1 /*
2 * Linux/PA-RISC Project (http://www.parisc-linux.org/)
3 *
4 * Floating-point emulation code
5 * Copyright (C) 2001 Hewlett-Packard (Paul Bame) <bame@debian.org>
6 *
7 * This program is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License as published by
9 * the Free Software Foundation; either version 2, or (at your option)
10 * any later version.
11 *
12 * This program is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 * GNU General Public License for more details.
16 *
17 * You should have received a copy of the GNU General Public License
18 * along with this program; if not, write to the Free Software
19 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
20 */
21 /*
22 * BEGIN_DESC
23 *
24 * File:
25 * @(#) pa/fp/denormal.c $ Revision: $
26 *
27 * Purpose:
28 * <<please update with a synopsis of the functionality provided by this file>>
29 *
30 * External Interfaces:
31 * <<the following list was autogenerated, please review>>
32 * dbl_denormalize(dbl_opndp1,dbl_opndp2,inexactflag,rmode)
33 * sgl_denormalize(sgl_opnd,inexactflag,rmode)
34 *
35 * Internal Interfaces:
36 * <<please update>>
37 *
38 * Theory:
39 * <<please update with a overview of the operation of this file>>
40 *
41 * END_DESC
42 */
43
44
45
46 #include "float.h"
47 #include "sgl_float.h"
48 #include "dbl_float.h"
49 #include "hppa.h"
50 #include "types.h"
51 /* #include <machine/sys/mdep_private.h> */
52
53 #undef Fpustatus_register
54 #define Fpustatus_register Fpu_register[0]
55
56 void
sgl_denormalize(unsigned int * sgl_opnd,boolean * inexactflag,int rmode)57 sgl_denormalize(unsigned int *sgl_opnd, boolean *inexactflag, int rmode)
58 {
59 unsigned int opnd;
60 int sign, exponent;
61 boolean guardbit = FALSE, stickybit, inexact;
62
63 opnd = *sgl_opnd;
64 stickybit = *inexactflag;
65 exponent = Sgl_exponent(opnd) - SGL_WRAP;
66 sign = Sgl_sign(opnd);
67 Sgl_denormalize(opnd,exponent,guardbit,stickybit,inexact);
68 if (inexact) {
69 switch (rmode) {
70 case ROUNDPLUS:
71 if (sign == 0) {
72 Sgl_increment(opnd);
73 }
74 break;
75 case ROUNDMINUS:
76 if (sign != 0) {
77 Sgl_increment(opnd);
78 }
79 break;
80 case ROUNDNEAREST:
81 if (guardbit && (stickybit ||
82 Sgl_isone_lowmantissa(opnd))) {
83 Sgl_increment(opnd);
84 }
85 break;
86 }
87 }
88 Sgl_set_sign(opnd,sign);
89 *sgl_opnd = opnd;
90 *inexactflag = inexact;
91 return;
92 }
93
94 void
dbl_denormalize(unsigned int * dbl_opndp1,unsigned int * dbl_opndp2,boolean * inexactflag,int rmode)95 dbl_denormalize(unsigned int *dbl_opndp1,
96 unsigned int * dbl_opndp2,
97 boolean *inexactflag,
98 int rmode)
99 {
100 unsigned int opndp1, opndp2;
101 int sign, exponent;
102 boolean guardbit = FALSE, stickybit, inexact;
103
104 opndp1 = *dbl_opndp1;
105 opndp2 = *dbl_opndp2;
106 stickybit = *inexactflag;
107 exponent = Dbl_exponent(opndp1) - DBL_WRAP;
108 sign = Dbl_sign(opndp1);
109 Dbl_denormalize(opndp1,opndp2,exponent,guardbit,stickybit,inexact);
110 if (inexact) {
111 switch (rmode) {
112 case ROUNDPLUS:
113 if (sign == 0) {
114 Dbl_increment(opndp1,opndp2);
115 }
116 break;
117 case ROUNDMINUS:
118 if (sign != 0) {
119 Dbl_increment(opndp1,opndp2);
120 }
121 break;
122 case ROUNDNEAREST:
123 if (guardbit && (stickybit ||
124 Dbl_isone_lowmantissap2(opndp2))) {
125 Dbl_increment(opndp1,opndp2);
126 }
127 break;
128 }
129 }
130 Dbl_set_sign(opndp1,sign);
131 *dbl_opndp1 = opndp1;
132 *dbl_opndp2 = opndp2;
133 *inexactflag = inexact;
134 return;
135 }
136