xref: /inferno-os/libmath/FPcontrol-NetBSD.c (revision 7ef44d652ae9e5e1f5b3465d73684e4a54de73c0)
1 #include "lib9.h"
2 #include "mathi.h"
3 
4 void
5 FPinit(void)
6 {
7 	setfsr(0);	/* Clear pending exceptions */
8 	setfcr(FPPDBL|FPRNR|FPINVAL|FPZDIV|FPUNFL|FPOVFL);
9 }
10 
11 ulong
12 getFPstatus(void)
13 {
14 	ulong fsr = 0, fsr9 = getfsr();
15 	/* on specific machines, could be table lookup */
16 	if(fsr9&FPAINEX) fsr |= INEX;
17 	if(fsr9&FPAOVFL) fsr |= OVFL;
18 	if(fsr9&FPAUNFL) fsr |= UNFL;
19 	if(fsr9&FPAZDIV) fsr |= ZDIV;
20 	if(fsr9&FPAINVAL) fsr |= INVAL;
21 	return fsr;
22 }
23 
24 ulong
25 FPstatus(ulong fsr, ulong mask)
26 {
27 	ulong fsr9 = 0;
28 	ulong old = getFPstatus();
29 	fsr = (fsr&mask) | (old&~mask);
30 	if(fsr&INEX) fsr9 |= FPAINEX;
31 	if(fsr&OVFL) fsr9 |= FPAOVFL;
32 	if(fsr&UNFL) fsr9 |= FPAUNFL;
33 	if(fsr&ZDIV) fsr9 |= FPAZDIV;
34 	if(fsr&INVAL) fsr9 |= FPAINVAL;
35 	setfsr(fsr9);
36 	return(old&mask);
37 }
38 
39 ulong
40 getFPcontrol(void)
41 {
42 	ulong fcr = 0, fcr9 = getfcr();
43 	switch(fcr9&FPRMASK){
44 		case FPRNR:	fcr = RND_NR; break;
45 		case FPRNINF:	fcr = RND_NINF; break;
46 		case FPRPINF:	fcr = RND_PINF; break;
47 		case FPRZ:	fcr = RND_Z; break;
48 	}
49 	if(fcr9&FPINEX) fcr |= INEX;
50 	if(fcr9&FPOVFL) fcr |= OVFL;
51 	if(fcr9&FPUNFL) fcr |= UNFL;
52 	if(fcr9&FPZDIV) fcr |= ZDIV;
53 	if(fcr9&FPINVAL) fcr |= INVAL;
54 	return fcr;
55 }
56 
57 ulong
58 FPcontrol(ulong fcr, ulong mask)
59 {
60 	ulong fcr9 = FPPDBL;
61 	ulong old = getFPcontrol();
62 	fcr = (fcr&mask) | (old&~mask);
63 	if(fcr&INEX) fcr9 |= FPINEX;
64 	if(fcr&OVFL) fcr9 |= FPOVFL;
65 	if(fcr&UNFL) fcr9 |= FPUNFL;
66 	if(fcr&ZDIV) fcr9 |= FPZDIV;
67 	if(fcr&INVAL) fcr9 |= FPINVAL;
68 	switch(fcr&RND_MASK){
69 		case RND_NR:	fcr9 |= FPRNR; break;
70 		case RND_NINF:	fcr9 |= FPRNINF; break;
71 		case RND_PINF:	fcr9 |= FPRPINF; break;
72 		case RND_Z:	fcr9 |= FPRZ; break;
73 	}
74 	setfcr(fcr9);
75 	return(old&mask);
76 }
77 
78