Sort out various issues with compilation flags

Also add ability to disable optimizations and add debugging flags


Former-commit-id: 3064d197009712af27b78692a93a353b6ff668fa

INSTALL.swift

+
+                                Building SWIFT
+                                ==============
+
+SWIFT is built from a clean source repository using the commands:
+
+   ./autogen
+   ./configure
+   make
+
+and from a distribution tarball using:
+
+   ./configure
+   make
+
+The compiler choice is GCC by default, but that can be changed using the "CC"
+environment variable. This can be just set, or passed on the ./configure
+command line, i.e.:
+
+   bash:
+      export CC=icc
+      ./configure
+
+   [t]csh:
+      setenv CC=icc
+      ./configure
+
+or:
+
+   ./configure CC=icc
+
+to use an Intel compiler. The main "programs" can be found in the "examples/"
+directory.
+
+By default an attempt to choose suitable set of optimizing compiler flags
+will be made, targetted for the host machine of the build. If this doesn't
+work or the binaries will for another architecture then you can stop the
+selection of flags using:
+
+   ./configure --disable-optimization
+
+and then supply your own flags using the "CFLAGS" environment variable, as for
+CC.
+
+Note that any CFLAGS that you supply will be added to those determined by
+configure in all circumstances. To build SWIFT with debugging support you
+can use:
+
+    ./configure --enable-debug --disable-optimization
+
+You could also add some additional flags:
+
+    ./configure --enable-debug --disable-optimization CFLAGS="-O2"
+
+for instance.
+
+Dependencies: needs to be filled in...
+
+
+    
+
+
+

configure.ac

 
 # This file is part of SWIFT.
-# Coypright (c) 2012 pedro.gonnet@durham.ac.uk.
+# Copyright (C) 2012 pedro.gonnet@durham.ac.uk.
 #
 # This program is free software: you can redistribute it and/or modify
 # it under the terms of the GNU General Public License as published by
@@ -15,25 +15,33 @@
 # You should have received a copy of the GNU General Public License
 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
-# init the project
+# Init the project.
 AC_INIT([SWIFT],[0.1.0])
 AC_CONFIG_SRCDIR([src/space.c])
 AM_INIT_AUTOMAKE
-AC_USE_SYSTEM_EXTENSIONS
-
-LT_INIT
 
-# my own macro collection
+# Add local macro collection.
 AC_CONFIG_MACRO_DIR([m4])
 
-# generate header file
+# Stop default CFLAGS from anyone except the environment.
+: ${CFLAGS=""}
+
+# Generate header file.
 AM_CONFIG_HEADER(config.h)
 
-# find and test the compiler
+# Find and test the compiler.
+AX_CHECK_ENABLE_DEBUG
 AC_PROG_CC
 AM_PROG_CC_C_O
 
-# Check for MPI. Need to do this before characterising the compiler (C99 mode).
+# Enable POSIX and platform extension preprocessor macros.
+AC_USE_SYSTEM_EXTENSIONS
+
+# Add libtool support.
+LT_INIT
+
+# Check for MPI. Need to do this before characterising the compiler (C99 mode),
+# as this changes the compiler.
 AC_ARG_ENABLE([mpi],
     [AS_HELP_STRING([--enable-mpi],[compile with functionality for distributed-memory parallelim using MPI @<:@default=yes@:>@])],
     [if test "x$enable_mpi" != "xno"
@@ -43,28 +51,51 @@ AC_ARG_ENABLE([mpi],
     [ACX_MPI([ CC="$MPICC" AC_DEFINE(HAVE_MPI,1,[Define if you have the MPI library.]) ])])
 AM_CONDITIONAL([HAVEMPI],[test -n "$MPICC"])
 
+# Need C99 and inline support.
 AC_PROG_CC_C99
 AC_C_INLINE
 
-AX_CC_MAXOPT
+# Define HAVE_POSIX_MEMALIGN if it works.
 AX_FUNC_POSIX_MEMALIGN
-AX_GCC_ARCHFLAG([no])
 
-#  Check SSE & AVX support.
-AX_EXT
-if test "$SIMD_FLAGS" != ""; then
-   CFLAGS="$CFLAGS $SIMD_FLAGS"
+#  Only optimize if allowed, otherwise assume user will set CFLAGS as
+#  appropriate. 
+AC_ARG_ENABLE(optimization,
+  [AC_HELP_STRING(
+    [--enable-optimization],
+    [Enable compile time optimization flags for host @<:@default=yes@:>@]
+  )],
+  [enable_opt="$enableval"],
+  [enable_opt="yes"]
+)
+
+if test "${enable_opt}" = "yes" ; then
+
+   # Add code optimisation flags and tuning to host. This is a funny macro
+   # that does not like CFLAGS being already set. Work around that as we have
+   # at least set it to "", so it is set.
+   ac_test_CFLAGS="no"
+   old_CFLAGS="$CFLAGS"
+   AX_CC_MAXOPT
+   ac_test_CFLAGS="yes"
+   CFLAGS="$old_CFLAGS $CFLAGS"
+
+   # Check SSE & AVX support (some overlap with AX_CC_MAXOPT).
+   AX_EXT
+   if test "$SIMD_FLAGS" != ""; then
+       CFLAGS="$CFLAGS $SIMD_FLAGS"
+   fi
 fi
 
-# autoconf stuff
+# Autoconf stuff.
 AC_PROG_INSTALL
 AC_PROG_MAKE_SET
 AC_HEADER_STDC
 
-# check for the libraries we will need
+# Check for the libraries we will need.
 AC_CHECK_LIB(m,sqrt,,AC_MSG_ERROR(something is wrong with the math library!))
 
-# Check for pthreads
+# Check for pthreads.
 ACX_PTHREAD([LIBS="$PTHREAD_LIBS $LIBS" CFLAGS="$CFLAGS $PTHREAD_CFLAGS"
     CC="$PTHREAD_CC" LDFLAGS="$PTHREAD_LIBS $LIBS"],
     AC_MSG_ERROR([Could not find a working version of
@@ -73,7 +104,7 @@ ACX_PTHREAD([LIBS="$PTHREAD_LIBS $LIBS" CFLAGS="$CFLAGS $PTHREAD_CFLAGS"
     non-standard location.]))
 
 
-# Check for OpenMP
+# Check for OpenMP.
 AC_OPENMP
 AC_SUBST(OPENMP_CFLAGS)
 if test -z "${OPENMP_CFLAGS}"; then
@@ -83,7 +114,7 @@ else
    CFLAGS="$CFLAGS $OPENMP_CFLAGS"
 fi
 
-# Check for metis
+# Check for metis.
 AC_ARG_WITH([metis],
     [AS_HELP_STRING([--with-metis=PATH],[prefix where the metis library is installed @<:@default=yes@:>@])],
     [if test "x$with_metis" != "xno"
@@ -102,39 +133,44 @@ AC_SUBST(METIS_LDFLAGS)
 AM_CONDITIONAL([HAVEMETIS],[test -n "$METIS_LDFLAGS"])
 
 
-# check for zlib
+# Check for zlib.
 AC_CHECK_LIB(z,gzopen,[
     AC_DEFINE([HAVE_LIBZ],[1],[Set to 1 if zlib is installed.])
     LDFLAGS="$LDFLAGS -lz"
     ],[])
 
 
-# Check for HDF5
-AX_LIB_HDF5()
+# Check for HDF5.
+AX_LIB_HDF5
 
-# check for setaffinity
+# Check for setaffinity.
 AC_CHECK_FUNC( pthread_setaffinity_np , AC_DEFINE([HAVE_SETAFFINITY],[true],
     [Defined if pthread_setaffinity_np exists.]) )
 
-# Check for timing functions needed by cycle.h
+# Check for timing functions needed by cycle.h.
 AC_HEADER_TIME
 AC_CHECK_HEADERS([sys/time.h c_asm.h intrinsics.h mach/mach_time.h])
-AC_CHECK_TYPE([hrtime_t],[AC_DEFINE(HAVE_HRTIME_T, 1, [Define to 1 if hrtime_t is defined in <sys/time.h>])],,[#if HAVE_SYS_TIME_H
+AC_CHECK_TYPE([hrtime_t],[AC_DEFINE(HAVE_HRTIME_T, 1, [Define to 1 if hrtime_t
+is defined in <sys/time.h>])],,
+[#if HAVE_SYS_TIME_H
 #include <sys/time.h>
 #endif])
 AC_CHECK_FUNCS([gethrtime read_real_time time_base_to_time clock_gettime mach_absolute_time])
 AC_MSG_CHECKING([for _rtc intrinsic])
 rtc_ok=yes
-AC_LINK_IFELSE([AC_LANG_PROGRAM([[#ifdef HAVE_INTRINSICS_H
+AC_LINK_IFELSE([AC_LANG_PROGRAM(
+[[#ifdef HAVE_INTRINSICS_H
 #include <intrinsics.h>
-#endif]], [[_rtc()]])],[AC_DEFINE(HAVE__RTC,1,[Define if you have the UNICOS _rtc() intrinsic.])],[rtc_ok=no])
+#endif]], 
+[[_rtc()]])],
+[AC_DEFINE(HAVE__RTC,1,[Define if you have the UNICOS _rtc() intrinsic.])],[rtc_ok=no])
 AC_MSG_RESULT($rtc_ok)
 
-# make the documentation
+# Make the documentation.
 DX_INIT_DOXYGEN(libswift,doc/Doxyfile,doc/)
 
-# .in files.
+# Handle .in files.
 AC_CONFIG_FILES([Makefile src/Makefile examples/Makefile doc/Makefile doc/Doxyfile])
 
-# generate output.
+# Generate output.
 AC_OUTPUT