JobCFloatXImp.cxx

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// $Id: JobCFloatXImp.cxx,v 1.6 2009/09/28 22:28:26 nickd Exp $
//
// Activate floating point exceptions. Code from Jim Kowalkowski
// <jbk@fnal.gov>.
//
// messier@indiana.edu
#include "JobControl/JobCFloatXImp.h"
#include <iostream>

#if defined(__APPLE__)
#include <fenv.h>
#include <signal.h>
#include <stdlib.h>
#include <string.h>

void macosx_fpe_handler( int a )
{
  std::cerr <<  "Floating point exception! (" 
            << strsignal(a)
            << ") Aborting!" << std::endl;
  exit(1);
}

// Got this stuff from http://developer.apple.com/documentation/Performance/Conceptual/Mac_OSX_Numerics/
// Mac_OSX_Numerics.pdf
// Nathaniel Tagg, Feb 2006
#define fegetenvd(x) asm volatile("mffs %0" : "=f" (x));
#define fesetenvd(x) asm volatile("mtfsf 255,%0" : : "f" (x));
enum {
 FE_ENABLE_INEXACT    = 0x00000008,
 FE_ENABLE_DIVBYZERO  = 0x00000010,
 FE_ENABLE_UNDERFLOW  = 0x00000020,
 FE_ENABLE_OVERFLOW   = 0x00000040,
 FE_ENABLE_INVALID    = 0x00000080,
 FE_ENABLE_ALL_EXCEPT = 0x000000F8
};
typedef union {
 struct {
  unsigned long hi;
  unsigned long lo;
 } i;
 double d;
} hexdouble;


#endif

//......................................................................

JobCFloatXImp::JobCFloatXImp(bool a):activate_(a) 
{
  if(activate_==true)
  {
    // only activate invalid operand, division by zero, and
    // overflow exceptions

#if defined(linux)    
#if defined(__GLIBC__)&&(__GLIBC__>2 || __GLIBC__==2 && __GLIBC_MINOR__>=1)
    // use fenv
    fenv_t newval;
    fegetenv(&old_setting);
    fegetenv(&newval);
    newval.__control_word &= ~(FE_INVALID|FE_DIVBYZERO|FE_OVERFLOW);
    fesetenv(&newval);
#else
    // fpu control stuff
    old_setting = __fpu_control;
    fpu_control_t newval =
      old_setting & ~(
                      _FPU_MASK_IM
                      |_FPU_MASK_ZM
                      |_FPU_MASK_OM
                      );
    
    _FPU_SETCW(newval);
#endif
#endif

#if defined(__APPLE__) 
#if defined(__i386__) 
  // for intel chips:
#elif defined(__x86_64__)
  // For 64bit apple installations84,85
#else 
  // for ppc chips:
  hexdouble t;
  fegetenvd(t.d);                                
  t.i.lo |=  FE_ENABLE_DIVBYZERO | FE_ENABLE_OVERFLOW | FE_ENABLE_INVALID;;
  fesetenvd(t.d);
  signal(SIGFPE,macosx_fpe_handler);
#endif
#endif

  }
}

//......................................................................

JobCFloatXImp::~JobCFloatXImp()
{
#if defined(linux)
if(activate_==true)
#if defined(__GLIBC__)&&(__GLIBC__>2 || __GLIBC__==2 && __GLIBC_MINOR__>=1)
  fesetenv(&old_setting);
#else
_FPU_SETCW(old_setting);
#endif
#endif
}

---