xref: /freebsd/contrib/llvm-project/llvm/lib/Target/RISCV/RISCVInstrFormats.td (revision 5ca8e32633c4ffbbcd6762e5888b6a4ba0708c6c)
1//===-- RISCVInstrFormats.td - RISC-V Instruction Formats --*- tablegen -*-===//
2//
3// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4// See https://llvm.org/LICENSE.txt for license information.
5// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6//
7//===----------------------------------------------------------------------===//
8
9//===----------------------------------------------------------------------===//
10//
11//  These instruction format definitions are structured to match the
12//  description in the RISC-V User-Level ISA specification as closely as
13//  possible. For instance, the specification describes instructions with the
14//  MSB (31st bit) on the left and the LSB (0th bit) on the right. This is
15//  reflected in the order of parameters to each instruction class.
16//
17//  One area of divergence is in the description of immediates. The
18//  specification describes immediate encoding in terms of bit-slicing
19//  operations on the logical value represented. The immediate argument to
20//  these instruction formats instead represents the bit sequence that will be
21//  inserted into the instruction. e.g. although JAL's immediate is logically
22//  a 21-bit value (where the LSB is always zero), we describe it as an imm20
23//  to match how it is encoded.
24//
25//===----------------------------------------------------------------------===//
26
27// Format specifies the encoding used by the instruction. This is used by
28// RISCVMCCodeEmitter to determine which form of fixup to use. These
29// definitions must be kept in-sync with RISCVBaseInfo.h.
30class InstFormat<bits<5> val> {
31  bits<5> Value = val;
32}
33def InstFormatPseudo : InstFormat<0>;
34def InstFormatR      : InstFormat<1>;
35def InstFormatR4     : InstFormat<2>;
36def InstFormatI      : InstFormat<3>;
37def InstFormatS      : InstFormat<4>;
38def InstFormatB      : InstFormat<5>;
39def InstFormatU      : InstFormat<6>;
40def InstFormatJ      : InstFormat<7>;
41def InstFormatCR     : InstFormat<8>;
42def InstFormatCI     : InstFormat<9>;
43def InstFormatCSS    : InstFormat<10>;
44def InstFormatCIW    : InstFormat<11>;
45def InstFormatCL     : InstFormat<12>;
46def InstFormatCS     : InstFormat<13>;
47def InstFormatCA     : InstFormat<14>;
48def InstFormatCB     : InstFormat<15>;
49def InstFormatCJ     : InstFormat<16>;
50def InstFormatCU     : InstFormat<17>;
51def InstFormatCLB    : InstFormat<18>;
52def InstFormatCLH    : InstFormat<19>;
53def InstFormatCSB    : InstFormat<20>;
54def InstFormatCSH    : InstFormat<21>;
55def InstFormatOther  : InstFormat<22>;
56
57class RISCVVConstraint<bits<3> val> {
58  bits<3> Value = val;
59}
60def NoConstraint  : RISCVVConstraint<0b000>;
61def VS2Constraint : RISCVVConstraint<0b001>;
62def VS1Constraint : RISCVVConstraint<0b010>;
63def VMConstraint  : RISCVVConstraint<0b100>;
64
65// Illegal instructions:
66//
67// * The destination vector register group for a masked vector instruction
68// cannot overlap the source mask register (v0), unless the destination vector
69// register is being written with a mask value (e.g., comparisons) or the
70// scalar result of a reduction.
71//
72// * Widening: The destination EEW is greater than the source EEW, the source
73// EMUL is at least 1. The destination vector register group cannot overlap
74// with the source vector register groups besides the highest-numbered part of
75// the destination register group.
76//
77// * Narrowing: The destination EEW is smaller than the source EEW. The
78// destination vector register group cannot overlap with the source vector
79// register groups besides the lowest-numbered part of the source register
80// group.
81//
82// * vmsbf.m/vmsif.m/vmsof.m: The destination register cannot overlap the
83// source register and, if masked, cannot overlap the mask register ('v0').
84//
85// * viota: The destination register cannot overlap the source register and,
86// if masked, cannot overlap the mask register ('v0').
87//
88// * v[f]slide[1]up: The destination vector register group for vslideup cannot
89// overlap the source vector register group.
90//
91// * vrgather: The destination vector register group cannot overlap with the
92// source vector register groups.
93//
94// * vcompress: The destination vector register group cannot overlap the
95// source vector register group or the source mask register
96def WidenV       : RISCVVConstraint<!or(VS2Constraint.Value,
97                                        VS1Constraint.Value,
98                                        VMConstraint.Value)>;
99def WidenW       : RISCVVConstraint<!or(VS1Constraint.Value,
100                                        VMConstraint.Value)>;
101def WidenCvt     : RISCVVConstraint<!or(VS2Constraint.Value,
102                                        VMConstraint.Value)>;
103def Iota         : RISCVVConstraint<!or(VS2Constraint.Value,
104                                        VMConstraint.Value)>;
105def SlideUp      : RISCVVConstraint<!or(VS2Constraint.Value,
106                                        VMConstraint.Value)>;
107def Vrgather     : RISCVVConstraint<!or(VS2Constraint.Value,
108                                        VS1Constraint.Value,
109                                        VMConstraint.Value)>;
110def Vcompress    : RISCVVConstraint<!or(VS2Constraint.Value,
111                                        VS1Constraint.Value)>;
112
113// The following opcode names match those given in Table 19.1 in the
114// RISC-V User-level ISA specification ("RISC-V base opcode map").
115class RISCVOpcode<string name, bits<7> val> {
116  string Name = name;
117  bits<7> Value = val;
118}
119def RISCVOpcodesList : GenericTable {
120  let FilterClass = "RISCVOpcode";
121  let Fields = [
122    "Name", "Value"
123  ];
124  let PrimaryKey = [ "Value" ];
125  let PrimaryKeyName = "lookupRISCVOpcodeByValue";
126}
127def lookupRISCVOpcodeByName : SearchIndex {
128  let Table = RISCVOpcodesList;
129  let Key = [ "Name" ];
130}
131def OPC_LOAD      : RISCVOpcode<"LOAD",      0b0000011>;
132def OPC_LOAD_FP   : RISCVOpcode<"LOAD_FP",   0b0000111>;
133def OPC_CUSTOM_0  : RISCVOpcode<"CUSTOM_0",  0b0001011>;
134def OPC_MISC_MEM  : RISCVOpcode<"MISC_MEM",  0b0001111>;
135def OPC_OP_IMM    : RISCVOpcode<"OP_IMM",    0b0010011>;
136def OPC_AUIPC     : RISCVOpcode<"AUIPC",     0b0010111>;
137def OPC_OP_IMM_32 : RISCVOpcode<"OP_IMM_32", 0b0011011>;
138def OPC_STORE     : RISCVOpcode<"STORE",     0b0100011>;
139def OPC_STORE_FP  : RISCVOpcode<"STORE_FP",  0b0100111>;
140def OPC_CUSTOM_1  : RISCVOpcode<"CUSTOM_1",  0b0101011>;
141def OPC_AMO       : RISCVOpcode<"AMO",       0b0101111>;
142def OPC_OP        : RISCVOpcode<"OP",        0b0110011>;
143def OPC_LUI       : RISCVOpcode<"LUI",       0b0110111>;
144def OPC_OP_32     : RISCVOpcode<"OP_32",     0b0111011>;
145def OPC_MADD      : RISCVOpcode<"MADD",      0b1000011>;
146def OPC_MSUB      : RISCVOpcode<"MSUB",      0b1000111>;
147def OPC_NMSUB     : RISCVOpcode<"NMSUB",     0b1001011>;
148def OPC_NMADD     : RISCVOpcode<"NMADD",     0b1001111>;
149def OPC_OP_FP     : RISCVOpcode<"OP_FP",     0b1010011>;
150def OPC_OP_V      : RISCVOpcode<"OP_V",      0b1010111>;
151def OPC_CUSTOM_2  : RISCVOpcode<"CUSTOM_2",  0b1011011>;
152def OPC_BRANCH    : RISCVOpcode<"BRANCH",    0b1100011>;
153def OPC_JALR      : RISCVOpcode<"JALR",      0b1100111>;
154def OPC_JAL       : RISCVOpcode<"JAL",       0b1101111>;
155def OPC_SYSTEM    : RISCVOpcode<"SYSTEM",    0b1110011>;
156def OPC_OP_P      : RISCVOpcode<"OP_P",      0b1110111>;
157def OPC_CUSTOM_3  : RISCVOpcode<"CUSTOM_3",  0b1111011>;
158
159class RVInstCommon<dag outs, dag ins, string opcodestr, string argstr,
160                   list<dag> pattern, InstFormat format> : Instruction {
161  let Namespace = "RISCV";
162
163  dag OutOperandList = outs;
164  dag InOperandList = ins;
165  let AsmString = opcodestr # !if(!empty(argstr), "", "\t" # argstr);
166  let Pattern = pattern;
167
168  let TSFlags{4-0} = format.Value;
169
170  // Defaults
171  RISCVVConstraint RVVConstraint = NoConstraint;
172  let TSFlags{7-5} = RVVConstraint.Value;
173
174  bits<3> VLMul = 0;
175  let TSFlags{10-8} = VLMul;
176
177  bit ForceTailAgnostic = false;
178  let TSFlags{11} = ForceTailAgnostic;
179
180  bit IsTiedPseudo = 0;
181  let TSFlags{12} = IsTiedPseudo;
182
183  bit HasSEWOp = 0;
184  let TSFlags{13} = HasSEWOp;
185
186  bit HasVLOp = 0;
187  let TSFlags{14} = HasVLOp;
188
189  bit HasVecPolicyOp = 0;
190  let TSFlags{15} = HasVecPolicyOp;
191
192  bit IsRVVWideningReduction = 0;
193  let TSFlags{16} = IsRVVWideningReduction;
194
195  bit UsesMaskPolicy = 0;
196  let TSFlags{17} = UsesMaskPolicy;
197
198  // Indicates that the result can be considered sign extended from bit 31. Some
199  // instructions with this flag aren't W instructions, but are either sign
200  // extended from a smaller size, always outputs a small integer, or put zeros
201  // in bits 63:31. Used by the SExtWRemoval pass.
202  bit IsSignExtendingOpW = 0;
203  let TSFlags{18} = IsSignExtendingOpW;
204
205  bit HasRoundModeOp = 0;
206  let TSFlags{19} =  HasRoundModeOp;
207
208  // This is only valid when HasRoundModeOp is set to 1. HasRoundModeOp is set
209  // to 1 for vector fixed-point or floating-point intrinsics. This bit is
210  // processed under pass 'RISCVInsertReadWriteCSR' pass to distinguish between
211  // fixed-point / floating-point instructions and emit appropriate read/write
212  // to the correct CSR.
213  bit UsesVXRM = 0;
214  let TSFlags{20} =  UsesVXRM;
215}
216
217class RVInst<dag outs, dag ins, string opcodestr, string argstr,
218             list<dag> pattern, InstFormat format>
219    : RVInstCommon<outs, ins, opcodestr, argstr, pattern, format> {
220  field bits<32> Inst;
221  // SoftFail is a field the disassembler can use to provide a way for
222  // instructions to not match without killing the whole decode process. It is
223  // mainly used for ARM, but Tablegen expects this field to exist or it fails
224  // to build the decode table.
225  field bits<32> SoftFail = 0;
226  let Size = 4;
227}
228
229// Pseudo instructions
230class Pseudo<dag outs, dag ins, list<dag> pattern, string opcodestr = "", string argstr = "">
231    : RVInst<outs, ins, opcodestr, argstr, pattern, InstFormatPseudo> {
232  let isPseudo = 1;
233  let isCodeGenOnly = 1;
234}
235
236class PseudoQuietFCMP<DAGOperand Ty>
237    : Pseudo<(outs GPR:$rd), (ins Ty:$rs1, Ty:$rs2), []> {
238  let hasSideEffects = 1;
239  let mayLoad = 0;
240  let mayStore = 0;
241}
242
243// Pseudo load instructions.
244class PseudoLoad<string opcodestr, RegisterClass rdty = GPR>
245    : Pseudo<(outs rdty:$rd), (ins bare_symbol:$addr), [], opcodestr, "$rd, $addr"> {
246  let hasSideEffects = 0;
247  let mayLoad = 1;
248  let mayStore = 0;
249  let isCodeGenOnly = 0;
250  let isAsmParserOnly = 1;
251}
252
253class PseudoFloatLoad<string opcodestr, RegisterClass rdty = GPR>
254    : Pseudo<(outs GPR:$tmp, rdty:$rd), (ins bare_symbol:$addr), [], opcodestr, "$rd, $addr, $tmp"> {
255  let hasSideEffects = 0;
256  let mayLoad = 1;
257  let mayStore = 0;
258  let isCodeGenOnly = 0;
259  let isAsmParserOnly = 1;
260}
261
262// Pseudo store instructions.
263class PseudoStore<string opcodestr, RegisterClass rsty = GPR>
264    : Pseudo<(outs GPR:$tmp), (ins rsty:$rs, bare_symbol:$addr), [], opcodestr, "$rs, $addr, $tmp"> {
265  let hasSideEffects = 0;
266  let mayLoad = 0;
267  let mayStore = 1;
268  let isCodeGenOnly = 0;
269  let isAsmParserOnly = 1;
270}
271
272// Instruction formats are listed in the order they appear in the RISC-V
273// instruction set manual (R, I, S, B, U, J) with sub-formats (e.g. RVInstR4,
274// RVInstRAtomic) sorted alphabetically.
275
276class RVInstR<bits<7> funct7, bits<3> funct3, RISCVOpcode opcode, dag outs,
277              dag ins, string opcodestr, string argstr>
278    : RVInst<outs, ins, opcodestr, argstr, [], InstFormatR> {
279  bits<5> rs2;
280  bits<5> rs1;
281  bits<5> rd;
282
283  let Inst{31-25} = funct7;
284  let Inst{24-20} = rs2;
285  let Inst{19-15} = rs1;
286  let Inst{14-12} = funct3;
287  let Inst{11-7} = rd;
288  let Inst{6-0} = opcode.Value;
289}
290
291class RVInstR4<bits<2> funct2, bits<3> funct3, RISCVOpcode opcode, dag outs,
292               dag ins, string opcodestr, string argstr>
293    : RVInst<outs, ins, opcodestr, argstr, [], InstFormatR4> {
294  bits<5> rs3;
295  bits<5> rs2;
296  bits<5> rs1;
297  bits<5> rd;
298
299  let Inst{31-27} = rs3;
300  let Inst{26-25} = funct2;
301  let Inst{24-20} = rs2;
302  let Inst{19-15} = rs1;
303  let Inst{14-12} = funct3;
304  let Inst{11-7} = rd;
305  let Inst{6-0} = opcode.Value;
306}
307
308class RVInstR4Frm<bits<2> funct2, RISCVOpcode opcode, dag outs, dag ins,
309                  string opcodestr, string argstr>
310    : RVInst<outs, ins, opcodestr, argstr, [], InstFormatR4> {
311  bits<5> rs3;
312  bits<5> rs2;
313  bits<5> rs1;
314  bits<3> frm;
315  bits<5> rd;
316
317  let Inst{31-27} = rs3;
318  let Inst{26-25} = funct2;
319  let Inst{24-20} = rs2;
320  let Inst{19-15} = rs1;
321  let Inst{14-12} = frm;
322  let Inst{11-7} = rd;
323  let Inst{6-0} = opcode.Value;
324}
325
326class RVInstRAtomic<bits<5> funct5, bit aq, bit rl, bits<3> funct3,
327                    RISCVOpcode opcode, dag outs, dag ins, string opcodestr,
328                    string argstr>
329    : RVInst<outs, ins, opcodestr, argstr, [], InstFormatR> {
330  bits<5> rs2;
331  bits<5> rs1;
332  bits<5> rd;
333
334  let Inst{31-27} = funct5;
335  let Inst{26} = aq;
336  let Inst{25} = rl;
337  let Inst{24-20} = rs2;
338  let Inst{19-15} = rs1;
339  let Inst{14-12} = funct3;
340  let Inst{11-7} = rd;
341  let Inst{6-0} = opcode.Value;
342}
343
344class RVInstRFrm<bits<7> funct7, RISCVOpcode opcode, dag outs, dag ins,
345                 string opcodestr, string argstr>
346    : RVInst<outs, ins, opcodestr, argstr, [], InstFormatR> {
347  bits<5> rs2;
348  bits<5> rs1;
349  bits<3> frm;
350  bits<5> rd;
351
352  let Inst{31-25} = funct7;
353  let Inst{24-20} = rs2;
354  let Inst{19-15} = rs1;
355  let Inst{14-12} = frm;
356  let Inst{11-7} = rd;
357  let Inst{6-0} = opcode.Value;
358}
359
360class RVInstI<bits<3> funct3, RISCVOpcode opcode, dag outs, dag ins,
361              string opcodestr, string argstr>
362    : RVInst<outs, ins, opcodestr, argstr, [], InstFormatI> {
363  bits<12> imm12;
364  bits<5> rs1;
365  bits<5> rd;
366
367  let Inst{31-20} = imm12;
368  let Inst{19-15} = rs1;
369  let Inst{14-12} = funct3;
370  let Inst{11-7} = rd;
371  let Inst{6-0} = opcode.Value;
372}
373
374class RVInstIShift<bits<5> imm11_7, bits<3> funct3, RISCVOpcode opcode,
375                   dag outs, dag ins, string opcodestr, string argstr>
376    : RVInst<outs, ins, opcodestr, argstr, [], InstFormatI> {
377  bits<6> shamt;
378  bits<5> rs1;
379  bits<5> rd;
380
381  let Inst{31-27} = imm11_7;
382  let Inst{26} = 0;
383  let Inst{25-20} = shamt;
384  let Inst{19-15} = rs1;
385  let Inst{14-12} = funct3;
386  let Inst{11-7} = rd;
387  let Inst{6-0} = opcode.Value;
388}
389
390class RVInstIShiftW<bits<7> imm11_5, bits<3> funct3, RISCVOpcode opcode,
391                    dag outs, dag ins, string opcodestr, string argstr>
392    : RVInst<outs, ins, opcodestr, argstr, [], InstFormatI> {
393  bits<5> shamt;
394  bits<5> rs1;
395  bits<5> rd;
396
397  let Inst{31-25} = imm11_5;
398  let Inst{24-20} = shamt;
399  let Inst{19-15} = rs1;
400  let Inst{14-12} = funct3;
401  let Inst{11-7} = rd;
402  let Inst{6-0} = opcode.Value;
403}
404
405class RVInstS<bits<3> funct3, RISCVOpcode opcode, dag outs, dag ins,
406              string opcodestr, string argstr>
407    : RVInst<outs, ins, opcodestr, argstr, [], InstFormatS> {
408  bits<12> imm12;
409  bits<5> rs2;
410  bits<5> rs1;
411
412  let Inst{31-25} = imm12{11-5};
413  let Inst{24-20} = rs2;
414  let Inst{19-15} = rs1;
415  let Inst{14-12} = funct3;
416  let Inst{11-7} = imm12{4-0};
417  let Inst{6-0} = opcode.Value;
418}
419
420class RVInstB<bits<3> funct3, RISCVOpcode opcode, dag outs, dag ins,
421              string opcodestr, string argstr>
422    : RVInst<outs, ins, opcodestr, argstr, [], InstFormatB> {
423  bits<12> imm12;
424  bits<5> rs2;
425  bits<5> rs1;
426
427  let Inst{31} = imm12{11};
428  let Inst{30-25} = imm12{9-4};
429  let Inst{24-20} = rs2;
430  let Inst{19-15} = rs1;
431  let Inst{14-12} = funct3;
432  let Inst{11-8} = imm12{3-0};
433  let Inst{7} = imm12{10};
434  let Inst{6-0} = opcode.Value;
435}
436
437class RVInstU<RISCVOpcode opcode, dag outs, dag ins, string opcodestr,
438              string argstr>
439    : RVInst<outs, ins, opcodestr, argstr, [], InstFormatU> {
440  bits<20> imm20;
441  bits<5> rd;
442
443  let Inst{31-12} = imm20;
444  let Inst{11-7} = rd;
445  let Inst{6-0} = opcode.Value;
446}
447
448class RVInstJ<RISCVOpcode opcode, dag outs, dag ins, string opcodestr,
449              string argstr>
450    : RVInst<outs, ins, opcodestr, argstr, [], InstFormatJ> {
451  bits<20> imm20;
452  bits<5> rd;
453
454  let Inst{31} = imm20{19};
455  let Inst{30-21} = imm20{9-0};
456  let Inst{20} = imm20{10};
457  let Inst{19-12} = imm20{18-11};
458  let Inst{11-7} = rd;
459  let Inst{6-0} = opcode.Value;
460}
461
462//===----------------------------------------------------------------------===//
463// Instruction classes for .insn directives
464//===----------------------------------------------------------------------===//
465
466class DirectiveInsnR<dag outs, dag ins, string argstr>
467  : RVInst<outs, ins, "", "", [], InstFormatR> {
468  bits<7> opcode;
469  bits<7> funct7;
470  bits<3> funct3;
471
472  bits<5> rs2;
473  bits<5> rs1;
474  bits<5> rd;
475
476  let Inst{31-25} = funct7;
477  let Inst{24-20} = rs2;
478  let Inst{19-15} = rs1;
479  let Inst{14-12} = funct3;
480  let Inst{11-7} = rd;
481  let Inst{6-0} = opcode;
482
483  let AsmString = ".insn r " # argstr;
484}
485
486class DirectiveInsnR4<dag outs, dag ins, string argstr>
487  : RVInst<outs, ins, "", "", [], InstFormatR4> {
488  bits<7> opcode;
489  bits<2> funct2;
490  bits<3> funct3;
491
492  bits<5> rs3;
493  bits<5> rs2;
494  bits<5> rs1;
495  bits<5> rd;
496
497  let Inst{31-27} = rs3;
498  let Inst{26-25} = funct2;
499  let Inst{24-20} = rs2;
500  let Inst{19-15} = rs1;
501  let Inst{14-12} = funct3;
502  let Inst{11-7} = rd;
503  let Inst{6-0} = opcode;
504
505  let AsmString = ".insn r4 " # argstr;
506}
507
508class DirectiveInsnI<dag outs, dag ins, string argstr>
509  : RVInst<outs, ins, "", "", [], InstFormatI> {
510  bits<7> opcode;
511  bits<3> funct3;
512
513  bits<12> imm12;
514  bits<5> rs1;
515  bits<5> rd;
516
517  let Inst{31-20} = imm12;
518  let Inst{19-15} = rs1;
519  let Inst{14-12} = funct3;
520  let Inst{11-7} = rd;
521  let Inst{6-0} = opcode;
522
523  let AsmString = ".insn i " # argstr;
524}
525
526class DirectiveInsnS<dag outs, dag ins, string argstr>
527  : RVInst<outs, ins, "", "", [], InstFormatS> {
528  bits<7> opcode;
529  bits<3> funct3;
530
531  bits<12> imm12;
532  bits<5> rs2;
533  bits<5> rs1;
534
535  let Inst{31-25} = imm12{11-5};
536  let Inst{24-20} = rs2;
537  let Inst{19-15} = rs1;
538  let Inst{14-12} = funct3;
539  let Inst{11-7} = imm12{4-0};
540  let Inst{6-0} = opcode;
541
542  let AsmString = ".insn s " # argstr;
543}
544
545class DirectiveInsnB<dag outs, dag ins, string argstr>
546  : RVInst<outs, ins, "", "", [], InstFormatB> {
547  bits<7> opcode;
548  bits<3> funct3;
549
550  bits<12> imm12;
551  bits<5> rs2;
552  bits<5> rs1;
553
554  let Inst{31} = imm12{11};
555  let Inst{30-25} = imm12{9-4};
556  let Inst{24-20} = rs2;
557  let Inst{19-15} = rs1;
558  let Inst{14-12} = funct3;
559  let Inst{11-8} = imm12{3-0};
560  let Inst{7} = imm12{10};
561  let Inst{6-0} = opcode;
562
563  let AsmString = ".insn b " # argstr;
564}
565
566class DirectiveInsnU<dag outs, dag ins, string argstr>
567  : RVInst<outs, ins, "", "", [], InstFormatU> {
568  bits<7> opcode;
569
570  bits<20> imm20;
571  bits<5> rd;
572
573  let Inst{31-12} = imm20;
574  let Inst{11-7} = rd;
575  let Inst{6-0} = opcode;
576
577  let AsmString = ".insn u " # argstr;
578}
579
580class DirectiveInsnJ<dag outs, dag ins, string argstr>
581  : RVInst<outs, ins, "", "", [], InstFormatJ> {
582  bits<7> opcode;
583
584  bits<20> imm20;
585  bits<5> rd;
586
587  let Inst{31-12} = imm20;
588  let Inst{11-7} = rd;
589  let Inst{6-0} = opcode;
590
591  let AsmString = ".insn j " # argstr;
592}
593