xref: /inferno-os/libmath/FPcontrol-FreeBSD.c (revision 46439007cf417cbd9ac8049bb4122c890097a0fa)
1  #include "lib9.h"
2  #include "fpuctl.h"
3  #include "mathi.h"
4  
5  void
6  FPinit(void)
7  {
8  	setfsr(0);	/* Clear pending exceptions */
9  	setfcr(FPPDBL|FPRNR|FPINVAL|FPZDIV|FPUNFL|FPOVFL);
10  }
11  
12  ulong
13  getFPstatus(void)
14  {
15  	ulong fsr = 0, fsr9 = getfsr();
16  	/* on specific machines, could be table lookup */
17  	if(fsr9&FPAINEX) fsr |= INEX;
18  	if(fsr9&FPAOVFL) fsr |= OVFL;
19  	if(fsr9&FPAUNFL) fsr |= UNFL;
20  	if(fsr9&FPAZDIV) fsr |= ZDIV;
21  	if(fsr9&FPAINVAL) fsr |= INVAL;
22  	return fsr;
23  }
24  
25  ulong
26  FPstatus(ulong fsr, ulong mask)
27  {
28  	ulong fsr9 = 0;
29  	ulong old = getFPstatus();
30  	fsr = (fsr&mask) | (old&~mask);
31  	if(fsr&INEX) fsr9 |= FPAINEX;
32  	if(fsr&OVFL) fsr9 |= FPAOVFL;
33  	if(fsr&UNFL) fsr9 |= FPAUNFL;
34  	if(fsr&ZDIV) fsr9 |= FPAZDIV;
35  	if(fsr&INVAL) fsr9 |= FPAINVAL;
36  	setfsr(fsr9);
37  	return(old&mask);
38  }
39  
40  ulong
41  getFPcontrol(void)
42  {
43  	ulong fcr = 0, fcr9 = getfcr();
44  	switch(fcr9&FPRMASK){
45  		case FPRNR:	fcr = RND_NR; break;
46  		case FPRNINF:	fcr = RND_NINF; break;
47  		case FPRPINF:	fcr = RND_PINF; break;
48  		case FPRZ:	fcr = RND_Z; break;
49  	}
50  	if(fcr9&FPINEX) fcr |= INEX;
51  	if(fcr9&FPOVFL) fcr |= OVFL;
52  	if(fcr9&FPUNFL) fcr |= UNFL;
53  	if(fcr9&FPZDIV) fcr |= ZDIV;
54  	if(fcr9&FPINVAL) fcr |= INVAL;
55  	return fcr;
56  }
57  
58  ulong
59  FPcontrol(ulong fcr, ulong mask)
60  {
61  	ulong fcr9 = FPPDBL;
62  	ulong old = getFPcontrol();
63  	fcr = (fcr&mask) | (old&~mask);
64  	if(fcr&INEX) fcr9 |= FPINEX;
65  	if(fcr&OVFL) fcr9 |= FPOVFL;
66  	if(fcr&UNFL) fcr9 |= FPUNFL;
67  	if(fcr&ZDIV) fcr9 |= FPZDIV;
68  	if(fcr&INVAL) fcr9 |= FPINVAL;
69  	switch(fcr&RND_MASK){
70  		case RND_NR:	fcr9 |= FPRNR; break;
71  		case RND_NINF:	fcr9 |= FPRNINF; break;
72  		case RND_PINF:	fcr9 |= FPRPINF; break;
73  		case RND_Z:	fcr9 |= FPRZ; break;
74  	}
75  	setfcr(fcr9);
76  	return(old&mask);
77  }
78  
79