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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 | /* NetWinder Floating Point Emulator (c) Rebel.COM, 1998,1999 (c) Philip Blundell, 2001 Direct questions, comments to Scott Bambrough <scottb@netwinder.org> This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later version. This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with this program; if not, write to the Free Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. */ #include "fpa11.h" #include "fpopcode.h" #include "fpmodule.h" #include "fpmodule.inl" #include <linux/config.h> #include <linux/compiler.h> #include <linux/string.h> #include <asm/system.h> /* forward declarations */ unsigned int EmulateCPDO(const unsigned int); unsigned int EmulateCPDT(const unsigned int); unsigned int EmulateCPRT(const unsigned int); /* Reset the FPA11 chip. Called to initialize and reset the emulator. */ static void resetFPA11(void) { int i; FPA11 *fpa11 = GET_FPA11(); /* initialize the register type array */ for (i = 0; i <= 7; i++) { fpa11->fType[i] = typeNone; } /* FPSR: set system id to FP_EMULATOR, set AC, clear all other bits */ fpa11->fpsr = FP_EMULATOR | BIT_AC; } void SetRoundingMode(const unsigned int opcode) { switch (opcode & MASK_ROUNDING_MODE) { default: case ROUND_TO_NEAREST: float_rounding_mode = float_round_nearest_even; break; case ROUND_TO_PLUS_INFINITY: float_rounding_mode = float_round_up; break; case ROUND_TO_MINUS_INFINITY: float_rounding_mode = float_round_down; break; case ROUND_TO_ZERO: float_rounding_mode = float_round_to_zero; break; } } void SetRoundingPrecision(const unsigned int opcode) { #ifdef CONFIG_FPE_NWFPE_XP switch (opcode & MASK_ROUNDING_PRECISION) { case ROUND_SINGLE: floatx80_rounding_precision = 32; break; case ROUND_DOUBLE: floatx80_rounding_precision = 64; break; case ROUND_EXTENDED: floatx80_rounding_precision = 80; break; default: floatx80_rounding_precision = 80; } #endif } void nwfpe_init_fpa(union fp_state *fp) { FPA11 *fpa11 = (FPA11 *)fp; #ifdef NWFPE_DEBUG printk("NWFPE: setting up state.\n"); #endif memset(fpa11, 0, sizeof(FPA11)); resetFPA11(); SetRoundingMode(ROUND_TO_NEAREST); SetRoundingPrecision(ROUND_EXTENDED); fpa11->initflag = 1; } /* Emulate the instruction in the opcode. */ unsigned int EmulateAll(unsigned int opcode) { unsigned int code; #ifdef NWFPE_DEBUG printk("NWFPE: emulating opcode %08x\n", opcode); #endif code = opcode & 0x00000f00; if (code == 0x00000100 || code == 0x00000200) { /* For coprocessor 1 or 2 (FPA11) */ code = opcode & 0x0e000000; if (code == 0x0e000000) { if (opcode & 0x00000010) { /* Emulate conversion opcodes. */ /* Emulate register transfer opcodes. */ /* Emulate comparison opcodes. */ return EmulateCPRT(opcode); } else { /* Emulate monadic arithmetic opcodes. */ /* Emulate dyadic arithmetic opcodes. */ return EmulateCPDO(opcode); } } else if (code == 0x0c000000) { /* Emulate load/store opcodes. */ /* Emulate load/store multiple opcodes. */ return EmulateCPDT(opcode); } } /* Invalid instruction detected. Return FALSE. */ return 0; } |