root / target-arm / nwfpe / fpa11.c @ 4118a970
History | View | Annotate | Download (5.5 kB)
1 |
/*
|
---|---|
2 |
NetWinder Floating Point Emulator
|
3 |
(c) Rebel.COM, 1998,1999
|
4 |
|
5 |
Direct questions, comments to Scott Bambrough <scottb@netwinder.org>
|
6 |
|
7 |
This program is free software; you can redistribute it and/or modify
|
8 |
it under the terms of the GNU General Public License as published by
|
9 |
the Free Software Foundation; either version 2 of the License, or
|
10 |
(at your option) any later version.
|
11 |
|
12 |
This program is distributed in the hope that it will be useful,
|
13 |
but WITHOUT ANY WARRANTY; without even the implied warranty of
|
14 |
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
15 |
GNU General Public License for more details.
|
16 |
|
17 |
You should have received a copy of the GNU General Public License
|
18 |
along with this program; if not, write to the Free Software
|
19 |
Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
|
20 |
*/
|
21 |
|
22 |
#include "fpa11.h" |
23 |
|
24 |
#include "fpopcode.h" |
25 |
|
26 |
//#include "fpmodule.h"
|
27 |
//#include "fpmodule.inl"
|
28 |
|
29 |
//#include <asm/system.h>
|
30 |
|
31 |
#include <stdio.h> |
32 |
|
33 |
/* forward declarations */
|
34 |
unsigned int EmulateCPDO(const unsigned int); |
35 |
unsigned int EmulateCPDT(const unsigned int); |
36 |
unsigned int EmulateCPRT(const unsigned int); |
37 |
|
38 |
FPA11* qemufpa=0;
|
39 |
CPUARMState* user_registers; |
40 |
|
41 |
/* Reset the FPA11 chip. Called to initialize and reset the emulator. */
|
42 |
void resetFPA11(void) |
43 |
{ |
44 |
int i;
|
45 |
FPA11 *fpa11 = GET_FPA11(); |
46 |
|
47 |
/* initialize the register type array */
|
48 |
for (i=0;i<=7;i++) |
49 |
{ |
50 |
fpa11->fType[i] = typeNone; |
51 |
} |
52 |
|
53 |
/* FPSR: set system id to FP_EMULATOR, set AC, clear all other bits */
|
54 |
fpa11->fpsr = FP_EMULATOR | BIT_AC; |
55 |
|
56 |
/* FPCR: set SB, AB and DA bits, clear all others */
|
57 |
#if MAINTAIN_FPCR
|
58 |
fpa11->fpcr = MASK_RESET; |
59 |
#endif
|
60 |
} |
61 |
|
62 |
void SetRoundingMode(const unsigned int opcode) |
63 |
{ |
64 |
int rounding_mode;
|
65 |
FPA11 *fpa11 = GET_FPA11(); |
66 |
|
67 |
#if MAINTAIN_FPCR
|
68 |
fpa11->fpcr &= ~MASK_ROUNDING_MODE; |
69 |
#endif
|
70 |
switch (opcode & MASK_ROUNDING_MODE)
|
71 |
{ |
72 |
default:
|
73 |
case ROUND_TO_NEAREST:
|
74 |
rounding_mode = float_round_nearest_even; |
75 |
#if MAINTAIN_FPCR
|
76 |
fpa11->fpcr |= ROUND_TO_NEAREST; |
77 |
#endif
|
78 |
break;
|
79 |
|
80 |
case ROUND_TO_PLUS_INFINITY:
|
81 |
rounding_mode = float_round_up; |
82 |
#if MAINTAIN_FPCR
|
83 |
fpa11->fpcr |= ROUND_TO_PLUS_INFINITY; |
84 |
#endif
|
85 |
break;
|
86 |
|
87 |
case ROUND_TO_MINUS_INFINITY:
|
88 |
rounding_mode = float_round_down; |
89 |
#if MAINTAIN_FPCR
|
90 |
fpa11->fpcr |= ROUND_TO_MINUS_INFINITY; |
91 |
#endif
|
92 |
break;
|
93 |
|
94 |
case ROUND_TO_ZERO:
|
95 |
rounding_mode = float_round_to_zero; |
96 |
#if MAINTAIN_FPCR
|
97 |
fpa11->fpcr |= ROUND_TO_ZERO; |
98 |
#endif
|
99 |
break;
|
100 |
} |
101 |
set_float_rounding_mode(rounding_mode, &fpa11->fp_status); |
102 |
} |
103 |
|
104 |
void SetRoundingPrecision(const unsigned int opcode) |
105 |
{ |
106 |
int rounding_precision;
|
107 |
FPA11 *fpa11 = GET_FPA11(); |
108 |
#if MAINTAIN_FPCR
|
109 |
fpa11->fpcr &= ~MASK_ROUNDING_PRECISION; |
110 |
#endif
|
111 |
switch (opcode & MASK_ROUNDING_PRECISION)
|
112 |
{ |
113 |
case ROUND_SINGLE:
|
114 |
rounding_precision = 32;
|
115 |
#if MAINTAIN_FPCR
|
116 |
fpa11->fpcr |= ROUND_SINGLE; |
117 |
#endif
|
118 |
break;
|
119 |
|
120 |
case ROUND_DOUBLE:
|
121 |
rounding_precision = 64;
|
122 |
#if MAINTAIN_FPCR
|
123 |
fpa11->fpcr |= ROUND_DOUBLE; |
124 |
#endif
|
125 |
break;
|
126 |
|
127 |
case ROUND_EXTENDED:
|
128 |
rounding_precision = 80;
|
129 |
#if MAINTAIN_FPCR
|
130 |
fpa11->fpcr |= ROUND_EXTENDED; |
131 |
#endif
|
132 |
break;
|
133 |
|
134 |
default: rounding_precision = 80; |
135 |
} |
136 |
set_floatx80_rounding_precision(rounding_precision, &fpa11->fp_status); |
137 |
} |
138 |
|
139 |
/* Emulate the instruction in the opcode. */
|
140 |
/* ??? This is not thread safe. */
|
141 |
unsigned int EmulateAll(unsigned int opcode, FPA11* qfpa, CPUARMState* qregs) |
142 |
{ |
143 |
unsigned int nRc = 0; |
144 |
// unsigned long flags;
|
145 |
FPA11 *fpa11; |
146 |
// save_flags(flags); sti();
|
147 |
|
148 |
qemufpa=qfpa; |
149 |
user_registers=qregs; |
150 |
|
151 |
#if 0
|
152 |
fprintf(stderr,"emulating FP insn 0x%08x, PC=0x%08x\n",
|
153 |
opcode, qregs[REG_PC]);
|
154 |
#endif
|
155 |
fpa11 = GET_FPA11(); |
156 |
|
157 |
if (fpa11->initflag == 0) /* good place for __builtin_expect */ |
158 |
{ |
159 |
resetFPA11(); |
160 |
SetRoundingMode(ROUND_TO_NEAREST); |
161 |
SetRoundingPrecision(ROUND_EXTENDED); |
162 |
fpa11->initflag = 1;
|
163 |
} |
164 |
|
165 |
if (TEST_OPCODE(opcode,MASK_CPRT))
|
166 |
{ |
167 |
//fprintf(stderr,"emulating CPRT\n");
|
168 |
/* Emulate conversion opcodes. */
|
169 |
/* Emulate register transfer opcodes. */
|
170 |
/* Emulate comparison opcodes. */
|
171 |
nRc = EmulateCPRT(opcode); |
172 |
} |
173 |
else if (TEST_OPCODE(opcode,MASK_CPDO)) |
174 |
{ |
175 |
//fprintf(stderr,"emulating CPDO\n");
|
176 |
/* Emulate monadic arithmetic opcodes. */
|
177 |
/* Emulate dyadic arithmetic opcodes. */
|
178 |
nRc = EmulateCPDO(opcode); |
179 |
} |
180 |
else if (TEST_OPCODE(opcode,MASK_CPDT)) |
181 |
{ |
182 |
//fprintf(stderr,"emulating CPDT\n");
|
183 |
/* Emulate load/store opcodes. */
|
184 |
/* Emulate load/store multiple opcodes. */
|
185 |
nRc = EmulateCPDT(opcode); |
186 |
} |
187 |
else
|
188 |
{ |
189 |
/* Invalid instruction detected. Return FALSE. */
|
190 |
nRc = 0;
|
191 |
} |
192 |
|
193 |
// restore_flags(flags);
|
194 |
|
195 |
//printf("returning %d\n",nRc);
|
196 |
return(nRc);
|
197 |
} |
198 |
|
199 |
#if 0
|
200 |
unsigned int EmulateAll1(unsigned int opcode)
|
201 |
{
|
202 |
switch ((opcode >> 24) & 0xf)
|
203 |
{
|
204 |
case 0xc:
|
205 |
case 0xd:
|
206 |
if ((opcode >> 20) & 0x1)
|
207 |
{
|
208 |
switch ((opcode >> 8) & 0xf)
|
209 |
{
|
210 |
case 0x1: return PerformLDF(opcode); break;
|
211 |
case 0x2: return PerformLFM(opcode); break;
|
212 |
default: return 0;
|
213 |
}
|
214 |
}
|
215 |
else
|
216 |
{
|
217 |
switch ((opcode >> 8) & 0xf)
|
218 |
{
|
219 |
case 0x1: return PerformSTF(opcode); break;
|
220 |
case 0x2: return PerformSFM(opcode); break;
|
221 |
default: return 0;
|
222 |
}
|
223 |
}
|
224 |
break;
|
225 |
|
226 |
case 0xe:
|
227 |
if (opcode & 0x10)
|
228 |
return EmulateCPDO(opcode);
|
229 |
else
|
230 |
return EmulateCPRT(opcode);
|
231 |
break;
|
232 |
|
233 |
default: return 0;
|
234 |
}
|
235 |
}
|
236 |
#endif
|
237 |
|