cpu.cpp

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/* This file is part of Cloudy and is copyright (C)1978-2013 by Gary J. Ferland and
 * others.  For conditions of distribution and use see copyright notice in license.txt */
#include "cdstd.h"
 
#if defined(__HP_aCC)
/* this is for the HP compiler on the sdx */
extern "C" unsigned long fegettrapenable();
extern "C" void fesettrapenable(unsigned long); 
#endif
 
#if defined(__ia64) && defined(__INTEL_COMPILER)
extern "C" unsigned long fpgetmask();
extern "C" void fpsetmask(unsigned long);
#endif  
 
#if defined(__sun) || defined(__sgi)
#include <ieeefp.h>
#if defined(HAVE_SUNMATH) || defined(FLUSH_DENORM_TO_ZERO)
#include <sunmath.h>
#endif
#endif
 
#if defined(__alpha) && defined(__linux__) && defined(__GNUC__)
#define __USE_GNU
#include <fenv.h>
#endif
 
#if defined(__SUNPRO_CC) && __SUNPRO_CC >= 0x5140
#include <fenv.h>
#endif
 
#if defined(__unix) || defined(__APPLE__)
#include <unistd.h>
#endif
 
#if defined(__APPLE__) || defined(__FreeBSD__) || defined(__NetBSD__) || defined(__OpenBSD__)
#include <sys/types.h>
#include <sys/sysctl.h>
#endif
 
/* the redefinition of float in cddefines.h can cause problems in system headers
 * hence these includes MUST come after the system header includes above */
#include "cddefines.h"
#include "cpu.h"
#include "path.h"
#include "trace.h"
 
STATIC NORETURN void AbortErrorMessage( const char* fname, vector<string>& PathList, access_scheme scheme );
 
// Use Schwartz/nifty counter to ensure that global policy class
// is set up before other globals/statics, and deleted last.
t_cpu_i *t_cpu::m_i;
static int cpu_count = 0;
t_cpu::t_cpu()
{
        if (0 == cpu_count++)
        {
                m_i = new t_cpu_i;
        }
}
t_cpu::~t_cpu()
{
        if (0 == --cpu_count)
        {
                delete m_i;
        }
}
 
/* NB NB - this constructor needs to be called before any of the user code is executed !! */
t_cpu_i::t_cpu_i()
{
        DEBUG_ENTRY( "t_cpu_i()" );
 
        // set up signal handlers so that we can control what happens...
        set_signal_handlers();
 
        p_exit_status.resize( ES_TOP, "--undefined--" );
        p_exit_status[ES_SUCCESS] = "ok";
        p_exit_status[ES_FAILURE] = "early termination";
        p_exit_status[ES_WARNINGS] = "warnings";
        p_exit_status[ES_BOTCHES] = "botched monitors";
        p_exit_status[ES_CLOUDY_ABORT] = "cloudy abort";
        p_exit_status[ES_BAD_ASSERT] = "failed assert";
        p_exit_status[ES_BAD_ALLOC] = "failed memory alloc";
        p_exit_status[ES_OUT_OF_RANGE] = "array bound exceeded";
        p_exit_status[ES_USER_INTERRUPT] = "user interrupt";
        p_exit_status[ES_TERMINATION_REQUEST] = "process killed";
        p_exit_status[ES_ILLEGAL_INSTRUCTION] = "illegal instruction";
        p_exit_status[ES_FP_EXCEPTION] = "fp exception";
        p_exit_status[ES_SEGFAULT] = "segmentation fault";
        p_exit_status[ES_BUS_ERROR] = "bus error";
        p_exit_status[ES_UNKNOWN_SIGNAL] = "unknown signal";
        p_exit_status[ES_UNKNOWN_EXCEPTION] = "unknown exception";
 
        /* >>chng 05 dec 14, add test of endianness of the CPU, PvH */
        endian.c[0] = 0x12;
        endian.c[1] = 0x34;
        endian.c[2] = 0x56;
        endian.c[3] = 0x78;
 
        /* >>chng 05 dec 15, add signaling NaN for float and double to cpu struct, PvH */
        /* in C++ this should be replaced by numeric_limits<TYPE>::signaling_NaN() */
        if( sizeof(sys_float) == 4 )
        {
#               ifdef __mips
                /* definition of signaling and quiet NaN is reversed on MIPS */
                Float_SNaN_Value = 0xffffffff;
#               else
                if( big_endian() || little_endian() )
                {
                        /* this should work on most modern CPU's */
                        Float_SNaN_Value = 0xffbfffff;
                }
                else
                {
                        /* this is an unusual CPU -> bit pattern for SNaN is unknown */
                        Float_SNaN_Value = -1;
                }
#               endif
        }
        else
        {
                /* this is an unusual CPU -> bit pattern for SNaN is unknown */
                Float_SNaN_Value = -1;
        }
 
#       ifdef HAVE_INT64
 
        if( sizeof(double) == 8 )
        {
#               ifdef __mips
                /* definition of signaling and quiet NaN is reversed on MIPS */
                Double_SNaN_Value = 0xffffffffffffffff;
#               else
                /* this should work on most modern CPU's */
                Double_SNaN_Value = 0xfff7ffffffbfffff;
#               endif
        }
        else
        {
                /* this is an unusual CPU -> bit pattern for SNaN is unknown */
                Double_SNaN_Value = -1;
        }
 
#       else
 
        if( sizeof(double) == 8 )
        {
#               ifdef __mips
                /* definition of signaling and quiet NaN is reversed on MIPS */
                Double_SNaN_Value[0] = 0xffffffff;
                Double_SNaN_Value[1] = 0xffffffff;
#               else
                if( big_endian() )
                {
                        /* this should work on most modern CPU's */
                        Double_SNaN_Value[0] = 0xfff7ffff;
                        Double_SNaN_Value[1] = 0xffbfffff;
                }
                else if( little_endian() )
                {
                        /* this should work on most modern CPU's */
                        Double_SNaN_Value[0] = 0xffbfffff;
                        Double_SNaN_Value[1] = 0xfff7ffff;
                }
                else
                {
                        /* this is an unusual CPU -> bit pattern for SNaN is unknown */
                        Double_SNaN_Value[0] = -1;
                        Double_SNaN_Value[1] = -1;
                }
#               endif
        }
        else
        {
                /* this is an unusual CPU -> bit pattern for SNaN is unknown */
                Double_SNaN_Value[0] = -1;
                Double_SNaN_Value[1] = -1;
        }
 
#       endif
 
        /* set FP environment to trap FP exceptions */
        enable_traps();
 
        ioStdin = stdin;
        ioQQQ = stdout;
        ioPrnErr = stderr;
        lgPrnErr = false;
 
        test_float = FLT_MIN;
        test_double = DBL_MIN;
 
        /* default is for failed asserts not to abort */
        p_lgAssertAbort = false;
 
        const char *str;
 
        /* determine the no. of CPUs on this machine; used by PHYMIR, grid command, .... */
#       if defined(_SC_NPROCESSORS_ONLN)  /* Linux, Sun Sparc, DEC Alpha, MacOS (OS releases >= 10.4) */
        n_avail_CPU = sysconf(_SC_NPROCESSORS_ONLN);
#       elif defined(_SC_NPROC_ONLN)      /* SGI Iris */
        n_avail_CPU = sysconf(_SC_NPROC_ONLN);
#       elif defined(_SC_CRAY_NCPU)       /* Cray */
        n_avail_CPU = sysconf(_SC_CRAY_NCPU);
#       elif defined(_WIN32)              /* Microsoft Windows */
        str = getenv( "NUMBER_OF_PROCESSORS" );
        if( str != NULL )
        {
                int found = sscanf( str, "%ld", &n_avail_CPU );
                if( found != 1 )
                        n_avail_CPU = 1;
        }
        else
        {
                n_avail_CPU = 1;
        }
#       elif defined(HW_AVAILCPU)         /* MacOS, BSD variants */
        int mib[2];
        size_t len = sizeof(n_avail_CPU);
        mib[0] = CTL_HW;
        mib[1] = HW_AVAILCPU;  // alternatively, try HW_NCPU;
        sysctl(mib, 2, &n_avail_CPU, &len, NULL, 0);
        if( n_avail_CPU < 1 ) 
        {
                mib[1] = HW_NCPU;
                sysctl(mib, 2, &n_avail_CPU, &len, NULL, 0);
                if( n_avail_CPU < 1 )
                        n_avail_CPU = 1;
        }
#       else                              
        /* Other systems, supply no. of CPUs on OPTIMIZE PHYMIR command line */
        n_avail_CPU = 1;
#       endif
        /* the constructor is run before MPI starts, so the rank is not available yet */
#       ifdef MPI_ENABLED
        p_lgMPI = true;
#       else
        p_lgMPI = false;
#       endif
        /* the default is for all ranks to cooperate on the same sim */
        p_lgMPISingleRankMode = false;
        n_rank = 0;
 
#       ifdef _WIN32    
        str = getenv( "COMPUTERNAME" );
#       else
        str = getenv( "HOSTNAME" );
#       endif
 
        if( str != NULL )
                strncpy( HostName, str, STDLEN );
        else
                strncpy( HostName, "unknown", STDLEN );
        HostName[STDLEN-1] = '\0';
 
        /* pick up the path from the environment, if set by user */
        const char *path = getenv( "CLOUDY_DATA_PATH" );
 
        /* if the environment variable was not set, the default set in path.h takes effect */
        string chSearchPathRaw = ( path != NULL ) ? string( path ) : string( CLOUDY_DATA_PATH );
 
#       ifdef _WIN32
        string separator( ";" );
        p_chDirSeparator = '\\';
#       else
        string separator( ":" );
        p_chDirSeparator = '/';
#       endif
 
        chSearchPath.push_back( "" ); // the current working directory should be first and last
        Split( chSearchPathRaw, separator, chSearchPath, SPM_RELAX );
        chSearchPath.push_back( "" );
 
        for( vector<string>::size_type i=0; i < chSearchPath.size(); ++i )
        {
                if( chSearchPath[i].length() > 0 )
                {
                        /* get last valid char */
                        char chEnd = *chSearchPath[i].rbegin();
 
                        /* make sure path ends with directory separator */
                        if( chEnd != p_chDirSeparator )
                                chSearchPath[i] += p_chDirSeparator;
                }
        }
 
        nFileDone = 0;
}
 
void t_cpu_i::enable_traps() const
{
        /* >>chng 01 aug 07, added code to circumvent math library bug with g++ on
         * alpha-linux machines, see bug report 51072 on http://bugzilla.redhat.com, PvH */
        /* >>chng 01 apr 17, added code for Solaris and SGI operating systems, PvH */
        /* this routine contains no code for alphas or crays, they do not need
         * special code to enable FP exceptions since they are enabled by default */
 
        /* there is no command line option on MS Visual Studio to force crash */
#       if defined(_MSC_VER)
        volatile unsigned int NewMask;
 
        /* | is a bitwise inclusive or, turns on bits
         * 0|0 = 0
         * 0|1 = 1|0 = 1|1 = 1 */
        NewMask = _EM_ZERODIVIDE | _EM_OVERFLOW | _EM_INVALID;
        /* ~ is the unary bitwise complement - all bits flip */ 
        NewMask = ~NewMask;
        _controlfp( NewMask , _MCW_EM );
 
        /* this is the code for Linux PC (but not Linux alpha) to force crash */
        /* >>chng 04 apr 26, added support for AMD64, enable FPE traps for SSE/SSE2, PvH */
        /* >>chng 06 aug 12, added support for Apple MacOSX, and hopefully also Solaris x86, PvH */
        // do not enable trapping FPEs for Clang compiler since it is not supported in v3.4 and later
#       elif defined(__GNUC__) && ( defined(__i386) || defined(__amd64) ) && !defined(__clang__)
        volatile unsigned int Old_Mask, New_Mask;
#       if defined(__SSE__) || defined(__SSE2__)
        volatile unsigned int SSE_Mask;
#       endif
 
#       define _FPU_MASK_IM  0x01  /* Invalid          */
#       define _FPU_MASK_DM  0x02  /* Denormalized     */
#       define _FPU_MASK_ZM  0x04  /* Division-by-zero */
#       define _FPU_MASK_OM  0x08  /* Overflow         */
#       define _FPU_MASK_UM  0x10  /* Underflow        */
#       define _FPU_MASK_PM  0x20  /* Inexact          */
 
        /*  | is a bitwise inclusive or, turns on bits     */
        /* 0|0 = 0                                         */
        /* 0|1 = 1|0 = 1|1 = 1                             */
 
        /*  ~ is the unary bitwise complement - all bits flip */
 
        /* this enables FPE traps for regular i387 FP instructions */
 
        volatile unsigned int UnMask = ~((unsigned int)( _FPU_MASK_ZM | _FPU_MASK_IM  | _FPU_MASK_OM ));
 
        __asm__ volatile("fnstcw %0" : "=m" (*&Old_Mask));
 
        New_Mask = Old_Mask & UnMask;
 
        __asm__ volatile("fldcw %0" : : "m" (*&New_Mask));
 
#       if defined(__SSE__) || defined(__SSE2__)
 
#       if defined(FLUSH_DENORM_TO_ZERO)
        /* using this causes denormalized numbers to be flushed to zero,
         * which will speed up the code on Pentium 4 processors */
        SSE_Mask = 0x9900;
#       else
        /* this version allows denormalized numbers to be retained */
        SSE_Mask = 0x1900;
#       endif
 
        /* this enables FPE traps for SSE/SSE2 instructions */
 
        __asm__ volatile( "ldmxcsr %0" : : "m" (*&SSE_Mask) );
 
#       endif
 
        /* this is for IA64 systems running g++ or icc (e.g. SGI, HP, ...) */
#       elif defined(__ia64)
 
#       define FPSR_TRAP_VD     (1 << 0)        /* invalid op trap disabled */
#       define FPSR_TRAP_DD     (1 << 1)        /* denormal trap disabled */
#       define FPSR_TRAP_ZD     (1 << 2)        /* zero-divide trap disabled */
#       define FPSR_TRAP_OD     (1 << 3)        /* overflow trap disabled */
#       define FPSR_TRAP_UD     (1 << 4)        /* underflow trap disabled */
#       define FPSR_TRAP_ID     (1 << 5)        /* inexact trap disabled */
 
#       define FPSR_SF0_FTZ     (1 << 6)        /* flush denormalized numbers to zero */
 
#       if defined(__GNUC_EXCL__)
        /* __asm__ instructions are not supported by icc as of v9.0 */
#       define _IA64_REG_AR_FPSR    40
 
#       define ia64_getreg( regnum )       __asm__ volatile( "mov %0=ar%1" : "=r" (fpsr) : "i"(regnum) )
#       define ia64_setreg( regnum, val )  __asm__ volatile( "mov ar%0=%1" :: "i" (regnum), "r"(val): "memory" )
#       define ia64_serialize              __asm__ volatile( "srlz.i" );
 
        volatile unsigned long fpsr, flags = FPSR_TRAP_VD | FPSR_TRAP_ZD | FPSR_TRAP_OD;
 
        ia64_getreg( _IA64_REG_AR_FPSR );
        fpsr &= ~flags;
#       if defined(FLUSH_DENORM_TO_ZERO)
        fpsr |= FPSR_SF0_FTZ;
#       endif
        ia64_setreg( _IA64_REG_AR_FPSR, fpsr );
        /* this prevents RAW and WAW dependency violations in case this ever gets inlined... */
        ia64_serialize;
 
#       elif defined(__INTEL_COMPILER)
        /* this is for icc on IA64 SGI machines */
        unsigned long fpsr = fpgetmask();
        fpsr |= FPSR_TRAP_VD | FPSR_TRAP_ZD | FPSR_TRAP_OD;
        fpsetmask( fpsr );
#       elif defined(__HP_aCC)
        /* this is for the HP compiler on the sdx */
        unsigned long fpsr = fegettrapenable(); 
        fpsr |= FPSR_TRAP_VD | FPSR_TRAP_ZD | FPSR_TRAP_OD;
        fesettrapenable( fpsr ); 
#       endif /* defined(__GNUC_EXCL__) */
 
        /* this is for Solaris and SGI to force crash */
#       elif defined(__sun) || defined(__sgi)
 
        fp_except mask;
 
        /* >>chng 05 dec 30, accept FLUSH_DENORM_TO_ZERO as a synonym for HAVE_SUNMATH, PvH */
#       if defined(HAVE_SUNMATH) || defined(FLUSH_DENORM_TO_ZERO)
 
        /* >>chng 01 oct 09, disable gradual underflow on ultrasparc whith g++
         * (only needed for versions < 3.1 or >= 4.3.0, see Note 1).
         *
         * compile this module with:
         *     g++ [ other options... ] -I<include-dir> -DHAVE_SUNMATH -c cpu.cpp
         * link the program with:
         *     g++ -L<library-dir> -o cloudy.exe *.o -lsunmath
         *
         * you probably need to use -I<include-dir> and -L<library-dir> to point the
         * compiler/linker to the location of the sunmath.h header file and libsunmath.so
         * library (e.g., -I/opt/SUNWspro/prod/include/cc -L/opt/SUNWspro/lib; note that
         * the actual location may vary from one installation to another).
         * See also bug report 4487 on http://gcc.gnu.org/bugzilla/
         *
         * Note 1: Starting with g++ 3.1, bug 4487 has been solved: -funsafe-math-optimizations
         * will automatically disable gradual underflow. Hence using nonstandard_arithmetic()
         * is no longer necessary. The option -funsafe-math-optimizations should be included
         * both when compiling and linking:
         *
         * g++ [ other options... ] -funsafe-math-optimizations -c *.c
         * g++ [ other options... ] -funsafe-math-optimizations -o cloudy.exe *.o
         *
         * Starting with g++ 4.3.0 the -funsafe-math-optimizations option can no longer be
         * used as it implicitly enables -fno-trapping-math, which is unsafe for Cloudy
         * because we do trap floating point exceptions.
         *
         * Note 2: Don't use nonstandard_arithmetic() with CC (the SunWorks/Forte compiler);
         * use the -fast commandline option instead to disable gradual underflow (or use
         * -fnonstd if you don't want all the other options enabled by -fast). The option
         * -fast (or -fnonstd) should be included both when compiling and linking:
         *
         * CC [ other options... ] -fast -c *.c
         * CC -fast -o cloudy.exe *.o
         *
         * PvH */
        nonstandard_arithmetic();
#       endif
 
        /* enable floating point exceptions on sun and sgi */
        mask = fpgetmask();
        mask = mask | FP_X_INV | FP_X_OFL | FP_X_DZ;
        fpsetmask(mask);
 
#       elif defined(__alpha) && defined(__linux__) && defined(__GNUC__)
 
        /* the following is not supported on all hardware platforms, but certainly for EV56
         * and later. earlier versions may work as well, but that has not been tested.
         * for details see https://bugzilla.redhat.com/bugzilla/show_bug.cgi?id=51072 */
#       ifdef FE_NONIEEE_ENV
        /* this prevents the infamous math library bug when compiling with gcc on alpha-linux
         * machines. if this doesn't work on your system, the only alternative is to link
         * against the Compaq math library: gcc *.o -lcpml -lm, or use ccc itself, PvH */
        fesetenv(FE_NONIEEE_ENV);
#       endif
 
#       elif defined(__SUNPRO_CC) && __SUNPRO_CC >= 0x5140
 
        // from Oracle Developer Studio 12.5 onwards, FP traps are not enebled by default
        feenableexcept(FE_INVALID | FE_DIVBYZERO | FE_OVERFLOW);
 
#       endif
}
 
void t_cpu_i::set_signal_handlers()
{
        DEBUG_ENTRY( "set_signal_handlers()" );
 
#ifdef CATCH_SIGNAL
#       ifdef __unix
        p_action.sa_handler = &signal_handler;
        sigemptyset( &p_action.sa_mask );
        p_action.sa_flags = SA_NODEFER;
 
        p_default.sa_handler = SIG_DFL;
        sigemptyset( &p_default.sa_mask );
        p_default.sa_flags = SA_NODEFER;
 
        for( int sig=1; sig <= 31; sig++ )
        {
                // is the signal valid?
                if( sigaction( sig, NULL, NULL ) == 0 )
                        // these two are for suspending and resuming a job
                        if( sig != SIGSTOP && sig != SIGCONT )
                                sigaction( sig, action(), NULL );
        }
#       endif
 
#       ifdef _MSC_VER
        signal( SIGABRT, &signal_handler );
        signal( SIGFPE, &signal_handler );
        signal( SIGILL, &signal_handler );
        signal( SIGINT, &signal_handler );
        signal( SIGSEGV, &signal_handler );
        signal( SIGTERM, &signal_handler );
#       endif
#endif
}
 
void t_cpu_i::signal_handler(int sig)
{
        // when an FPE is caught, the mask is reset...
        cpu.i().enable_traps();
#       ifdef _MSC_VER
        // at this point the signal handler has reverted to the default handler
        signal( sig, &signal_handler );
#       endif
        throw bad_signal( sig );
}
 
 
void t_cpu_i::printDataPath() const
{
        fprintf(ioQQQ, "The path is:\n");
        for( vector<string>::size_type i=1; i < chSearchPath.size()-1; ++i )
                fprintf( ioQQQ, "   ==%s==\n", chSearchPath[i].c_str() );
}
 
// this routine generates a list of all full paths to the locations where we should look for the file
void t_cpu_i::getPathList( const char* fname, vector<string>& PathList, access_scheme scheme ) const
{
        DEBUG_ENTRY( "getPathList()" );
 
        vector<string>::size_type begin, end;
 
        switch( scheme )
        {
        case AS_DATA_ONLY:
        case AS_DATA_ONLY_TRY:
        case AS_DATA_OPTIONAL:
                begin = 1;
                end = cpu.i().chSearchPath.size()-1;
                break;
        case AS_DATA_LOCAL:
        case AS_DATA_LOCAL_TRY:
                begin = 1;
                end = cpu.i().chSearchPath.size();
                break;
        case AS_LOCAL_DATA:
        case AS_LOCAL_DATA_TRY:
                begin = 0;
                end = cpu.i().chSearchPath.size()-1;
                break;
        case AS_LOCAL_ONLY:
        case AS_LOCAL_ONLY_TRY:
        case AS_SILENT_TRY:
                begin = 0;
                end = 1;
                break;
        default:
                TotalInsanity();
        }
 
        PathList.clear();
        string FileName( fname );
        for( vector<string>::size_type i=begin; i < end; ++i )
                PathList.push_back( cpu.i().chSearchPath[i] + FileName );
}
 
STATIC NORETURN void AbortErrorMessage( const char* fname, vector<string>& PathList, access_scheme scheme )
{
        DEBUG_ENTRY( "AbortErrorMessage()" );
 
        if( scheme == AS_DATA_OPTIONAL )
                // presence is optional -> make warning less scary...
                fprintf( ioQQQ, "\nI could not open the data file %s\n\n", fname );
        else
                fprintf( ioQQQ, "\nPROBLEM DISASTER I could not open the data file %s\n\n", fname );
        if( cpu.i().firstOpen() || scheme == AS_DATA_ONLY )
        {
                // failed on very first open -> most likely path is not correct
                // failed on AS_DATA_ONLY -> CLOUDY_DATA_PATH may point to obsolete data dir
                fprintf( ioQQQ, "Although there may be other reasons you have received this error,\n");
                fprintf( ioQQQ, "the most likely are that the path has not been properly set\n");
                fprintf( ioQQQ, "or that the path points to an old version of the data.\n\n");
                fprintf( ioQQQ, "Please have a look at the file path.h in the source directory\n");
                fprintf( ioQQQ, "to check how the variable CLOUDY_DATA_PATH is set - \n");
                fprintf( ioQQQ, "it should give the location of the data files I need.\n");
                fprintf( ioQQQ, "These are the files in the data download from the web site.\n\n");
                fprintf( ioQQQ, "Recompile the code with the correct data path set in path.h\n");
                fprintf( ioQQQ, "or use the shell command \nexport CLOUDY_DATA_PATH=\"/path/to/data\"\n to set the\n");
                fprintf( ioQQQ, "path from a bash command prompt.\n\n");
                cpu.i().printDataPath();
        }
        else
        {
                // failed on search including local directory -> most likely the file name
                // was mistyped on a compile command, or Cloudy is run in the wrong directory
                // if scheme == AS_DATA_OPTIONAL, this most likely is a stellar grid that is not installed.
                fprintf( ioQQQ, "These are all the paths I tried:\n" );
                for( vector<string>::const_iterator ptr=PathList.begin(); ptr != PathList.end(); ++ptr )
                        fprintf( ioQQQ, "   ==%s==\n", ptr->c_str() );
                // AS_DATA_OPTIONAL files should provide their own message (currently only stellar grids)
                if( scheme != AS_DATA_OPTIONAL )
                {
                        fprintf( ioQQQ, "\nAlthough there may be other reasons you have received this error,\n");
                        fprintf( ioQQQ, "the most likely are that you mistyped the file name, or that you\n");
                        fprintf( ioQQQ, "are running Cloudy in the wrong directory. If you are running a\n");
                        fprintf( ioQQQ, "COMPILE command, this needs to be done in the data directory.\n\n");
                        fprintf( ioQQQ, "Otherwise, please have a look at the file path.h in the source\n");
                        fprintf( ioQQQ, "directory to check how the variable CLOUDY_DATA_PATH is set - \n");
                        fprintf( ioQQQ, "it should give the location of the data files I need.\n");
                        fprintf( ioQQQ, "These are the files in the data download from the web site.\n\n");
                        fprintf( ioQQQ, "Recompile the code with the correct data path set in path.h\n");
                        fprintf( ioQQQ, "or use the shell command \nexport CLOUDY_DATA_PATH=\"/path/to/data\"\n to set the\n");
                        fprintf( ioQQQ, "path from a bash command prompt.\n\n");
                }
        }
        fprintf(ioQQQ, "Sorry.\n\n\n");
        cdEXIT(EXIT_FAILURE);
}
 
FILE* open_data( const char* fname, const char* mode, access_scheme scheme )
{
        DEBUG_ENTRY( "open_data()" );
 
        bool lgAbort = ( scheme == AS_DATA_ONLY || scheme == AS_DATA_OPTIONAL || scheme == AS_DATA_LOCAL ||
                         scheme == AS_LOCAL_DATA || scheme == AS_LOCAL_ONLY );
 
        vector<string> PathList;
        cpu.i().getPathList( fname, PathList, scheme );
 
        FILE* handle = NULL;
        vector<string>::const_iterator ptr;
        for( ptr=PathList.begin(); ptr != PathList.end() && handle == NULL; ++ptr )
        {
                handle = fopen( ptr->c_str(), mode );
                if( trace.lgTrace && scheme != AS_SILENT_TRY )
                        fprintf( ioQQQ, " open_data trying %s mode %s handle %p\n", ptr->c_str(), mode, handle );
        }
 
        if( handle == NULL && lgAbort )
                AbortErrorMessage( fname, PathList, scheme );
 
        ++cpu.i().nFileDone;
 
        return handle;
}
 
void open_data( fstream& stream, const char* fname, ios_base::openmode mode, access_scheme scheme )
{
        DEBUG_ENTRY( "open_data()" );
 
        bool lgAbort = ( scheme == AS_DATA_ONLY || scheme == AS_DATA_OPTIONAL || scheme == AS_DATA_LOCAL ||
                         scheme == AS_LOCAL_DATA || scheme == AS_LOCAL_ONLY );
 
        vector<string> PathList;
        cpu.i().getPathList( fname, PathList, scheme );
 
        ASSERT( !stream.is_open() );
        vector<string>::const_iterator ptr;
        for( ptr=PathList.begin(); ptr != PathList.end() && !stream.is_open(); ++ptr )
        {
                stream.open( ptr->c_str(), mode );
                if( trace.lgTrace && scheme != AS_SILENT_TRY )
                        fprintf( ioQQQ, " open_data trying %s succes? %c\n", ptr->c_str(), TorF(stream.is_open()) );
        }
 
        if( !stream.is_open() && lgAbort )
                AbortErrorMessage( fname, PathList, scheme );
 
        ++cpu.i().nFileDone;
}
 
void set_NaN(sys_float &x)
{
        if( sizeof(sys_float) == 4 )
                *reinterpret_cast<int32*>(&x) = cpu.i().Float_SNaN_Value;
        else
                x = -FLT_MAX;
}
 
void set_NaN(sys_float x[], /* x[n] */
             long n)
{
        long i;
 
        if( sizeof(sys_float) == 4 )
        {
                int32 *y = reinterpret_cast<int32*>(x);
                for( i=0; i < n; i++ )
                        *y++ = cpu.i().Float_SNaN_Value;
        }
        else
        {
                for( i=0; i < n; i++ )
                        x[i] = -FLT_MAX;
        }
}
 
void set_NaN(double &x)
{
        if( sizeof(double) == 8 )
        {
#               ifdef HAVE_INT64
                *reinterpret_cast<int64*>(&x) = cpu.i().Double_SNaN_Value;
#               else
                int32 *y = reinterpret_cast<int32*>(&x);
                *y++ = cpu.i().Double_SNaN_Value[0];
                *y = cpu.i().Double_SNaN_Value[1];
#               endif
        }
        else
                x = -DBL_MAX;
}
 
/* set_NaN - set NaN */
void set_NaN(double x[], /* x[n] */
             long n)
{
        long i;
 
        if( sizeof(double) == 8 )
        {
#               ifdef HAVE_INT64
                int64 *y = reinterpret_cast<int64*>(x);
                for( i=0; i < n; i++ )
                        *y++ = cpu.i().Double_SNaN_Value;
#               else
                int32 *y = reinterpret_cast<int32*>(x);
                for( i=0; i < n; i++ )
                {
                        *y++ = cpu.i().Double_SNaN_Value[0];
                        *y++ = cpu.i().Double_SNaN_Value[1];
                }
#               endif
        }
        else
        {
                for( i=0; i < n; i++ )
                        x[i] = -DBL_MAX;
        }
}
 
bool MyIsnan(const sys_float &x)
{
        if( sizeof(sys_float) == 4 && FLT_MAX_EXP-FLT_MIN_EXP+3 == 256 )
        {
                const int32 *p = reinterpret_cast<const int32*>(&x);
                int32 r = *p & 0x7f800000; r ^= 0x7f800000;
                int32 s = *p & 0x007fffff;
                return ( r == 0 && s != 0 );
        }
        else
                /* we don't understand this CPU */
                return false;
}
 
bool MyIsnan(const double &x)
{
        if( sizeof(double) == 8 && DBL_MAX_EXP-DBL_MIN_EXP+3 == 2048 )
        {
#               ifdef HAVE_INT64
                const int64 *p = reinterpret_cast<const int64*>(&x);
                int64 r = *p & 0x7ff0000000000000; r ^= 0x7ff0000000000000;
                int64 s = *p & 0x000fffffffffffff;
                return ( r == 0 && s != 0 );
#               else
                const int32 *p = reinterpret_cast<const int32*>(&x);
                if( cpu.i().little_endian() )
                {
                        int32 r = p[1] & 0x7ff00000; r ^= 0x7ff00000;
                        int32 s = p[1] & 0x000fffff; s |= p[0];
                        return ( r == 0 && s != 0 );
                }
                else if( cpu.i().big_endian() )
                {
                        int32 r = p[0] & 0x7ff00000; r ^= 0x7ff00000;
                        int32 s = p[0] & 0x000fffff; s |= p[1];
                        return ( r == 0 && s != 0 );
                }
                else
                        /* we don't understand this CPU */
                        return false;
#               endif
        }
        else
                /* we don't understand this CPU */
                return false;
}