1//===--- X86InstPrinterCommon.cpp - X86 assembly instruction printing -----===//
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// This file includes common code for rendering MCInst instances as Intel-style
10// and Intel-style assembly.
11//
12//===----------------------------------------------------------------------===//
13
14#include "X86InstPrinterCommon.h"
15#include "X86BaseInfo.h"
16#include "llvm/MC/MCAsmInfo.h"
17#include "llvm/MC/MCExpr.h"
18#include "llvm/MC/MCInst.h"
19#include "llvm/MC/MCInstrDesc.h"
20#include "llvm/MC/MCInstrInfo.h"
21#include "llvm/MC/MCSubtargetInfo.h"
22#include "llvm/Support/Casting.h"
23#include "llvm/Support/raw_ostream.h"
24#include <cassert>
25#include <cstdint>
26
27using namespace llvm;
28
29void X86InstPrinterCommon::printExprOperand(raw_ostream &OS, const MCExpr &E) {
30 MAI.printExpr(OS, E);
31}
32
33void X86InstPrinterCommon::printCondCode(const MCInst *MI, unsigned Op,
34 raw_ostream &O) {
35 int64_t Imm = MI->getOperand(i: Op).getImm();
36 unsigned Opc = MI->getOpcode();
37 bool IsCCMPOrCTEST = X86::isCCMPCC(Opcode: Opc) || X86::isCTESTCC(Opcode: Opc);
38
39 // clang-format off
40 switch (Imm) {
41 default: llvm_unreachable("Invalid condcode argument!");
42 case 0: O << "o"; break;
43 case 1: O << "no"; break;
44 case 2: O << "b"; break;
45 case 3: O << "ae"; break;
46 case 4: O << "e"; break;
47 case 5: O << "ne"; break;
48 case 6: O << "be"; break;
49 case 7: O << "a"; break;
50 case 8: O << "s"; break;
51 case 9: O << "ns"; break;
52 case 0xa: O << (IsCCMPOrCTEST ? "t" : "p"); break;
53 case 0xb: O << (IsCCMPOrCTEST ? "f" : "np"); break;
54 case 0xc: O << "l"; break;
55 case 0xd: O << "ge"; break;
56 case 0xe: O << "le"; break;
57 case 0xf: O << "g"; break;
58 }
59 // clang-format on
60}
61
62void X86InstPrinterCommon::printCondFlags(const MCInst *MI, unsigned Op,
63 raw_ostream &O) {
64 // +----+----+----+----+
65 // | OF | SF | ZF | CF |
66 // +----+----+----+----+
67 int64_t Imm = MI->getOperand(i: Op).getImm();
68 assert(Imm >= 0 && Imm < 16 && "Invalid condition flags");
69 O << "{dfv=";
70 std::string Flags;
71 if (Imm & 0x8)
72 Flags += "of,";
73 if (Imm & 0x4)
74 Flags += "sf,";
75 if (Imm & 0x2)
76 Flags += "zf,";
77 if (Imm & 0x1)
78 Flags += "cf,";
79 StringRef SimplifiedFlags = StringRef(Flags).rtrim(Chars: ",");
80 O << SimplifiedFlags << "}";
81}
82
83void X86InstPrinterCommon::printSSEAVXCC(const MCInst *MI, unsigned Op,
84 raw_ostream &O) {
85 int64_t Imm = MI->getOperand(i: Op).getImm();
86 switch (Imm) {
87 default: llvm_unreachable("Invalid ssecc/avxcc argument!");
88 case 0: O << "eq"; break;
89 case 1: O << "lt"; break;
90 case 2: O << "le"; break;
91 case 3: O << "unord"; break;
92 case 4: O << "neq"; break;
93 case 5: O << "nlt"; break;
94 case 6: O << "nle"; break;
95 case 7: O << "ord"; break;
96 case 8: O << "eq_uq"; break;
97 case 9: O << "nge"; break;
98 case 0xa: O << "ngt"; break;
99 case 0xb: O << "false"; break;
100 case 0xc: O << "neq_oq"; break;
101 case 0xd: O << "ge"; break;
102 case 0xe: O << "gt"; break;
103 case 0xf: O << "true"; break;
104 case 0x10: O << "eq_os"; break;
105 case 0x11: O << "lt_oq"; break;
106 case 0x12: O << "le_oq"; break;
107 case 0x13: O << "unord_s"; break;
108 case 0x14: O << "neq_us"; break;
109 case 0x15: O << "nlt_uq"; break;
110 case 0x16: O << "nle_uq"; break;
111 case 0x17: O << "ord_s"; break;
112 case 0x18: O << "eq_us"; break;
113 case 0x19: O << "nge_uq"; break;
114 case 0x1a: O << "ngt_uq"; break;
115 case 0x1b: O << "false_os"; break;
116 case 0x1c: O << "neq_os"; break;
117 case 0x1d: O << "ge_oq"; break;
118 case 0x1e: O << "gt_oq"; break;
119 case 0x1f: O << "true_us"; break;
120 }
121}
122
123void X86InstPrinterCommon::printVPCOMMnemonic(const MCInst *MI,
124 raw_ostream &OS) {
125 OS << "vpcom";
126
127 int64_t Imm = MI->getOperand(i: MI->getNumOperands() - 1).getImm();
128 switch (Imm) {
129 default: llvm_unreachable("Invalid vpcom argument!");
130 case 0: OS << "lt"; break;
131 case 1: OS << "le"; break;
132 case 2: OS << "gt"; break;
133 case 3: OS << "ge"; break;
134 case 4: OS << "eq"; break;
135 case 5: OS << "neq"; break;
136 case 6: OS << "false"; break;
137 case 7: OS << "true"; break;
138 }
139
140 switch (MI->getOpcode()) {
141 default: llvm_unreachable("Unexpected opcode!");
142 case X86::VPCOMBmi: case X86::VPCOMBri: OS << "b\t"; break;
143 case X86::VPCOMDmi: case X86::VPCOMDri: OS << "d\t"; break;
144 case X86::VPCOMQmi: case X86::VPCOMQri: OS << "q\t"; break;
145 case X86::VPCOMUBmi: case X86::VPCOMUBri: OS << "ub\t"; break;
146 case X86::VPCOMUDmi: case X86::VPCOMUDri: OS << "ud\t"; break;
147 case X86::VPCOMUQmi: case X86::VPCOMUQri: OS << "uq\t"; break;
148 case X86::VPCOMUWmi: case X86::VPCOMUWri: OS << "uw\t"; break;
149 case X86::VPCOMWmi: case X86::VPCOMWri: OS << "w\t"; break;
150 }
151}
152
153void X86InstPrinterCommon::printVPCMPMnemonic(const MCInst *MI,
154 raw_ostream &OS) {
155 OS << "vpcmp";
156
157 printSSEAVXCC(MI, Op: MI->getNumOperands() - 1, O&: OS);
158
159 switch (MI->getOpcode()) {
160 default: llvm_unreachable("Unexpected opcode!");
161 case X86::VPCMPBZ128rmi: case X86::VPCMPBZ128rri:
162 case X86::VPCMPBZ256rmi: case X86::VPCMPBZ256rri:
163 case X86::VPCMPBZrmi: case X86::VPCMPBZrri:
164 case X86::VPCMPBZ128rmik: case X86::VPCMPBZ128rrik:
165 case X86::VPCMPBZ256rmik: case X86::VPCMPBZ256rrik:
166 case X86::VPCMPBZrmik: case X86::VPCMPBZrrik:
167 OS << "b\t";
168 break;
169 case X86::VPCMPDZ128rmi: case X86::VPCMPDZ128rri:
170 case X86::VPCMPDZ256rmi: case X86::VPCMPDZ256rri:
171 case X86::VPCMPDZrmi: case X86::VPCMPDZrri:
172 case X86::VPCMPDZ128rmik: case X86::VPCMPDZ128rrik:
173 case X86::VPCMPDZ256rmik: case X86::VPCMPDZ256rrik:
174 case X86::VPCMPDZrmik: case X86::VPCMPDZrrik:
175 case X86::VPCMPDZ128rmbi: case X86::VPCMPDZ128rmbik:
176 case X86::VPCMPDZ256rmbi: case X86::VPCMPDZ256rmbik:
177 case X86::VPCMPDZrmbi: case X86::VPCMPDZrmbik:
178 OS << "d\t";
179 break;
180 case X86::VPCMPQZ128rmi: case X86::VPCMPQZ128rri:
181 case X86::VPCMPQZ256rmi: case X86::VPCMPQZ256rri:
182 case X86::VPCMPQZrmi: case X86::VPCMPQZrri:
183 case X86::VPCMPQZ128rmik: case X86::VPCMPQZ128rrik:
184 case X86::VPCMPQZ256rmik: case X86::VPCMPQZ256rrik:
185 case X86::VPCMPQZrmik: case X86::VPCMPQZrrik:
186 case X86::VPCMPQZ128rmbi: case X86::VPCMPQZ128rmbik:
187 case X86::VPCMPQZ256rmbi: case X86::VPCMPQZ256rmbik:
188 case X86::VPCMPQZrmbi: case X86::VPCMPQZrmbik:
189 OS << "q\t";
190 break;
191 case X86::VPCMPUBZ128rmi: case X86::VPCMPUBZ128rri:
192 case X86::VPCMPUBZ256rmi: case X86::VPCMPUBZ256rri:
193 case X86::VPCMPUBZrmi: case X86::VPCMPUBZrri:
194 case X86::VPCMPUBZ128rmik: case X86::VPCMPUBZ128rrik:
195 case X86::VPCMPUBZ256rmik: case X86::VPCMPUBZ256rrik:
196 case X86::VPCMPUBZrmik: case X86::VPCMPUBZrrik:
197 OS << "ub\t";
198 break;
199 case X86::VPCMPUDZ128rmi: case X86::VPCMPUDZ128rri:
200 case X86::VPCMPUDZ256rmi: case X86::VPCMPUDZ256rri:
201 case X86::VPCMPUDZrmi: case X86::VPCMPUDZrri:
202 case X86::VPCMPUDZ128rmik: case X86::VPCMPUDZ128rrik:
203 case X86::VPCMPUDZ256rmik: case X86::VPCMPUDZ256rrik:
204 case X86::VPCMPUDZrmik: case X86::VPCMPUDZrrik:
205 case X86::VPCMPUDZ128rmbi: case X86::VPCMPUDZ128rmbik:
206 case X86::VPCMPUDZ256rmbi: case X86::VPCMPUDZ256rmbik:
207 case X86::VPCMPUDZrmbi: case X86::VPCMPUDZrmbik:
208 OS << "ud\t";
209 break;
210 case X86::VPCMPUQZ128rmi: case X86::VPCMPUQZ128rri:
211 case X86::VPCMPUQZ256rmi: case X86::VPCMPUQZ256rri:
212 case X86::VPCMPUQZrmi: case X86::VPCMPUQZrri:
213 case X86::VPCMPUQZ128rmik: case X86::VPCMPUQZ128rrik:
214 case X86::VPCMPUQZ256rmik: case X86::VPCMPUQZ256rrik:
215 case X86::VPCMPUQZrmik: case X86::VPCMPUQZrrik:
216 case X86::VPCMPUQZ128rmbi: case X86::VPCMPUQZ128rmbik:
217 case X86::VPCMPUQZ256rmbi: case X86::VPCMPUQZ256rmbik:
218 case X86::VPCMPUQZrmbi: case X86::VPCMPUQZrmbik:
219 OS << "uq\t";
220 break;
221 case X86::VPCMPUWZ128rmi: case X86::VPCMPUWZ128rri:
222 case X86::VPCMPUWZ256rri: case X86::VPCMPUWZ256rmi:
223 case X86::VPCMPUWZrmi: case X86::VPCMPUWZrri:
224 case X86::VPCMPUWZ128rmik: case X86::VPCMPUWZ128rrik:
225 case X86::VPCMPUWZ256rrik: case X86::VPCMPUWZ256rmik:
226 case X86::VPCMPUWZrmik: case X86::VPCMPUWZrrik:
227 OS << "uw\t";
228 break;
229 case X86::VPCMPWZ128rmi: case X86::VPCMPWZ128rri:
230 case X86::VPCMPWZ256rmi: case X86::VPCMPWZ256rri:
231 case X86::VPCMPWZrmi: case X86::VPCMPWZrri:
232 case X86::VPCMPWZ128rmik: case X86::VPCMPWZ128rrik:
233 case X86::VPCMPWZ256rmik: case X86::VPCMPWZ256rrik:
234 case X86::VPCMPWZrmik: case X86::VPCMPWZrrik:
235 OS << "w\t";
236 break;
237 }
238}
239
240void X86InstPrinterCommon::printCMPMnemonic(const MCInst *MI, bool IsVCmp,
241 raw_ostream &OS) {
242 OS << (IsVCmp ? "vcmp" : "cmp");
243
244 printSSEAVXCC(MI, Op: MI->getNumOperands() - 1, O&: OS);
245
246 switch (MI->getOpcode()) {
247 default: llvm_unreachable("Unexpected opcode!");
248 case X86::CMPPDrmi: case X86::CMPPDrri:
249 case X86::VCMPPDrmi: case X86::VCMPPDrri:
250 case X86::VCMPPDYrmi: case X86::VCMPPDYrri:
251 case X86::VCMPPDZ128rmi: case X86::VCMPPDZ128rri:
252 case X86::VCMPPDZ256rmi: case X86::VCMPPDZ256rri:
253 case X86::VCMPPDZrmi: case X86::VCMPPDZrri:
254 case X86::VCMPPDZ128rmik: case X86::VCMPPDZ128rrik:
255 case X86::VCMPPDZ256rmik: case X86::VCMPPDZ256rrik:
256 case X86::VCMPPDZrmik: case X86::VCMPPDZrrik:
257 case X86::VCMPPDZ128rmbi: case X86::VCMPPDZ128rmbik:
258 case X86::VCMPPDZ256rmbi: case X86::VCMPPDZ256rmbik:
259 case X86::VCMPPDZrmbi: case X86::VCMPPDZrmbik:
260 case X86::VCMPPDZrrib: case X86::VCMPPDZrribk:
261 OS << "pd\t";
262 break;
263 case X86::CMPPSrmi: case X86::CMPPSrri:
264 case X86::VCMPPSrmi: case X86::VCMPPSrri:
265 case X86::VCMPPSYrmi: case X86::VCMPPSYrri:
266 case X86::VCMPPSZ128rmi: case X86::VCMPPSZ128rri:
267 case X86::VCMPPSZ256rmi: case X86::VCMPPSZ256rri:
268 case X86::VCMPPSZrmi: case X86::VCMPPSZrri:
269 case X86::VCMPPSZ128rmik: case X86::VCMPPSZ128rrik:
270 case X86::VCMPPSZ256rmik: case X86::VCMPPSZ256rrik:
271 case X86::VCMPPSZrmik: case X86::VCMPPSZrrik:
272 case X86::VCMPPSZ128rmbi: case X86::VCMPPSZ128rmbik:
273 case X86::VCMPPSZ256rmbi: case X86::VCMPPSZ256rmbik:
274 case X86::VCMPPSZrmbi: case X86::VCMPPSZrmbik:
275 case X86::VCMPPSZrrib: case X86::VCMPPSZrribk:
276 OS << "ps\t";
277 break;
278 case X86::CMPSDrmi: case X86::CMPSDrri:
279 case X86::CMPSDrmi_Int: case X86::CMPSDrri_Int:
280 case X86::VCMPSDrmi: case X86::VCMPSDrri:
281 case X86::VCMPSDrmi_Int: case X86::VCMPSDrri_Int:
282 case X86::VCMPSDZrmi: case X86::VCMPSDZrri:
283 case X86::VCMPSDZrmi_Int: case X86::VCMPSDZrri_Int:
284 case X86::VCMPSDZrmik_Int: case X86::VCMPSDZrrik_Int:
285 case X86::VCMPSDZrrib_Int: case X86::VCMPSDZrribk_Int:
286 OS << "sd\t";
287 break;
288 case X86::CMPSSrmi: case X86::CMPSSrri:
289 case X86::CMPSSrmi_Int: case X86::CMPSSrri_Int:
290 case X86::VCMPSSrmi: case X86::VCMPSSrri:
291 case X86::VCMPSSrmi_Int: case X86::VCMPSSrri_Int:
292 case X86::VCMPSSZrmi: case X86::VCMPSSZrri:
293 case X86::VCMPSSZrmi_Int: case X86::VCMPSSZrri_Int:
294 case X86::VCMPSSZrmik_Int: case X86::VCMPSSZrrik_Int:
295 case X86::VCMPSSZrrib_Int: case X86::VCMPSSZrribk_Int:
296 OS << "ss\t";
297 break;
298 case X86::VCMPPHZ128rmi: case X86::VCMPPHZ128rri:
299 case X86::VCMPPHZ256rmi: case X86::VCMPPHZ256rri:
300 case X86::VCMPPHZrmi: case X86::VCMPPHZrri:
301 case X86::VCMPPHZ128rmik: case X86::VCMPPHZ128rrik:
302 case X86::VCMPPHZ256rmik: case X86::VCMPPHZ256rrik:
303 case X86::VCMPPHZrmik: case X86::VCMPPHZrrik:
304 case X86::VCMPPHZ128rmbi: case X86::VCMPPHZ128rmbik:
305 case X86::VCMPPHZ256rmbi: case X86::VCMPPHZ256rmbik:
306 case X86::VCMPPHZrmbi: case X86::VCMPPHZrmbik:
307 case X86::VCMPPHZrrib: case X86::VCMPPHZrribk:
308 OS << "ph\t";
309 break;
310 case X86::VCMPSHZrmi: case X86::VCMPSHZrri:
311 case X86::VCMPSHZrmi_Int: case X86::VCMPSHZrri_Int:
312 case X86::VCMPSHZrrib_Int: case X86::VCMPSHZrribk_Int:
313 case X86::VCMPSHZrmik_Int: case X86::VCMPSHZrrik_Int:
314 OS << "sh\t";
315 break;
316 case X86::VCMPBF16Z128rmi: case X86::VCMPBF16Z128rri:
317 case X86::VCMPBF16Z256rmi: case X86::VCMPBF16Z256rri:
318 case X86::VCMPBF16Zrmi: case X86::VCMPBF16Zrri:
319 case X86::VCMPBF16Z128rmik: case X86::VCMPBF16Z128rrik:
320 case X86::VCMPBF16Z256rmik: case X86::VCMPBF16Z256rrik:
321 case X86::VCMPBF16Zrmik: case X86::VCMPBF16Zrrik:
322 case X86::VCMPBF16Z128rmbi: case X86::VCMPBF16Z128rmbik:
323 case X86::VCMPBF16Z256rmbi: case X86::VCMPBF16Z256rmbik:
324 case X86::VCMPBF16Zrmbi: case X86::VCMPBF16Zrmbik:
325 OS << "bf16\t";
326 break;
327 }
328}
329
330void X86InstPrinterCommon::printRoundingControl(const MCInst *MI, unsigned Op,
331 raw_ostream &O) {
332 int64_t Imm = MI->getOperand(i: Op).getImm();
333 switch (Imm) {
334 default:
335 llvm_unreachable("Invalid rounding control!");
336 case X86::TO_NEAREST_INT:
337 O << "{rn-sae}";
338 break;
339 case X86::TO_NEG_INF:
340 O << "{rd-sae}";
341 break;
342 case X86::TO_POS_INF:
343 O << "{ru-sae}";
344 break;
345 case X86::TO_ZERO:
346 O << "{rz-sae}";
347 break;
348 }
349}
350
351/// value (e.g. for jumps and calls). In Intel-style these print slightly
352/// differently than normal immediates. For example, a $ is not emitted.
353///
354/// \p Address The address of the next instruction.
355/// \see MCInstPrinter::printInst
356void X86InstPrinterCommon::printPCRelImm(const MCInst *MI, uint64_t Address,
357 unsigned OpNo, raw_ostream &O) {
358 // Do not print the numberic target address when symbolizing.
359 if (SymbolizeOperands)
360 return;
361
362 const MCOperand &Op = MI->getOperand(i: OpNo);
363 if (Op.isImm()) {
364 if (PrintBranchImmAsAddress) {
365 uint64_t Target = Address + Op.getImm();
366 if (MAI.getCodePointerSize() == 4)
367 Target &= 0xffffffff;
368 markup(OS&: O, M: Markup::Target) << formatHex(Value: Target);
369 } else
370 markup(OS&: O, M: Markup::Immediate) << formatImm(Value: Op.getImm());
371 } else {
372 assert(Op.isExpr() && "unknown pcrel immediate operand");
373 // If a symbolic branch target was added as a constant expression then print
374 // that address in hex.
375 const MCConstantExpr *BranchTarget = dyn_cast<MCConstantExpr>(Val: Op.getExpr());
376 int64_t Address;
377 if (BranchTarget && BranchTarget->evaluateAsAbsolute(Res&: Address)) {
378 markup(OS&: O, M: Markup::Immediate) << formatHex(Value: (uint64_t)Address);
379 } else {
380 // Otherwise, just print the expression.
381 printExprOperand(OS&: O, E: *Op.getExpr());
382 }
383 }
384}
385
386void X86InstPrinterCommon::printOptionalSegReg(const MCInst *MI, unsigned OpNo,
387 raw_ostream &O) {
388 if (MI->getOperand(i: OpNo).getReg()) {
389 printOperand(MI, OpNo, O);
390 O << ':';
391 }
392}
393
394void X86InstPrinterCommon::printInstFlags(const MCInst *MI, raw_ostream &O,
395 const MCSubtargetInfo &STI) {
396 const MCInstrDesc &Desc = MII.get(Opcode: MI->getOpcode());
397 uint64_t TSFlags = Desc.TSFlags;
398 unsigned Flags = MI->getFlags();
399
400 if ((TSFlags & X86II::LOCK) || (Flags & X86::IP_HAS_LOCK))
401 O << "\tlock\t";
402
403 if ((TSFlags & X86II::NOTRACK) || (Flags & X86::IP_HAS_NOTRACK))
404 O << "\tnotrack\t";
405
406 if (Flags & X86::IP_HAS_REPEAT_NE)
407 O << "\trepne\t";
408 else if (Flags & X86::IP_HAS_REPEAT)
409 O << "\trep\t";
410
411 if (TSFlags & X86II::EVEX_NF && !X86::isCFCMOVCC(Opcode: MI->getOpcode()))
412 O << "\t{nf}";
413
414 // These all require a pseudo prefix
415 if ((Flags & X86::IP_USE_VEX) ||
416 (TSFlags & X86II::ExplicitOpPrefixMask) == X86II::ExplicitVEXPrefix)
417 O << "\t{vex}";
418 else if (Flags & X86::IP_USE_VEX2)
419 O << "\t{vex2}";
420 else if (Flags & X86::IP_USE_VEX3)
421 O << "\t{vex3}";
422 else if ((Flags & X86::IP_USE_EVEX) ||
423 (TSFlags & X86II::ExplicitOpPrefixMask) == X86II::ExplicitEVEXPrefix)
424 O << "\t{evex}";
425
426 if (Flags & X86::IP_USE_DISP8)
427 O << "\t{disp8}";
428 else if (Flags & X86::IP_USE_DISP32)
429 O << "\t{disp32}";
430
431 // Determine where the memory operand starts, if present
432 int MemoryOperand = X86II::getMemoryOperandNo(TSFlags);
433 if (MemoryOperand != -1)
434 MemoryOperand += X86II::getOperandBias(Desc);
435
436 // Address-Size override prefix
437 if (Flags & X86::IP_HAS_AD_SIZE &&
438 !X86_MC::needsAddressSizeOverride(MI: *MI, STI, MemoryOperand, TSFlags)) {
439 if (STI.hasFeature(Feature: X86::Is16Bit) || STI.hasFeature(Feature: X86::Is64Bit))
440 O << "\taddr32\t";
441 else if (STI.hasFeature(Feature: X86::Is32Bit))
442 O << "\taddr16\t";
443 }
444}
445
446void X86InstPrinterCommon::printVKPair(const MCInst *MI, unsigned OpNo,
447 raw_ostream &OS) {
448 // In assembly listings, a pair is represented by one of its members, any
449 // of the two. Here, we pick k0, k2, k4, k6, but we could as well
450 // print K2_K3 as "k3". It would probably make a lot more sense, if
451 // the assembly would look something like:
452 // "vp2intersect %zmm5, %zmm7, {%k2, %k3}"
453 // but this can work too.
454 switch (MI->getOperand(i: OpNo).getReg().id()) {
455 case X86::K0_K1:
456 printRegName(OS, Reg: X86::K0);
457 return;
458 case X86::K2_K3:
459 printRegName(OS, Reg: X86::K2);
460 return;
461 case X86::K4_K5:
462 printRegName(OS, Reg: X86::K4);
463 return;
464 case X86::K6_K7:
465 printRegName(OS, Reg: X86::K6);
466 return;
467 }
468 llvm_unreachable("Unknown mask pair register name");
469}
470