1/*
2    NetWinder Floating Point Emulator
3    (c) Rebel.COM, 1998,1999
4
5    Direct questions, comments to Scott Bambrough <scottb@netwinder.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 of the License, or
10    (at your option) 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#include "fpa11.h"
23#include "fpopcode.h"
24
25unsigned int SingleCPDO(const unsigned int opcode);
26unsigned int DoubleCPDO(const unsigned int opcode);
27unsigned int ExtendedCPDO(const unsigned int opcode);
28
29unsigned int EmulateCPDO(const unsigned int opcode)
30{
31   FPA11 *fpa11 = GET_FPA11();
32   unsigned int Fd, nType, nDest, nRc = 1;
33
34   //printk("EmulateCPDO(0x%08x)\n",opcode);
35
36   /* Get the destination size.  If not valid let Linux perform
37      an invalid instruction trap. */
38   nDest = getDestinationSize(opcode);
39   if (typeNone == nDest) return 0;
40
41   SetRoundingMode(opcode);
42
43   /* Compare the size of the operands in Fn and Fm.
44      Choose the largest size and perform operations in that size,
45      in order to make use of all the precision of the operands.
46      If Fm is a constant, we just grab a constant of a size
47      matching the size of the operand in Fn. */
48   if (MONADIC_INSTRUCTION(opcode))
49     nType = nDest;
50   else
51     nType = fpa11->fType[getFn(opcode)];
52
53   if (!CONSTANT_FM(opcode))
54   {
55     register unsigned int Fm = getFm(opcode);
56     if (nType < fpa11->fType[Fm])
57     {
58        nType = fpa11->fType[Fm];
59     }
60   }
61
62   switch (nType)
63   {
64      case typeSingle   : nRc = SingleCPDO(opcode);   break;
65      case typeDouble   : nRc = DoubleCPDO(opcode);   break;
66      case typeExtended : nRc = ExtendedCPDO(opcode); break;
67      default           : nRc = 0;
68   }
69
70   /* If the operation succeeded, check to see if the result in the
71      destination register is the correct size.  If not force it
72      to be. */
73   Fd = getFd(opcode);
74   nType = fpa11->fType[Fd];
75   if ((0 != nRc) && (nDest != nType))
76   {
77     switch (nDest)
78     {
79       case typeSingle:
80       {
81         if (typeDouble == nType)
82           fpa11->fpreg[Fd].fSingle =
83              float64_to_float32(fpa11->fpreg[Fd].fDouble);
84         else
85           fpa11->fpreg[Fd].fSingle =
86              floatx80_to_float32(fpa11->fpreg[Fd].fExtended);
87       }
88       break;
89
90       case typeDouble:
91       {
92         if (typeSingle == nType)
93           fpa11->fpreg[Fd].fDouble =
94              float32_to_float64(fpa11->fpreg[Fd].fSingle);
95         else
96           fpa11->fpreg[Fd].fDouble =
97              floatx80_to_float64(fpa11->fpreg[Fd].fExtended);
98       }
99       break;
100
101       case typeExtended:
102       {
103         if (typeSingle == nType)
104           fpa11->fpreg[Fd].fExtended =
105              float32_to_floatx80(fpa11->fpreg[Fd].fSingle);
106         else
107           fpa11->fpreg[Fd].fExtended =
108              float64_to_floatx80(fpa11->fpreg[Fd].fDouble);
109       }
110       break;
111     }
112
113     fpa11->fType[Fd] = nDest;
114   }
115
116   return nRc;
117}
118