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, see <http://www.gnu.org/licenses/>. 19 */ 20 21 #include "fpa11.h" 22 #include "fpopcode.h" 23 24 unsigned int EmulateCPDO(const unsigned int opcode) 25 { 26 FPA11 *fpa11 = GET_FPA11(); 27 unsigned int Fd, nType, nDest, nRc = 1; 28 29 //printk("EmulateCPDO(0x%08x)\n",opcode); 30 31 /* Get the destination size. If not valid let Linux perform 32 an invalid instruction trap. */ 33 nDest = getDestinationSize(opcode); 34 if (typeNone == nDest) return 0; 35 36 SetRoundingMode(opcode); 37 38 /* Compare the size of the operands in Fn and Fm. 39 Choose the largest size and perform operations in that size, 40 in order to make use of all the precision of the operands. 41 If Fm is a constant, we just grab a constant of a size 42 matching the size of the operand in Fn. */ 43 if (MONADIC_INSTRUCTION(opcode)) 44 nType = nDest; 45 else 46 nType = fpa11->fType[getFn(opcode)]; 47 48 if (!CONSTANT_FM(opcode)) 49 { 50 register unsigned int Fm = getFm(opcode); 51 if (nType < fpa11->fType[Fm]) 52 { 53 nType = fpa11->fType[Fm]; 54 } 55 } 56 57 switch (nType) 58 { 59 case typeSingle : nRc = SingleCPDO(opcode); break; 60 case typeDouble : nRc = DoubleCPDO(opcode); break; 61 case typeExtended : nRc = ExtendedCPDO(opcode); break; 62 default : nRc = 0; 63 } 64 65 /* If the operation succeeded, check to see if the result in the 66 destination register is the correct size. If not force it 67 to be. */ 68 Fd = getFd(opcode); 69 nType = fpa11->fType[Fd]; 70 if ((0 != nRc) && (nDest != nType)) 71 { 72 switch (nDest) 73 { 74 case typeSingle: 75 { 76 if (typeDouble == nType) 77 fpa11->fpreg[Fd].fSingle = 78 float64_to_float32(fpa11->fpreg[Fd].fDouble, &fpa11->fp_status); 79 else 80 fpa11->fpreg[Fd].fSingle = 81 floatx80_to_float32(fpa11->fpreg[Fd].fExtended, &fpa11->fp_status); 82 } 83 break; 84 85 case typeDouble: 86 { 87 if (typeSingle == nType) 88 fpa11->fpreg[Fd].fDouble = 89 float32_to_float64(fpa11->fpreg[Fd].fSingle, &fpa11->fp_status); 90 else 91 fpa11->fpreg[Fd].fDouble = 92 floatx80_to_float64(fpa11->fpreg[Fd].fExtended, &fpa11->fp_status); 93 } 94 break; 95 96 case typeExtended: 97 { 98 if (typeSingle == nType) 99 fpa11->fpreg[Fd].fExtended = 100 float32_to_floatx80(fpa11->fpreg[Fd].fSingle, &fpa11->fp_status); 101 else 102 fpa11->fpreg[Fd].fExtended = 103 float64_to_floatx80(fpa11->fpreg[Fd].fDouble, &fpa11->fp_status); 104 } 105 break; 106 } 107 108 fpa11->fType[Fd] = nDest; 109 } 110 111 return nRc; 112 } 113