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1da177e4 LT |
1 | /* |
2 | NetWinder Floating Point Emulator | |
3 | (c) Rebel.COM, 1998,1999 | |
4 | (c) Philip Blundell, 2001 | |
5 | ||
6 | Direct questions, comments to Scott Bambrough <scottb@netwinder.org> | |
7 | ||
8 | This program is free software; you can redistribute it and/or modify | |
9 | it under the terms of the GNU General Public License as published by | |
10 | the Free Software Foundation; either version 2 of the License, or | |
11 | (at your option) any later version. | |
12 | ||
13 | This program is distributed in the hope that it will be useful, | |
14 | but WITHOUT ANY WARRANTY; without even the implied warranty of | |
15 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
16 | GNU General Public License for more details. | |
17 | ||
18 | You should have received a copy of the GNU General Public License | |
19 | along with this program; if not, write to the Free Software | |
20 | Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. | |
21 | */ | |
22 | ||
23 | #include <linux/config.h> | |
24 | #include "fpa11.h" | |
25 | #include "fpopcode.h" | |
26 | ||
27 | unsigned int SingleCPDO(const unsigned int opcode, FPREG * rFd); | |
28 | unsigned int DoubleCPDO(const unsigned int opcode, FPREG * rFd); | |
29 | unsigned int ExtendedCPDO(const unsigned int opcode, FPREG * rFd); | |
30 | ||
31 | unsigned int EmulateCPDO(const unsigned int opcode) | |
32 | { | |
33 | FPA11 *fpa11 = GET_FPA11(); | |
34 | FPREG *rFd; | |
35 | unsigned int nType, nDest, nRc; | |
36 | ||
37 | /* Get the destination size. If not valid let Linux perform | |
38 | an invalid instruction trap. */ | |
39 | nDest = getDestinationSize(opcode); | |
40 | if (typeNone == nDest) | |
41 | return 0; | |
42 | ||
43 | SetRoundingMode(opcode); | |
44 | ||
45 | /* Compare the size of the operands in Fn and Fm. | |
46 | Choose the largest size and perform operations in that size, | |
47 | in order to make use of all the precision of the operands. | |
48 | If Fm is a constant, we just grab a constant of a size | |
49 | matching the size of the operand in Fn. */ | |
50 | if (MONADIC_INSTRUCTION(opcode)) | |
51 | nType = nDest; | |
52 | else | |
53 | nType = fpa11->fType[getFn(opcode)]; | |
54 | ||
55 | if (!CONSTANT_FM(opcode)) { | |
56 | register unsigned int Fm = getFm(opcode); | |
57 | if (nType < fpa11->fType[Fm]) { | |
58 | nType = fpa11->fType[Fm]; | |
59 | } | |
60 | } | |
61 | ||
62 | rFd = &fpa11->fpreg[getFd(opcode)]; | |
63 | ||
64 | switch (nType) { | |
65 | case typeSingle: | |
66 | nRc = SingleCPDO(opcode, rFd); | |
67 | break; | |
68 | case typeDouble: | |
69 | nRc = DoubleCPDO(opcode, rFd); | |
70 | break; | |
71 | #ifdef CONFIG_FPE_NWFPE_XP | |
72 | case typeExtended: | |
73 | nRc = ExtendedCPDO(opcode, rFd); | |
74 | break; | |
75 | #endif | |
76 | default: | |
77 | nRc = 0; | |
78 | } | |
79 | ||
80 | /* The CPDO functions used to always set the destination type | |
81 | to be the same as their working size. */ | |
82 | ||
83 | if (nRc != 0) { | |
84 | /* If the operation succeeded, check to see if the result in the | |
85 | destination register is the correct size. If not force it | |
86 | to be. */ | |
87 | ||
88 | fpa11->fType[getFd(opcode)] = nDest; | |
89 | ||
90 | #ifdef CONFIG_FPE_NWFPE_XP | |
91 | if (nDest != nType) { | |
92 | switch (nDest) { | |
93 | case typeSingle: | |
94 | { | |
95 | if (typeDouble == nType) | |
96 | rFd->fSingle = float64_to_float32(rFd->fDouble); | |
97 | else | |
98 | rFd->fSingle = floatx80_to_float32(rFd->fExtended); | |
99 | } | |
100 | break; | |
101 | ||
102 | case typeDouble: | |
103 | { | |
104 | if (typeSingle == nType) | |
105 | rFd->fDouble = float32_to_float64(rFd->fSingle); | |
106 | else | |
107 | rFd->fDouble = floatx80_to_float64(rFd->fExtended); | |
108 | } | |
109 | break; | |
110 | ||
111 | case typeExtended: | |
112 | { | |
113 | if (typeSingle == nType) | |
114 | rFd->fExtended = float32_to_floatx80(rFd->fSingle); | |
115 | else | |
116 | rFd->fExtended = float64_to_floatx80(rFd->fDouble); | |
117 | } | |
118 | break; | |
119 | } | |
120 | } | |
121 | #else | |
122 | if (nDest != nType) { | |
123 | if (nDest == typeSingle) | |
124 | rFd->fSingle = float64_to_float32(rFd->fDouble); | |
125 | else | |
126 | rFd->fDouble = float32_to_float64(rFd->fSingle); | |
127 | } | |
128 | #endif | |
129 | } | |
130 | ||
131 | return nRc; | |
132 | } |