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 #include <asm/system.h> 32 33 /* Reset the FPA11 chip. Called to initialize and reset the emulator. */ 34 static void resetFPA11(void) 35 { 36 int i; 37 FPA11 *fpa11 = GET_FPA11(); 38 39 /* initialize the register type array */ 40 for (i = 0; i <= 7; i++) { 41 fpa11->fType[i] = typeNone; 42 } 43 44 /* FPSR: set system id to FP_EMULATOR, set AC, clear all other bits */ 45 fpa11->fpsr = FP_EMULATOR | BIT_AC; 46 } 47 48 int8 SetRoundingMode(const unsigned int opcode) 49 { 50 switch (opcode & MASK_ROUNDING_MODE) { 51 default: 52 case ROUND_TO_NEAREST: 53 return float_round_nearest_even; 54 55 case ROUND_TO_PLUS_INFINITY: 56 return float_round_up; 57 58 case ROUND_TO_MINUS_INFINITY: 59 return float_round_down; 60 61 case ROUND_TO_ZERO: 62 return float_round_to_zero; 63 } 64 } 65 66 int8 SetRoundingPrecision(const unsigned int opcode) 67 { 68 #ifdef CONFIG_FPE_NWFPE_XP 69 switch (opcode & MASK_ROUNDING_PRECISION) { 70 case ROUND_SINGLE: 71 return 32; 72 73 case ROUND_DOUBLE: 74 return 64; 75 76 case ROUND_EXTENDED: 77 return 80; 78 79 default: 80 return 80; 81 } 82 #endif 83 return 80; 84 } 85 86 void nwfpe_init_fpa(union fp_state *fp) 87 { 88 FPA11 *fpa11 = (FPA11 *)fp; 89 #ifdef NWFPE_DEBUG 90 printk("NWFPE: setting up state.\n"); 91 #endif 92 memset(fpa11, 0, sizeof(FPA11)); 93 resetFPA11(); 94 fpa11->initflag = 1; 95 } 96 97 /* Emulate the instruction in the opcode. */ 98 unsigned int EmulateAll(unsigned int opcode) 99 { 100 unsigned int code; 101 102 #ifdef NWFPE_DEBUG 103 printk("NWFPE: emulating opcode %08x\n", opcode); 104 #endif 105 code = opcode & 0x00000f00; 106 if (code == 0x00000100 || code == 0x00000200) { 107 /* For coprocessor 1 or 2 (FPA11) */ 108 code = opcode & 0x0e000000; 109 if (code == 0x0e000000) { 110 if (opcode & 0x00000010) { 111 /* Emulate conversion opcodes. */ 112 /* Emulate register transfer opcodes. */ 113 /* Emulate comparison opcodes. */ 114 return EmulateCPRT(opcode); 115 } else { 116 /* Emulate monadic arithmetic opcodes. */ 117 /* Emulate dyadic arithmetic opcodes. */ 118 return EmulateCPDO(opcode); 119 } 120 } else if (code == 0x0c000000) { 121 /* Emulate load/store opcodes. */ 122 /* Emulate load/store multiple opcodes. */ 123 return EmulateCPDT(opcode); 124 } 125 } 126 127 /* Invalid instruction detected. Return FALSE. */ 128 return 0; 129 } 130