1*4882a593Smuzhiyun // SPDX-License-Identifier: GPL-2.0-or-later
2*4882a593Smuzhiyun /*
3*4882a593Smuzhiyun * Linux/PA-RISC Project (http://www.parisc-linux.org/)
4*4882a593Smuzhiyun *
5*4882a593Smuzhiyun * Floating-point emulation code
6*4882a593Smuzhiyun * Copyright (C) 2001 Hewlett-Packard (Paul Bame) <bame@debian.org>
7*4882a593Smuzhiyun */
8*4882a593Smuzhiyun /*
9*4882a593Smuzhiyun * BEGIN_DESC
10*4882a593Smuzhiyun *
11*4882a593Smuzhiyun * File:
12*4882a593Smuzhiyun * @(#) pa/fp/denormal.c $ Revision: $
13*4882a593Smuzhiyun *
14*4882a593Smuzhiyun * Purpose:
15*4882a593Smuzhiyun * <<please update with a synopsis of the functionality provided by this file>>
16*4882a593Smuzhiyun *
17*4882a593Smuzhiyun * External Interfaces:
18*4882a593Smuzhiyun * <<the following list was autogenerated, please review>>
19*4882a593Smuzhiyun * dbl_denormalize(dbl_opndp1,dbl_opndp2,inexactflag,rmode)
20*4882a593Smuzhiyun * sgl_denormalize(sgl_opnd,inexactflag,rmode)
21*4882a593Smuzhiyun *
22*4882a593Smuzhiyun * Internal Interfaces:
23*4882a593Smuzhiyun * <<please update>>
24*4882a593Smuzhiyun *
25*4882a593Smuzhiyun * Theory:
26*4882a593Smuzhiyun * <<please update with a overview of the operation of this file>>
27*4882a593Smuzhiyun *
28*4882a593Smuzhiyun * END_DESC
29*4882a593Smuzhiyun */
30*4882a593Smuzhiyun
31*4882a593Smuzhiyun
32*4882a593Smuzhiyun
33*4882a593Smuzhiyun #include "float.h"
34*4882a593Smuzhiyun #include "sgl_float.h"
35*4882a593Smuzhiyun #include "dbl_float.h"
36*4882a593Smuzhiyun #include "hppa.h"
37*4882a593Smuzhiyun #include <linux/kernel.h>
38*4882a593Smuzhiyun /* #include <machine/sys/mdep_private.h> */
39*4882a593Smuzhiyun
40*4882a593Smuzhiyun #undef Fpustatus_register
41*4882a593Smuzhiyun #define Fpustatus_register Fpu_register[0]
42*4882a593Smuzhiyun
43*4882a593Smuzhiyun void
sgl_denormalize(unsigned int * sgl_opnd,boolean * inexactflag,int rmode)44*4882a593Smuzhiyun sgl_denormalize(unsigned int *sgl_opnd, boolean *inexactflag, int rmode)
45*4882a593Smuzhiyun {
46*4882a593Smuzhiyun unsigned int opnd;
47*4882a593Smuzhiyun int sign, exponent;
48*4882a593Smuzhiyun boolean guardbit = FALSE, stickybit, inexact;
49*4882a593Smuzhiyun
50*4882a593Smuzhiyun opnd = *sgl_opnd;
51*4882a593Smuzhiyun stickybit = *inexactflag;
52*4882a593Smuzhiyun exponent = Sgl_exponent(opnd) - SGL_WRAP;
53*4882a593Smuzhiyun sign = Sgl_sign(opnd);
54*4882a593Smuzhiyun Sgl_denormalize(opnd,exponent,guardbit,stickybit,inexact);
55*4882a593Smuzhiyun if (inexact) {
56*4882a593Smuzhiyun switch (rmode) {
57*4882a593Smuzhiyun case ROUNDPLUS:
58*4882a593Smuzhiyun if (sign == 0) {
59*4882a593Smuzhiyun Sgl_increment(opnd);
60*4882a593Smuzhiyun }
61*4882a593Smuzhiyun break;
62*4882a593Smuzhiyun case ROUNDMINUS:
63*4882a593Smuzhiyun if (sign != 0) {
64*4882a593Smuzhiyun Sgl_increment(opnd);
65*4882a593Smuzhiyun }
66*4882a593Smuzhiyun break;
67*4882a593Smuzhiyun case ROUNDNEAREST:
68*4882a593Smuzhiyun if (guardbit && (stickybit ||
69*4882a593Smuzhiyun Sgl_isone_lowmantissa(opnd))) {
70*4882a593Smuzhiyun Sgl_increment(opnd);
71*4882a593Smuzhiyun }
72*4882a593Smuzhiyun break;
73*4882a593Smuzhiyun }
74*4882a593Smuzhiyun }
75*4882a593Smuzhiyun Sgl_set_sign(opnd,sign);
76*4882a593Smuzhiyun *sgl_opnd = opnd;
77*4882a593Smuzhiyun *inexactflag = inexact;
78*4882a593Smuzhiyun return;
79*4882a593Smuzhiyun }
80*4882a593Smuzhiyun
81*4882a593Smuzhiyun void
dbl_denormalize(unsigned int * dbl_opndp1,unsigned int * dbl_opndp2,boolean * inexactflag,int rmode)82*4882a593Smuzhiyun dbl_denormalize(unsigned int *dbl_opndp1,
83*4882a593Smuzhiyun unsigned int * dbl_opndp2,
84*4882a593Smuzhiyun boolean *inexactflag,
85*4882a593Smuzhiyun int rmode)
86*4882a593Smuzhiyun {
87*4882a593Smuzhiyun unsigned int opndp1, opndp2;
88*4882a593Smuzhiyun int sign, exponent;
89*4882a593Smuzhiyun boolean guardbit = FALSE, stickybit, inexact;
90*4882a593Smuzhiyun
91*4882a593Smuzhiyun opndp1 = *dbl_opndp1;
92*4882a593Smuzhiyun opndp2 = *dbl_opndp2;
93*4882a593Smuzhiyun stickybit = *inexactflag;
94*4882a593Smuzhiyun exponent = Dbl_exponent(opndp1) - DBL_WRAP;
95*4882a593Smuzhiyun sign = Dbl_sign(opndp1);
96*4882a593Smuzhiyun Dbl_denormalize(opndp1,opndp2,exponent,guardbit,stickybit,inexact);
97*4882a593Smuzhiyun if (inexact) {
98*4882a593Smuzhiyun switch (rmode) {
99*4882a593Smuzhiyun case ROUNDPLUS:
100*4882a593Smuzhiyun if (sign == 0) {
101*4882a593Smuzhiyun Dbl_increment(opndp1,opndp2);
102*4882a593Smuzhiyun }
103*4882a593Smuzhiyun break;
104*4882a593Smuzhiyun case ROUNDMINUS:
105*4882a593Smuzhiyun if (sign != 0) {
106*4882a593Smuzhiyun Dbl_increment(opndp1,opndp2);
107*4882a593Smuzhiyun }
108*4882a593Smuzhiyun break;
109*4882a593Smuzhiyun case ROUNDNEAREST:
110*4882a593Smuzhiyun if (guardbit && (stickybit ||
111*4882a593Smuzhiyun Dbl_isone_lowmantissap2(opndp2))) {
112*4882a593Smuzhiyun Dbl_increment(opndp1,opndp2);
113*4882a593Smuzhiyun }
114*4882a593Smuzhiyun break;
115*4882a593Smuzhiyun }
116*4882a593Smuzhiyun }
117*4882a593Smuzhiyun Dbl_set_sign(opndp1,sign);
118*4882a593Smuzhiyun *dbl_opndp1 = opndp1;
119*4882a593Smuzhiyun *dbl_opndp2 = opndp2;
120*4882a593Smuzhiyun *inexactflag = inexact;
121*4882a593Smuzhiyun return;
122*4882a593Smuzhiyun }
123