llvm-6502/include/llvm/Support/PatternMatch.h

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//===-- 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"
#include "llvm/Operator.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 SubPattern_t>
struct OneUse_match {
SubPattern_t SubPattern;
OneUse_match(const SubPattern_t &SP) : SubPattern(SP) {}
template<typename OpTy>
bool match(OpTy *V) {
return V->hasOneUse() && SubPattern.match(V);
}
};
template<typename T>
inline OneUse_match<T> m_OneUse(const T &SubPattern) { return SubPattern; }
template<typename Class>
struct class_match {
template<typename ITy>
bool match(ITy *V) { return isa<Class>(V); }
};
/// m_Value() - Match an arbitrary value and ignore it.
inline class_match<Value> m_Value() { return class_match<Value>(); }
/// m_ConstantInt() - Match an arbitrary ConstantInt and ignore it.
inline class_match<ConstantInt> m_ConstantInt() {
return class_match<ConstantInt>();
}
/// m_Undef() - Match an arbitrary undef constant.
inline class_match<UndefValue> m_Undef() { return class_match<UndefValue>(); }
inline class_match<Constant> m_Constant() { return class_match<Constant>(); }
struct match_zero {
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. This includes
/// zero_initializer for vectors and ConstantPointerNull for pointers.
inline match_zero m_Zero() { return match_zero(); }
struct apint_match {
const APInt *&Res;
apint_match(const APInt *&R) : Res(R) {}
template<typename ITy>
bool match(ITy *V) {
if (ConstantInt *CI = dyn_cast<ConstantInt>(V)) {
Res = &CI->getValue();
return true;
}
// FIXME: Remove this.
if (ConstantVector *CV = dyn_cast<ConstantVector>(V))
if (ConstantInt *CI =
dyn_cast_or_null<ConstantInt>(CV->getSplatValue())) {
Res = &CI->getValue();
return true;
}
if (ConstantDataVector *CV = dyn_cast<ConstantDataVector>(V))
if (ConstantInt *CI =
dyn_cast_or_null<ConstantInt>(CV->getSplatValue())) {
Res = &CI->getValue();
return true;
}
return false;
}
};
/// m_APInt - Match a ConstantInt or splatted ConstantVector, binding the
/// specified pointer to the contained APInt.
inline apint_match m_APInt(const APInt *&Res) { return Res; }
template<int64_t Val>
struct constantint_match {
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.
template<int64_t Val>
inline constantint_match<Val> m_ConstantInt() {
return constantint_match<Val>();
}
/// cst_pred_ty - This helper class is used to match scalar and vector constants
/// that satisfy a specified predicate.
template<typename Predicate>
struct cst_pred_ty : public Predicate {
template<typename ITy>
bool match(ITy *V) {
if (const ConstantInt *CI = dyn_cast<ConstantInt>(V))
return this->isValue(CI->getValue());
// FIXME: Remove this.
if (const ConstantVector *CV = dyn_cast<ConstantVector>(V))
if (ConstantInt *CI = dyn_cast_or_null<ConstantInt>(CV->getSplatValue()))
return this->isValue(CI->getValue());
if (const ConstantDataVector *CV = dyn_cast<ConstantDataVector>(V))
if (ConstantInt *CI = dyn_cast_or_null<ConstantInt>(CV->getSplatValue()))
return this->isValue(CI->getValue());
return false;
}
};
/// api_pred_ty - This helper class is used to match scalar and vector constants
/// that satisfy a specified predicate, and bind them to an APInt.
template<typename Predicate>
struct api_pred_ty : public Predicate {
const APInt *&Res;
api_pred_ty(const APInt *&R) : Res(R) {}
template<typename ITy>
bool match(ITy *V) {
if (const ConstantInt *CI = dyn_cast<ConstantInt>(V))
if (this->isValue(CI->getValue())) {
Res = &CI->getValue();
return true;
}
// FIXME: remove.
if (const ConstantVector *CV = dyn_cast<ConstantVector>(V))
if (ConstantInt *CI = dyn_cast_or_null<ConstantInt>(CV->getSplatValue()))
if (this->isValue(CI->getValue())) {
Res = &CI->getValue();
return true;
}
if (const ConstantDataVector *CV = dyn_cast<ConstantDataVector>(V))
if (ConstantInt *CI = dyn_cast_or_null<ConstantInt>(CV->getSplatValue()))
if (this->isValue(CI->getValue())) {
Res = &CI->getValue();
return true;
}
return false;
}
};
struct is_one {
bool isValue(const APInt &C) { return C == 1; }
};
/// m_One() - Match an integer 1 or a vector with all elements equal to 1.
inline cst_pred_ty<is_one> m_One() { return cst_pred_ty<is_one>(); }
inline api_pred_ty<is_one> m_One(const APInt *&V) { return V; }
struct is_all_ones {
bool isValue(const APInt &C) { return C.isAllOnesValue(); }
};
/// m_AllOnes() - Match an integer or vector with all bits set to true.
inline cst_pred_ty<is_all_ones> m_AllOnes() {return cst_pred_ty<is_all_ones>();}
inline api_pred_ty<is_all_ones> m_AllOnes(const APInt *&V) { return V; }
struct is_sign_bit {
bool isValue(const APInt &C) { return C.isSignBit(); }
};
/// m_SignBit() - Match an integer or vector with only the sign bit(s) set.
inline cst_pred_ty<is_sign_bit> m_SignBit() {return cst_pred_ty<is_sign_bit>();}
inline api_pred_ty<is_sign_bit> m_SignBit(const APInt *&V) { return V; }
struct is_power2 {
bool isValue(const APInt &C) { return C.isPowerOf2(); }
};
/// m_Power2() - Match an integer or vector power of 2.
inline cst_pred_ty<is_power2> m_Power2() { return cst_pred_ty<is_power2>(); }
inline api_pred_ty<is_power2> m_Power2(const APInt *&V) { return V; }
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; }
/// m_Constant - Match a Constant, capturing the value if we match.
inline bind_ty<Constant> m_Constant(Constant *&C) { return C; }
/// 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; }
struct bind_const_intval_ty {
uint64_t &VR;
bind_const_intval_ty(uint64_t &V) : VR(V) {}
template<typename ITy>
bool match(ITy *V) {
if (ConstantInt *CV = dyn_cast<ConstantInt>(V))
if (CV->getBitWidth() <= 64) {
VR = CV->getZExtValue();
return true;
}
return false;
}
};
/// m_ConstantInt - Match a ConstantInt and bind to its value. This does not
/// match ConstantInts wider than 64-bits.
inline bind_const_intval_ty m_ConstantInt(uint64_t &V) { return V; }
//===----------------------------------------------------------------------===//
// Matchers for specific binary operators.
//
template<typename LHS_t, typename RHS_t, unsigned Opcode>
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) {
BinaryOperator *I = cast<BinaryOperator>(V);
return 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);
}
//===----------------------------------------------------------------------===//
// Class that matches two different binary ops.
//
template<typename LHS_t, typename RHS_t, unsigned Opc1, unsigned Opc2>
struct BinOp2_match {
LHS_t L;
RHS_t R;
BinOp2_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 + Opc1 ||
V->getValueID() == Value::InstructionVal + Opc2) {
BinaryOperator *I = cast<BinaryOperator>(V);
return L.match(I->getOperand(0)) && R.match(I->getOperand(1));
}
if (ConstantExpr *CE = dyn_cast<ConstantExpr>(V))
return (CE->getOpcode() == Opc1 || CE->getOpcode() == Opc2) &&
L.match(CE->getOperand(0)) && R.match(CE->getOperand(1));
return false;
}
};
/// m_Shr - Matches LShr or AShr.
template<typename LHS, typename RHS>
inline BinOp2_match<LHS, RHS, Instruction::LShr, Instruction::AShr>
m_Shr(const LHS &L, const RHS &R) {
return BinOp2_match<LHS, RHS, Instruction::LShr, Instruction::AShr>(L, R);
}
/// m_LogicalShift - Matches LShr or Shl.
template<typename LHS, typename RHS>
inline BinOp2_match<LHS, RHS, Instruction::LShr, Instruction::Shl>
m_LogicalShift(const LHS &L, const RHS &R) {
return BinOp2_match<LHS, RHS, Instruction::LShr, Instruction::Shl>(L, R);
}
/// m_IDiv - Matches UDiv and SDiv.
template<typename LHS, typename RHS>
inline BinOp2_match<LHS, RHS, Instruction::SDiv, Instruction::UDiv>
m_IDiv(const LHS &L, const RHS &R) {
return BinOp2_match<LHS, RHS, Instruction::SDiv, Instruction::UDiv>(L, R);
}
//===----------------------------------------------------------------------===//
// Class that matches exact binary ops.
//
template<typename SubPattern_t>
struct Exact_match {
SubPattern_t SubPattern;
Exact_match(const SubPattern_t &SP) : SubPattern(SP) {}
template<typename OpTy>
bool match(OpTy *V) {
if (PossiblyExactOperator *PEO = dyn_cast<PossiblyExactOperator>(V))
return PEO->isExact() && SubPattern.match(V);
return false;
}
};
template<typename T>
inline Exact_match<T> m_Exact(const T &SubPattern) { return SubPattern; }
//===----------------------------------------------------------------------===//
// 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<-1, 0>(m_Value(V))
template<int64_t L, int64_t R, typename Cond>
inline SelectClass_match<Cond, constantint_match<L>, constantint_match<R> >
m_SelectCst(const Cond &C) {
return m_Select(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 (Operator *O = dyn_cast<Operator>(V))
return O->getOpcode() == Opcode && Op.match(O->getOperand(0));
return false;
}
};
/// m_BitCast
template<typename OpTy>
inline CastClass_match<OpTy, Instruction::BitCast>
m_BitCast(const OpTy &Op) {
return CastClass_match<OpTy, Instruction::BitCast>(Op);
}
/// 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);
}
/// m_SExt
template<typename OpTy>
inline CastClass_match<OpTy, Instruction::SExt>
m_SExt(const OpTy &Op) {
return CastClass_match<OpTy, Instruction::SExt>(Op);
}
/// m_ZExt
template<typename OpTy>
inline CastClass_match<OpTy, Instruction::ZExt>
m_ZExt(const OpTy &Op) {
return CastClass_match<OpTy, Instruction::ZExt>(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 (Operator *O = dyn_cast<Operator>(V))
if (O->getOpcode() == Instruction::Xor)
return matchIfNot(O->getOperand(0), O->getOperand(1));
return false;
}
private:
bool matchIfNot(Value *LHS, Value *RHS) {
return (isa<ConstantInt>(RHS) || isa<ConstantDataVector>(RHS) ||
// FIXME: Remove CV.
isa<ConstantVector>(RHS)) &&
cast<Constant>(RHS)->isAllOnesValue() &&
L.match(LHS);
}
};
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 (Operator *O = dyn_cast<Operator>(V))
if (O->getOpcode() == Instruction::Sub)
return matchIfNeg(O->getOperand(0), O->getOperand(1));
return false;
}
private:
bool matchIfNeg(Value *LHS, Value *RHS) {
return ((isa<ConstantInt>(LHS) && cast<ConstantInt>(LHS)->isZero()) ||
isa<ConstantAggregateZero>(LHS)) &&
L.match(RHS);
}
};
/// m_Neg - Match an integer negate.
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 (Operator *O = dyn_cast<Operator>(V))
if (O->getOpcode() == Instruction::FSub)
return matchIfFNeg(O->getOperand(0), O->getOperand(1));
return false;
}
private:
bool matchIfFNeg(Value *LHS, Value *RHS) {
if (ConstantFP *C = dyn_cast<ConstantFP>(LHS))
return C->isNegativeZeroValue() && L.match(RHS);
return false;
}
};
/// m_FNeg - Match a floating point negate.
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() && 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);
}
//===----------------------------------------------------------------------===//
// Matchers for max/min idioms, eg: "select (sgt x, y), x, y" -> smax(x,y).
//
template<typename LHS_t, typename RHS_t, typename Pred_t>
struct MaxMin_match {
LHS_t L;
RHS_t R;
MaxMin_match(const LHS_t &LHS, const RHS_t &RHS)
: L(LHS), R(RHS) {}
template<typename OpTy>
bool match(OpTy *V) {
// Look for "(x pred y) ? x : y" or "(x pred y) ? y : x".
SelectInst *SI = dyn_cast<SelectInst>(V);
if (!SI)
return false;
ICmpInst *Cmp = dyn_cast<ICmpInst>(SI->getCondition());
if (!Cmp)
return false;
// At this point we have a select conditioned on a comparison. Check that
// it is the values returned by the select that are being compared.
Value *TrueVal = SI->getTrueValue();
Value *FalseVal = SI->getFalseValue();
Value *LHS = Cmp->getOperand(0);
Value *RHS = Cmp->getOperand(1);
if ((TrueVal != LHS || FalseVal != RHS) &&
(TrueVal != RHS || FalseVal != LHS))
return false;
ICmpInst::Predicate Pred = LHS == TrueVal ?
Cmp->getPredicate() : Cmp->getSwappedPredicate();
// Does "(x pred y) ? x : y" represent the desired max/min operation?
if (!Pred_t::match(Pred))
return false;
// It does! Bind the operands.
return L.match(LHS) && R.match(RHS);
}
};
/// smax_pred_ty - Helper class for identifying signed max predicates.
struct smax_pred_ty {
static bool match(ICmpInst::Predicate Pred) {
return Pred == CmpInst::ICMP_SGT || Pred == CmpInst::ICMP_SGE;
}
};
/// smin_pred_ty - Helper class for identifying signed min predicates.
struct smin_pred_ty {
static bool match(ICmpInst::Predicate Pred) {
return Pred == CmpInst::ICMP_SLT || Pred == CmpInst::ICMP_SLE;
}
};
/// umax_pred_ty - Helper class for identifying unsigned max predicates.
struct umax_pred_ty {
static bool match(ICmpInst::Predicate Pred) {
return Pred == CmpInst::ICMP_UGT || Pred == CmpInst::ICMP_UGE;
}
};
/// umin_pred_ty - Helper class for identifying unsigned min predicates.
struct umin_pred_ty {
static bool match(ICmpInst::Predicate Pred) {
return Pred == CmpInst::ICMP_ULT || Pred == CmpInst::ICMP_ULE;
}
};
template<typename LHS, typename RHS>
inline MaxMin_match<LHS, RHS, smax_pred_ty>
m_SMax(const LHS &L, const RHS &R) {
return MaxMin_match<LHS, RHS, smax_pred_ty>(L, R);
}
template<typename LHS, typename RHS>
inline MaxMin_match<LHS, RHS, smin_pred_ty>
m_SMin(const LHS &L, const RHS &R) {
return MaxMin_match<LHS, RHS, smin_pred_ty>(L, R);
}
template<typename LHS, typename RHS>
inline MaxMin_match<LHS, RHS, umax_pred_ty>
m_UMax(const LHS &L, const RHS &R) {
return MaxMin_match<LHS, RHS, umax_pred_ty>(L, R);
}
template<typename LHS, typename RHS>
inline MaxMin_match<LHS, RHS, umin_pred_ty>
m_UMin(const LHS &L, const RHS &R) {
return MaxMin_match<LHS, RHS, umin_pred_ty>(L, R);
}
} // end namespace PatternMatch
} // end namespace llvm
#endif