xref: /freebsd/contrib/llvm-project/llvm/lib/Target/AArch64/MCTargetDesc/AArch64AddressingModes.h (revision 5f757f3ff9144b609b3c433dfd370cc6bdc191ad) 
1 //===- AArch64AddressingModes.h - AArch64 Addressing Modes ------*- C++ -*-===//
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 contains the AArch64 addressing mode implementation stuff.
10 //
11 //===----------------------------------------------------------------------===//
12 
13 #ifndef LLVM_LIB_TARGET_AARCH64_MCTARGETDESC_AARCH64ADDRESSINGMODES_H
14 #define LLVM_LIB_TARGET_AARCH64_MCTARGETDESC_AARCH64ADDRESSINGMODES_H
15 
16 #include "llvm/ADT/APFloat.h"
17 #include "llvm/ADT/APInt.h"
18 #include "llvm/ADT/bit.h"
19 #include "llvm/Support/ErrorHandling.h"
20 #include "llvm/Support/MathExtras.h"
21 #include <cassert>
22 
23 namespace llvm {
24 
25 /// AArch64_AM - AArch64 Addressing Mode Stuff
26 namespace AArch64_AM {
27 
28 //===----------------------------------------------------------------------===//
29 // Shifts
30 //
31 
32 enum ShiftExtendType {
33   InvalidShiftExtend = -1,
34   LSL = 0,
35   LSR,
36   ASR,
37   ROR,
38   MSL,
39 
40   UXTB,
41   UXTH,
42   UXTW,
43   UXTX,
44 
45   SXTB,
46   SXTH,
47   SXTW,
48   SXTX,
49 };
50 
51 /// getShiftName - Get the string encoding for the shift type.
52 static inline const char *getShiftExtendName(AArch64_AM::ShiftExtendType ST) {
53   switch (ST) {
54   default: llvm_unreachable("unhandled shift type!");
55   case AArch64_AM::LSL: return "lsl";
56   case AArch64_AM::LSR: return "lsr";
57   case AArch64_AM::ASR: return "asr";
58   case AArch64_AM::ROR: return "ror";
59   case AArch64_AM::MSL: return "msl";
60   case AArch64_AM::UXTB: return "uxtb";
61   case AArch64_AM::UXTH: return "uxth";
62   case AArch64_AM::UXTW: return "uxtw";
63   case AArch64_AM::UXTX: return "uxtx";
64   case AArch64_AM::SXTB: return "sxtb";
65   case AArch64_AM::SXTH: return "sxth";
66   case AArch64_AM::SXTW: return "sxtw";
67   case AArch64_AM::SXTX: return "sxtx";
68   }
69   return nullptr;
70 }
71 
72 /// getShiftType - Extract the shift type.
73 static inline AArch64_AM::ShiftExtendType getShiftType(unsigned Imm) {
74   switch ((Imm >> 6) & 0x7) {
75   default: return AArch64_AM::InvalidShiftExtend;
76   case 0: return AArch64_AM::LSL;
77   case 1: return AArch64_AM::LSR;
78   case 2: return AArch64_AM::ASR;
79   case 3: return AArch64_AM::ROR;
80   case 4: return AArch64_AM::MSL;
81   }
82 }
83 
84 /// getShiftValue - Extract the shift value.
85 static inline unsigned getShiftValue(unsigned Imm) {
86   return Imm & 0x3f;
87 }
88 
89 /// getShifterImm - Encode the shift type and amount:
90 ///   imm:     6-bit shift amount
91 ///   shifter: 000 ==> lsl
92 ///            001 ==> lsr
93 ///            010 ==> asr
94 ///            011 ==> ror
95 ///            100 ==> msl
96 ///   {8-6}  = shifter
97 ///   {5-0}  = imm
98 static inline unsigned getShifterImm(AArch64_AM::ShiftExtendType ST,
99                                      unsigned Imm) {
100   assert((Imm & 0x3f) == Imm && "Illegal shifted immedate value!");
101   unsigned STEnc = 0;
102   switch (ST) {
103   default:  llvm_unreachable("Invalid shift requested");
104   case AArch64_AM::LSL: STEnc = 0; break;
105   case AArch64_AM::LSR: STEnc = 1; break;
106   case AArch64_AM::ASR: STEnc = 2; break;
107   case AArch64_AM::ROR: STEnc = 3; break;
108   case AArch64_AM::MSL: STEnc = 4; break;
109   }
110   return (STEnc << 6) | (Imm & 0x3f);
111 }
112 
113 //===----------------------------------------------------------------------===//
114 // Extends
115 //
116 
117 /// getArithShiftValue - get the arithmetic shift value.
118 static inline unsigned getArithShiftValue(unsigned Imm) {
119   return Imm & 0x7;
120 }
121 
122 /// getExtendType - Extract the extend type for operands of arithmetic ops.
123 static inline AArch64_AM::ShiftExtendType getExtendType(unsigned Imm) {
124   assert((Imm & 0x7) == Imm && "invalid immediate!");
125   switch (Imm) {
126   default: llvm_unreachable("Compiler bug!");
127   case 0: return AArch64_AM::UXTB;
128   case 1: return AArch64_AM::UXTH;
129   case 2: return AArch64_AM::UXTW;
130   case 3: return AArch64_AM::UXTX;
131   case 4: return AArch64_AM::SXTB;
132   case 5: return AArch64_AM::SXTH;
133   case 6: return AArch64_AM::SXTW;
134   case 7: return AArch64_AM::SXTX;
135   }
136 }
137 
138 static inline AArch64_AM::ShiftExtendType getArithExtendType(unsigned Imm) {
139   return getExtendType((Imm >> 3) & 0x7);
140 }
141 
142 /// Mapping from extend bits to required operation:
143 ///   shifter: 000 ==> uxtb
144 ///            001 ==> uxth
145 ///            010 ==> uxtw
146 ///            011 ==> uxtx
147 ///            100 ==> sxtb
148 ///            101 ==> sxth
149 ///            110 ==> sxtw
150 ///            111 ==> sxtx
151 inline unsigned getExtendEncoding(AArch64_AM::ShiftExtendType ET) {
152   switch (ET) {
153   default: llvm_unreachable("Invalid extend type requested");
154   case AArch64_AM::UXTB: return 0; break;
155   case AArch64_AM::UXTH: return 1; break;
156   case AArch64_AM::UXTW: return 2; break;
157   case AArch64_AM::UXTX: return 3; break;
158   case AArch64_AM::SXTB: return 4; break;
159   case AArch64_AM::SXTH: return 5; break;
160   case AArch64_AM::SXTW: return 6; break;
161   case AArch64_AM::SXTX: return 7; break;
162   }
163 }
164 
165 /// getArithExtendImm - Encode the extend type and shift amount for an
166 ///                     arithmetic instruction:
167 ///   imm:     3-bit extend amount
168 ///   {5-3}  = shifter
169 ///   {2-0}  = imm3
170 static inline unsigned getArithExtendImm(AArch64_AM::ShiftExtendType ET,
171                                          unsigned Imm) {
172   assert((Imm & 0x7) == Imm && "Illegal shifted immedate value!");
173   return (getExtendEncoding(ET) << 3) | (Imm & 0x7);
174 }
175 
176 /// getMemDoShift - Extract the "do shift" flag value for load/store
177 /// instructions.
178 static inline bool getMemDoShift(unsigned Imm) {
179   return (Imm & 0x1) != 0;
180 }
181 
182 /// getExtendType - Extract the extend type for the offset operand of
183 /// loads/stores.
184 static inline AArch64_AM::ShiftExtendType getMemExtendType(unsigned Imm) {
185   return getExtendType((Imm >> 1) & 0x7);
186 }
187 
188 /// getExtendImm - Encode the extend type and amount for a load/store inst:
189 ///   doshift:     should the offset be scaled by the access size
190 ///   shifter: 000 ==> uxtb
191 ///            001 ==> uxth
192 ///            010 ==> uxtw
193 ///            011 ==> uxtx
194 ///            100 ==> sxtb
195 ///            101 ==> sxth
196 ///            110 ==> sxtw
197 ///            111 ==> sxtx
198 ///   {3-1}  = shifter
199 ///   {0}  = doshift
200 static inline unsigned getMemExtendImm(AArch64_AM::ShiftExtendType ET,
201                                        bool DoShift) {
202   return (getExtendEncoding(ET) << 1) | unsigned(DoShift);
203 }
204 
205 static inline uint64_t ror(uint64_t elt, unsigned size) {
206   return ((elt & 1) << (size-1)) | (elt >> 1);
207 }
208 
209 /// processLogicalImmediate - Determine if an immediate value can be encoded
210 /// as the immediate operand of a logical instruction for the given register
211 /// size.  If so, return true with "encoding" set to the encoded value in
212 /// the form N:immr:imms.
213 static inline bool processLogicalImmediate(uint64_t Imm, unsigned RegSize,
214                                            uint64_t &Encoding) {
215   if (Imm == 0ULL || Imm == ~0ULL ||
216       (RegSize != 64 &&
217         (Imm >> RegSize != 0 || Imm == (~0ULL >> (64 - RegSize)))))
218     return false;
219 
220   // First, determine the element size.
221   unsigned Size = RegSize;
222 
223   do {
224     Size /= 2;
225     uint64_t Mask = (1ULL << Size) - 1;
226 
227     if ((Imm & Mask) != ((Imm >> Size) & Mask)) {
228       Size *= 2;
229       break;
230     }
231   } while (Size > 2);
232 
233   // Second, determine the rotation to make the element be: 0^m 1^n.
234   uint32_t CTO, I;
235   uint64_t Mask = ((uint64_t)-1LL) >> (64 - Size);
236   Imm &= Mask;
237 
238   if (isShiftedMask_64(Imm)) {
239     I = llvm::countr_zero(Imm);
240     assert(I < 64 && "undefined behavior");
241     CTO = llvm::countr_one(Imm >> I);
242   } else {
243     Imm |= ~Mask;
244     if (!isShiftedMask_64(~Imm))
245       return false;
246 
247     unsigned CLO = llvm::countl_one(Imm);
248     I = 64 - CLO;
249     CTO = CLO + llvm::countr_one(Imm) - (64 - Size);
250   }
251 
252   // Encode in Immr the number of RORs it would take to get *from* 0^m 1^n
253   // to our target value, where I is the number of RORs to go the opposite
254   // direction.
255   assert(Size > I && "I should be smaller than element size");
256   unsigned Immr = (Size - I) & (Size - 1);
257 
258   // If size has a 1 in the n'th bit, create a value that has zeroes in
259   // bits [0, n] and ones above that.
260   uint64_t NImms = ~(Size-1) << 1;
261 
262   // Or the CTO value into the low bits, which must be below the Nth bit
263   // bit mentioned above.
264   NImms |= (CTO-1);
265 
266   // Extract the seventh bit and toggle it to create the N field.
267   unsigned N = ((NImms >> 6) & 1) ^ 1;
268 
269   Encoding = (N << 12) | (Immr << 6) | (NImms & 0x3f);
270   return true;
271 }
272 
273 /// isLogicalImmediate - Return true if the immediate is valid for a logical
274 /// immediate instruction of the given register size. Return false otherwise.
275 static inline bool isLogicalImmediate(uint64_t imm, unsigned regSize) {
276   uint64_t encoding;
277   return processLogicalImmediate(imm, regSize, encoding);
278 }
279 
280 /// encodeLogicalImmediate - Return the encoded immediate value for a logical
281 /// immediate instruction of the given register size.
282 static inline uint64_t encodeLogicalImmediate(uint64_t imm, unsigned regSize) {
283   uint64_t encoding = 0;
284   bool res = processLogicalImmediate(imm, regSize, encoding);
285   assert(res && "invalid logical immediate");
286   (void)res;
287   return encoding;
288 }
289 
290 /// decodeLogicalImmediate - Decode a logical immediate value in the form
291 /// "N:immr:imms" (where the immr and imms fields are each 6 bits) into the
292 /// integer value it represents with regSize bits.
293 static inline uint64_t decodeLogicalImmediate(uint64_t val, unsigned regSize) {
294   // Extract the N, imms, and immr fields.
295   unsigned N = (val >> 12) & 1;
296   unsigned immr = (val >> 6) & 0x3f;
297   unsigned imms = val & 0x3f;
298 
299   assert((regSize == 64 || N == 0) && "undefined logical immediate encoding");
300   int len = 31 - llvm::countl_zero((N << 6) | (~imms & 0x3f));
301   assert(len >= 0 && "undefined logical immediate encoding");
302   unsigned size = (1 << len);
303   unsigned R = immr & (size - 1);
304   unsigned S = imms & (size - 1);
305   assert(S != size - 1 && "undefined logical immediate encoding");
306   uint64_t pattern = (1ULL << (S + 1)) - 1;
307   for (unsigned i = 0; i < R; ++i)
308     pattern = ror(pattern, size);
309 
310   // Replicate the pattern to fill the regSize.
311   while (size != regSize) {
312     pattern |= (pattern << size);
313     size *= 2;
314   }
315   return pattern;
316 }
317 
318 /// isValidDecodeLogicalImmediate - Check to see if the logical immediate value
319 /// in the form "N:immr:imms" (where the immr and imms fields are each 6 bits)
320 /// is a valid encoding for an integer value with regSize bits.
321 static inline bool isValidDecodeLogicalImmediate(uint64_t val,
322                                                  unsigned regSize) {
323   // Extract the N and imms fields needed for checking.
324   unsigned N = (val >> 12) & 1;
325   unsigned imms = val & 0x3f;
326 
327   if (regSize == 32 && N != 0) // undefined logical immediate encoding
328     return false;
329   int len = 31 - llvm::countl_zero((N << 6) | (~imms & 0x3f));
330   if (len < 0) // undefined logical immediate encoding
331     return false;
332   unsigned size = (1 << len);
333   unsigned S = imms & (size - 1);
334   if (S == size - 1) // undefined logical immediate encoding
335     return false;
336 
337   return true;
338 }
339 
340 //===----------------------------------------------------------------------===//
341 // Floating-point Immediates
342 //
343 static inline float getFPImmFloat(unsigned Imm) {
344   // We expect an 8-bit binary encoding of a floating-point number here.
345 
346   uint8_t Sign = (Imm >> 7) & 0x1;
347   uint8_t Exp = (Imm >> 4) & 0x7;
348   uint8_t Mantissa = Imm & 0xf;
349 
350   //   8-bit FP    IEEE Float Encoding
351   //   abcd efgh   aBbbbbbc defgh000 00000000 00000000
352   //
353   // where B = NOT(b);
354 
355   uint32_t I = 0;
356   I |= Sign << 31;
357   I |= ((Exp & 0x4) != 0 ? 0 : 1) << 30;
358   I |= ((Exp & 0x4) != 0 ? 0x1f : 0) << 25;
359   I |= (Exp & 0x3) << 23;
360   I |= Mantissa << 19;
361   return bit_cast<float>(I);
362 }
363 
364 /// getFP16Imm - Return an 8-bit floating-point version of the 16-bit
365 /// floating-point value. If the value cannot be represented as an 8-bit
366 /// floating-point value, then return -1.
367 static inline int getFP16Imm(const APInt &Imm) {
368   uint32_t Sign = Imm.lshr(15).getZExtValue() & 1;
369   int32_t Exp = (Imm.lshr(10).getSExtValue() & 0x1f) - 15;  // -14 to 15
370   int32_t Mantissa = Imm.getZExtValue() & 0x3ff;  // 10 bits
371 
372   // We can handle 4 bits of mantissa.
373   // mantissa = (16+UInt(e:f:g:h))/16.
374   if (Mantissa & 0x3f)
375     return -1;
376   Mantissa >>= 6;
377 
378   // We can handle 3 bits of exponent: exp == UInt(NOT(b):c:d)-3
379   if (Exp < -3 || Exp > 4)
380     return -1;
381   Exp = ((Exp+3) & 0x7) ^ 4;
382 
383   return ((int)Sign << 7) | (Exp << 4) | Mantissa;
384 }
385 
386 static inline int getFP16Imm(const APFloat &FPImm) {
387   return getFP16Imm(FPImm.bitcastToAPInt());
388 }
389 
390 /// getFP32Imm - Return an 8-bit floating-point version of the 32-bit
391 /// floating-point value. If the value cannot be represented as an 8-bit
392 /// floating-point value, then return -1.
393 static inline int getFP32Imm(const APInt &Imm) {
394   uint32_t Sign = Imm.lshr(31).getZExtValue() & 1;
395   int32_t Exp = (Imm.lshr(23).getSExtValue() & 0xff) - 127;  // -126 to 127
396   int64_t Mantissa = Imm.getZExtValue() & 0x7fffff;  // 23 bits
397 
398   // We can handle 4 bits of mantissa.
399   // mantissa = (16+UInt(e:f:g:h))/16.
400   if (Mantissa & 0x7ffff)
401     return -1;
402   Mantissa >>= 19;
403   if ((Mantissa & 0xf) != Mantissa)
404     return -1;
405 
406   // We can handle 3 bits of exponent: exp == UInt(NOT(b):c:d)-3
407   if (Exp < -3 || Exp > 4)
408     return -1;
409   Exp = ((Exp+3) & 0x7) ^ 4;
410 
411   return ((int)Sign << 7) | (Exp << 4) | Mantissa;
412 }
413 
414 static inline int getFP32Imm(const APFloat &FPImm) {
415   return getFP32Imm(FPImm.bitcastToAPInt());
416 }
417 
418 /// getFP64Imm - Return an 8-bit floating-point version of the 64-bit
419 /// floating-point value. If the value cannot be represented as an 8-bit
420 /// floating-point value, then return -1.
421 static inline int getFP64Imm(const APInt &Imm) {
422   uint64_t Sign = Imm.lshr(63).getZExtValue() & 1;
423   int64_t Exp = (Imm.lshr(52).getSExtValue() & 0x7ff) - 1023;   // -1022 to 1023
424   uint64_t Mantissa = Imm.getZExtValue() & 0xfffffffffffffULL;
425 
426   // We can handle 4 bits of mantissa.
427   // mantissa = (16+UInt(e:f:g:h))/16.
428   if (Mantissa & 0xffffffffffffULL)
429     return -1;
430   Mantissa >>= 48;
431   if ((Mantissa & 0xf) != Mantissa)
432     return -1;
433 
434   // We can handle 3 bits of exponent: exp == UInt(NOT(b):c:d)-3
435   if (Exp < -3 || Exp > 4)
436     return -1;
437   Exp = ((Exp+3) & 0x7) ^ 4;
438 
439   return ((int)Sign << 7) | (Exp << 4) | Mantissa;
440 }
441 
442 static inline int getFP64Imm(const APFloat &FPImm) {
443   return getFP64Imm(FPImm.bitcastToAPInt());
444 }
445 
446 //===--------------------------------------------------------------------===//
447 // AdvSIMD Modified Immediates
448 //===--------------------------------------------------------------------===//
449 
450 // 0x00 0x00 0x00 abcdefgh 0x00 0x00 0x00 abcdefgh
451 static inline bool isAdvSIMDModImmType1(uint64_t Imm) {
452   return ((Imm >> 32) == (Imm & 0xffffffffULL)) &&
453          ((Imm & 0xffffff00ffffff00ULL) == 0);
454 }
455 
456 static inline uint8_t encodeAdvSIMDModImmType1(uint64_t Imm) {
457   return (Imm & 0xffULL);
458 }
459 
460 static inline uint64_t decodeAdvSIMDModImmType1(uint8_t Imm) {
461   uint64_t EncVal = Imm;
462   return (EncVal << 32) | EncVal;
463 }
464 
465 // 0x00 0x00 abcdefgh 0x00 0x00 0x00 abcdefgh 0x00
466 static inline bool isAdvSIMDModImmType2(uint64_t Imm) {
467   return ((Imm >> 32) == (Imm & 0xffffffffULL)) &&
468          ((Imm & 0xffff00ffffff00ffULL) == 0);
469 }
470 
471 static inline uint8_t encodeAdvSIMDModImmType2(uint64_t Imm) {
472   return (Imm & 0xff00ULL) >> 8;
473 }
474 
475 static inline uint64_t decodeAdvSIMDModImmType2(uint8_t Imm) {
476   uint64_t EncVal = Imm;
477   return (EncVal << 40) | (EncVal << 8);
478 }
479 
480 // 0x00 abcdefgh 0x00 0x00 0x00 abcdefgh 0x00 0x00
481 static inline bool isAdvSIMDModImmType3(uint64_t Imm) {
482   return ((Imm >> 32) == (Imm & 0xffffffffULL)) &&
483          ((Imm & 0xff00ffffff00ffffULL) == 0);
484 }
485 
486 static inline uint8_t encodeAdvSIMDModImmType3(uint64_t Imm) {
487   return (Imm & 0xff0000ULL) >> 16;
488 }
489 
490 static inline uint64_t decodeAdvSIMDModImmType3(uint8_t Imm) {
491   uint64_t EncVal = Imm;
492   return (EncVal << 48) | (EncVal << 16);
493 }
494 
495 // abcdefgh 0x00 0x00 0x00 abcdefgh 0x00 0x00 0x00
496 static inline bool isAdvSIMDModImmType4(uint64_t Imm) {
497   return ((Imm >> 32) == (Imm & 0xffffffffULL)) &&
498          ((Imm & 0x00ffffff00ffffffULL) == 0);
499 }
500 
501 static inline uint8_t encodeAdvSIMDModImmType4(uint64_t Imm) {
502   return (Imm & 0xff000000ULL) >> 24;
503 }
504 
505 static inline uint64_t decodeAdvSIMDModImmType4(uint8_t Imm) {
506   uint64_t EncVal = Imm;
507   return (EncVal << 56) | (EncVal << 24);
508 }
509 
510 // 0x00 abcdefgh 0x00 abcdefgh 0x00 abcdefgh 0x00 abcdefgh
511 static inline bool isAdvSIMDModImmType5(uint64_t Imm) {
512   return ((Imm >> 32) == (Imm & 0xffffffffULL)) &&
513          (((Imm & 0x00ff0000ULL) >> 16) == (Imm & 0x000000ffULL)) &&
514          ((Imm & 0xff00ff00ff00ff00ULL) == 0);
515 }
516 
517 static inline uint8_t encodeAdvSIMDModImmType5(uint64_t Imm) {
518   return (Imm & 0xffULL);
519 }
520 
521 static inline uint64_t decodeAdvSIMDModImmType5(uint8_t Imm) {
522   uint64_t EncVal = Imm;
523   return (EncVal << 48) | (EncVal << 32) | (EncVal << 16) | EncVal;
524 }
525 
526 // abcdefgh 0x00 abcdefgh 0x00 abcdefgh 0x00 abcdefgh 0x00
527 static inline bool isAdvSIMDModImmType6(uint64_t Imm) {
528   return ((Imm >> 32) == (Imm & 0xffffffffULL)) &&
529          (((Imm & 0xff000000ULL) >> 16) == (Imm & 0x0000ff00ULL)) &&
530          ((Imm & 0x00ff00ff00ff00ffULL) == 0);
531 }
532 
533 static inline uint8_t encodeAdvSIMDModImmType6(uint64_t Imm) {
534   return (Imm & 0xff00ULL) >> 8;
535 }
536 
537 static inline uint64_t decodeAdvSIMDModImmType6(uint8_t Imm) {
538   uint64_t EncVal = Imm;
539   return (EncVal << 56) | (EncVal << 40) | (EncVal << 24) | (EncVal << 8);
540 }
541 
542 // 0x00 0x00 abcdefgh 0xFF 0x00 0x00 abcdefgh 0xFF
543 static inline bool isAdvSIMDModImmType7(uint64_t Imm) {
544   return ((Imm >> 32) == (Imm & 0xffffffffULL)) &&
545          ((Imm & 0xffff00ffffff00ffULL) == 0x000000ff000000ffULL);
546 }
547 
548 static inline uint8_t encodeAdvSIMDModImmType7(uint64_t Imm) {
549   return (Imm & 0xff00ULL) >> 8;
550 }
551 
552 static inline uint64_t decodeAdvSIMDModImmType7(uint8_t Imm) {
553   uint64_t EncVal = Imm;
554   return (EncVal << 40) | (EncVal << 8) | 0x000000ff000000ffULL;
555 }
556 
557 // 0x00 abcdefgh 0xFF 0xFF 0x00 abcdefgh 0xFF 0xFF
558 static inline bool isAdvSIMDModImmType8(uint64_t Imm) {
559   return ((Imm >> 32) == (Imm & 0xffffffffULL)) &&
560          ((Imm & 0xff00ffffff00ffffULL) == 0x0000ffff0000ffffULL);
561 }
562 
563 static inline uint64_t decodeAdvSIMDModImmType8(uint8_t Imm) {
564   uint64_t EncVal = Imm;
565   return (EncVal << 48) | (EncVal << 16) | 0x0000ffff0000ffffULL;
566 }
567 
568 static inline uint8_t encodeAdvSIMDModImmType8(uint64_t Imm) {
569   return (Imm & 0x00ff0000ULL) >> 16;
570 }
571 
572 // abcdefgh abcdefgh abcdefgh abcdefgh abcdefgh abcdefgh abcdefgh abcdefgh
573 static inline bool isAdvSIMDModImmType9(uint64_t Imm) {
574   return ((Imm >> 32) == (Imm & 0xffffffffULL)) &&
575          ((Imm >> 48) == (Imm & 0x0000ffffULL)) &&
576          ((Imm >> 56) == (Imm & 0x000000ffULL));
577 }
578 
579 static inline uint8_t encodeAdvSIMDModImmType9(uint64_t Imm) {
580   return (Imm & 0xffULL);
581 }
582 
583 static inline uint64_t decodeAdvSIMDModImmType9(uint8_t Imm) {
584   uint64_t EncVal = Imm;
585   EncVal |= (EncVal << 8);
586   EncVal |= (EncVal << 16);
587   EncVal |= (EncVal << 32);
588   return EncVal;
589 }
590 
591 // aaaaaaaa bbbbbbbb cccccccc dddddddd eeeeeeee ffffffff gggggggg hhhhhhhh
592 // cmode: 1110, op: 1
593 static inline bool isAdvSIMDModImmType10(uint64_t Imm) {
594 #if defined(_MSC_VER) && _MSC_VER == 1937 && !defined(__clang__) &&            \
595     defined(_M_ARM64)
596   // The MSVC compiler 19.37 for ARM64 has an optimization bug that
597   // causes an incorrect behavior with the orignal version. Work around
598   // by using a slightly different variation.
599   // https://developercommunity.visualstudio.com/t/C-ARM64-compiler-optimization-bug/10481261
600   constexpr uint64_t Mask = 0xFFULL;
601   uint64_t ByteA = (Imm >> 56) & Mask;
602   uint64_t ByteB = (Imm >> 48) & Mask;
603   uint64_t ByteC = (Imm >> 40) & Mask;
604   uint64_t ByteD = (Imm >> 32) & Mask;
605   uint64_t ByteE = (Imm >> 24) & Mask;
606   uint64_t ByteF = (Imm >> 16) & Mask;
607   uint64_t ByteG = (Imm >> 8) & Mask;
608   uint64_t ByteH = Imm & Mask;
609 
610   return (ByteA == 0ULL || ByteA == Mask) && (ByteB == 0ULL || ByteB == Mask) &&
611          (ByteC == 0ULL || ByteC == Mask) && (ByteD == 0ULL || ByteD == Mask) &&
612          (ByteE == 0ULL || ByteE == Mask) && (ByteF == 0ULL || ByteF == Mask) &&
613          (ByteG == 0ULL || ByteG == Mask) && (ByteH == 0ULL || ByteH == Mask);
614 #else
615   uint64_t ByteA = Imm & 0xff00000000000000ULL;
616   uint64_t ByteB = Imm & 0x00ff000000000000ULL;
617   uint64_t ByteC = Imm & 0x0000ff0000000000ULL;
618   uint64_t ByteD = Imm & 0x000000ff00000000ULL;
619   uint64_t ByteE = Imm & 0x00000000ff000000ULL;
620   uint64_t ByteF = Imm & 0x0000000000ff0000ULL;
621   uint64_t ByteG = Imm & 0x000000000000ff00ULL;
622   uint64_t ByteH = Imm & 0x00000000000000ffULL;
623 
624   return (ByteA == 0ULL || ByteA == 0xff00000000000000ULL) &&
625          (ByteB == 0ULL || ByteB == 0x00ff000000000000ULL) &&
626          (ByteC == 0ULL || ByteC == 0x0000ff0000000000ULL) &&
627          (ByteD == 0ULL || ByteD == 0x000000ff00000000ULL) &&
628          (ByteE == 0ULL || ByteE == 0x00000000ff000000ULL) &&
629          (ByteF == 0ULL || ByteF == 0x0000000000ff0000ULL) &&
630          (ByteG == 0ULL || ByteG == 0x000000000000ff00ULL) &&
631          (ByteH == 0ULL || ByteH == 0x00000000000000ffULL);
632 #endif
633 }
634 
635 static inline uint8_t encodeAdvSIMDModImmType10(uint64_t Imm) {
636   uint8_t BitA = (Imm & 0xff00000000000000ULL) != 0;
637   uint8_t BitB = (Imm & 0x00ff000000000000ULL) != 0;
638   uint8_t BitC = (Imm & 0x0000ff0000000000ULL) != 0;
639   uint8_t BitD = (Imm & 0x000000ff00000000ULL) != 0;
640   uint8_t BitE = (Imm & 0x00000000ff000000ULL) != 0;
641   uint8_t BitF = (Imm & 0x0000000000ff0000ULL) != 0;
642   uint8_t BitG = (Imm & 0x000000000000ff00ULL) != 0;
643   uint8_t BitH = (Imm & 0x00000000000000ffULL) != 0;
644 
645   uint8_t EncVal = BitA;
646   EncVal <<= 1;
647   EncVal |= BitB;
648   EncVal <<= 1;
649   EncVal |= BitC;
650   EncVal <<= 1;
651   EncVal |= BitD;
652   EncVal <<= 1;
653   EncVal |= BitE;
654   EncVal <<= 1;
655   EncVal |= BitF;
656   EncVal <<= 1;
657   EncVal |= BitG;
658   EncVal <<= 1;
659   EncVal |= BitH;
660   return EncVal;
661 }
662 
663 static inline uint64_t decodeAdvSIMDModImmType10(uint8_t Imm) {
664   uint64_t EncVal = 0;
665   if (Imm & 0x80) EncVal |= 0xff00000000000000ULL;
666   if (Imm & 0x40) EncVal |= 0x00ff000000000000ULL;
667   if (Imm & 0x20) EncVal |= 0x0000ff0000000000ULL;
668   if (Imm & 0x10) EncVal |= 0x000000ff00000000ULL;
669   if (Imm & 0x08) EncVal |= 0x00000000ff000000ULL;
670   if (Imm & 0x04) EncVal |= 0x0000000000ff0000ULL;
671   if (Imm & 0x02) EncVal |= 0x000000000000ff00ULL;
672   if (Imm & 0x01) EncVal |= 0x00000000000000ffULL;
673   return EncVal;
674 }
675 
676 // aBbbbbbc defgh000 0x00 0x00 aBbbbbbc defgh000 0x00 0x00
677 static inline bool isAdvSIMDModImmType11(uint64_t Imm) {
678   uint64_t BString = (Imm & 0x7E000000ULL) >> 25;
679   return ((Imm >> 32) == (Imm & 0xffffffffULL)) &&
680          (BString == 0x1f || BString == 0x20) &&
681          ((Imm & 0x0007ffff0007ffffULL) == 0);
682 }
683 
684 static inline uint8_t encodeAdvSIMDModImmType11(uint64_t Imm) {
685   uint8_t BitA = (Imm & 0x80000000ULL) != 0;
686   uint8_t BitB = (Imm & 0x20000000ULL) != 0;
687   uint8_t BitC = (Imm & 0x01000000ULL) != 0;
688   uint8_t BitD = (Imm & 0x00800000ULL) != 0;
689   uint8_t BitE = (Imm & 0x00400000ULL) != 0;
690   uint8_t BitF = (Imm & 0x00200000ULL) != 0;
691   uint8_t BitG = (Imm & 0x00100000ULL) != 0;
692   uint8_t BitH = (Imm & 0x00080000ULL) != 0;
693 
694   uint8_t EncVal = BitA;
695   EncVal <<= 1;
696   EncVal |= BitB;
697   EncVal <<= 1;
698   EncVal |= BitC;
699   EncVal <<= 1;
700   EncVal |= BitD;
701   EncVal <<= 1;
702   EncVal |= BitE;
703   EncVal <<= 1;
704   EncVal |= BitF;
705   EncVal <<= 1;
706   EncVal |= BitG;
707   EncVal <<= 1;
708   EncVal |= BitH;
709   return EncVal;
710 }
711 
712 static inline uint64_t decodeAdvSIMDModImmType11(uint8_t Imm) {
713   uint64_t EncVal = 0;
714   if (Imm & 0x80) EncVal |= 0x80000000ULL;
715   if (Imm & 0x40) EncVal |= 0x3e000000ULL;
716   else            EncVal |= 0x40000000ULL;
717   if (Imm & 0x20) EncVal |= 0x01000000ULL;
718   if (Imm & 0x10) EncVal |= 0x00800000ULL;
719   if (Imm & 0x08) EncVal |= 0x00400000ULL;
720   if (Imm & 0x04) EncVal |= 0x00200000ULL;
721   if (Imm & 0x02) EncVal |= 0x00100000ULL;
722   if (Imm & 0x01) EncVal |= 0x00080000ULL;
723   return (EncVal << 32) | EncVal;
724 }
725 
726 // aBbbbbbb bbcdefgh 0x00 0x00 0x00 0x00 0x00 0x00
727 static inline bool isAdvSIMDModImmType12(uint64_t Imm) {
728   uint64_t BString = (Imm & 0x7fc0000000000000ULL) >> 54;
729   return ((BString == 0xff || BString == 0x100) &&
730          ((Imm & 0x0000ffffffffffffULL) == 0));
731 }
732 
733 static inline uint8_t encodeAdvSIMDModImmType12(uint64_t Imm) {
734   uint8_t BitA = (Imm & 0x8000000000000000ULL) != 0;
735   uint8_t BitB = (Imm & 0x0040000000000000ULL) != 0;
736   uint8_t BitC = (Imm & 0x0020000000000000ULL) != 0;
737   uint8_t BitD = (Imm & 0x0010000000000000ULL) != 0;
738   uint8_t BitE = (Imm & 0x0008000000000000ULL) != 0;
739   uint8_t BitF = (Imm & 0x0004000000000000ULL) != 0;
740   uint8_t BitG = (Imm & 0x0002000000000000ULL) != 0;
741   uint8_t BitH = (Imm & 0x0001000000000000ULL) != 0;
742 
743   uint8_t EncVal = BitA;
744   EncVal <<= 1;
745   EncVal |= BitB;
746   EncVal <<= 1;
747   EncVal |= BitC;
748   EncVal <<= 1;
749   EncVal |= BitD;
750   EncVal <<= 1;
751   EncVal |= BitE;
752   EncVal <<= 1;
753   EncVal |= BitF;
754   EncVal <<= 1;
755   EncVal |= BitG;
756   EncVal <<= 1;
757   EncVal |= BitH;
758   return EncVal;
759 }
760 
761 static inline uint64_t decodeAdvSIMDModImmType12(uint8_t Imm) {
762   uint64_t EncVal = 0;
763   if (Imm & 0x80) EncVal |= 0x8000000000000000ULL;
764   if (Imm & 0x40) EncVal |= 0x3fc0000000000000ULL;
765   else            EncVal |= 0x4000000000000000ULL;
766   if (Imm & 0x20) EncVal |= 0x0020000000000000ULL;
767   if (Imm & 0x10) EncVal |= 0x0010000000000000ULL;
768   if (Imm & 0x08) EncVal |= 0x0008000000000000ULL;
769   if (Imm & 0x04) EncVal |= 0x0004000000000000ULL;
770   if (Imm & 0x02) EncVal |= 0x0002000000000000ULL;
771   if (Imm & 0x01) EncVal |= 0x0001000000000000ULL;
772   return (EncVal << 32) | EncVal;
773 }
774 
775 /// Returns true if Imm is the concatenation of a repeating pattern of type T.
776 template <typename T>
777 static inline bool isSVEMaskOfIdenticalElements(int64_t Imm) {
778   auto Parts = bit_cast<std::array<T, sizeof(int64_t) / sizeof(T)>>(Imm);
779   return llvm::all_equal(Parts);
780 }
781 
782 /// Returns true if Imm is valid for CPY/DUP.
783 template <typename T>
784 static inline bool isSVECpyImm(int64_t Imm) {
785   // Imm is interpreted as a signed value, which means top bits must be all ones
786   // (sign bits if the immediate value is negative and passed in a larger
787   // container), or all zeroes.
788   int64_t Mask = ~int64_t(std::numeric_limits<std::make_unsigned_t<T>>::max());
789   if ((Imm & Mask) != 0 && (Imm & Mask) != Mask)
790     return false;
791 
792   // Imm is a signed 8-bit value.
793   // Top bits must be zeroes or sign bits.
794   if (Imm & 0xff)
795     return int8_t(Imm) == T(Imm);
796 
797   // Imm is a signed 16-bit value and multiple of 256.
798   // Top bits must be zeroes or sign bits.
799   if (Imm & 0xff00)
800     return int16_t(Imm) == T(Imm);
801 
802   return Imm == 0;
803 }
804 
805 /// Returns true if Imm is valid for ADD/SUB.
806 template <typename T>
807 static inline bool isSVEAddSubImm(int64_t Imm) {
808   bool IsInt8t = std::is_same<int8_t, std::make_signed_t<T>>::value ||
809                  std::is_same<int8_t, T>::value;
810   return uint8_t(Imm) == Imm || (!IsInt8t && uint16_t(Imm & ~0xff) == Imm);
811 }
812 
813 /// Return true if Imm is valid for DUPM and has no single CPY/DUP equivalent.
814 static inline bool isSVEMoveMaskPreferredLogicalImmediate(int64_t Imm) {
815   if (isSVECpyImm<int64_t>(Imm))
816     return false;
817 
818   auto S = bit_cast<std::array<int32_t, 2>>(Imm);
819   auto H = bit_cast<std::array<int16_t, 4>>(Imm);
820   auto B = bit_cast<std::array<int8_t, 8>>(Imm);
821 
822   if (isSVEMaskOfIdenticalElements<int32_t>(Imm) && isSVECpyImm<int32_t>(S[0]))
823     return false;
824   if (isSVEMaskOfIdenticalElements<int16_t>(Imm) && isSVECpyImm<int16_t>(H[0]))
825     return false;
826   if (isSVEMaskOfIdenticalElements<int8_t>(Imm) && isSVECpyImm<int8_t>(B[0]))
827     return false;
828   return isLogicalImmediate(Imm, 64);
829 }
830 
831 inline static bool isAnyMOVZMovAlias(uint64_t Value, int RegWidth) {
832   for (int Shift = 0; Shift <= RegWidth - 16; Shift += 16)
833     if ((Value & ~(0xffffULL << Shift)) == 0)
834       return true;
835 
836   return false;
837 }
838 
839 inline static bool isMOVZMovAlias(uint64_t Value, int Shift, int RegWidth) {
840   if (RegWidth == 32)
841     Value &= 0xffffffffULL;
842 
843   // "lsl #0" takes precedence: in practice this only affects "#0, lsl #0".
844   if (Value == 0 && Shift != 0)
845     return false;
846 
847   return (Value & ~(0xffffULL << Shift)) == 0;
848 }
849 
850 inline static bool isMOVNMovAlias(uint64_t Value, int Shift, int RegWidth) {
851   // MOVZ takes precedence over MOVN.
852   if (isAnyMOVZMovAlias(Value, RegWidth))
853     return false;
854 
855   Value = ~Value;
856   if (RegWidth == 32)
857     Value &= 0xffffffffULL;
858 
859   return isMOVZMovAlias(Value, Shift, RegWidth);
860 }
861 
862 inline static bool isAnyMOVWMovAlias(uint64_t Value, int RegWidth) {
863   if (isAnyMOVZMovAlias(Value, RegWidth))
864     return true;
865 
866   // It's not a MOVZ, but it might be a MOVN.
867   Value = ~Value;
868   if (RegWidth == 32)
869     Value &= 0xffffffffULL;
870 
871   return isAnyMOVZMovAlias(Value, RegWidth);
872 }
873 
874 } // end namespace AArch64_AM
875 
876 } // end namespace llvm
877 
878 #endif
879