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 } 133