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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 | ||
25 | unsigned int SingleCPDO(const unsigned int opcode); | |
26 | unsigned int DoubleCPDO(const unsigned int opcode); | |
27 | unsigned int ExtendedCPDO(const unsigned int opcode); | |
28 | ||
29 | unsigned 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 | } |