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#include "softfloat.h"
24#include "fpopcode.h"
25#include "fpsr.h"
26#include "fpmodule.h"
27#include "fpmodule.inl"
28
29const floatx80 floatx80Constant[] = {
30  { 0x0000, 0x0000000000000000ULL},	/* extended 0.0 */
31  { 0x3fff, 0x8000000000000000ULL},	/* extended 1.0 */
32  { 0x4000, 0x8000000000000000ULL},	/* extended 2.0 */
33  { 0x4000, 0xc000000000000000ULL},	/* extended 3.0 */
34  { 0x4001, 0x8000000000000000ULL},	/* extended 4.0 */
35  { 0x4001, 0xa000000000000000ULL},	/* extended 5.0 */
36  { 0x3ffe, 0x8000000000000000ULL},	/* extended 0.5 */
37  { 0x4002, 0xa000000000000000ULL}	/* extended 10.0 */
38};
39
40const float64 float64Constant[] = {
41  0x0000000000000000ULL,		/* double 0.0 */
42  0x3ff0000000000000ULL,		/* double 1.0 */
43  0x4000000000000000ULL,		/* double 2.0 */
44  0x4008000000000000ULL,		/* double 3.0 */
45  0x4010000000000000ULL,		/* double 4.0 */
46  0x4014000000000000ULL,		/* double 5.0 */
47  0x3fe0000000000000ULL,		/* double 0.5 */
48  0x4024000000000000ULL			/* double 10.0 */
49};
50
51const float32 float32Constant[] = {
52  0x00000000,				/* single 0.0 */
53  0x3f800000,				/* single 1.0 */
54  0x40000000,				/* single 2.0 */
55  0x40400000,				/* single 3.0 */
56  0x40800000,				/* single 4.0 */
57  0x40a00000,				/* single 5.0 */
58  0x3f000000,				/* single 0.5 */
59  0x41200000				/* single 10.0 */
60};
61
62unsigned int getTransferLength(const unsigned int opcode)
63{
64  unsigned int nRc;
65
66  switch (opcode & MASK_TRANSFER_LENGTH)
67  {
68    case 0x00000000: nRc = 1; break; /* single precision */
69    case 0x00008000: nRc = 2; break; /* double precision */
70    case 0x00400000: nRc = 3; break; /* extended precision */
71    default: nRc = 0;
72  }
73
74  return(nRc);
75}
76
77unsigned int getRegisterCount(const unsigned int opcode)
78{
79  unsigned int nRc;
80
81  switch (opcode & MASK_REGISTER_COUNT)
82  {
83    case 0x00000000: nRc = 4; break;
84    case 0x00008000: nRc = 1; break;
85    case 0x00400000: nRc = 2; break;
86    case 0x00408000: nRc = 3; break;
87    default: nRc = 0;
88  }
89
90  return(nRc);
91}
92
93unsigned int getRoundingPrecision(const unsigned int opcode)
94{
95  unsigned int nRc;
96
97  switch (opcode & MASK_ROUNDING_PRECISION)
98  {
99    case 0x00000000: nRc = 1; break;
100    case 0x00000080: nRc = 2; break;
101    case 0x00080000: nRc = 3; break;
102    default: nRc = 0;
103  }
104
105  return(nRc);
106}
107
108unsigned int getDestinationSize(const unsigned int opcode)
109{
110  unsigned int nRc;
111
112  switch (opcode & MASK_DESTINATION_SIZE)
113  {
114    case 0x00000000: nRc = typeSingle; break;
115    case 0x00000080: nRc = typeDouble; break;
116    case 0x00080000: nRc = typeExtended; break;
117    default: nRc = typeNone;
118  }
119
120  return(nRc);
121}
122
123/* condition code lookup table
124 index into the table is test code: EQ, NE, ... LT, GT, AL, NV
125 bit position in short is condition code: NZCV */
126static const unsigned short aCC[16] = {
127    0xF0F0, // EQ == Z set
128    0x0F0F, // NE
129    0xCCCC, // CS == C set
130    0x3333, // CC
131    0xFF00, // MI == N set
132    0x00FF, // PL
133    0xAAAA, // VS == V set
134    0x5555, // VC
135    0x0C0C, // HI == C set && Z clear
136    0xF3F3, // LS == C clear || Z set
137    0xAA55, // GE == (N==V)
138    0x55AA, // LT == (N!=V)
139    0x0A05, // GT == (!Z && (N==V))
140    0xF5FA, // LE == (Z || (N!=V))
141    0xFFFF, // AL always
142    0 // NV
143};
144
145unsigned int checkCondition(const unsigned int opcode, const unsigned int ccodes)
146{
147  return (aCC[opcode>>28] >> (ccodes>>28)) & 1;
148}
149