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 #include "fpmodule.h" 27 #include "fpmodule.inl" 28 29 #include <linux/compiler.h> 30 #include <linux/string.h> 31 32 /* Reset the FPA11 chip. Called to initialize and reset the emulator. */ 33 static void resetFPA11(void) 34 { 35 int i; 36 FPA11 *fpa11 = GET_FPA11(); 37 38 /* initialize the register type array */ 39 for (i = 0; i <= 7; i++) { 40 fpa11->fType[i] = typeNone; 41 } 42 43 /* FPSR: set system id to FP_EMULATOR, set AC, clear all other bits */ 44 fpa11->fpsr = FP_EMULATOR | BIT_AC; 45 } 46 47 int8 SetRoundingMode(const unsigned int opcode) 48 { 49 switch (opcode & MASK_ROUNDING_MODE) { 50 default: 51 case ROUND_TO_NEAREST: 52 return float_round_nearest_even; 53 54 case ROUND_TO_PLUS_INFINITY: 55 return float_round_up; 56 57 case ROUND_TO_MINUS_INFINITY: 58 return float_round_down; 59 60 case ROUND_TO_ZERO: 61 return float_round_to_zero; 62 } 63 } 64 65 int8 SetRoundingPrecision(const unsigned int opcode) 66 { 67 #ifdef CONFIG_FPE_NWFPE_XP 68 switch (opcode & MASK_ROUNDING_PRECISION) { 69 case ROUND_SINGLE: 70 return 32; 71 72 case ROUND_DOUBLE: 73 return 64; 74 75 case ROUND_EXTENDED: 76 return 80; 77 78 default: 79 return 80; 80 } 81 #endif 82 return 80; 83 } 84 85 void nwfpe_init_fpa(union fp_state *fp) 86 { 87 FPA11 *fpa11 = (FPA11 *)fp; 88 #ifdef NWFPE_DEBUG 89 printk("NWFPE: setting up state.\n"); 90 #endif 91 memset(fpa11, 0, sizeof(FPA11)); 92 resetFPA11(); 93 fpa11->initflag = 1; 94 } 95 96 /* Emulate the instruction in the opcode. */ 97 unsigned int EmulateAll(unsigned int opcode) 98 { 99 unsigned int code; 100 101 #ifdef NWFPE_DEBUG 102 printk("NWFPE: emulating opcode %08x\n", opcode); 103 #endif 104 code = opcode & 0x00000f00; 105 if (code == 0x00000100 || code == 0x00000200) { 106 /* For coprocessor 1 or 2 (FPA11) */ 107 code = opcode & 0x0e000000; 108 if (code == 0x0e000000) { 109 if (opcode & 0x00000010) { 110 /* Emulate conversion opcodes. */ 111 /* Emulate register transfer opcodes. */ 112 /* Emulate comparison opcodes. */ 113 return EmulateCPRT(opcode); 114 } else { 115 /* Emulate monadic arithmetic opcodes. */ 116 /* Emulate dyadic arithmetic opcodes. */ 117 return EmulateCPDO(opcode); 118 } 119 } else if (code == 0x0c000000) { 120 /* Emulate load/store opcodes. */ 121 /* Emulate load/store multiple opcodes. */ 122 return EmulateCPDT(opcode); 123 } 124 } 125 126 /* Invalid instruction detected. Return FALSE. */ 127 return 0; 128 } 129