xref: /inferno-os/libmath/FPcontrol-Solaris.c (revision 46439007cf417cbd9ac8049bb4122c890097a0fa)
1 #include <ieeefp.h>
2 #include "lib9.h"
3 #include "mathi.h"
4 
5 void
6 FPinit(void)
7 {
8 	fpsetsticky(0);		/* Clear pending exceptions */
9 	fpsetround(FP_RN);
10 	fpsetmask(FP_X_INV|FP_X_DZ|FP_X_UFL|FP_X_OFL);
11 }
12 
13 ulong
14 getFPstatus(void)
15 {
16 	ulong fsr = 0;
17 	fp_except fsr9=fpgetsticky();
18 	if(fsr9&FP_X_IMP) fsr |= INEX;
19 	if(fsr9&FP_X_OFL) fsr |= OVFL;
20 	if(fsr9&FP_X_UFL) fsr |= UNFL;
21 	if(fsr9&FP_X_DZ) fsr |= ZDIV;
22 	if(fsr9&FP_X_INV) fsr |= INVAL;
23 	return fsr;
24 }
25 
26 ulong
27 FPstatus(ulong fsr, ulong mask)
28 {
29 	ulong fsr9 = 0;
30 	ulong old = getFPstatus();
31 	fsr = (fsr&mask) | (old&~mask);
32 	if(fsr&INEX) fsr9 |= FP_X_IMP;
33 	if(fsr&OVFL) fsr9 |= FP_X_OFL;
34 	if(fsr&UNFL) fsr9 |= FP_X_UFL;
35 	if(fsr&ZDIV) fsr9 |= FP_X_DZ;
36 	if(fsr&INVAL) fsr9 |= FP_X_INV;
37 	/* fpsetmask(fsr9); */
38 	fpsetsticky(fsr9);
39 	return(old&mask);
40 }
41 
42 ulong
43 getFPcontrol(void)
44 {
45 	ulong fcr = 0;
46 	fp_except fpc = fpgetmask();
47 	fp_rnd fpround = fpgetround();
48 
49 	if(fpc&FP_X_INV)
50 		fcr|=INVAL;
51 	if(fpc&FP_X_DZ)
52 		fcr|=ZDIV;
53 	if(fpc&FP_X_OFL)
54 		fcr|=OVFL;
55 	if(fpc&FP_X_UFL)
56 		fcr|=UNFL;
57 	if(fpc&FP_X_IMP)
58 		fcr|=INEX;
59 	switch(fpround){
60 	case FP_RZ:
61 		fcr|=RND_Z;
62 		break;
63     	case FP_RN:
64 		fcr|=RND_NINF;
65 		break;
66     	case FP_RP:
67 		fcr|=RND_PINF;
68 		break;
69     	case FP_RM:
70 		fcr|=RND_NR;
71 	}
72 	return fcr;
73 }
74 ulong
75 FPcontrol(ulong fcr, ulong mask)
76 {
77 	fp_except fc=0;
78 	fp_rnd round;
79 	ulong old = getFPcontrol();
80 	ulong changed = mask&(fcr^old);
81 	fcr = (fcr&mask) | (old&~mask);
82 
83 	if(fcr&INEX) fc |= FP_X_IMP;
84 	if(fcr&OVFL) fc |= FP_X_OFL;
85 	if(fcr&UNFL) fc |= FP_X_UFL;
86 	if(fcr&ZDIV) fc |= FP_X_DZ;
87 	if(fcr&INVAL) fc |= FP_X_INV;
88 
89 	switch(fcr&RND_MASK){
90 		case RND_NR:    round |= FP_RM; break;
91 		case RND_NINF:  round |= FP_RN; break;
92 		case RND_PINF:  round |= FP_RP; break;
93 		case RND_Z:     round |= FP_RZ; break;
94 	}
95 
96 	fpsetround(round);
97 	fpsetmask(fc);
98 	return(old&mask);
99 }
100