1/* Copyright (c) 2007-2008 The Florida State University
2 * All rights reserved.
3 *
4 * Redistribution and use in source and binary forms, with or without
5 * modification, are permitted provided that the following conditions are
6 * met: redistributions of source code must retain the above copyright
7 * notice, this list of conditions and the following disclaimer;
8 * redistributions in binary form must reproduce the above copyright

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23 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
24 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
25 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
26 *
27 * Authors: Stephen Hines
28 */
29
30#include "arch/arm/insts/static_inst.hh"
31#include "base/condcodes.hh"
32
33namespace ArmISA
34{
35// Shift Rm by an immediate value
36int32_t
37ArmStaticInst::shift_rm_imm(uint32_t base, uint32_t shamt,
38 uint32_t type, uint32_t cfval) const
39{
40 assert(shamt < 32);
41 ArmShiftType shiftType;
42 shiftType = (ArmShiftType)type;
43
44 switch (shiftType)
45 {
46 case LSL:
47 return base << shamt;
48 case LSR:
49 if (shamt == 0)
50 return 0;
51 else
52 return base >> shamt;
53 case ASR:
54 if (shamt == 0)
55 return (int32_t)base >> 31;
56 else
57 return (int32_t)base >> shamt;
58 case ROR:
59 if (shamt == 0)
60 return (cfval << 31) | (base >> 1); // RRX
61 else
62 return (base << (32 - shamt)) | (base >> shamt);
63 default:
64 fprintf(stderr, "Unhandled shift type\n");
65 exit(1);
66 break;
67 }
68 return 0;
69}
70
71// Shift Rm by Rs
72int32_t
73ArmStaticInst::shift_rm_rs(uint32_t base, uint32_t shamt,
74 uint32_t type, uint32_t cfval) const
75{
76 enum ArmShiftType shiftType;
77 shiftType = (enum ArmShiftType) type;
78
79 switch (shiftType)
80 {
81 case LSL:
82 if (shamt >= 32)
83 return 0;
84 else
85 return base << shamt;
86 case LSR:
87 if (shamt >= 32)
88 return 0;
89 else
90 return base >> shamt;
91 case ASR:
92 if (shamt >= 32)
93 return (int32_t)base >> 31;
94 else
95 return (int32_t)base >> shamt;
96 case ROR:
97 shamt = shamt & 0x1f;
98 if (shamt == 0)
99 return base;
100 else
101 return (base << (32 - shamt)) | (base >> shamt);
102 default:
103 fprintf(stderr, "Unhandled shift type\n");
104 exit(1);
105 break;
106 }
107 return 0;
108}
109
110
111// Generate C for a shift by immediate
112bool
113ArmStaticInst::shift_carry_imm(uint32_t base, uint32_t shamt,
114 uint32_t type, uint32_t cfval) const
115{
116 enum ArmShiftType shiftType;
117 shiftType = (enum ArmShiftType) type;
118
119 switch (shiftType)
120 {
121 case LSL:
122 if (shamt == 0)
123 return cfval;
124 else
125 return (base >> (32 - shamt)) & 1;
126 case LSR:
127 if (shamt == 0)
128 return (base >> 31);
129 else
130 return (base >> (shamt - 1)) & 1;
131 case ASR:
132 if (shamt == 0)
133 return (base >> 31);
134 else
135 return (base >> (shamt - 1)) & 1;
136 case ROR:
137 shamt = shamt & 0x1f;
138 if (shamt == 0)
139 return (base & 1); // RRX
140 else
141 return (base >> (shamt - 1)) & 1;
142 default:
143 fprintf(stderr, "Unhandled shift type\n");
144 exit(1);
145 break;
146 }
147 return 0;
148}
149
150
151// Generate C for a shift by Rs
152bool
153ArmStaticInst::shift_carry_rs(uint32_t base, uint32_t shamt,
154 uint32_t type, uint32_t cfval) const
155{
156 enum ArmShiftType shiftType;
157 shiftType = (enum ArmShiftType) type;
158
159 if (shamt == 0)
160 return cfval;
161
162 switch (shiftType)
163 {
164 case LSL:
165 if (shamt > 32)
166 return 0;
167 else
168 return (base >> (32 - shamt)) & 1;
169 case LSR:
170 if (shamt > 32)
171 return 0;
172 else
173 return (base >> (shamt - 1)) & 1;
174 case ASR:
175 if (shamt > 32)
176 shamt = 32;
177 return (base >> (shamt - 1)) & 1;
178 case ROR:
179 shamt = shamt & 0x1f;
180 if (shamt == 0)
181 shamt = 32;
182 return (base >> (shamt - 1)) & 1;
183 default:
184 fprintf(stderr, "Unhandled shift type\n");
185 exit(1);
186 break;
187 }
188 return 0;
189}
190
191
192// Generate the appropriate carry bit for an addition operation
193bool
194ArmStaticInst::arm_add_carry(int32_t result, int32_t lhs, int32_t rhs) const
195{
196 return findCarry(32, result, lhs, rhs);
197}
198
199// Generate the appropriate carry bit for a subtraction operation
200bool
201ArmStaticInst::arm_sub_carry(int32_t result, int32_t lhs, int32_t rhs) const
202{
203 return findCarry(32, result, lhs, ~rhs);
204}
205
206bool
207ArmStaticInst::arm_add_overflow(int32_t result, int32_t lhs, int32_t rhs) const
208{
209 return findOverflow(32, result, lhs, rhs);
210}
211
212bool
213ArmStaticInst::arm_sub_overflow(int32_t result, int32_t lhs, int32_t rhs) const
214{
215 return findOverflow(32, result, lhs, ~rhs);
216}
217
218void
219ArmStaticInst::printReg(std::ostream &os, int reg) const
220{
221 if (reg < FP_Base_DepTag) {
222 ccprintf(os, "r%d", reg);
223 }

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