Implemented debug and optimization flags

configure.ac

@@ -11,6 +11,14 @@ AC_INIT([Nek5000], [1.0], [nek5000-users@lists.mcs.anl.gov])
 # COMMAND-LINE OPTS
 ###############################################################################
 
+AC_ARG_ENABLE([debug],
+              [AC_HELP_STRING([--disable-debug]), [compile without debug flags (-g) @<:@default: enabled@:>@]],
+              [debug="$enableval"], [debug="yes"])
+
+AC_ARG_ENABLE([opt],
+              [AC_HELP_STRING([--enable-opt]), [compile with optimization flags (-O3) @<:@default: disabled@:>@]],
+              [opt="$enableval"], [opt="no"])
+
 AC_ARG_ENABLE([mpi],
               [AS_HELP_STRING([--disable-mpi], [compile without mpi @<:@default: enabled@:>@])],
               [mpi=${enableval}], [mpi=yes])
@@ -70,12 +78,15 @@ AC_ARG_ENABLE([extbar],
 ###############################################################################
 
 # C compiler checks
-AC_PROG_CC
-AC_PROG_CC_C_O
+: ${CFLAGS=""}              # Do not use autconf's default "-g -O2"
+AC_PROG_CC                  # Validate C Compiler
+AC_PROG_CC_C_O              # Necessary for automake
 AC_CHECK_SIZEOF([int *])    # Get sizeof int*, set SIZEOF_INT_P. If SIZEOF_INT_P == 8, then Nek needs -DPTRSIZE8
 AC_CHECK_SIZEOF([long int]) # Get sizeof long int, set SIZEOF_LONG_INT
 
-# F77 compiler checks
+# Fortran compiler checks
+: ${FFLAGS="$FFLAGS"}   # Do not use autconf's default "-g -O2"
+: ${FCFLAGS="$FCFLAGS"} # Do not use autconf's default "-g -O2"
 AC_PROG_F77             # Validate F77 compiler
 AC_PROG_F77_C_O         # Necessary for automake
 AC_F77_LIBRARY_LDFLAGS  # Determine -l and -L flags, append to $FLIBS
@@ -91,8 +102,9 @@ FC="$old_fc"
 # FIND F77 FLAG FOR DEFAULT 8-BYTE FLOATS
 ###############################################################################
 
-real8_fflags=""
 AC_LANG_PUSH([Fortran 77])
+old_fflags="$FFLAGS"
+real8_fflags=""
 for flag in                             dnl
   "-r8 -fpconstant"                     dnl Intel
   "-r8"                                 dnl PGI, some others
@@ -100,7 +112,6 @@ for flag in                             dnl
   "-qrealsize=8 -qdpc=e"                dnl IBM
   "-s default64";                       dnl Cray
 do
-  old_fflags="$FFLAGS"
   FFLAGS="$flag"
   AC_MSG_CHECKING([if Fortran 77 compiler accepts $flag])
   AC_COMPILE_IFELSE( 
@@ -122,6 +133,24 @@ fi
 # SET NEK's PREPROCESSOR MACROS
 ###############################################################################
 
+# Enable debug flags
+if test "x$debug" = "xyes"; then
+  CFLAGS="-g $CFLAGS"
+  FFLAGS="-g $FFLAGS"
+  FCFLAGS="-g $FCFLAGS"
+fi
+
+# Enable optimization flags
+if test "x$opt" = "xyes" || "x$bgq" = "xyes"; then
+  CFLAGS="-O3 $CFLAGS"
+  FFLAGS="-O3 $FFLAGS"
+  FCFLAGS="-O3 $FCFLAGS"
+else
+  CFLAGS="-O2 $CFLAGS"
+  FFLAGS="-O2 $FFLAGS"
+  FCFLAGS="-O2 $FCFLAGS"
+fi
+
 # Check if pointer size == 8
 if test "$ac_cv_sizeof_int_p" -eq 8; then
   AC_DEFINE([PTRSIZE8], 1, [If sizeof *int is 8])