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/config.h> 30 #include <linux/compiler.h> 31 #include <linux/string.h> 32 #include <asm/system.h> 33 34 /* Reset the FPA11 chip. Called to initialize and reset the emulator. */ 35 static void resetFPA11(void) 36 { 37 int i; 38 FPA11 *fpa11 = GET_FPA11(); 39 40 /* initialize the register type array */ 41 for (i = 0; i <= 7; i++) { 42 fpa11->fType[i] = typeNone; 43 } 44 45 /* FPSR: set system id to FP_EMULATOR, set AC, clear all other bits */ 46 fpa11->fpsr = FP_EMULATOR | BIT_AC; 47 } 48 49 int8 SetRoundingMode(const unsigned int opcode) 50 { 51 switch (opcode & MASK_ROUNDING_MODE) { 52 default: 53 case ROUND_TO_NEAREST: 54 return float_round_nearest_even; 55 56 case ROUND_TO_PLUS_INFINITY: 57 return float_round_up; 58 59 case ROUND_TO_MINUS_INFINITY: 60 return float_round_down; 61 62 case ROUND_TO_ZERO: 63 return float_round_to_zero; 64 } 65 } 66 67 int8 SetRoundingPrecision(const unsigned int opcode) 68 { 69 #ifdef CONFIG_FPE_NWFPE_XP 70 switch (opcode & MASK_ROUNDING_PRECISION) { 71 case ROUND_SINGLE: 72 return 32; 73 74 case ROUND_DOUBLE: 75 return 64; 76 77 case ROUND_EXTENDED: 78 return 80; 79 80 default: 81 return 80; 82 } 83 #endif 84 return 80; 85 } 86 87 void nwfpe_init_fpa(union fp_state *fp) 88 { 89 FPA11 *fpa11 = (FPA11 *)fp; 90 #ifdef NWFPE_DEBUG 91 printk("NWFPE: setting up state.\n"); 92 #endif 93 memset(fpa11, 0, sizeof(FPA11)); 94 resetFPA11(); 95 fpa11->initflag = 1; 96 } 97 98 /* Emulate the instruction in the opcode. */ 99 unsigned int EmulateAll(unsigned int opcode) 100 { 101 unsigned int code; 102 103 #ifdef NWFPE_DEBUG 104 printk("NWFPE: emulating opcode %08x\n", opcode); 105 #endif 106 code = opcode & 0x00000f00; 107 if (code == 0x00000100 || code == 0x00000200) { 108 /* For coprocessor 1 or 2 (FPA11) */ 109 code = opcode & 0x0e000000; 110 if (code == 0x0e000000) { 111 if (opcode & 0x00000010) { 112 /* Emulate conversion opcodes. */ 113 /* Emulate register transfer opcodes. */ 114 /* Emulate comparison opcodes. */ 115 return EmulateCPRT(opcode); 116 } else { 117 /* Emulate monadic arithmetic opcodes. */ 118 /* Emulate dyadic arithmetic opcodes. */ 119 return EmulateCPDO(opcode); 120 } 121 } else if (code == 0x0c000000) { 122 /* Emulate load/store opcodes. */ 123 /* Emulate load/store multiple opcodes. */ 124 return EmulateCPDT(opcode); 125 } 126 } 127 128 /* Invalid instruction detected. Return FALSE. */ 129 return 0; 130 } 131