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//===------ subzero/src/IcePhiLoweringImpl.h - Phi lowering -----*- C++ -*-===//
//
// The Subzero Code Generator
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
///
/// \file
/// \brief Utilities for targets to lower Phis.
///
//===----------------------------------------------------------------------===//
#ifndef SUBZERO_SRC_ICEPHILOWERINGIMPL_H
#define SUBZERO_SRC_ICEPHILOWERINGIMPL_H
#include "IceCfg.h"
#include "IceCfgNode.h"
#include "IceDefs.h"
#include "IceInst.h"
#include "IceOperand.h"
namespace Ice {
namespace PhiLowering {
/// Turn an i64 Phi instruction into a pair of i32 Phi instructions, to preserve
/// integrity of liveness analysis. This is needed for 32-bit targets. This
/// assumes the 32-bit target has loOperand, hiOperand, and legalizeUndef
/// methods. Undef values are also legalized, since loOperand() and hiOperand()
/// don't expect Undef input.
template <class TargetT>
void prelowerPhis32Bit(TargetT *Target, CfgNode *Node, Cfg *Func) {
for (Inst &I : Node->getPhis()) {
auto *Phi = llvm::dyn_cast<InstPhi>(&I);
if (Phi->isDeleted())
continue;
Variable *Dest = Phi->getDest();
Type DestTy = Dest->getType();
if (DestTy == IceType_i64) {
auto *DestLo = llvm::cast<Variable>(Target->loOperand(Dest));
auto *DestHi = llvm::cast<Variable>(Target->hiOperand(Dest));
auto *PhiLo = InstPhi::create(Func, Phi->getSrcSize(), DestLo);
auto *PhiHi = InstPhi::create(Func, Phi->getSrcSize(), DestHi);
for (SizeT I = 0; I < Phi->getSrcSize(); ++I) {
Operand *Src = Phi->getSrc(I);
CfgNode *Label = Phi->getLabel(I);
Src = Target->legalizeUndef(Src);
PhiLo->addArgument(Target->loOperand(Src), Label);
PhiHi->addArgument(Target->hiOperand(Src), Label);
}
Node->getPhis().push_back(PhiLo);
Node->getPhis().push_back(PhiHi);
Phi->setDeleted();
} else if (isVectorType(DestTy) &&
Target->shouldSplitToVariableVecOn32(DestTy)) {
auto *DstVec = llvm::cast<VariableVecOn32>(Dest);
SizeT Idx = 0;
for (Variable *DestElem : DstVec->getContainers()) {
auto *PhiElem = InstPhi::create(Func, Phi->getSrcSize(), DestElem);
for (SizeT I = 0; I < Phi->getSrcSize(); ++I) {
Operand *Src = Phi->getSrc(I);
CfgNode *Label = Phi->getLabel(I);
Src = Target->legalizeUndef(Src);
auto *SrcVec = llvm::cast<VariableVecOn32>(Src);
PhiElem->addArgument(SrcVec->getContainers()[Idx], Label);
}
++Idx;
Node->getPhis().push_back(PhiElem);
}
Phi->setDeleted();
}
}
}
} // end of namespace PhiLowering
} // end of namespace Ice
#endif // SUBZERO_SRC_ICEPHILOWERINGIMPL_H