| 1 |
1275 |
phoenix |
/*
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| 2 |
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NetWinder Floating Point Emulator
|
| 3 |
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(c) Rebel.COM, 1998,1999
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| 4 |
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(c) Philip Blundell, 1999, 2001
|
| 5 |
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| 6 |
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Direct questions, comments to Scott Bambrough <scottb@netwinder.org>
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| 7 |
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| 8 |
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This program is free software; you can redistribute it and/or modify
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it under the terms of the GNU General Public License as published by
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the Free Software Foundation; either version 2 of the License, or
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| 11 |
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(at your option) any later version.
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| 13 |
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This program is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU General Public License for more details.
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| 18 |
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You should have received a copy of the GNU General Public License
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| 19 |
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along with this program; if not, write to the Free Software
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Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
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| 21 |
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*/
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| 22 |
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| 23 |
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#include "fpa11.h"
|
| 24 |
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#include "fpopcode.h"
|
| 25 |
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#include "fpa11.inl"
|
| 26 |
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#include "fpmodule.h"
|
| 27 |
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#include "fpmodule.inl"
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| 28 |
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| 29 |
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#ifdef CONFIG_FPE_NWFPE_XP
|
| 30 |
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extern flag floatx80_is_nan(floatx80);
|
| 31 |
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#endif
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| 32 |
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extern flag float64_is_nan(float64);
|
| 33 |
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extern flag float32_is_nan(float32);
|
| 34 |
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| 35 |
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void SetRoundingMode(const unsigned int opcode);
|
| 36 |
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| 37 |
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unsigned int PerformFLT(const unsigned int opcode);
|
| 38 |
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unsigned int PerformFIX(const unsigned int opcode);
|
| 39 |
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| 40 |
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static unsigned int PerformComparison(const unsigned int opcode);
|
| 41 |
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|
| 42 |
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unsigned int EmulateCPRT(const unsigned int opcode)
|
| 43 |
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{
|
| 44 |
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|
| 45 |
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if (opcode & 0x800000) {
|
| 46 |
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/* This is some variant of a comparison (PerformComparison
|
| 47 |
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will sort out which one). Since most of the other CPRT
|
| 48 |
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instructions are oddball cases of some sort or other it
|
| 49 |
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makes sense to pull this out into a fast path. */
|
| 50 |
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return PerformComparison(opcode);
|
| 51 |
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}
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| 52 |
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| 53 |
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/* Hint to GCC that we'd like a jump table rather than a load of CMPs */
|
| 54 |
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switch ((opcode & 0x700000) >> 20) {
|
| 55 |
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case FLT_CODE >> 20:
|
| 56 |
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return PerformFLT(opcode);
|
| 57 |
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break;
|
| 58 |
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case FIX_CODE >> 20:
|
| 59 |
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return PerformFIX(opcode);
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| 60 |
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break;
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| 61 |
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| 62 |
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case WFS_CODE >> 20:
|
| 63 |
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writeFPSR(readRegister(getRd(opcode)));
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| 64 |
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break;
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| 65 |
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case RFS_CODE >> 20:
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| 66 |
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writeRegister(getRd(opcode), readFPSR());
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| 67 |
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break;
|
| 68 |
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| 69 |
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default:
|
| 70 |
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return 0;
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| 71 |
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}
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| 72 |
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| 73 |
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return 1;
|
| 74 |
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}
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| 75 |
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| 76 |
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unsigned int PerformFLT(const unsigned int opcode)
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| 77 |
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{
|
| 78 |
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FPA11 *fpa11 = GET_FPA11();
|
| 79 |
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SetRoundingMode(opcode);
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| 80 |
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SetRoundingPrecision(opcode);
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| 81 |
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| 82 |
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switch (opcode & MASK_ROUNDING_PRECISION) {
|
| 83 |
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case ROUND_SINGLE:
|
| 84 |
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{
|
| 85 |
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fpa11->fType[getFn(opcode)] = typeSingle;
|
| 86 |
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fpa11->fpreg[getFn(opcode)].fSingle = int32_to_float32(readRegister(getRd(opcode)));
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| 87 |
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}
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| 88 |
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break;
|
| 89 |
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| 90 |
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case ROUND_DOUBLE:
|
| 91 |
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{
|
| 92 |
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fpa11->fType[getFn(opcode)] = typeDouble;
|
| 93 |
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fpa11->fpreg[getFn(opcode)].fDouble = int32_to_float64(readRegister(getRd(opcode)));
|
| 94 |
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}
|
| 95 |
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break;
|
| 96 |
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|
| 97 |
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#ifdef CONFIG_FPE_NWFPE_XP
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| 98 |
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case ROUND_EXTENDED:
|
| 99 |
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{
|
| 100 |
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fpa11->fType[getFn(opcode)] = typeExtended;
|
| 101 |
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fpa11->fpreg[getFn(opcode)].fExtended = int32_to_floatx80(readRegister(getRd(opcode)));
|
| 102 |
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}
|
| 103 |
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break;
|
| 104 |
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#endif
|
| 105 |
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| 106 |
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default:
|
| 107 |
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return 0;
|
| 108 |
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}
|
| 109 |
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|
| 110 |
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return 1;
|
| 111 |
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}
|
| 112 |
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|
| 113 |
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unsigned int PerformFIX(const unsigned int opcode)
|
| 114 |
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{
|
| 115 |
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FPA11 *fpa11 = GET_FPA11();
|
| 116 |
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unsigned int Fn = getFm(opcode);
|
| 117 |
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| 118 |
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SetRoundingMode(opcode);
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| 119 |
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| 120 |
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switch (fpa11->fType[Fn]) {
|
| 121 |
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case typeSingle:
|
| 122 |
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{
|
| 123 |
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writeRegister(getRd(opcode), float32_to_int32(fpa11->fpreg[Fn].fSingle));
|
| 124 |
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}
|
| 125 |
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break;
|
| 126 |
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|
| 127 |
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case typeDouble:
|
| 128 |
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{
|
| 129 |
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writeRegister(getRd(opcode), float64_to_int32(fpa11->fpreg[Fn].fDouble));
|
| 130 |
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}
|
| 131 |
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break;
|
| 132 |
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|
| 133 |
|
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#ifdef CONFIG_FPE_NWFPE_XP
|
| 134 |
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case typeExtended:
|
| 135 |
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{
|
| 136 |
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writeRegister(getRd(opcode), floatx80_to_int32(fpa11->fpreg[Fn].fExtended));
|
| 137 |
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}
|
| 138 |
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break;
|
| 139 |
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#endif
|
| 140 |
|
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|
| 141 |
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default:
|
| 142 |
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return 0;
|
| 143 |
|
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}
|
| 144 |
|
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|
| 145 |
|
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return 1;
|
| 146 |
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}
|
| 147 |
|
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|
| 148 |
|
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/* This instruction sets the flags N, Z, C, V in the FPSR. */
|
| 149 |
|
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static unsigned int PerformComparison(const unsigned int opcode)
|
| 150 |
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{
|
| 151 |
|
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FPA11 *fpa11 = GET_FPA11();
|
| 152 |
|
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unsigned int Fn = getFn(opcode), Fm = getFm(opcode);
|
| 153 |
|
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int e_flag = opcode & 0x400000; /* 1 if CxFE */
|
| 154 |
|
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int n_flag = opcode & 0x200000; /* 1 if CNxx */
|
| 155 |
|
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unsigned int flags = 0;
|
| 156 |
|
|
|
| 157 |
|
|
#ifdef CONFIG_FPE_NWFPE_XP
|
| 158 |
|
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floatx80 rFn, rFm;
|
| 159 |
|
|
|
| 160 |
|
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/* Check for unordered condition and convert all operands to 80-bit
|
| 161 |
|
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format.
|
| 162 |
|
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?? Might be some mileage in avoiding this conversion if possible.
|
| 163 |
|
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Eg, if both operands are 32-bit, detect this and do a 32-bit
|
| 164 |
|
|
comparison (cheaper than an 80-bit one). */
|
| 165 |
|
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switch (fpa11->fType[Fn]) {
|
| 166 |
|
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case typeSingle:
|
| 167 |
|
|
//printk("single.\n");
|
| 168 |
|
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if (float32_is_nan(fpa11->fpreg[Fn].fSingle))
|
| 169 |
|
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goto unordered;
|
| 170 |
|
|
rFn = float32_to_floatx80(fpa11->fpreg[Fn].fSingle);
|
| 171 |
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|
break;
|
| 172 |
|
|
|
| 173 |
|
|
case typeDouble:
|
| 174 |
|
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//printk("double.\n");
|
| 175 |
|
|
if (float64_is_nan(fpa11->fpreg[Fn].fDouble))
|
| 176 |
|
|
goto unordered;
|
| 177 |
|
|
rFn = float64_to_floatx80(fpa11->fpreg[Fn].fDouble);
|
| 178 |
|
|
break;
|
| 179 |
|
|
|
| 180 |
|
|
case typeExtended:
|
| 181 |
|
|
//printk("extended.\n");
|
| 182 |
|
|
if (floatx80_is_nan(fpa11->fpreg[Fn].fExtended))
|
| 183 |
|
|
goto unordered;
|
| 184 |
|
|
rFn = fpa11->fpreg[Fn].fExtended;
|
| 185 |
|
|
break;
|
| 186 |
|
|
|
| 187 |
|
|
default:
|
| 188 |
|
|
return 0;
|
| 189 |
|
|
}
|
| 190 |
|
|
|
| 191 |
|
|
if (CONSTANT_FM(opcode)) {
|
| 192 |
|
|
//printk("Fm is a constant: #%d.\n",Fm);
|
| 193 |
|
|
rFm = getExtendedConstant(Fm);
|
| 194 |
|
|
if (floatx80_is_nan(rFm))
|
| 195 |
|
|
goto unordered;
|
| 196 |
|
|
} else {
|
| 197 |
|
|
//printk("Fm = r%d which contains a ",Fm);
|
| 198 |
|
|
switch (fpa11->fType[Fm]) {
|
| 199 |
|
|
case typeSingle:
|
| 200 |
|
|
//printk("single.\n");
|
| 201 |
|
|
if (float32_is_nan(fpa11->fpreg[Fm].fSingle))
|
| 202 |
|
|
goto unordered;
|
| 203 |
|
|
rFm = float32_to_floatx80(fpa11->fpreg[Fm].fSingle);
|
| 204 |
|
|
break;
|
| 205 |
|
|
|
| 206 |
|
|
case typeDouble:
|
| 207 |
|
|
//printk("double.\n");
|
| 208 |
|
|
if (float64_is_nan(fpa11->fpreg[Fm].fDouble))
|
| 209 |
|
|
goto unordered;
|
| 210 |
|
|
rFm = float64_to_floatx80(fpa11->fpreg[Fm].fDouble);
|
| 211 |
|
|
break;
|
| 212 |
|
|
|
| 213 |
|
|
case typeExtended:
|
| 214 |
|
|
//printk("extended.\n");
|
| 215 |
|
|
if (floatx80_is_nan(fpa11->fpreg[Fm].fExtended))
|
| 216 |
|
|
goto unordered;
|
| 217 |
|
|
rFm = fpa11->fpreg[Fm].fExtended;
|
| 218 |
|
|
break;
|
| 219 |
|
|
|
| 220 |
|
|
default:
|
| 221 |
|
|
return 0;
|
| 222 |
|
|
}
|
| 223 |
|
|
}
|
| 224 |
|
|
|
| 225 |
|
|
if (n_flag)
|
| 226 |
|
|
rFm.high ^= 0x8000;
|
| 227 |
|
|
|
| 228 |
|
|
/* test for less than condition */
|
| 229 |
|
|
if (floatx80_lt(rFn, rFm))
|
| 230 |
|
|
flags |= CC_NEGATIVE;
|
| 231 |
|
|
|
| 232 |
|
|
/* test for equal condition */
|
| 233 |
|
|
if (floatx80_eq(rFn, rFm))
|
| 234 |
|
|
flags |= CC_ZERO;
|
| 235 |
|
|
|
| 236 |
|
|
/* test for greater than or equal condition */
|
| 237 |
|
|
if (floatx80_lt(rFm, rFn))
|
| 238 |
|
|
flags |= CC_CARRY;
|
| 239 |
|
|
|
| 240 |
|
|
#else
|
| 241 |
|
|
if (CONSTANT_FM(opcode)) {
|
| 242 |
|
|
/* Fm is a constant. Do the comparison in whatever precision
|
| 243 |
|
|
Fn happens to be stored in. */
|
| 244 |
|
|
if (fpa11->fType[Fn] == typeSingle) {
|
| 245 |
|
|
float32 rFm = getSingleConstant(Fm);
|
| 246 |
|
|
float32 rFn = fpa11->fpreg[Fn].fSingle;
|
| 247 |
|
|
|
| 248 |
|
|
if (float32_is_nan(rFn))
|
| 249 |
|
|
goto unordered;
|
| 250 |
|
|
|
| 251 |
|
|
if (n_flag)
|
| 252 |
|
|
rFm ^= 0x80000000;
|
| 253 |
|
|
|
| 254 |
|
|
/* test for less than condition */
|
| 255 |
|
|
if (float32_lt_nocheck(rFn, rFm))
|
| 256 |
|
|
flags |= CC_NEGATIVE;
|
| 257 |
|
|
|
| 258 |
|
|
/* test for equal condition */
|
| 259 |
|
|
if (float32_eq_nocheck(rFn, rFm))
|
| 260 |
|
|
flags |= CC_ZERO;
|
| 261 |
|
|
|
| 262 |
|
|
/* test for greater than or equal condition */
|
| 263 |
|
|
if (float32_lt_nocheck(rFm, rFn))
|
| 264 |
|
|
flags |= CC_CARRY;
|
| 265 |
|
|
} else {
|
| 266 |
|
|
float64 rFm = getDoubleConstant(Fm);
|
| 267 |
|
|
float64 rFn = fpa11->fpreg[Fn].fDouble;
|
| 268 |
|
|
|
| 269 |
|
|
if (float64_is_nan(rFn))
|
| 270 |
|
|
goto unordered;
|
| 271 |
|
|
|
| 272 |
|
|
if (n_flag)
|
| 273 |
|
|
rFm ^= 0x8000000000000000ULL;
|
| 274 |
|
|
|
| 275 |
|
|
/* test for less than condition */
|
| 276 |
|
|
if (float64_lt_nocheck(rFn, rFm))
|
| 277 |
|
|
flags |= CC_NEGATIVE;
|
| 278 |
|
|
|
| 279 |
|
|
/* test for equal condition */
|
| 280 |
|
|
if (float64_eq_nocheck(rFn, rFm))
|
| 281 |
|
|
flags |= CC_ZERO;
|
| 282 |
|
|
|
| 283 |
|
|
/* test for greater than or equal condition */
|
| 284 |
|
|
if (float64_lt_nocheck(rFm, rFn))
|
| 285 |
|
|
flags |= CC_CARRY;
|
| 286 |
|
|
}
|
| 287 |
|
|
} else {
|
| 288 |
|
|
/* Both operands are in registers. */
|
| 289 |
|
|
if (fpa11->fType[Fn] == typeSingle
|
| 290 |
|
|
&& fpa11->fType[Fm] == typeSingle) {
|
| 291 |
|
|
float32 rFm = fpa11->fpreg[Fm].fSingle;
|
| 292 |
|
|
float32 rFn = fpa11->fpreg[Fn].fSingle;
|
| 293 |
|
|
|
| 294 |
|
|
if (float32_is_nan(rFn)
|
| 295 |
|
|
|| float32_is_nan(rFm))
|
| 296 |
|
|
goto unordered;
|
| 297 |
|
|
|
| 298 |
|
|
if (n_flag)
|
| 299 |
|
|
rFm ^= 0x80000000;
|
| 300 |
|
|
|
| 301 |
|
|
/* test for less than condition */
|
| 302 |
|
|
if (float32_lt_nocheck(rFn, rFm))
|
| 303 |
|
|
flags |= CC_NEGATIVE;
|
| 304 |
|
|
|
| 305 |
|
|
/* test for equal condition */
|
| 306 |
|
|
if (float32_eq_nocheck(rFn, rFm))
|
| 307 |
|
|
flags |= CC_ZERO;
|
| 308 |
|
|
|
| 309 |
|
|
/* test for greater than or equal condition */
|
| 310 |
|
|
if (float32_lt_nocheck(rFm, rFn))
|
| 311 |
|
|
flags |= CC_CARRY;
|
| 312 |
|
|
} else {
|
| 313 |
|
|
/* Promote 32-bit operand to 64 bits. */
|
| 314 |
|
|
float64 rFm, rFn;
|
| 315 |
|
|
|
| 316 |
|
|
rFm = (fpa11->fType[Fm] == typeSingle) ?
|
| 317 |
|
|
float32_to_float64(fpa11->fpreg[Fm].fSingle)
|
| 318 |
|
|
: fpa11->fpreg[Fm].fDouble;
|
| 319 |
|
|
|
| 320 |
|
|
rFn = (fpa11->fType[Fn] == typeSingle) ?
|
| 321 |
|
|
float32_to_float64(fpa11->fpreg[Fn].fSingle)
|
| 322 |
|
|
: fpa11->fpreg[Fn].fDouble;
|
| 323 |
|
|
|
| 324 |
|
|
if (float64_is_nan(rFn)
|
| 325 |
|
|
|| float64_is_nan(rFm))
|
| 326 |
|
|
goto unordered;
|
| 327 |
|
|
|
| 328 |
|
|
if (n_flag)
|
| 329 |
|
|
rFm ^= 0x8000000000000000ULL;
|
| 330 |
|
|
|
| 331 |
|
|
/* test for less than condition */
|
| 332 |
|
|
if (float64_lt_nocheck(rFn, rFm))
|
| 333 |
|
|
flags |= CC_NEGATIVE;
|
| 334 |
|
|
|
| 335 |
|
|
/* test for equal condition */
|
| 336 |
|
|
if (float64_eq_nocheck(rFn, rFm))
|
| 337 |
|
|
flags |= CC_ZERO;
|
| 338 |
|
|
|
| 339 |
|
|
/* test for greater than or equal condition */
|
| 340 |
|
|
if (float64_lt_nocheck(rFm, rFn))
|
| 341 |
|
|
flags |= CC_CARRY;
|
| 342 |
|
|
}
|
| 343 |
|
|
}
|
| 344 |
|
|
|
| 345 |
|
|
#endif
|
| 346 |
|
|
|
| 347 |
|
|
writeConditionCodes(flags);
|
| 348 |
|
|
|
| 349 |
|
|
return 1;
|
| 350 |
|
|
|
| 351 |
|
|
unordered:
|
| 352 |
|
|
/* ?? The FPA data sheet is pretty vague about this, in particular
|
| 353 |
|
|
about whether the non-E comparisons can ever raise exceptions.
|
| 354 |
|
|
This implementation is based on a combination of what it says in
|
| 355 |
|
|
the data sheet, observation of how the Acorn emulator actually
|
| 356 |
|
|
behaves (and how programs expect it to) and guesswork. */
|
| 357 |
|
|
flags |= CC_OVERFLOW;
|
| 358 |
|
|
flags &= ~(CC_ZERO | CC_NEGATIVE);
|
| 359 |
|
|
|
| 360 |
|
|
if (BIT_AC & readFPSR())
|
| 361 |
|
|
flags |= CC_CARRY;
|
| 362 |
|
|
|
| 363 |
|
|
if (e_flag)
|
| 364 |
|
|
float_raise(float_flag_invalid);
|
| 365 |
|
|
|
| 366 |
|
|
writeConditionCodes(flags);
|
| 367 |
|
|
return 1;
|
| 368 |
|
|
}
|
