GMP_LIP=on

# Set to 'off' if you don't want to use GMP, the GNU Multi-Precision package,
# as the primary long integer package.
# This will lead to significantly slower code, and is not 
# recommended.


GMP_PREFIX=$(DEF_PREFIX)

# If GMP was installed in a standard system directory, e.g., /usr/local,
# then do not set this variable.
# Otherwise, if you want to use GMP and GMP was installed in
# a directory <gmp_prefix>, then set GMP_PREFIX=<gmp_prefix>.
# This works if the directory <gmp_prefix>/include contains gmp.h
# and <gmp_prefix>/lib contains libgmp.a.  
# For finer-grained control, set the variables GMP_INCDIR and GMP_LIBDIR 
# instead (see below).


########## GF2X variables:

NTL_GF2X_LIB=off

# Set to 'on' if you want to use the gf2x library for faster
# arithmetic over GF(2)[X] (the NTL class GF2X).

# If you set this flag, please note the following.
# If you have installed gf2x in a standard "system" location, this is
# all you have to do.  Otherwise, if gf2x is built, but not installed
# in a standard place, you have to set the variable GF2X_PREFIX.


GF2X_PREFIX=$(DEF_PREFIX)

# If gf2x was installed in a standard system directory, e.g., /usr/local,
# then do not set this variable.
# Otherwise, if you want to use gf2x and gf2x was installed in
# a directory <gf2x_prefix>, then set GF2X_PREFIX=<gf2x_prefix>.
# This works if the directory <gf2x_prefix>/include contains gf2x.h
# and <gf2x_prefix>/lib contains libgf2x.a.  
# For finer-grained control, set the variables GF2X_INCDIR and GF2X_LIBDIR 
# instead (see below).



########### Examples:

# If you are happy with all the default values:

   ./configure

# Actually, the initially installed makefile and config.h files
# already reflect the default values. 




# If your C++ compiler is called CC:

   ./configure CXX=CC




# If GMP was installed in a non-standard directory, say,  $HOME/sw:

   ./configure GMP_PREFIX=$HOME/sw 


# If you want to use the options -g and -O for compiling C++,
# just execute

   ./configure "CXXFLAGS=-g -O"

# Note the use of quotes to keep the argument in one piece.


# If you want to use the gf2x library:

   ./configure NTL_GF2X_LIB=on



########### 
########### A little magic
###########

CXXAUTOFLAGS=

# This is a variable that is automagically set by the configuration script.
# These are C++ compiler flags that are selected depending on
# the choice of other configuration options, and is geared towards gcc.
# The configuration script always prints out the value it chooses.
# If you explicitly set a value when invoking the configuration script,
# then it will not change that value.



########### Here is a complete list of the remaining variables,
########### with their default values.  These variables are pretty 
########### esoteric, and you will probably never change their
########### default values.

AR=ar
ARFLAGS=ruv
RANLIB=ranlib
LDFLAGS=
LDLIBS=-lm
CPPFLAGS=
LIBTOOL=libtool

LIBDIR=$(PREFIX)/lib
INCLUDEDIR=$(PREFIX)/include
DOCDIR=$(PREFIX)/share/doc

NTL_DISABLE_TLS_HACK=off
NTL_ENABLE_TLS_HACK=off

NTL_LEGACY_NO_NAMESPACE=off
NTL_LEGACY_INPUT_ERROR=off

NTL_LEGACY_SP_MULMOD=off

NTL_UNSIGNED_LONG_LONG_TYPE=undefined
NTL_CLEAN_INT=off
NTL_CLEAN_PTR=off
NTL_RANGE_CHECK=off
NTL_X86_FIX=off
NTL_NO_X86_FIX=off
NTL_NO_INIT_TRANS=off
NTL_DISABLE_LONGDOUBLE=off
NTL_DISABLE_LONGLONG=off
NTL_DISABLE_LL_ASM=off
NTL_MAXIMIZE_SP_NBITS=off

WIZARD=on
NTL_SPMM_ULL=off
NTL_SPMM_ASM=off
NTL_FFT_BIGTAB=off
NTL_FFT_LAZYMUL=off
NTL_TBL_REM=off
NTL_AVOID_BRANCHING=off
NTL_GF2X_NOINLINE=off
NTL_GF2X_ALTCODE=off
NTL_GF2X_ALTCODE1=off
NTL_PCLMUL=off

GMP_INCDIR=$(GMP_PREFIX)/include
GMP_LIBDIR=$(GMP_PREFIX)/lib

GF2X_INCDIR=$(GF2X_PREFIX)/include
GF2X_LIBDIR=$(GF2X_PREFIX)/lib




########### Here is a more detailed description of these variables.

########### Further compilation variables:


AR=ar

# command to make a library



ARFLAGS=ruv

# arguments for AR



RANLIB=ranlib

# set to echo if you want to disable it completely



LDFLAGS=

# arguments for linker for C++ programs




LDLIBS=-lm

# libraries for linking C++ programs



CPPFLAGS=

# arguments for the C preprocessor

LIBTOOL=libtool

# the libtool command -- only needed if SHARED=on




########### Details of the compilation process (when SHARED=off)


# When a C++ file foo.c is compiled:
   $(CXX) -I../include $(CPPFLAGS) $(CXXFLAGS) -c foo.c

# When a C++ file foo.c is compiled and linked:
   $(CXX) -I../include $(CPPFLAGS) $(CXXFLAGS) $(LDFLAGS) \ 
      -o foo foo.c $(LDLIBS)

# When the library ntl.a is built
   $(AR) $(ARFLAGS) ntl.a [ object files ]...
   $(RANLIB) ntl.a
# If the ranlib command does not exist, everything will still function OK.



########### Further installation variables:

LIBDIR=$(PREFIX)/lib
INCLUDEDIR=$(PREFIX)/include
DOCDIR=$(PREFIX)/share/doc
# Where to install NTL.
# Execution of 'make install' copies header files into $(INCLUDEDIR)/NTL,
# copies the library itself to $(LIBDIR)/libntl.a, and copies the
# documentation files into $(DOCDIR)/NTL.

########## Disable/enable TLS hack

NTL_DISABLE_TLS_HACK=off
NTL_ENABLE_TLS_HACK=off

# when building NTL with NTL_THREADS=on, if the compiler is gcc-compatible, a
# "TLS hack" may be used to workaround the fact that many compilers do not
# (correctly) implement C++11's thread_local feature.  The workaround is to use
# gcc's more limited __thread feature, and to emulate thread_local semantics
# using pthread routines.
# 
# "gcc-compatible" means that the "__GNUC__" macro is defined, which means the
# TLS hack may be used for gcc, clang, and icc compilers.  The current version
# of NTL will enable this hack by default, but you can disable it by specifying
# NTL_DISABLE_TLS_HACK=on.  At some point in the future, this default behavior
# may change, in which case you will still be able to force the TLS hack by
# specifying NTL_ENABLE_TLS_HACK=on.






########## Legacy switches

NTL_LEGACY_NO_NAMESPACE=off 

# put NTL components in the global namespace



NTL_LEGACY_INPUT_ERROR=off
 
# abort on input errors, instead of just setting the
# "fail bit" of the istream object

NTL_LEGACY_SP_MULMOD=off

# use pre-9.0 interfaces for single-precision MulMod routines.
# See discussion in ZZ.txt for details.



########### Basic Configuration Options:

NTL_UNSIGNED_LONG_LONG_TYPE=undefined

# Name of double-word unsigned integer type.
# This is a non-standard type, and is called 'long long' by many
# compilers.  MS C++ calls it 'unsigned __int64'.
#
# Note that the new C99 standard defines the type 'unsigned long long'
# to be at least 64-bits wide.  On 32-bit machines, this is just right.
# Although not officially part of the C++ standard (which predates C99),
# it is widely supported by C++ compilers, and is likely to be added
# to the C++ standard.
#
# Unfortunately, 64-bit machines usually define 'unsigned long long'
# to also be 64-bits wide, which is kind of useless.
# However, GCC provides a type __uint128_t which does the job.
#
# If left undefined, NTL will use some "ifdef magic" to find
# the type most suitable for your machine (based on compiler and
# word size).



NTL_CLEAN_INT=off

# Setting this to 'on' disables the use of some non-standard
# integer arithmetic which would yield slightly better performance.


NTL_CLEAN_PTR=off

# Setting this to 'on' disables the use of some non-standard
# pointer arithmetic which would yield slightly better performance.


NTL_RANGE_CHECK=off

# Setting this to 'on' will generate vector subscript range-check code.
# Useful for debugging, but it slows things down of course.



NTL_X86_FIX=off

# Set to 'on' to force the "x86 floating point fix", 
# overriding the default behavior.
# By default, NTL will apply the "fix" if it looks like it is
# necessary, and if it knows how to fix it.
# The problem addressed here is that x86 processors sometimes
# run in a mode where FP registers have more precision than doubles.
# This will cause code in quad_float.c some trouble.
# NTL can normally automatically detect the problem, and fix it,
# so you shouldn't need to worry about this or the next flag.



NTL_NO_X86_FIX=off

# Set to 'on' to forces no "x86 floating point fix", 
# overriding the default behavior.



NTL_NO_INIT_TRANS=off

# When 'off', NTL uses a special code sequence to avoid
# copying large objects in return statements.  However, if your
# compiler optimizes away the return of a *named* local object,
# this is not necessary, and setting this flag to 'on' will result
# in *slightly* more compact and efficient code.  The C++
# standard explicitly allows compilers to perform this optimization,
# and with time, more compilers actually do this.
# Traditionally, however, most will only avoid copying *temporary* 
# objects in return statements, and NTL's default code sequence 
# exploits this fact.



NTL_DISABLE_LONGDOUBLE=off

# Explicitly disables use of long double arithmetic 

NTL_DISABLE_LONGLONG=off

# Explicitly disables use of long long arithmetic 

NTL_DISABLE_LL_ASM=off

# Explicitly disables use of inline asm as replacement for
# long long arithmetic

NTL_MAXIMIZE_SP_NBITS=on

# Allows for 62-bit single-precision moduli on 64-bit platforms.
# By default, such moduli are restricted to 60 bits, which
# usually gives *slightly* better performance across a range of
# of parameters.





########## Performance Options:

WIZARD=on

# Set to 'off' if you want to bypass the wizard; otherwise, set to 'on'.
# The wizard is a script that runs when NTL is built that sets the following
# flags to 'optimize' performance on the current platform.



NTL_SPMM_ULL=off

# Implement the MulModPrecon code using "unsigned long long"
# (or specify NTL_UNSIGNED_LONG_LONG_TYPE to override the default).


NTL_SPMM_ASM=off

# Similar to NTL_SPMM_ULL, but relies on double-word unsigned multiplication
# using assembly code.  Only supported on select machines 
# and only under GCC.

NTL_FFT_BIGTAB=off

# Precomputed tables are used to store all the roots of unity
# used in FFT computations.


NTL_FFT_LAZYMUL=off

# This flag only has an effect when combined with 
# either the NTL_SPMM_ULL or NTL_SPMM_ASM flags. 
# When set, a "lazy multiplication" strategy due to David Harvey:
# see his paper "FASTER ARITHMETIC FOR NUMBER-THEORETIC TRANSFORMS".



NTL_TBL_REM=off

# With this flag, some divisions are avoided in the
# ZZ_pX multiplication routines.  



NTL_AVOID_BRANCHING=off

# With this option, branches are replaced at several
# key points with equivalent code using shifts and masks.
# Recommended for use with RISC architectures, especially
# ones with deep pipelines and high branch penalities.
# This flag is becoming less helpful as newer machines
# have much smaller branch penalties, but still may be worth a try.




NTL_GF2X_NOINLINE=off

# By default, the low-level GF2X multiplication routine in inlined.
# This can potentially lead to some trouble on some platforms,
# and you can override the default by setting this flag.




NTL_GF2X_ALTCODE=off

# With this option, the default strategy for implmenting low-level
# GF2X multiplication is replaced with an alternative strategy.
# This alternative strategy seems to work better on RISC machines
# with deep pipelines and high branch penalties (like a powerpc),
# but does no better (or even worse) on x86s.


NTL_GF2X_ALTCODE1=off

# Yet another alternative implementation for GF2X multiplication.

NTL_PCLMUL=off 

# switch to enable the PCLMUL instruction on x86 machines for faster arithmetic
# over GF(2)[X] (without relying on the gf2x package)



########## More GMP Options:


GMP_INCDIR=$(GMP_PREFIX)/include
# directory containing gmp.h

GMP_LIBDIR=$(GMP_PREFIX)/lib
# directory containing libgmp.a


####### More gf2x options:

GF2X_INCDIR=$(GF2X_PREFIX)/include
# directory containing gf2x.h

GF2X_LIBDIR=$(GF2X_PREFIX)/lib
# directory containing libgf2x.a

