1 //===-- llvm/Support/PatternMatch.h - Match on the LLVM IR ------*- C++ -*-===//
2 //
3 // The LLVM Compiler Infrastructure
4 //
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
7 //
8 //===----------------------------------------------------------------------===//
9 //
10 // This file provides a simple and efficient mechanism for performing general
11 // tree-based pattern matches on the LLVM IR. The power of these routines is
12 // that it allows you to write concise patterns that are expressive and easy to
13 // understand. The other major advantage of this is that it allows you to
14 // trivially capture/bind elements in the pattern to variables. For example,
15 // you can do something like this:
16 //
17 // Value *Exp = ...
18 // Value *X, *Y; ConstantInt *C1, *C2; // (X & C1) | (Y & C2)
19 // if (match(Exp, m_Or(m_And(m_Value(X), m_ConstantInt(C1)),
20 // m_And(m_Value(Y), m_ConstantInt(C2))))) {
21 // ... Pattern is matched and variables are bound ...
22 // }
23 //
24 // This is primarily useful to things like the instruction combiner, but can
25 // also be useful for static analysis tools or code generators.
26 //
27 //===----------------------------------------------------------------------===//
28
29 #ifndef LLVM_SUPPORT_PATTERNMATCH_H
30 #define LLVM_SUPPORT_PATTERNMATCH_H
31
32 #include "llvm/Constants.h"
33 #include "llvm/Instructions.h"
34 #include "llvm/Operator.h"
35
36 namespace llvm {
37 namespace PatternMatch {
38
39 template<typename Val, typename Pattern>
match(Val * V,const Pattern & P)40 bool match(Val *V, const Pattern &P) {
41 return const_cast<Pattern&>(P).match(V);
42 }
43
44
45 template<typename SubPattern_t>
46 struct OneUse_match {
47 SubPattern_t SubPattern;
48
OneUse_matchOneUse_match49 OneUse_match(const SubPattern_t &SP) : SubPattern(SP) {}
50
51 template<typename OpTy>
matchOneUse_match52 bool match(OpTy *V) {
53 return V->hasOneUse() && SubPattern.match(V);
54 }
55 };
56
57 template<typename T>
m_OneUse(const T & SubPattern)58 inline OneUse_match<T> m_OneUse(const T &SubPattern) { return SubPattern; }
59
60
61 template<typename Class>
62 struct class_match {
63 template<typename ITy>
matchclass_match64 bool match(ITy *V) { return isa<Class>(V); }
65 };
66
67 /// m_Value() - Match an arbitrary value and ignore it.
m_Value()68 inline class_match<Value> m_Value() { return class_match<Value>(); }
69 /// m_ConstantInt() - Match an arbitrary ConstantInt and ignore it.
m_ConstantInt()70 inline class_match<ConstantInt> m_ConstantInt() {
71 return class_match<ConstantInt>();
72 }
73 /// m_Undef() - Match an arbitrary undef constant.
m_Undef()74 inline class_match<UndefValue> m_Undef() { return class_match<UndefValue>(); }
75
m_Constant()76 inline class_match<Constant> m_Constant() { return class_match<Constant>(); }
77
78 struct match_zero {
79 template<typename ITy>
matchmatch_zero80 bool match(ITy *V) {
81 if (const Constant *C = dyn_cast<Constant>(V))
82 return C->isNullValue();
83 return false;
84 }
85 };
86
87 /// m_Zero() - Match an arbitrary zero/null constant. This includes
88 /// zero_initializer for vectors and ConstantPointerNull for pointers.
m_Zero()89 inline match_zero m_Zero() { return match_zero(); }
90
91
92 struct apint_match {
93 const APInt *&Res;
apint_matchapint_match94 apint_match(const APInt *&R) : Res(R) {}
95 template<typename ITy>
matchapint_match96 bool match(ITy *V) {
97 if (ConstantInt *CI = dyn_cast<ConstantInt>(V)) {
98 Res = &CI->getValue();
99 return true;
100 }
101 // FIXME: Remove this.
102 if (ConstantVector *CV = dyn_cast<ConstantVector>(V))
103 if (ConstantInt *CI =
104 dyn_cast_or_null<ConstantInt>(CV->getSplatValue())) {
105 Res = &CI->getValue();
106 return true;
107 }
108 if (ConstantDataVector *CV = dyn_cast<ConstantDataVector>(V))
109 if (ConstantInt *CI =
110 dyn_cast_or_null<ConstantInt>(CV->getSplatValue())) {
111 Res = &CI->getValue();
112 return true;
113 }
114 return false;
115 }
116 };
117
118 /// m_APInt - Match a ConstantInt or splatted ConstantVector, binding the
119 /// specified pointer to the contained APInt.
m_APInt(const APInt * & Res)120 inline apint_match m_APInt(const APInt *&Res) { return Res; }
121
122
123 template<int64_t Val>
124 struct constantint_match {
125 template<typename ITy>
matchconstantint_match126 bool match(ITy *V) {
127 if (const ConstantInt *CI = dyn_cast<ConstantInt>(V)) {
128 const APInt &CIV = CI->getValue();
129 if (Val >= 0)
130 return CIV == static_cast<uint64_t>(Val);
131 // If Val is negative, and CI is shorter than it, truncate to the right
132 // number of bits. If it is larger, then we have to sign extend. Just
133 // compare their negated values.
134 return -CIV == -Val;
135 }
136 return false;
137 }
138 };
139
140 /// m_ConstantInt<int64_t> - Match a ConstantInt with a specific value.
141 template<int64_t Val>
m_ConstantInt()142 inline constantint_match<Val> m_ConstantInt() {
143 return constantint_match<Val>();
144 }
145
146 /// cst_pred_ty - This helper class is used to match scalar and vector constants
147 /// that satisfy a specified predicate.
148 template<typename Predicate>
149 struct cst_pred_ty : public Predicate {
150 template<typename ITy>
matchcst_pred_ty151 bool match(ITy *V) {
152 if (const ConstantInt *CI = dyn_cast<ConstantInt>(V))
153 return this->isValue(CI->getValue());
154 // FIXME: Remove this.
155 if (const ConstantVector *CV = dyn_cast<ConstantVector>(V))
156 if (ConstantInt *CI = dyn_cast_or_null<ConstantInt>(CV->getSplatValue()))
157 return this->isValue(CI->getValue());
158 if (const ConstantDataVector *CV = dyn_cast<ConstantDataVector>(V))
159 if (ConstantInt *CI = dyn_cast_or_null<ConstantInt>(CV->getSplatValue()))
160 return this->isValue(CI->getValue());
161 return false;
162 }
163 };
164
165 /// api_pred_ty - This helper class is used to match scalar and vector constants
166 /// that satisfy a specified predicate, and bind them to an APInt.
167 template<typename Predicate>
168 struct api_pred_ty : public Predicate {
169 const APInt *&Res;
api_pred_tyapi_pred_ty170 api_pred_ty(const APInt *&R) : Res(R) {}
171 template<typename ITy>
matchapi_pred_ty172 bool match(ITy *V) {
173 if (const ConstantInt *CI = dyn_cast<ConstantInt>(V))
174 if (this->isValue(CI->getValue())) {
175 Res = &CI->getValue();
176 return true;
177 }
178
179 // FIXME: remove.
180 if (const ConstantVector *CV = dyn_cast<ConstantVector>(V))
181 if (ConstantInt *CI = dyn_cast_or_null<ConstantInt>(CV->getSplatValue()))
182 if (this->isValue(CI->getValue())) {
183 Res = &CI->getValue();
184 return true;
185 }
186
187 if (const ConstantDataVector *CV = dyn_cast<ConstantDataVector>(V))
188 if (ConstantInt *CI = dyn_cast_or_null<ConstantInt>(CV->getSplatValue()))
189 if (this->isValue(CI->getValue())) {
190 Res = &CI->getValue();
191 return true;
192 }
193
194 return false;
195 }
196 };
197
198
199 struct is_one {
isValueis_one200 bool isValue(const APInt &C) { return C == 1; }
201 };
202
203 /// m_One() - Match an integer 1 or a vector with all elements equal to 1.
m_One()204 inline cst_pred_ty<is_one> m_One() { return cst_pred_ty<is_one>(); }
m_One(const APInt * & V)205 inline api_pred_ty<is_one> m_One(const APInt *&V) { return V; }
206
207 struct is_all_ones {
isValueis_all_ones208 bool isValue(const APInt &C) { return C.isAllOnesValue(); }
209 };
210
211 /// m_AllOnes() - Match an integer or vector with all bits set to true.
m_AllOnes()212 inline cst_pred_ty<is_all_ones> m_AllOnes() {return cst_pred_ty<is_all_ones>();}
m_AllOnes(const APInt * & V)213 inline api_pred_ty<is_all_ones> m_AllOnes(const APInt *&V) { return V; }
214
215 struct is_sign_bit {
isValueis_sign_bit216 bool isValue(const APInt &C) { return C.isSignBit(); }
217 };
218
219 /// m_SignBit() - Match an integer or vector with only the sign bit(s) set.
m_SignBit()220 inline cst_pred_ty<is_sign_bit> m_SignBit() {return cst_pred_ty<is_sign_bit>();}
m_SignBit(const APInt * & V)221 inline api_pred_ty<is_sign_bit> m_SignBit(const APInt *&V) { return V; }
222
223 struct is_power2 {
isValueis_power2224 bool isValue(const APInt &C) { return C.isPowerOf2(); }
225 };
226
227 /// m_Power2() - Match an integer or vector power of 2.
m_Power2()228 inline cst_pred_ty<is_power2> m_Power2() { return cst_pred_ty<is_power2>(); }
m_Power2(const APInt * & V)229 inline api_pred_ty<is_power2> m_Power2(const APInt *&V) { return V; }
230
231 template<typename Class>
232 struct bind_ty {
233 Class *&VR;
bind_tybind_ty234 bind_ty(Class *&V) : VR(V) {}
235
236 template<typename ITy>
matchbind_ty237 bool match(ITy *V) {
238 if (Class *CV = dyn_cast<Class>(V)) {
239 VR = CV;
240 return true;
241 }
242 return false;
243 }
244 };
245
246 /// m_Value - Match a value, capturing it if we match.
m_Value(Value * & V)247 inline bind_ty<Value> m_Value(Value *&V) { return V; }
248
249 /// m_ConstantInt - Match a ConstantInt, capturing the value if we match.
m_ConstantInt(ConstantInt * & CI)250 inline bind_ty<ConstantInt> m_ConstantInt(ConstantInt *&CI) { return CI; }
251
252 /// m_Constant - Match a Constant, capturing the value if we match.
m_Constant(Constant * & C)253 inline bind_ty<Constant> m_Constant(Constant *&C) { return C; }
254
255 /// specificval_ty - Match a specified Value*.
256 struct specificval_ty {
257 const Value *Val;
specificval_tyspecificval_ty258 specificval_ty(const Value *V) : Val(V) {}
259
260 template<typename ITy>
matchspecificval_ty261 bool match(ITy *V) {
262 return V == Val;
263 }
264 };
265
266 /// m_Specific - Match if we have a specific specified value.
m_Specific(const Value * V)267 inline specificval_ty m_Specific(const Value *V) { return V; }
268
269 struct bind_const_intval_ty {
270 uint64_t &VR;
bind_const_intval_tybind_const_intval_ty271 bind_const_intval_ty(uint64_t &V) : VR(V) {}
272
273 template<typename ITy>
matchbind_const_intval_ty274 bool match(ITy *V) {
275 if (ConstantInt *CV = dyn_cast<ConstantInt>(V))
276 if (CV->getBitWidth() <= 64) {
277 VR = CV->getZExtValue();
278 return true;
279 }
280 return false;
281 }
282 };
283
284 /// m_ConstantInt - Match a ConstantInt and bind to its value. This does not
285 /// match ConstantInts wider than 64-bits.
m_ConstantInt(uint64_t & V)286 inline bind_const_intval_ty m_ConstantInt(uint64_t &V) { return V; }
287
288 //===----------------------------------------------------------------------===//
289 // Matchers for specific binary operators.
290 //
291
292 template<typename LHS_t, typename RHS_t, unsigned Opcode>
293 struct BinaryOp_match {
294 LHS_t L;
295 RHS_t R;
296
BinaryOp_matchBinaryOp_match297 BinaryOp_match(const LHS_t &LHS, const RHS_t &RHS) : L(LHS), R(RHS) {}
298
299 template<typename OpTy>
matchBinaryOp_match300 bool match(OpTy *V) {
301 if (V->getValueID() == Value::InstructionVal + Opcode) {
302 BinaryOperator *I = cast<BinaryOperator>(V);
303 return L.match(I->getOperand(0)) && R.match(I->getOperand(1));
304 }
305 if (ConstantExpr *CE = dyn_cast<ConstantExpr>(V))
306 return CE->getOpcode() == Opcode && L.match(CE->getOperand(0)) &&
307 R.match(CE->getOperand(1));
308 return false;
309 }
310 };
311
312 template<typename LHS, typename RHS>
313 inline BinaryOp_match<LHS, RHS, Instruction::Add>
m_Add(const LHS & L,const RHS & R)314 m_Add(const LHS &L, const RHS &R) {
315 return BinaryOp_match<LHS, RHS, Instruction::Add>(L, R);
316 }
317
318 template<typename LHS, typename RHS>
319 inline BinaryOp_match<LHS, RHS, Instruction::FAdd>
m_FAdd(const LHS & L,const RHS & R)320 m_FAdd(const LHS &L, const RHS &R) {
321 return BinaryOp_match<LHS, RHS, Instruction::FAdd>(L, R);
322 }
323
324 template<typename LHS, typename RHS>
325 inline BinaryOp_match<LHS, RHS, Instruction::Sub>
m_Sub(const LHS & L,const RHS & R)326 m_Sub(const LHS &L, const RHS &R) {
327 return BinaryOp_match<LHS, RHS, Instruction::Sub>(L, R);
328 }
329
330 template<typename LHS, typename RHS>
331 inline BinaryOp_match<LHS, RHS, Instruction::FSub>
m_FSub(const LHS & L,const RHS & R)332 m_FSub(const LHS &L, const RHS &R) {
333 return BinaryOp_match<LHS, RHS, Instruction::FSub>(L, R);
334 }
335
336 template<typename LHS, typename RHS>
337 inline BinaryOp_match<LHS, RHS, Instruction::Mul>
m_Mul(const LHS & L,const RHS & R)338 m_Mul(const LHS &L, const RHS &R) {
339 return BinaryOp_match<LHS, RHS, Instruction::Mul>(L, R);
340 }
341
342 template<typename LHS, typename RHS>
343 inline BinaryOp_match<LHS, RHS, Instruction::FMul>
m_FMul(const LHS & L,const RHS & R)344 m_FMul(const LHS &L, const RHS &R) {
345 return BinaryOp_match<LHS, RHS, Instruction::FMul>(L, R);
346 }
347
348 template<typename LHS, typename RHS>
349 inline BinaryOp_match<LHS, RHS, Instruction::UDiv>
m_UDiv(const LHS & L,const RHS & R)350 m_UDiv(const LHS &L, const RHS &R) {
351 return BinaryOp_match<LHS, RHS, Instruction::UDiv>(L, R);
352 }
353
354 template<typename LHS, typename RHS>
355 inline BinaryOp_match<LHS, RHS, Instruction::SDiv>
m_SDiv(const LHS & L,const RHS & R)356 m_SDiv(const LHS &L, const RHS &R) {
357 return BinaryOp_match<LHS, RHS, Instruction::SDiv>(L, R);
358 }
359
360 template<typename LHS, typename RHS>
361 inline BinaryOp_match<LHS, RHS, Instruction::FDiv>
m_FDiv(const LHS & L,const RHS & R)362 m_FDiv(const LHS &L, const RHS &R) {
363 return BinaryOp_match<LHS, RHS, Instruction::FDiv>(L, R);
364 }
365
366 template<typename LHS, typename RHS>
367 inline BinaryOp_match<LHS, RHS, Instruction::URem>
m_URem(const LHS & L,const RHS & R)368 m_URem(const LHS &L, const RHS &R) {
369 return BinaryOp_match<LHS, RHS, Instruction::URem>(L, R);
370 }
371
372 template<typename LHS, typename RHS>
373 inline BinaryOp_match<LHS, RHS, Instruction::SRem>
m_SRem(const LHS & L,const RHS & R)374 m_SRem(const LHS &L, const RHS &R) {
375 return BinaryOp_match<LHS, RHS, Instruction::SRem>(L, R);
376 }
377
378 template<typename LHS, typename RHS>
379 inline BinaryOp_match<LHS, RHS, Instruction::FRem>
m_FRem(const LHS & L,const RHS & R)380 m_FRem(const LHS &L, const RHS &R) {
381 return BinaryOp_match<LHS, RHS, Instruction::FRem>(L, R);
382 }
383
384 template<typename LHS, typename RHS>
385 inline BinaryOp_match<LHS, RHS, Instruction::And>
m_And(const LHS & L,const RHS & R)386 m_And(const LHS &L, const RHS &R) {
387 return BinaryOp_match<LHS, RHS, Instruction::And>(L, R);
388 }
389
390 template<typename LHS, typename RHS>
391 inline BinaryOp_match<LHS, RHS, Instruction::Or>
m_Or(const LHS & L,const RHS & R)392 m_Or(const LHS &L, const RHS &R) {
393 return BinaryOp_match<LHS, RHS, Instruction::Or>(L, R);
394 }
395
396 template<typename LHS, typename RHS>
397 inline BinaryOp_match<LHS, RHS, Instruction::Xor>
m_Xor(const LHS & L,const RHS & R)398 m_Xor(const LHS &L, const RHS &R) {
399 return BinaryOp_match<LHS, RHS, Instruction::Xor>(L, R);
400 }
401
402 template<typename LHS, typename RHS>
403 inline BinaryOp_match<LHS, RHS, Instruction::Shl>
m_Shl(const LHS & L,const RHS & R)404 m_Shl(const LHS &L, const RHS &R) {
405 return BinaryOp_match<LHS, RHS, Instruction::Shl>(L, R);
406 }
407
408 template<typename LHS, typename RHS>
409 inline BinaryOp_match<LHS, RHS, Instruction::LShr>
m_LShr(const LHS & L,const RHS & R)410 m_LShr(const LHS &L, const RHS &R) {
411 return BinaryOp_match<LHS, RHS, Instruction::LShr>(L, R);
412 }
413
414 template<typename LHS, typename RHS>
415 inline BinaryOp_match<LHS, RHS, Instruction::AShr>
m_AShr(const LHS & L,const RHS & R)416 m_AShr(const LHS &L, const RHS &R) {
417 return BinaryOp_match<LHS, RHS, Instruction::AShr>(L, R);
418 }
419
420 //===----------------------------------------------------------------------===//
421 // Class that matches two different binary ops.
422 //
423 template<typename LHS_t, typename RHS_t, unsigned Opc1, unsigned Opc2>
424 struct BinOp2_match {
425 LHS_t L;
426 RHS_t R;
427
BinOp2_matchBinOp2_match428 BinOp2_match(const LHS_t &LHS, const RHS_t &RHS) : L(LHS), R(RHS) {}
429
430 template<typename OpTy>
matchBinOp2_match431 bool match(OpTy *V) {
432 if (V->getValueID() == Value::InstructionVal + Opc1 ||
433 V->getValueID() == Value::InstructionVal + Opc2) {
434 BinaryOperator *I = cast<BinaryOperator>(V);
435 return L.match(I->getOperand(0)) && R.match(I->getOperand(1));
436 }
437 if (ConstantExpr *CE = dyn_cast<ConstantExpr>(V))
438 return (CE->getOpcode() == Opc1 || CE->getOpcode() == Opc2) &&
439 L.match(CE->getOperand(0)) && R.match(CE->getOperand(1));
440 return false;
441 }
442 };
443
444 /// m_Shr - Matches LShr or AShr.
445 template<typename LHS, typename RHS>
446 inline BinOp2_match<LHS, RHS, Instruction::LShr, Instruction::AShr>
m_Shr(const LHS & L,const RHS & R)447 m_Shr(const LHS &L, const RHS &R) {
448 return BinOp2_match<LHS, RHS, Instruction::LShr, Instruction::AShr>(L, R);
449 }
450
451 /// m_LogicalShift - Matches LShr or Shl.
452 template<typename LHS, typename RHS>
453 inline BinOp2_match<LHS, RHS, Instruction::LShr, Instruction::Shl>
m_LogicalShift(const LHS & L,const RHS & R)454 m_LogicalShift(const LHS &L, const RHS &R) {
455 return BinOp2_match<LHS, RHS, Instruction::LShr, Instruction::Shl>(L, R);
456 }
457
458 /// m_IDiv - Matches UDiv and SDiv.
459 template<typename LHS, typename RHS>
460 inline BinOp2_match<LHS, RHS, Instruction::SDiv, Instruction::UDiv>
m_IDiv(const LHS & L,const RHS & R)461 m_IDiv(const LHS &L, const RHS &R) {
462 return BinOp2_match<LHS, RHS, Instruction::SDiv, Instruction::UDiv>(L, R);
463 }
464
465 //===----------------------------------------------------------------------===//
466 // Class that matches exact binary ops.
467 //
468 template<typename SubPattern_t>
469 struct Exact_match {
470 SubPattern_t SubPattern;
471
Exact_matchExact_match472 Exact_match(const SubPattern_t &SP) : SubPattern(SP) {}
473
474 template<typename OpTy>
matchExact_match475 bool match(OpTy *V) {
476 if (PossiblyExactOperator *PEO = dyn_cast<PossiblyExactOperator>(V))
477 return PEO->isExact() && SubPattern.match(V);
478 return false;
479 }
480 };
481
482 template<typename T>
m_Exact(const T & SubPattern)483 inline Exact_match<T> m_Exact(const T &SubPattern) { return SubPattern; }
484
485 //===----------------------------------------------------------------------===//
486 // Matchers for CmpInst classes
487 //
488
489 template<typename LHS_t, typename RHS_t, typename Class, typename PredicateTy>
490 struct CmpClass_match {
491 PredicateTy &Predicate;
492 LHS_t L;
493 RHS_t R;
494
CmpClass_matchCmpClass_match495 CmpClass_match(PredicateTy &Pred, const LHS_t &LHS, const RHS_t &RHS)
496 : Predicate(Pred), L(LHS), R(RHS) {}
497
498 template<typename OpTy>
matchCmpClass_match499 bool match(OpTy *V) {
500 if (Class *I = dyn_cast<Class>(V))
501 if (L.match(I->getOperand(0)) && R.match(I->getOperand(1))) {
502 Predicate = I->getPredicate();
503 return true;
504 }
505 return false;
506 }
507 };
508
509 template<typename LHS, typename RHS>
510 inline CmpClass_match<LHS, RHS, ICmpInst, ICmpInst::Predicate>
m_ICmp(ICmpInst::Predicate & Pred,const LHS & L,const RHS & R)511 m_ICmp(ICmpInst::Predicate &Pred, const LHS &L, const RHS &R) {
512 return CmpClass_match<LHS, RHS,
513 ICmpInst, ICmpInst::Predicate>(Pred, L, R);
514 }
515
516 template<typename LHS, typename RHS>
517 inline CmpClass_match<LHS, RHS, FCmpInst, FCmpInst::Predicate>
m_FCmp(FCmpInst::Predicate & Pred,const LHS & L,const RHS & R)518 m_FCmp(FCmpInst::Predicate &Pred, const LHS &L, const RHS &R) {
519 return CmpClass_match<LHS, RHS,
520 FCmpInst, FCmpInst::Predicate>(Pred, L, R);
521 }
522
523 //===----------------------------------------------------------------------===//
524 // Matchers for SelectInst classes
525 //
526
527 template<typename Cond_t, typename LHS_t, typename RHS_t>
528 struct SelectClass_match {
529 Cond_t C;
530 LHS_t L;
531 RHS_t R;
532
SelectClass_matchSelectClass_match533 SelectClass_match(const Cond_t &Cond, const LHS_t &LHS,
534 const RHS_t &RHS)
535 : C(Cond), L(LHS), R(RHS) {}
536
537 template<typename OpTy>
matchSelectClass_match538 bool match(OpTy *V) {
539 if (SelectInst *I = dyn_cast<SelectInst>(V))
540 return C.match(I->getOperand(0)) &&
541 L.match(I->getOperand(1)) &&
542 R.match(I->getOperand(2));
543 return false;
544 }
545 };
546
547 template<typename Cond, typename LHS, typename RHS>
548 inline SelectClass_match<Cond, LHS, RHS>
m_Select(const Cond & C,const LHS & L,const RHS & R)549 m_Select(const Cond &C, const LHS &L, const RHS &R) {
550 return SelectClass_match<Cond, LHS, RHS>(C, L, R);
551 }
552
553 /// m_SelectCst - This matches a select of two constants, e.g.:
554 /// m_SelectCst<-1, 0>(m_Value(V))
555 template<int64_t L, int64_t R, typename Cond>
556 inline SelectClass_match<Cond, constantint_match<L>, constantint_match<R> >
m_SelectCst(const Cond & C)557 m_SelectCst(const Cond &C) {
558 return m_Select(C, m_ConstantInt<L>(), m_ConstantInt<R>());
559 }
560
561
562 //===----------------------------------------------------------------------===//
563 // Matchers for CastInst classes
564 //
565
566 template<typename Op_t, unsigned Opcode>
567 struct CastClass_match {
568 Op_t Op;
569
CastClass_matchCastClass_match570 CastClass_match(const Op_t &OpMatch) : Op(OpMatch) {}
571
572 template<typename OpTy>
matchCastClass_match573 bool match(OpTy *V) {
574 if (Operator *O = dyn_cast<Operator>(V))
575 return O->getOpcode() == Opcode && Op.match(O->getOperand(0));
576 return false;
577 }
578 };
579
580 /// m_BitCast
581 template<typename OpTy>
582 inline CastClass_match<OpTy, Instruction::BitCast>
m_BitCast(const OpTy & Op)583 m_BitCast(const OpTy &Op) {
584 return CastClass_match<OpTy, Instruction::BitCast>(Op);
585 }
586
587 /// m_PtrToInt
588 template<typename OpTy>
589 inline CastClass_match<OpTy, Instruction::PtrToInt>
m_PtrToInt(const OpTy & Op)590 m_PtrToInt(const OpTy &Op) {
591 return CastClass_match<OpTy, Instruction::PtrToInt>(Op);
592 }
593
594 /// m_Trunc
595 template<typename OpTy>
596 inline CastClass_match<OpTy, Instruction::Trunc>
m_Trunc(const OpTy & Op)597 m_Trunc(const OpTy &Op) {
598 return CastClass_match<OpTy, Instruction::Trunc>(Op);
599 }
600
601 /// m_SExt
602 template<typename OpTy>
603 inline CastClass_match<OpTy, Instruction::SExt>
m_SExt(const OpTy & Op)604 m_SExt(const OpTy &Op) {
605 return CastClass_match<OpTy, Instruction::SExt>(Op);
606 }
607
608 /// m_ZExt
609 template<typename OpTy>
610 inline CastClass_match<OpTy, Instruction::ZExt>
m_ZExt(const OpTy & Op)611 m_ZExt(const OpTy &Op) {
612 return CastClass_match<OpTy, Instruction::ZExt>(Op);
613 }
614
615
616 //===----------------------------------------------------------------------===//
617 // Matchers for unary operators
618 //
619
620 template<typename LHS_t>
621 struct not_match {
622 LHS_t L;
623
not_matchnot_match624 not_match(const LHS_t &LHS) : L(LHS) {}
625
626 template<typename OpTy>
matchnot_match627 bool match(OpTy *V) {
628 if (Operator *O = dyn_cast<Operator>(V))
629 if (O->getOpcode() == Instruction::Xor)
630 return matchIfNot(O->getOperand(0), O->getOperand(1));
631 return false;
632 }
633 private:
matchIfNotnot_match634 bool matchIfNot(Value *LHS, Value *RHS) {
635 return (isa<ConstantInt>(RHS) || isa<ConstantDataVector>(RHS) ||
636 // FIXME: Remove CV.
637 isa<ConstantVector>(RHS)) &&
638 cast<Constant>(RHS)->isAllOnesValue() &&
639 L.match(LHS);
640 }
641 };
642
643 template<typename LHS>
m_Not(const LHS & L)644 inline not_match<LHS> m_Not(const LHS &L) { return L; }
645
646
647 template<typename LHS_t>
648 struct neg_match {
649 LHS_t L;
650
neg_matchneg_match651 neg_match(const LHS_t &LHS) : L(LHS) {}
652
653 template<typename OpTy>
matchneg_match654 bool match(OpTy *V) {
655 if (Operator *O = dyn_cast<Operator>(V))
656 if (O->getOpcode() == Instruction::Sub)
657 return matchIfNeg(O->getOperand(0), O->getOperand(1));
658 return false;
659 }
660 private:
matchIfNegneg_match661 bool matchIfNeg(Value *LHS, Value *RHS) {
662 return ((isa<ConstantInt>(LHS) && cast<ConstantInt>(LHS)->isZero()) ||
663 isa<ConstantAggregateZero>(LHS)) &&
664 L.match(RHS);
665 }
666 };
667
668 /// m_Neg - Match an integer negate.
669 template<typename LHS>
m_Neg(const LHS & L)670 inline neg_match<LHS> m_Neg(const LHS &L) { return L; }
671
672
673 template<typename LHS_t>
674 struct fneg_match {
675 LHS_t L;
676
fneg_matchfneg_match677 fneg_match(const LHS_t &LHS) : L(LHS) {}
678
679 template<typename OpTy>
matchfneg_match680 bool match(OpTy *V) {
681 if (Operator *O = dyn_cast<Operator>(V))
682 if (O->getOpcode() == Instruction::FSub)
683 return matchIfFNeg(O->getOperand(0), O->getOperand(1));
684 return false;
685 }
686 private:
matchIfFNegfneg_match687 bool matchIfFNeg(Value *LHS, Value *RHS) {
688 if (ConstantFP *C = dyn_cast<ConstantFP>(LHS))
689 return C->isNegativeZeroValue() && L.match(RHS);
690 return false;
691 }
692 };
693
694 /// m_FNeg - Match a floating point negate.
695 template<typename LHS>
m_FNeg(const LHS & L)696 inline fneg_match<LHS> m_FNeg(const LHS &L) { return L; }
697
698
699 //===----------------------------------------------------------------------===//
700 // Matchers for control flow.
701 //
702
703 template<typename Cond_t>
704 struct brc_match {
705 Cond_t Cond;
706 BasicBlock *&T, *&F;
brc_matchbrc_match707 brc_match(const Cond_t &C, BasicBlock *&t, BasicBlock *&f)
708 : Cond(C), T(t), F(f) {
709 }
710
711 template<typename OpTy>
matchbrc_match712 bool match(OpTy *V) {
713 if (BranchInst *BI = dyn_cast<BranchInst>(V))
714 if (BI->isConditional() && Cond.match(BI->getCondition())) {
715 T = BI->getSuccessor(0);
716 F = BI->getSuccessor(1);
717 return true;
718 }
719 return false;
720 }
721 };
722
723 template<typename Cond_t>
m_Br(const Cond_t & C,BasicBlock * & T,BasicBlock * & F)724 inline brc_match<Cond_t> m_Br(const Cond_t &C, BasicBlock *&T, BasicBlock *&F) {
725 return brc_match<Cond_t>(C, T, F);
726 }
727
728
729 //===----------------------------------------------------------------------===//
730 // Matchers for max/min idioms, eg: "select (sgt x, y), x, y" -> smax(x,y).
731 //
732
733 template<typename LHS_t, typename RHS_t, typename Pred_t>
734 struct MaxMin_match {
735 LHS_t L;
736 RHS_t R;
737
MaxMin_matchMaxMin_match738 MaxMin_match(const LHS_t &LHS, const RHS_t &RHS)
739 : L(LHS), R(RHS) {}
740
741 template<typename OpTy>
matchMaxMin_match742 bool match(OpTy *V) {
743 // Look for "(x pred y) ? x : y" or "(x pred y) ? y : x".
744 SelectInst *SI = dyn_cast<SelectInst>(V);
745 if (!SI)
746 return false;
747 ICmpInst *Cmp = dyn_cast<ICmpInst>(SI->getCondition());
748 if (!Cmp)
749 return false;
750 // At this point we have a select conditioned on a comparison. Check that
751 // it is the values returned by the select that are being compared.
752 Value *TrueVal = SI->getTrueValue();
753 Value *FalseVal = SI->getFalseValue();
754 Value *LHS = Cmp->getOperand(0);
755 Value *RHS = Cmp->getOperand(1);
756 if ((TrueVal != LHS || FalseVal != RHS) &&
757 (TrueVal != RHS || FalseVal != LHS))
758 return false;
759 ICmpInst::Predicate Pred = LHS == TrueVal ?
760 Cmp->getPredicate() : Cmp->getSwappedPredicate();
761 // Does "(x pred y) ? x : y" represent the desired max/min operation?
762 if (!Pred_t::match(Pred))
763 return false;
764 // It does! Bind the operands.
765 return L.match(LHS) && R.match(RHS);
766 }
767 };
768
769 /// smax_pred_ty - Helper class for identifying signed max predicates.
770 struct smax_pred_ty {
matchsmax_pred_ty771 static bool match(ICmpInst::Predicate Pred) {
772 return Pred == CmpInst::ICMP_SGT || Pred == CmpInst::ICMP_SGE;
773 }
774 };
775
776 /// smin_pred_ty - Helper class for identifying signed min predicates.
777 struct smin_pred_ty {
matchsmin_pred_ty778 static bool match(ICmpInst::Predicate Pred) {
779 return Pred == CmpInst::ICMP_SLT || Pred == CmpInst::ICMP_SLE;
780 }
781 };
782
783 /// umax_pred_ty - Helper class for identifying unsigned max predicates.
784 struct umax_pred_ty {
matchumax_pred_ty785 static bool match(ICmpInst::Predicate Pred) {
786 return Pred == CmpInst::ICMP_UGT || Pred == CmpInst::ICMP_UGE;
787 }
788 };
789
790 /// umin_pred_ty - Helper class for identifying unsigned min predicates.
791 struct umin_pred_ty {
matchumin_pred_ty792 static bool match(ICmpInst::Predicate Pred) {
793 return Pred == CmpInst::ICMP_ULT || Pred == CmpInst::ICMP_ULE;
794 }
795 };
796
797 template<typename LHS, typename RHS>
798 inline MaxMin_match<LHS, RHS, smax_pred_ty>
m_SMax(const LHS & L,const RHS & R)799 m_SMax(const LHS &L, const RHS &R) {
800 return MaxMin_match<LHS, RHS, smax_pred_ty>(L, R);
801 }
802
803 template<typename LHS, typename RHS>
804 inline MaxMin_match<LHS, RHS, smin_pred_ty>
m_SMin(const LHS & L,const RHS & R)805 m_SMin(const LHS &L, const RHS &R) {
806 return MaxMin_match<LHS, RHS, smin_pred_ty>(L, R);
807 }
808
809 template<typename LHS, typename RHS>
810 inline MaxMin_match<LHS, RHS, umax_pred_ty>
m_UMax(const LHS & L,const RHS & R)811 m_UMax(const LHS &L, const RHS &R) {
812 return MaxMin_match<LHS, RHS, umax_pred_ty>(L, R);
813 }
814
815 template<typename LHS, typename RHS>
816 inline MaxMin_match<LHS, RHS, umin_pred_ty>
m_UMin(const LHS & L,const RHS & R)817 m_UMin(const LHS &L, const RHS &R) {
818 return MaxMin_match<LHS, RHS, umin_pred_ty>(L, R);
819 }
820
821 } // end namespace PatternMatch
822 } // end namespace llvm
823
824 #endif
825