xref: /openbmc/qemu/target/arm/tcg/t16.decode (revision 34cc54fb)
1# Thumb1 instructions
2#
3#  Copyright (c) 2019 Linaro, Ltd
4#
5# This library is free software; you can redistribute it and/or
6# modify it under the terms of the GNU Lesser General Public
7# License as published by the Free Software Foundation; either
8# version 2.1 of the License, or (at your option) any later version.
9#
10# This library is distributed in the hope that it will be useful,
11# but WITHOUT ANY WARRANTY; without even the implied warranty of
12# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
13# Lesser General Public License for more details.
14#
15# You should have received a copy of the GNU Lesser General Public
16# License along with this library; if not, see <http://www.gnu.org/licenses/>.
17
18#
19# This file is processed by scripts/decodetree.py
20#
21
22&empty           !extern
23&s_rrr_shi       !extern s rd rn rm shim shty
24&s_rrr_shr       !extern s rn rd rm rs shty
25&s_rri_rot       !extern s rn rd imm rot
26&s_rrrr          !extern s rd rn rm ra
27&rrr_rot         !extern rd rn rm rot
28&rr              !extern rd rm
29&ri              !extern rd imm
30&r               !extern rm
31&i               !extern imm
32&ldst_rr         !extern p w u rn rt rm shimm shtype
33&ldst_ri         !extern p w u rn rt imm
34&ldst_block      !extern rn i b u w list
35&setend          !extern E
36&cps             !extern mode imod M A I F
37&ci              !extern cond imm
38
39# Set S if the instruction is outside of an IT block.
40%s               !function=t16_setflags
41
42# Data-processing (two low registers)
43
44%reg_0           0:3
45
46@lll_noshr       ...... .... rm:3 rd:3 \
47                 &s_rrr_shi %s rn=%reg_0 shim=0 shty=0
48@xll_noshr       ...... .... rm:3 rn:3 \
49                 &s_rrr_shi s=1 rd=0 shim=0 shty=0
50@lxl_shr         ...... .... rs:3 rd:3 \
51                 &s_rrr_shr %s rm=%reg_0 rn=0
52
53AND_rrri         010000 0000 ... ...            @lll_noshr
54EOR_rrri         010000 0001 ... ...            @lll_noshr
55MOV_rxrr         010000 0010 ... ...            @lxl_shr shty=0  # LSL
56MOV_rxrr         010000 0011 ... ...            @lxl_shr shty=1  # LSR
57MOV_rxrr         010000 0100 ... ...            @lxl_shr shty=2  # ASR
58ADC_rrri         010000 0101 ... ...            @lll_noshr
59SBC_rrri         010000 0110 ... ...            @lll_noshr
60MOV_rxrr         010000 0111 ... ...            @lxl_shr shty=3  # ROR
61TST_xrri         010000 1000 ... ...            @xll_noshr
62RSB_rri          010000 1001 rn:3 rd:3          &s_rri_rot %s imm=0 rot=0
63CMP_xrri         010000 1010 ... ...            @xll_noshr
64CMN_xrri         010000 1011 ... ...            @xll_noshr
65ORR_rrri         010000 1100 ... ...            @lll_noshr
66MUL              010000 1101 rn:3 rd:3          &s_rrrr %s rm=%reg_0 ra=0
67BIC_rrri         010000 1110 ... ...            @lll_noshr
68MVN_rxri         010000 1111 ... ...            @lll_noshr
69
70# Load/store (register offset)
71
72@ldst_rr         ....... rm:3 rn:3 rt:3 \
73                 &ldst_rr p=1 w=0 u=1 shimm=0 shtype=0
74
75STR_rr           0101 000 ... ... ...           @ldst_rr
76STRH_rr          0101 001 ... ... ...           @ldst_rr
77STRB_rr          0101 010 ... ... ...           @ldst_rr
78LDRSB_rr         0101 011 ... ... ...           @ldst_rr
79LDR_rr           0101 100 ... ... ...           @ldst_rr
80LDRH_rr          0101 101 ... ... ...           @ldst_rr
81LDRB_rr          0101 110 ... ... ...           @ldst_rr
82LDRSH_rr         0101 111 ... ... ...           @ldst_rr
83
84# Load/store word/byte (immediate offset)
85
86%imm5_6x4       6:5 !function=times_4
87
88@ldst_ri_1      ..... imm:5 rn:3 rt:3 \
89                &ldst_ri p=1 w=0 u=1
90@ldst_ri_4      ..... ..... rn:3 rt:3 \
91                &ldst_ri p=1 w=0 u=1 imm=%imm5_6x4
92
93STR_ri          01100 ..... ... ...             @ldst_ri_4
94LDR_ri          01101 ..... ... ...             @ldst_ri_4
95STRB_ri         01110 ..... ... ...             @ldst_ri_1
96LDRB_ri         01111 ..... ... ...             @ldst_ri_1
97
98# Load/store halfword (immediate offset)
99
100%imm5_6x2       6:5 !function=times_2
101@ldst_ri_2      ..... ..... rn:3 rt:3 \
102                &ldst_ri p=1 w=0 u=1 imm=%imm5_6x2
103
104STRH_ri         10000 ..... ... ...             @ldst_ri_2
105LDRH_ri         10001 ..... ... ...             @ldst_ri_2
106
107# Load/store (SP-relative)
108
109%imm8_0x4       0:8 !function=times_4
110@ldst_spec_i    ..... rt:3 ........ \
111                &ldst_ri p=1 w=0 u=1 imm=%imm8_0x4
112
113STR_ri          10010 ... ........              @ldst_spec_i rn=13
114LDR_ri          10011 ... ........              @ldst_spec_i rn=13
115
116# Load (PC-relative)
117
118LDR_ri          01001 ... ........              @ldst_spec_i rn=15
119
120# Add PC/SP (immediate)
121
122ADR             10100 rd:3 ........             imm=%imm8_0x4
123ADD_rri         10101 rd:3 ........ \
124                &s_rri_rot rn=13 s=0 rot=0 imm=%imm8_0x4  # SP
125
126# Load/store multiple
127
128@ldstm          ..... rn:3 list:8               &ldst_block i=1 b=0 u=0 w=1
129
130STM             11000 ... ........              @ldstm
131LDM_t16         11001 ... ........              @ldstm
132
133# Shift (immediate)
134
135@shift_i        ..... shim:5 rm:3 rd:3          &s_rrr_shi %s rn=%reg_0
136
137MOV_rxri        000 00 ..... ... ...            @shift_i shty=0  # LSL
138MOV_rxri        000 01 ..... ... ...            @shift_i shty=1  # LSR
139MOV_rxri        000 10 ..... ... ...            @shift_i shty=2  # ASR
140
141# Add/subtract (three low registers)
142
143@addsub_3       ....... rm:3 rn:3 rd:3 \
144                &s_rrr_shi %s shim=0 shty=0
145
146ADD_rrri        0001100 ... ... ...             @addsub_3
147SUB_rrri        0001101 ... ... ...             @addsub_3
148
149# Add/subtract (two low registers and immediate)
150
151@addsub_2i      ....... imm:3 rn:3 rd:3 \
152                &s_rri_rot %s rot=0
153
154ADD_rri         0001 110 ... ... ...            @addsub_2i
155SUB_rri         0001 111 ... ... ...            @addsub_2i
156
157# Add, subtract, compare, move (one low register and immediate)
158
159%reg_8          8:3
160@arith_1i       ..... rd:3 imm:8 \
161                &s_rri_rot rot=0 rn=%reg_8
162
163MOV_rxi         00100 ... ........              @arith_1i %s
164CMP_xri         00101 ... ........              @arith_1i s=1
165ADD_rri         00110 ... ........              @arith_1i %s
166SUB_rri         00111 ... ........              @arith_1i %s
167
168# Add, compare, move (two high registers)
169
170%reg_0_7        7:1 0:3
171@addsub_2h      .... .... . rm:4 ... \
172                &s_rrr_shi rd=%reg_0_7 rn=%reg_0_7 shim=0 shty=0
173
174ADD_rrri        0100 0100 . .... ...            @addsub_2h s=0
175CMP_xrri        0100 0101 . .... ...            @addsub_2h s=1
176MOV_rxri        0100 0110 . .... ...            @addsub_2h s=0
177
178# Adjust SP (immediate)
179
180%imm7_0x4       0:7 !function=times_4
181@addsub_sp_i    .... .... . ....... \
182                &s_rri_rot s=0 rd=13 rn=13 rot=0 imm=%imm7_0x4
183
184ADD_rri         1011 0000 0 .......             @addsub_sp_i
185SUB_rri         1011 0000 1 .......             @addsub_sp_i
186
187# Branch and exchange
188
189@branchr        .... .... . rm:4 ...            &r
190
191BX              0100 0111 0 .... 000            @branchr
192BLX_r           0100 0111 1 .... 000            @branchr
193BXNS            0100 0111 0 .... 100            @branchr
194BLXNS           0100 0111 1 .... 100            @branchr
195
196# Extend
197
198@extend         .... .... .. rm:3 rd:3          &rrr_rot rn=15 rot=0
199
200SXTAH           1011 0010 00 ... ...            @extend
201SXTAB           1011 0010 01 ... ...            @extend
202UXTAH           1011 0010 10 ... ...            @extend
203UXTAB           1011 0010 11 ... ...            @extend
204
205# Change processor state
206
207%imod           4:1 !function=plus_2
208
209SETEND          1011 0110 010 1 E:1 000         &setend
210{
211  CPS           1011 0110 011 . 0 A:1 I:1 F:1   &cps mode=0 M=0 %imod
212  CPS_v7m       1011 0110 011 im:1 00 I:1 F:1
213}
214
215# Reverse bytes
216
217@rdm            .... .... .. rm:3 rd:3          &rr
218
219REV             1011 1010 00 ... ...            @rdm
220REV16           1011 1010 01 ... ...            @rdm
221REVSH           1011 1010 11 ... ...            @rdm
222
223# Hints
224
225{
226  {
227    YIELD       1011 1111 0001 0000
228    WFE         1011 1111 0010 0000
229    WFI         1011 1111 0011 0000
230
231    # TODO: Implement SEV, SEVL; may help SMP performance.
232    # SEV       1011 1111 0100 0000
233    # SEVL      1011 1111 0101 0000
234
235    # The canonical nop has the second nibble as 0000, but the whole of the
236    # rest of the space is a reserved hint, behaves as nop.
237    NOP         1011 1111 ---- 0000
238  }
239  IT            1011 1111 cond_mask:8
240}
241
242# Miscellaneous 16-bit instructions
243
244%imm6_9_3       9:1 3:5 !function=times_2
245
246HLT             1011 1010 10 imm:6              &i
247BKPT            1011 1110 imm:8                 &i
248CBZ             1011 nz:1 0.1 ..... rn:3        imm=%imm6_9_3
249
250# Push and Pop
251
252%push_list      0:9 !function=t16_push_list
253%pop_list       0:9 !function=t16_pop_list
254
255STM             1011 010 ......... \
256                &ldst_block i=0 b=1 u=0 w=1 rn=13 list=%push_list
257LDM_t16         1011 110 ......... \
258                &ldst_block i=1 b=0 u=0 w=1 rn=13 list=%pop_list
259
260# Conditional branches, Supervisor call
261
262%imm8_0x2       0:s8 !function=times_2
263
264{
265  UDF           1101 1110 ---- ----
266  SVC           1101 1111 imm:8                 &i
267  B_cond_thumb  1101 cond:4 ........            &ci imm=%imm8_0x2
268}
269
270# Unconditional Branch
271
272%imm11_0x2      0:s11 !function=times_2
273
274B               11100 ...........               &i imm=%imm11_0x2
275
276# thumb_insn_is_16bit() ensures we won't be decoding these as
277# T16 instructions for a Thumb2 CPU, so these patterns must be
278# a Thumb1 split BL/BLX.
279BLX_suffix      11101 imm:11                    &i
280BL_BLX_prefix   11110 imm:s11                   &i
281BL_suffix       11111 imm:11                    &i
282