root / target-arm / nwfpe / fpa11_cprt.c @ d3c61721
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1 | 00406dff | bellard | /*
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2 | 00406dff | bellard | NetWinder Floating Point Emulator
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3 | 00406dff | bellard | (c) Rebel.COM, 1998,1999
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4 | 00406dff | bellard | (c) Philip Blundell, 1999
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5 | 00406dff | bellard | |
6 | 00406dff | bellard | Direct questions, comments to Scott Bambrough <scottb@netwinder.org>
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7 | 00406dff | bellard | |
8 | 00406dff | bellard | This program is free software; you can redistribute it and/or modify
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9 | 00406dff | bellard | it under the terms of the GNU General Public License as published by
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10 | 00406dff | bellard | the Free Software Foundation; either version 2 of the License, or
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11 | 00406dff | bellard | (at your option) any later version.
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12 | 00406dff | bellard | |
13 | 00406dff | bellard | This program is distributed in the hope that it will be useful,
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14 | 00406dff | bellard | but WITHOUT ANY WARRANTY; without even the implied warranty of
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15 | 00406dff | bellard | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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16 | 00406dff | bellard | GNU General Public License for more details.
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17 | 00406dff | bellard | |
18 | 00406dff | bellard | You should have received a copy of the GNU General Public License
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19 | 00406dff | bellard | along with this program; if not, write to the Free Software
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20 | 00406dff | bellard | Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
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21 | 00406dff | bellard | */
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22 | 00406dff | bellard | |
23 | 00406dff | bellard | #include "fpa11.h" |
24 | 00406dff | bellard | #include "milieu.h" |
25 | 00406dff | bellard | #include "softfloat.h" |
26 | 00406dff | bellard | #include "fpopcode.h" |
27 | 00406dff | bellard | #include "fpa11.inl" |
28 | 00406dff | bellard | //#include "fpmodule.h"
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29 | 00406dff | bellard | //#include "fpmodule.inl"
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30 | 00406dff | bellard | |
31 | 00406dff | bellard | extern flag floatx80_is_nan(floatx80);
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32 | 00406dff | bellard | extern flag float64_is_nan( float64);
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33 | 00406dff | bellard | extern flag float32_is_nan( float32);
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34 | 00406dff | bellard | |
35 | 00406dff | bellard | void SetRoundingMode(const unsigned int opcode); |
36 | 00406dff | bellard | |
37 | 00406dff | bellard | unsigned int PerformFLT(const unsigned int opcode); |
38 | 00406dff | bellard | unsigned int PerformFIX(const unsigned int opcode); |
39 | 00406dff | bellard | |
40 | 00406dff | bellard | static unsigned int |
41 | 00406dff | bellard | PerformComparison(const unsigned int opcode); |
42 | 00406dff | bellard | |
43 | 00406dff | bellard | unsigned int EmulateCPRT(const unsigned int opcode) |
44 | 00406dff | bellard | { |
45 | 00406dff | bellard | unsigned int nRc = 1; |
46 | 00406dff | bellard | |
47 | 00406dff | bellard | //printk("EmulateCPRT(0x%08x)\n",opcode);
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48 | 00406dff | bellard | |
49 | 00406dff | bellard | if (opcode & 0x800000) |
50 | 00406dff | bellard | { |
51 | 00406dff | bellard | /* This is some variant of a comparison (PerformComparison will
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52 | 00406dff | bellard | sort out which one). Since most of the other CPRT
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53 | 00406dff | bellard | instructions are oddball cases of some sort or other it makes
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54 | 00406dff | bellard | sense to pull this out into a fast path. */
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55 | 00406dff | bellard | return PerformComparison(opcode);
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56 | 00406dff | bellard | } |
57 | 00406dff | bellard | |
58 | 00406dff | bellard | /* Hint to GCC that we'd like a jump table rather than a load of CMPs */
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59 | 00406dff | bellard | switch ((opcode & 0x700000) >> 20) |
60 | 00406dff | bellard | { |
61 | 00406dff | bellard | case FLT_CODE >> 20: nRc = PerformFLT(opcode); break; |
62 | 00406dff | bellard | case FIX_CODE >> 20: nRc = PerformFIX(opcode); break; |
63 | 00406dff | bellard | |
64 | 00406dff | bellard | case WFS_CODE >> 20: writeFPSR(readRegister(getRd(opcode))); break; |
65 | 00406dff | bellard | case RFS_CODE >> 20: writeRegister(getRd(opcode),readFPSR()); break; |
66 | 00406dff | bellard | |
67 | 00406dff | bellard | #if 0 /* We currently have no use for the FPCR, so there's no point
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68 | 00406dff | bellard | in emulating it. */
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69 | 00406dff | bellard | case WFC_CODE >> 20: writeFPCR(readRegister(getRd(opcode)));
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70 | 00406dff | bellard | case RFC_CODE >> 20: writeRegister(getRd(opcode),readFPCR()); break;
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71 | 00406dff | bellard | #endif
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72 | 00406dff | bellard | |
73 | 00406dff | bellard | default: nRc = 0; |
74 | 00406dff | bellard | } |
75 | 00406dff | bellard | |
76 | 00406dff | bellard | return nRc;
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77 | 00406dff | bellard | } |
78 | 00406dff | bellard | |
79 | 00406dff | bellard | unsigned int PerformFLT(const unsigned int opcode) |
80 | 00406dff | bellard | { |
81 | 00406dff | bellard | FPA11 *fpa11 = GET_FPA11(); |
82 | 00406dff | bellard | |
83 | 00406dff | bellard | unsigned int nRc = 1; |
84 | 00406dff | bellard | SetRoundingMode(opcode); |
85 | 00406dff | bellard | |
86 | 00406dff | bellard | switch (opcode & MASK_ROUNDING_PRECISION)
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87 | 00406dff | bellard | { |
88 | 00406dff | bellard | case ROUND_SINGLE:
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89 | 00406dff | bellard | { |
90 | 00406dff | bellard | fpa11->fType[getFn(opcode)] = typeSingle; |
91 | 00406dff | bellard | fpa11->fpreg[getFn(opcode)].fSingle = |
92 | 00406dff | bellard | int32_to_float32(readRegister(getRd(opcode))); |
93 | 00406dff | bellard | } |
94 | 00406dff | bellard | break;
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95 | 00406dff | bellard | |
96 | 00406dff | bellard | case ROUND_DOUBLE:
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97 | 00406dff | bellard | { |
98 | 00406dff | bellard | fpa11->fType[getFn(opcode)] = typeDouble; |
99 | 00406dff | bellard | fpa11->fpreg[getFn(opcode)].fDouble = |
100 | 00406dff | bellard | int32_to_float64(readRegister(getRd(opcode))); |
101 | 00406dff | bellard | } |
102 | 00406dff | bellard | break;
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103 | 00406dff | bellard | |
104 | 00406dff | bellard | case ROUND_EXTENDED:
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105 | 00406dff | bellard | { |
106 | 00406dff | bellard | fpa11->fType[getFn(opcode)] = typeExtended; |
107 | 00406dff | bellard | fpa11->fpreg[getFn(opcode)].fExtended = |
108 | 00406dff | bellard | int32_to_floatx80(readRegister(getRd(opcode))); |
109 | 00406dff | bellard | } |
110 | 00406dff | bellard | break;
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111 | 00406dff | bellard | |
112 | 00406dff | bellard | default: nRc = 0; |
113 | 00406dff | bellard | } |
114 | 00406dff | bellard | |
115 | 00406dff | bellard | return nRc;
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116 | 00406dff | bellard | } |
117 | 00406dff | bellard | |
118 | 00406dff | bellard | unsigned int PerformFIX(const unsigned int opcode) |
119 | 00406dff | bellard | { |
120 | 00406dff | bellard | FPA11 *fpa11 = GET_FPA11(); |
121 | 00406dff | bellard | unsigned int nRc = 1; |
122 | 00406dff | bellard | unsigned int Fn = getFm(opcode); |
123 | 00406dff | bellard | |
124 | 00406dff | bellard | SetRoundingMode(opcode); |
125 | 00406dff | bellard | |
126 | 00406dff | bellard | switch (fpa11->fType[Fn])
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127 | 00406dff | bellard | { |
128 | 00406dff | bellard | case typeSingle:
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129 | 00406dff | bellard | { |
130 | 00406dff | bellard | writeRegister(getRd(opcode), |
131 | 00406dff | bellard | float32_to_int32(fpa11->fpreg[Fn].fSingle)); |
132 | 00406dff | bellard | } |
133 | 00406dff | bellard | break;
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134 | 00406dff | bellard | |
135 | 00406dff | bellard | case typeDouble:
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136 | 00406dff | bellard | { |
137 | 00406dff | bellard | //printf("F%d is 0x%llx\n",Fn,fpa11->fpreg[Fn].fDouble);
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138 | 00406dff | bellard | writeRegister(getRd(opcode), |
139 | 00406dff | bellard | float64_to_int32(fpa11->fpreg[Fn].fDouble)); |
140 | 00406dff | bellard | } |
141 | 00406dff | bellard | break;
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142 | 00406dff | bellard | |
143 | 00406dff | bellard | case typeExtended:
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144 | 00406dff | bellard | { |
145 | 00406dff | bellard | writeRegister(getRd(opcode), |
146 | 00406dff | bellard | floatx80_to_int32(fpa11->fpreg[Fn].fExtended)); |
147 | 00406dff | bellard | } |
148 | 00406dff | bellard | break;
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149 | 00406dff | bellard | |
150 | 00406dff | bellard | default: nRc = 0; |
151 | 00406dff | bellard | } |
152 | 00406dff | bellard | |
153 | 00406dff | bellard | return nRc;
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154 | 00406dff | bellard | } |
155 | 00406dff | bellard | |
156 | 00406dff | bellard | |
157 | 00406dff | bellard | static unsigned int __inline__ |
158 | 00406dff | bellard | PerformComparisonOperation(floatx80 Fn, floatx80 Fm) |
159 | 00406dff | bellard | { |
160 | 00406dff | bellard | unsigned int flags = 0; |
161 | 00406dff | bellard | |
162 | 00406dff | bellard | /* test for less than condition */
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163 | 00406dff | bellard | if (floatx80_lt(Fn,Fm))
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164 | 00406dff | bellard | { |
165 | 00406dff | bellard | flags |= CC_NEGATIVE; |
166 | 00406dff | bellard | } |
167 | 00406dff | bellard | |
168 | 00406dff | bellard | /* test for equal condition */
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169 | 00406dff | bellard | if (floatx80_eq(Fn,Fm))
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170 | 00406dff | bellard | { |
171 | 00406dff | bellard | flags |= CC_ZERO; |
172 | 00406dff | bellard | } |
173 | 00406dff | bellard | |
174 | 00406dff | bellard | /* test for greater than or equal condition */
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175 | 00406dff | bellard | if (floatx80_lt(Fm,Fn))
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176 | 00406dff | bellard | { |
177 | 00406dff | bellard | flags |= CC_CARRY; |
178 | 00406dff | bellard | } |
179 | 00406dff | bellard | |
180 | 00406dff | bellard | writeConditionCodes(flags); |
181 | 00406dff | bellard | return 1; |
182 | 00406dff | bellard | } |
183 | 00406dff | bellard | |
184 | 00406dff | bellard | /* This instruction sets the flags N, Z, C, V in the FPSR. */
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185 | 00406dff | bellard | |
186 | 00406dff | bellard | static unsigned int PerformComparison(const unsigned int opcode) |
187 | 00406dff | bellard | { |
188 | 00406dff | bellard | FPA11 *fpa11 = GET_FPA11(); |
189 | 00406dff | bellard | unsigned int Fn, Fm; |
190 | 00406dff | bellard | floatx80 rFn, rFm; |
191 | 00406dff | bellard | int e_flag = opcode & 0x400000; /* 1 if CxFE */ |
192 | 00406dff | bellard | int n_flag = opcode & 0x200000; /* 1 if CNxx */ |
193 | 00406dff | bellard | unsigned int flags = 0; |
194 | 00406dff | bellard | |
195 | 00406dff | bellard | //printk("PerformComparison(0x%08x)\n",opcode);
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196 | 00406dff | bellard | |
197 | 00406dff | bellard | Fn = getFn(opcode); |
198 | 00406dff | bellard | Fm = getFm(opcode); |
199 | 00406dff | bellard | |
200 | 00406dff | bellard | /* Check for unordered condition and convert all operands to 80-bit
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201 | 00406dff | bellard | format.
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202 | 00406dff | bellard | ?? Might be some mileage in avoiding this conversion if possible.
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203 | 00406dff | bellard | Eg, if both operands are 32-bit, detect this and do a 32-bit
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204 | 00406dff | bellard | comparison (cheaper than an 80-bit one). */
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205 | 00406dff | bellard | switch (fpa11->fType[Fn])
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206 | 00406dff | bellard | { |
207 | 00406dff | bellard | case typeSingle:
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208 | 00406dff | bellard | //printk("single.\n");
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209 | 00406dff | bellard | if (float32_is_nan(fpa11->fpreg[Fn].fSingle))
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210 | 00406dff | bellard | goto unordered;
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211 | 00406dff | bellard | rFn = float32_to_floatx80(fpa11->fpreg[Fn].fSingle); |
212 | 00406dff | bellard | break;
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213 | 00406dff | bellard | |
214 | 00406dff | bellard | case typeDouble:
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215 | 00406dff | bellard | //printk("double.\n");
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216 | 00406dff | bellard | if (float64_is_nan(fpa11->fpreg[Fn].fDouble))
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217 | 00406dff | bellard | goto unordered;
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218 | 00406dff | bellard | rFn = float64_to_floatx80(fpa11->fpreg[Fn].fDouble); |
219 | 00406dff | bellard | break;
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220 | 00406dff | bellard | |
221 | 00406dff | bellard | case typeExtended:
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222 | 00406dff | bellard | //printk("extended.\n");
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223 | 00406dff | bellard | if (floatx80_is_nan(fpa11->fpreg[Fn].fExtended))
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224 | 00406dff | bellard | goto unordered;
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225 | 00406dff | bellard | rFn = fpa11->fpreg[Fn].fExtended; |
226 | 00406dff | bellard | break;
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227 | 00406dff | bellard | |
228 | 00406dff | bellard | default: return 0; |
229 | 00406dff | bellard | } |
230 | 00406dff | bellard | |
231 | 00406dff | bellard | if (CONSTANT_FM(opcode))
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232 | 00406dff | bellard | { |
233 | 00406dff | bellard | //printk("Fm is a constant: #%d.\n",Fm);
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234 | 00406dff | bellard | rFm = getExtendedConstant(Fm); |
235 | 00406dff | bellard | if (floatx80_is_nan(rFm))
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236 | 00406dff | bellard | goto unordered;
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237 | 00406dff | bellard | } |
238 | 00406dff | bellard | else
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239 | 00406dff | bellard | { |
240 | 00406dff | bellard | //printk("Fm = r%d which contains a ",Fm);
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241 | 00406dff | bellard | switch (fpa11->fType[Fm])
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242 | 00406dff | bellard | { |
243 | 00406dff | bellard | case typeSingle:
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244 | 00406dff | bellard | //printk("single.\n");
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245 | 00406dff | bellard | if (float32_is_nan(fpa11->fpreg[Fm].fSingle))
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246 | 00406dff | bellard | goto unordered;
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247 | 00406dff | bellard | rFm = float32_to_floatx80(fpa11->fpreg[Fm].fSingle); |
248 | 00406dff | bellard | break;
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249 | 00406dff | bellard | |
250 | 00406dff | bellard | case typeDouble:
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251 | 00406dff | bellard | //printk("double.\n");
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252 | 00406dff | bellard | if (float64_is_nan(fpa11->fpreg[Fm].fDouble))
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253 | 00406dff | bellard | goto unordered;
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254 | 00406dff | bellard | rFm = float64_to_floatx80(fpa11->fpreg[Fm].fDouble); |
255 | 00406dff | bellard | break;
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256 | 00406dff | bellard | |
257 | 00406dff | bellard | case typeExtended:
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258 | 00406dff | bellard | //printk("extended.\n");
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259 | 00406dff | bellard | if (floatx80_is_nan(fpa11->fpreg[Fm].fExtended))
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260 | 00406dff | bellard | goto unordered;
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261 | 00406dff | bellard | rFm = fpa11->fpreg[Fm].fExtended; |
262 | 00406dff | bellard | break;
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263 | 00406dff | bellard | |
264 | 00406dff | bellard | default: return 0; |
265 | 00406dff | bellard | } |
266 | 00406dff | bellard | } |
267 | 00406dff | bellard | |
268 | 00406dff | bellard | if (n_flag)
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269 | 00406dff | bellard | { |
270 | 00406dff | bellard | rFm.high ^= 0x8000;
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271 | 00406dff | bellard | } |
272 | 00406dff | bellard | |
273 | 00406dff | bellard | return PerformComparisonOperation(rFn,rFm);
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274 | 00406dff | bellard | |
275 | 00406dff | bellard | unordered:
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276 | 00406dff | bellard | /* ?? The FPA data sheet is pretty vague about this, in particular
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277 | 00406dff | bellard | about whether the non-E comparisons can ever raise exceptions.
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278 | 00406dff | bellard | This implementation is based on a combination of what it says in
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279 | 00406dff | bellard | the data sheet, observation of how the Acorn emulator actually
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280 | 00406dff | bellard | behaves (and how programs expect it to) and guesswork. */
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281 | 00406dff | bellard | flags |= CC_OVERFLOW; |
282 | 00406dff | bellard | flags &= ~(CC_ZERO | CC_NEGATIVE); |
283 | 00406dff | bellard | |
284 | 00406dff | bellard | if (BIT_AC & readFPSR()) flags |= CC_CARRY;
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285 | 00406dff | bellard | |
286 | 00406dff | bellard | if (e_flag) float_raise(float_flag_invalid);
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287 | 00406dff | bellard | |
288 | 00406dff | bellard | writeConditionCodes(flags); |
289 | 00406dff | bellard | return 1; |
290 | 00406dff | bellard | } |