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 "fpa11.h" 24 #include "fpopcode.h" 25 26 unsigned int SingleCPDO(struct roundingData *roundData, const unsigned int opcode, FPREG * rFd); 27 unsigned int DoubleCPDO(struct roundingData *roundData, const unsigned int opcode, FPREG * rFd); 28 unsigned int ExtendedCPDO(struct roundingData *roundData, const unsigned int opcode, FPREG * rFd); 29 30 unsigned int EmulateCPDO(const unsigned int opcode) 31 { 32 FPA11 *fpa11 = GET_FPA11(); 33 FPREG *rFd; 34 unsigned int nType, nDest, nRc; 35 struct roundingData roundData; 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 roundData.mode = SetRoundingMode(opcode); 44 roundData.precision = SetRoundingPrecision(opcode); 45 roundData.exception = 0; 46 47 /* Compare the size of the operands in Fn and Fm. 48 Choose the largest size and perform operations in that size, 49 in order to make use of all the precision of the operands. 50 If Fm is a constant, we just grab a constant of a size 51 matching the size of the operand in Fn. */ 52 if (MONADIC_INSTRUCTION(opcode)) 53 nType = nDest; 54 else 55 nType = fpa11->fType[getFn(opcode)]; 56 57 if (!CONSTANT_FM(opcode)) { 58 register unsigned int Fm = getFm(opcode); 59 if (nType < fpa11->fType[Fm]) { 60 nType = fpa11->fType[Fm]; 61 } 62 } 63 64 rFd = &fpa11->fpreg[getFd(opcode)]; 65 66 switch (nType) { 67 case typeSingle: 68 nRc = SingleCPDO(&roundData, opcode, rFd); 69 break; 70 case typeDouble: 71 nRc = DoubleCPDO(&roundData, opcode, rFd); 72 break; 73 #ifdef CONFIG_FPE_NWFPE_XP 74 case typeExtended: 75 nRc = ExtendedCPDO(&roundData, opcode, rFd); 76 break; 77 #endif 78 default: 79 nRc = 0; 80 } 81 82 /* The CPDO functions used to always set the destination type 83 to be the same as their working size. */ 84 85 if (nRc != 0) { 86 /* If the operation succeeded, check to see if the result in the 87 destination register is the correct size. If not force it 88 to be. */ 89 90 fpa11->fType[getFd(opcode)] = nDest; 91 92 #ifdef CONFIG_FPE_NWFPE_XP 93 if (nDest != nType) { 94 switch (nDest) { 95 case typeSingle: 96 { 97 if (typeDouble == nType) 98 rFd->fSingle = float64_to_float32(&roundData, rFd->fDouble); 99 else 100 rFd->fSingle = floatx80_to_float32(&roundData, rFd->fExtended); 101 } 102 break; 103 104 case typeDouble: 105 { 106 if (typeSingle == nType) 107 rFd->fDouble = float32_to_float64(rFd->fSingle); 108 else 109 rFd->fDouble = floatx80_to_float64(&roundData, rFd->fExtended); 110 } 111 break; 112 113 case typeExtended: 114 { 115 if (typeSingle == nType) 116 rFd->fExtended = float32_to_floatx80(rFd->fSingle); 117 else 118 rFd->fExtended = float64_to_floatx80(rFd->fDouble); 119 } 120 break; 121 } 122 } 123 #else 124 if (nDest != nType) { 125 if (nDest == typeSingle) 126 rFd->fSingle = float64_to_float32(&roundData, rFd->fDouble); 127 else 128 rFd->fDouble = float32_to_float64(rFd->fSingle); 129 } 130 #endif 131 } 132 133 if (roundData.exception) 134 float_raise(roundData.exception); 135 136 return nRc; 137 } 138