text: #include <ieeefp.h>
  #include "lib9.h"
  #include "mathi.h"
  
  void
  FPinit(void)
  {
  	fpsetsticky(0);		/* Clear pending exceptions */
  	fpsetround(FP_RN);
  	fpsetmask(FP_X_INV|FP_X_DZ|FP_X_UFL|FP_X_OFL);
  }
  
  ulong
  getFPstatus(void)
  {
  	ulong fsr = 0;
  	fp_except fsr9=fpgetsticky();
  	if(fsr9&FP_X_IMP) fsr |= INEX;
  	if(fsr9&FP_X_OFL) fsr |= OVFL;
  	if(fsr9&FP_X_UFL) fsr |= UNFL;
  	if(fsr9&FP_X_DZ) fsr |= ZDIV;
  	if(fsr9&FP_X_INV) fsr |= INVAL;
  	return fsr;
  }
  
  ulong
  FPstatus(ulong fsr, ulong mask)
  {
  	ulong fsr9 = 0;
  	ulong old = getFPstatus();
  	fsr = (fsr&mask) | (old&~mask);
  	if(fsr&INEX) fsr9 |= FP_X_IMP;
  	if(fsr&OVFL) fsr9 |= FP_X_OFL;
  	if(fsr&UNFL) fsr9 |= FP_X_UFL;
  	if(fsr&ZDIV) fsr9 |= FP_X_DZ;
  	if(fsr&INVAL) fsr9 |= FP_X_INV;
  	/* fpsetmask(fsr9); */
  	fpsetsticky(fsr9);
  	return(old&mask);
  }
  
  ulong
  getFPcontrol(void)
  {
  	ulong fcr = 0;
  	fp_except fpc = fpgetmask();
  	fp_rnd fpround = fpgetround();
  
  	if(fpc&FP_X_INV)
  		fcr|=INVAL;
  	if(fpc&FP_X_DZ)
  		fcr|=ZDIV;
  	if(fpc&FP_X_OFL)
  		fcr|=OVFL;
  	if(fpc&FP_X_UFL)
  		fcr|=UNFL;
  	if(fpc&FP_X_IMP)
  		fcr|=INEX;
  	switch(fpround){
  	case FP_RZ:
  		fcr|=RND_Z;
  		break;
      	case FP_RN:
  		fcr|=RND_NINF;
  		break;
      	case FP_RP:
  		fcr|=RND_PINF;
  		break;
      	case FP_RM:
  		fcr|=RND_NR;
  	}
  	return fcr;
  }
  ulong
  FPcontrol(ulong fcr, ulong mask)
  {
  	fp_except fc=0;
  	fp_rnd round;
  	ulong old = getFPcontrol();
  	ulong changed = mask&(fcr^old);
  	fcr = (fcr&mask) | (old&~mask);
  
  	if(fcr&INEX) fc |= FP_X_IMP;
  	if(fcr&OVFL) fc |= FP_X_OFL;
  	if(fcr&UNFL) fc |= FP_X_UFL;
  	if(fcr&ZDIV) fc |= FP_X_DZ;
  	if(fcr&INVAL) fc |= FP_X_INV;
  
  	switch(fcr&RND_MASK){
  		case RND_NR:    round |= FP_RM; break;
  		case RND_NINF:  round |= FP_RN; break;
  		case RND_PINF:  round |= FP_RP; break;
  		case RND_Z:     round |= FP_RZ; break;
  	}
  
  	fpsetround(round);
  	fpsetmask(fc);
  	return(old&mask);
  }
  