llvm-mirror/include/llvm/Support/PatternMatch.h
Chris Lattner 89b1b63bdf teach instcombine to optimize pointer difference idioms involving constant
expressions.  This is a step towards comment #4 in PR3351.

llvm-svn: 92401
2010-01-01 22:29:12 +00:00

604 lines
19 KiB
C++

//===-- llvm/Support/PatternMatch.h - Match on the LLVM IR ------*- C++ -*-===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file provides a simple and efficient mechanism for performing general
// tree-based pattern matches on the LLVM IR. The power of these routines is
// that it allows you to write concise patterns that are expressive and easy to
// understand. The other major advantage of this is that it allows you to
// trivially capture/bind elements in the pattern to variables. For example,
// you can do something like this:
//
// Value *Exp = ...
// Value *X, *Y; ConstantInt *C1, *C2; // (X & C1) | (Y & C2)
// if (match(Exp, m_Or(m_And(m_Value(X), m_ConstantInt(C1)),
// m_And(m_Value(Y), m_ConstantInt(C2))))) {
// ... Pattern is matched and variables are bound ...
// }
//
// This is primarily useful to things like the instruction combiner, but can
// also be useful for static analysis tools or code generators.
//
//===----------------------------------------------------------------------===//
#ifndef LLVM_SUPPORT_PATTERNMATCH_H
#define LLVM_SUPPORT_PATTERNMATCH_H
#include "llvm/Constants.h"
#include "llvm/Instructions.h"
namespace llvm {
namespace PatternMatch {
template<typename Val, typename Pattern>
bool match(Val *V, const Pattern &P) {
return const_cast<Pattern&>(P).match(V);
}
template<typename Class>
struct leaf_ty {
template<typename ITy>
bool match(ITy *V) { return isa<Class>(V); }
};
/// m_Value() - Match an arbitrary value and ignore it.
inline leaf_ty<Value> m_Value() { return leaf_ty<Value>(); }
/// m_ConstantInt() - Match an arbitrary ConstantInt and ignore it.
inline leaf_ty<ConstantInt> m_ConstantInt() { return leaf_ty<ConstantInt>(); }
template<int64_t Val>
struct constantint_ty {
template<typename ITy>
bool match(ITy *V) {
if (const ConstantInt *CI = dyn_cast<ConstantInt>(V)) {
const APInt &CIV = CI->getValue();
if (Val >= 0)
return CIV == static_cast<uint64_t>(Val);
// If Val is negative, and CI is shorter than it, truncate to the right
// number of bits. If it is larger, then we have to sign extend. Just
// compare their negated values.
return -CIV == -Val;
}
return false;
}
};
/// m_ConstantInt(int64_t) - Match a ConstantInt with a specific value
/// and ignore it.
template<int64_t Val>
inline constantint_ty<Val> m_ConstantInt() {
return constantint_ty<Val>();
}
struct zero_ty {
template<typename ITy>
bool match(ITy *V) {
if (const Constant *C = dyn_cast<Constant>(V))
return C->isNullValue();
return false;
}
};
/// m_Zero() - Match an arbitrary zero/null constant.
inline zero_ty m_Zero() { return zero_ty(); }
struct one_ty {
template<typename ITy>
bool match(ITy *V) {
if (const ConstantInt *C = dyn_cast<ConstantInt>(V))
return C->isOne();
return false;
}
};
/// m_One() - Match a an integer 1.
inline one_ty m_One() { return one_ty(); }
template<typename Class>
struct bind_ty {
Class *&VR;
bind_ty(Class *&V) : VR(V) {}
template<typename ITy>
bool match(ITy *V) {
if (Class *CV = dyn_cast<Class>(V)) {
VR = CV;
return true;
}
return false;
}
};
/// m_Value - Match a value, capturing it if we match.
inline bind_ty<Value> m_Value(Value *&V) { return V; }
/// m_ConstantInt - Match a ConstantInt, capturing the value if we match.
inline bind_ty<ConstantInt> m_ConstantInt(ConstantInt *&CI) { return CI; }
/// specificval_ty - Match a specified Value*.
struct specificval_ty {
const Value *Val;
specificval_ty(const Value *V) : Val(V) {}
template<typename ITy>
bool match(ITy *V) {
return V == Val;
}
};
/// m_Specific - Match if we have a specific specified value.
inline specificval_ty m_Specific(const Value *V) { return V; }
//===----------------------------------------------------------------------===//
// Matchers for specific binary operators.
//
template<typename LHS_t, typename RHS_t,
unsigned Opcode, typename ConcreteTy = BinaryOperator>
struct BinaryOp_match {
LHS_t L;
RHS_t R;
BinaryOp_match(const LHS_t &LHS, const RHS_t &RHS) : L(LHS), R(RHS) {}
template<typename OpTy>
bool match(OpTy *V) {
if (V->getValueID() == Value::InstructionVal + Opcode) {
ConcreteTy *I = cast<ConcreteTy>(V);
return I->getOpcode() == Opcode && L.match(I->getOperand(0)) &&
R.match(I->getOperand(1));
}
if (ConstantExpr *CE = dyn_cast<ConstantExpr>(V))
return CE->getOpcode() == Opcode && L.match(CE->getOperand(0)) &&
R.match(CE->getOperand(1));
return false;
}
};
template<typename LHS, typename RHS>
inline BinaryOp_match<LHS, RHS, Instruction::Add> m_Add(const LHS &L,
const RHS &R) {
return BinaryOp_match<LHS, RHS, Instruction::Add>(L, R);
}
template<typename LHS, typename RHS>
inline BinaryOp_match<LHS, RHS, Instruction::FAdd> m_FAdd(const LHS &L,
const RHS &R) {
return BinaryOp_match<LHS, RHS, Instruction::FAdd>(L, R);
}
template<typename LHS, typename RHS>
inline BinaryOp_match<LHS, RHS, Instruction::Sub> m_Sub(const LHS &L,
const RHS &R) {
return BinaryOp_match<LHS, RHS, Instruction::Sub>(L, R);
}
template<typename LHS, typename RHS>
inline BinaryOp_match<LHS, RHS, Instruction::FSub> m_FSub(const LHS &L,
const RHS &R) {
return BinaryOp_match<LHS, RHS, Instruction::FSub>(L, R);
}
template<typename LHS, typename RHS>
inline BinaryOp_match<LHS, RHS, Instruction::Mul> m_Mul(const LHS &L,
const RHS &R) {
return BinaryOp_match<LHS, RHS, Instruction::Mul>(L, R);
}
template<typename LHS, typename RHS>
inline BinaryOp_match<LHS, RHS, Instruction::FMul> m_FMul(const LHS &L,
const RHS &R) {
return BinaryOp_match<LHS, RHS, Instruction::FMul>(L, R);
}
template<typename LHS, typename RHS>
inline BinaryOp_match<LHS, RHS, Instruction::UDiv> m_UDiv(const LHS &L,
const RHS &R) {
return BinaryOp_match<LHS, RHS, Instruction::UDiv>(L, R);
}
template<typename LHS, typename RHS>
inline BinaryOp_match<LHS, RHS, Instruction::SDiv> m_SDiv(const LHS &L,
const RHS &R) {
return BinaryOp_match<LHS, RHS, Instruction::SDiv>(L, R);
}
template<typename LHS, typename RHS>
inline BinaryOp_match<LHS, RHS, Instruction::FDiv> m_FDiv(const LHS &L,
const RHS &R) {
return BinaryOp_match<LHS, RHS, Instruction::FDiv>(L, R);
}
template<typename LHS, typename RHS>
inline BinaryOp_match<LHS, RHS, Instruction::URem> m_URem(const LHS &L,
const RHS &R) {
return BinaryOp_match<LHS, RHS, Instruction::URem>(L, R);
}
template<typename LHS, typename RHS>
inline BinaryOp_match<LHS, RHS, Instruction::SRem> m_SRem(const LHS &L,
const RHS &R) {
return BinaryOp_match<LHS, RHS, Instruction::SRem>(L, R);
}
template<typename LHS, typename RHS>
inline BinaryOp_match<LHS, RHS, Instruction::FRem> m_FRem(const LHS &L,
const RHS &R) {
return BinaryOp_match<LHS, RHS, Instruction::FRem>(L, R);
}
template<typename LHS, typename RHS>
inline BinaryOp_match<LHS, RHS, Instruction::And> m_And(const LHS &L,
const RHS &R) {
return BinaryOp_match<LHS, RHS, Instruction::And>(L, R);
}
template<typename LHS, typename RHS>
inline BinaryOp_match<LHS, RHS, Instruction::Or> m_Or(const LHS &L,
const RHS &R) {
return BinaryOp_match<LHS, RHS, Instruction::Or>(L, R);
}
template<typename LHS, typename RHS>
inline BinaryOp_match<LHS, RHS, Instruction::Xor> m_Xor(const LHS &L,
const RHS &R) {
return BinaryOp_match<LHS, RHS, Instruction::Xor>(L, R);
}
template<typename LHS, typename RHS>
inline BinaryOp_match<LHS, RHS, Instruction::Shl> m_Shl(const LHS &L,
const RHS &R) {
return BinaryOp_match<LHS, RHS, Instruction::Shl>(L, R);
}
template<typename LHS, typename RHS>
inline BinaryOp_match<LHS, RHS, Instruction::LShr> m_LShr(const LHS &L,
const RHS &R) {
return BinaryOp_match<LHS, RHS, Instruction::LShr>(L, R);
}
template<typename LHS, typename RHS>
inline BinaryOp_match<LHS, RHS, Instruction::AShr> m_AShr(const LHS &L,
const RHS &R) {
return BinaryOp_match<LHS, RHS, Instruction::AShr>(L, R);
}
//===----------------------------------------------------------------------===//
// Matchers for either AShr or LShr .. for convenience
//
template<typename LHS_t, typename RHS_t, typename ConcreteTy = BinaryOperator>
struct Shr_match {
LHS_t L;
RHS_t R;
Shr_match(const LHS_t &LHS, const RHS_t &RHS) : L(LHS), R(RHS) {}
template<typename OpTy>
bool match(OpTy *V) {
if (V->getValueID() == Value::InstructionVal + Instruction::LShr ||
V->getValueID() == Value::InstructionVal + Instruction::AShr) {
ConcreteTy *I = cast<ConcreteTy>(V);
return (I->getOpcode() == Instruction::AShr ||
I->getOpcode() == Instruction::LShr) &&
L.match(I->getOperand(0)) &&
R.match(I->getOperand(1));
}
if (ConstantExpr *CE = dyn_cast<ConstantExpr>(V))
return (CE->getOpcode() == Instruction::LShr ||
CE->getOpcode() == Instruction::AShr) &&
L.match(CE->getOperand(0)) &&
R.match(CE->getOperand(1));
return false;
}
};
template<typename LHS, typename RHS>
inline Shr_match<LHS, RHS> m_Shr(const LHS &L, const RHS &R) {
return Shr_match<LHS, RHS>(L, R);
}
//===----------------------------------------------------------------------===//
// Matchers for binary classes
//
template<typename LHS_t, typename RHS_t, typename Class, typename OpcType>
struct BinaryOpClass_match {
OpcType *Opcode;
LHS_t L;
RHS_t R;
BinaryOpClass_match(OpcType &Op, const LHS_t &LHS,
const RHS_t &RHS)
: Opcode(&Op), L(LHS), R(RHS) {}
BinaryOpClass_match(const LHS_t &LHS, const RHS_t &RHS)
: Opcode(0), L(LHS), R(RHS) {}
template<typename OpTy>
bool match(OpTy *V) {
if (Class *I = dyn_cast<Class>(V))
if (L.match(I->getOperand(0)) &&
R.match(I->getOperand(1))) {
if (Opcode)
*Opcode = I->getOpcode();
return true;
}
#if 0 // Doesn't handle constantexprs yet!
if (ConstantExpr *CE = dyn_cast<ConstantExpr>(V))
return CE->getOpcode() == Opcode && L.match(CE->getOperand(0)) &&
R.match(CE->getOperand(1));
#endif
return false;
}
};
template<typename LHS, typename RHS>
inline BinaryOpClass_match<LHS, RHS, BinaryOperator, Instruction::BinaryOps>
m_Shift(Instruction::BinaryOps &Op, const LHS &L, const RHS &R) {
return BinaryOpClass_match<LHS, RHS,
BinaryOperator, Instruction::BinaryOps>(Op, L, R);
}
template<typename LHS, typename RHS>
inline BinaryOpClass_match<LHS, RHS, BinaryOperator, Instruction::BinaryOps>
m_Shift(const LHS &L, const RHS &R) {
return BinaryOpClass_match<LHS, RHS,
BinaryOperator, Instruction::BinaryOps>(L, R);
}
//===----------------------------------------------------------------------===//
// Matchers for CmpInst classes
//
template<typename LHS_t, typename RHS_t, typename Class, typename PredicateTy>
struct CmpClass_match {
PredicateTy &Predicate;
LHS_t L;
RHS_t R;
CmpClass_match(PredicateTy &Pred, const LHS_t &LHS,
const RHS_t &RHS)
: Predicate(Pred), L(LHS), R(RHS) {}
template<typename OpTy>
bool match(OpTy *V) {
if (Class *I = dyn_cast<Class>(V))
if (L.match(I->getOperand(0)) &&
R.match(I->getOperand(1))) {
Predicate = I->getPredicate();
return true;
}
return false;
}
};
template<typename LHS, typename RHS>
inline CmpClass_match<LHS, RHS, ICmpInst, ICmpInst::Predicate>
m_ICmp(ICmpInst::Predicate &Pred, const LHS &L, const RHS &R) {
return CmpClass_match<LHS, RHS,
ICmpInst, ICmpInst::Predicate>(Pred, L, R);
}
template<typename LHS, typename RHS>
inline CmpClass_match<LHS, RHS, FCmpInst, FCmpInst::Predicate>
m_FCmp(FCmpInst::Predicate &Pred, const LHS &L, const RHS &R) {
return CmpClass_match<LHS, RHS,
FCmpInst, FCmpInst::Predicate>(Pred, L, R);
}
//===----------------------------------------------------------------------===//
// Matchers for SelectInst classes
//
template<typename Cond_t, typename LHS_t, typename RHS_t>
struct SelectClass_match {
Cond_t C;
LHS_t L;
RHS_t R;
SelectClass_match(const Cond_t &Cond, const LHS_t &LHS,
const RHS_t &RHS)
: C(Cond), L(LHS), R(RHS) {}
template<typename OpTy>
bool match(OpTy *V) {
if (SelectInst *I = dyn_cast<SelectInst>(V))
return C.match(I->getOperand(0)) &&
L.match(I->getOperand(1)) &&
R.match(I->getOperand(2));
return false;
}
};
template<typename Cond, typename LHS, typename RHS>
inline SelectClass_match<Cond, LHS, RHS>
m_Select(const Cond &C, const LHS &L, const RHS &R) {
return SelectClass_match<Cond, LHS, RHS>(C, L, R);
}
/// m_SelectCst - This matches a select of two constants, e.g.:
/// m_SelectCst(m_Value(V), -1, 0)
template<int64_t L, int64_t R, typename Cond>
inline SelectClass_match<Cond, constantint_ty<L>, constantint_ty<R> >
m_SelectCst(const Cond &C) {
return SelectClass_match<Cond, constantint_ty<L>,
constantint_ty<R> >(C, m_ConstantInt<L>(),
m_ConstantInt<R>());
}
//===----------------------------------------------------------------------===//
// Matchers for CastInst classes
//
template<typename Op_t, unsigned Opcode>
struct CastClass_match {
Op_t Op;
CastClass_match(const Op_t &OpMatch) : Op(OpMatch) {}
template<typename OpTy>
bool match(OpTy *V) {
if (CastInst *I = dyn_cast<CastInst>(V))
return I->getOpcode() == Opcode && Op.match(I->getOperand(0));
if (ConstantExpr *CE = dyn_cast<ConstantExpr>(V))
return CE->getOpcode() == Opcode && Op.match(CE->getOperand(0));
return false;
}
};
/// m_PtrToInt
template<typename OpTy>
inline CastClass_match<OpTy, Instruction::PtrToInt>
m_PtrToInt(const OpTy &Op) {
return CastClass_match<OpTy, Instruction::PtrToInt>(Op);
}
/// m_Trunc
template<typename OpTy>
inline CastClass_match<OpTy, Instruction::Trunc>
m_Trunc(const OpTy &Op) {
return CastClass_match<OpTy, Instruction::Trunc>(Op);
}
//===----------------------------------------------------------------------===//
// Matchers for unary operators
//
template<typename LHS_t>
struct not_match {
LHS_t L;
not_match(const LHS_t &LHS) : L(LHS) {}
template<typename OpTy>
bool match(OpTy *V) {
if (Instruction *I = dyn_cast<Instruction>(V))
if (I->getOpcode() == Instruction::Xor)
return matchIfNot(I->getOperand(0), I->getOperand(1));
if (ConstantExpr *CE = dyn_cast<ConstantExpr>(V))
if (CE->getOpcode() == Instruction::Xor)
return matchIfNot(CE->getOperand(0), CE->getOperand(1));
if (ConstantInt *CI = dyn_cast<ConstantInt>(V))
return L.match(ConstantExpr::getNot(CI));
return false;
}
private:
bool matchIfNot(Value *LHS, Value *RHS) {
if (ConstantInt *CI = dyn_cast<ConstantInt>(RHS))
return CI->isAllOnesValue() && L.match(LHS);
if (ConstantInt *CI = dyn_cast<ConstantInt>(LHS))
return CI->isAllOnesValue() && L.match(RHS);
if (ConstantVector *CV = dyn_cast<ConstantVector>(RHS))
return CV->isAllOnesValue() && L.match(LHS);
if (ConstantVector *CV = dyn_cast<ConstantVector>(LHS))
return CV->isAllOnesValue() && L.match(RHS);
return false;
}
};
template<typename LHS>
inline not_match<LHS> m_Not(const LHS &L) { return L; }
template<typename LHS_t>
struct neg_match {
LHS_t L;
neg_match(const LHS_t &LHS) : L(LHS) {}
template<typename OpTy>
bool match(OpTy *V) {
if (Instruction *I = dyn_cast<Instruction>(V))
if (I->getOpcode() == Instruction::Sub)
return matchIfNeg(I->getOperand(0), I->getOperand(1));
if (ConstantExpr *CE = dyn_cast<ConstantExpr>(V))
if (CE->getOpcode() == Instruction::Sub)
return matchIfNeg(CE->getOperand(0), CE->getOperand(1));
if (ConstantInt *CI = dyn_cast<ConstantInt>(V))
return L.match(ConstantExpr::getNeg(CI));
return false;
}
private:
bool matchIfNeg(Value *LHS, Value *RHS) {
return LHS == ConstantFP::getZeroValueForNegation(LHS->getType()) &&
L.match(RHS);
}
};
template<typename LHS>
inline neg_match<LHS> m_Neg(const LHS &L) { return L; }
template<typename LHS_t>
struct fneg_match {
LHS_t L;
fneg_match(const LHS_t &LHS) : L(LHS) {}
template<typename OpTy>
bool match(OpTy *V) {
if (Instruction *I = dyn_cast<Instruction>(V))
if (I->getOpcode() == Instruction::FSub)
return matchIfFNeg(I->getOperand(0), I->getOperand(1));
if (ConstantExpr *CE = dyn_cast<ConstantExpr>(V))
if (CE->getOpcode() == Instruction::FSub)
return matchIfFNeg(CE->getOperand(0), CE->getOperand(1));
if (ConstantFP *CF = dyn_cast<ConstantFP>(V))
return L.match(ConstantExpr::getFNeg(CF));
return false;
}
private:
bool matchIfFNeg(Value *LHS, Value *RHS) {
return LHS == ConstantFP::getZeroValueForNegation(LHS->getType()) &&
L.match(RHS);
}
};
template<typename LHS>
inline fneg_match<LHS> m_FNeg(const LHS &L) { return L; }
//===----------------------------------------------------------------------===//
// Matchers for control flow
//
template<typename Cond_t>
struct brc_match {
Cond_t Cond;
BasicBlock *&T, *&F;
brc_match(const Cond_t &C, BasicBlock *&t, BasicBlock *&f)
: Cond(C), T(t), F(f) {
}
template<typename OpTy>
bool match(OpTy *V) {
if (BranchInst *BI = dyn_cast<BranchInst>(V))
if (BI->isConditional()) {
if (Cond.match(BI->getCondition())) {
T = BI->getSuccessor(0);
F = BI->getSuccessor(1);
return true;
}
}
return false;
}
};
template<typename Cond_t>
inline brc_match<Cond_t> m_Br(const Cond_t &C, BasicBlock *&T, BasicBlock *&F) {
return brc_match<Cond_t>(C, T, F);
}
} // end namespace PatternMatch
} // end namespace llvm
#endif