| Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 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 | } |