mirror of
https://github.com/c64scene-ar/llvm-6502.git
synced 2024-08-02 09:29:24 +00:00
c0b9dc5be7
ilist of MachineInstr objects. This allows constant time removal and insertion of MachineInstr instances from anywhere in each MachineBasicBlock. It also allows for constant time splicing of MachineInstrs into or out of MachineBasicBlocks. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@11340 91177308-0d34-0410-b5e6-96231b3b80d8
233 lines
8.0 KiB
C++
233 lines
8.0 KiB
C++
//===-- BBLiveVar.cpp - Live Variable Analysis for a BasicBlock -----------===//
|
|
//
|
|
// The LLVM Compiler Infrastructure
|
|
//
|
|
// This file was developed by the LLVM research group and is distributed under
|
|
// the University of Illinois Open Source License. See LICENSE.TXT for details.
|
|
//
|
|
//===----------------------------------------------------------------------===//
|
|
//
|
|
// This is a wrapper class for BasicBlock which is used by live var analysis.
|
|
//
|
|
//===----------------------------------------------------------------------===//
|
|
|
|
#include "BBLiveVar.h"
|
|
#include "llvm/CodeGen/FunctionLiveVarInfo.h"
|
|
#include "llvm/CodeGen/MachineInstr.h"
|
|
#include "llvm/CodeGen/MachineBasicBlock.h"
|
|
#include "llvm/Support/CFG.h"
|
|
#include "Support/SetOperations.h"
|
|
#include "../SparcInternals.h"
|
|
|
|
namespace llvm {
|
|
|
|
BBLiveVar::BBLiveVar(const BasicBlock &bb,
|
|
const MachineBasicBlock &mbb,
|
|
unsigned id)
|
|
: BB(bb), MBB(mbb), POID(id) {
|
|
InSetChanged = OutSetChanged = false;
|
|
|
|
calcDefUseSets();
|
|
}
|
|
|
|
//-----------------------------------------------------------------------------
|
|
// calculates def and use sets for each BB
|
|
// There are two passes over operands of a machine instruction. This is
|
|
// because, we can have instructions like V = V + 1, since we no longer
|
|
// assume single definition.
|
|
//-----------------------------------------------------------------------------
|
|
|
|
void BBLiveVar::calcDefUseSets() {
|
|
// iterate over all the machine instructions in BB
|
|
for (MachineBasicBlock::const_reverse_iterator MII = MBB.rbegin(),
|
|
MIE = MBB.rend(); MII != MIE; ++MII) {
|
|
const MachineInstr *MI = &*MII;
|
|
|
|
if (DEBUG_LV >= LV_DEBUG_Verbose) {
|
|
std::cerr << " *Iterating over machine instr ";
|
|
MI->dump();
|
|
std::cerr << "\n";
|
|
}
|
|
|
|
// iterate over MI operands to find defs
|
|
for (MachineInstr::const_val_op_iterator OpI = MI->begin(), OpE = MI->end();
|
|
OpI != OpE; ++OpI)
|
|
if (OpI.isDef()) // add to Defs if this operand is a def
|
|
addDef(*OpI);
|
|
|
|
// do for implicit operands as well
|
|
for (unsigned i = 0; i < MI->getNumImplicitRefs(); ++i)
|
|
if (MI->getImplicitOp(i).isDef())
|
|
addDef(MI->getImplicitRef(i));
|
|
|
|
// iterate over MI operands to find uses
|
|
for (MachineInstr::const_val_op_iterator OpI = MI->begin(), OpE = MI->end();
|
|
OpI != OpE; ++OpI) {
|
|
const Value *Op = *OpI;
|
|
|
|
if (isa<BasicBlock>(Op))
|
|
continue; // don't process labels
|
|
|
|
if (OpI.isUse()) { // add to Uses only if this operand is a use
|
|
//
|
|
// *** WARNING: The following code for handling dummy PHI machine
|
|
// instructions is untested. The previous code was broken and I
|
|
// fixed it, but it turned out to be unused as long as Phi
|
|
// elimination is performed during instruction selection.
|
|
//
|
|
// Put Phi operands in UseSet for the incoming edge, not node.
|
|
// They must not "hide" later defs, and must be handled specially
|
|
// during set propagation over the CFG.
|
|
if (MI->getOpcode() == V9::PHI) { // for a phi node
|
|
const Value *ArgVal = Op;
|
|
const BasicBlock *PredBB = cast<BasicBlock>(*++OpI); // next ptr is BB
|
|
|
|
PredToEdgeInSetMap[PredBB].insert(ArgVal);
|
|
|
|
if (DEBUG_LV >= LV_DEBUG_Verbose)
|
|
std::cerr << " - phi operand " << RAV(ArgVal) << " came from BB "
|
|
<< RAV(PredBB) << "\n";
|
|
} // if( IsPhi )
|
|
else {
|
|
// It is not a Phi use: add to regular use set and remove later defs.
|
|
addUse(Op);
|
|
}
|
|
} // if a use
|
|
} // for all operands
|
|
|
|
// do for implicit operands as well
|
|
for (unsigned i = 0; i < MI->getNumImplicitRefs(); ++i) {
|
|
assert(MI->getOpcode() != V9::PHI && "Phi cannot have implicit operands");
|
|
const Value *Op = MI->getImplicitRef(i);
|
|
|
|
if (Op->getType() == Type::LabelTy) // don't process labels
|
|
continue;
|
|
|
|
if (MI->getImplicitOp(i).isUse())
|
|
addUse(Op);
|
|
}
|
|
} // for all machine instructions
|
|
}
|
|
|
|
|
|
|
|
//-----------------------------------------------------------------------------
|
|
// To add an operand which is a def
|
|
//-----------------------------------------------------------------------------
|
|
void BBLiveVar::addDef(const Value *Op) {
|
|
DefSet.insert(Op); // operand is a def - so add to def set
|
|
InSet.erase(Op); // this definition kills any later uses
|
|
InSetChanged = true;
|
|
|
|
if (DEBUG_LV >= LV_DEBUG_Verbose) std::cerr << " +Def: " << RAV(Op) << "\n";
|
|
}
|
|
|
|
|
|
//-----------------------------------------------------------------------------
|
|
// To add an operand which is a use
|
|
//-----------------------------------------------------------------------------
|
|
void BBLiveVar::addUse(const Value *Op) {
|
|
InSet.insert(Op); // An operand is a use - so add to use set
|
|
DefSet.erase(Op); // remove if there is a def below this use
|
|
InSetChanged = true;
|
|
|
|
if (DEBUG_LV >= LV_DEBUG_Verbose) std::cerr << " Use: " << RAV(Op) << "\n";
|
|
}
|
|
|
|
|
|
//-----------------------------------------------------------------------------
|
|
// Applies the transfer function to a basic block to produce the InSet using
|
|
// the OutSet.
|
|
//-----------------------------------------------------------------------------
|
|
|
|
bool BBLiveVar::applyTransferFunc() {
|
|
// IMPORTANT: caller should check whether the OutSet changed
|
|
// (else no point in calling)
|
|
|
|
ValueSet OutMinusDef = set_difference(OutSet, DefSet);
|
|
InSetChanged = set_union(InSet, OutMinusDef);
|
|
|
|
OutSetChanged = false; // no change to OutSet since transf func applied
|
|
return InSetChanged;
|
|
}
|
|
|
|
|
|
//-----------------------------------------------------------------------------
|
|
// calculates Out set using In sets of the successors
|
|
//-----------------------------------------------------------------------------
|
|
|
|
bool BBLiveVar::setPropagate(ValueSet *OutSet, const ValueSet *InSet,
|
|
const BasicBlock *PredBB) {
|
|
bool Changed = false;
|
|
|
|
// merge all members of InSet into OutSet of the predecessor
|
|
for (ValueSet::const_iterator InIt = InSet->begin(), InE = InSet->end();
|
|
InIt != InE; ++InIt)
|
|
if ((OutSet->insert(*InIt)).second)
|
|
Changed = true;
|
|
|
|
//
|
|
//**** WARNING: The following code for handling dummy PHI machine
|
|
// instructions is untested. See explanation above.
|
|
//
|
|
// then merge all members of the EdgeInSet for the predecessor into the OutSet
|
|
const ValueSet& EdgeInSet = PredToEdgeInSetMap[PredBB];
|
|
for (ValueSet::const_iterator InIt = EdgeInSet.begin(), InE = EdgeInSet.end();
|
|
InIt != InE; ++InIt)
|
|
if ((OutSet->insert(*InIt)).second)
|
|
Changed = true;
|
|
//
|
|
//****
|
|
|
|
return Changed;
|
|
}
|
|
|
|
|
|
//-----------------------------------------------------------------------------
|
|
// propagates in set to OutSets of PREDECESSORs
|
|
//-----------------------------------------------------------------------------
|
|
|
|
bool BBLiveVar::applyFlowFunc(hash_map<const BasicBlock*,
|
|
BBLiveVar*> &BBLiveVarInfo) {
|
|
// IMPORTANT: caller should check whether inset changed
|
|
// (else no point in calling)
|
|
|
|
// If this BB changed any OutSets of preds whose POID is lower, than we need
|
|
// another iteration...
|
|
//
|
|
bool needAnotherIt = false;
|
|
|
|
for (pred_const_iterator PI = pred_begin(&BB), PE = pred_end(&BB);
|
|
PI != PE ; ++PI) {
|
|
BBLiveVar *PredLVBB = BBLiveVarInfo[*PI];
|
|
|
|
// do set union
|
|
if (setPropagate(&PredLVBB->OutSet, &InSet, *PI)) {
|
|
PredLVBB->OutSetChanged = true;
|
|
|
|
// if the predec POID is lower than mine
|
|
if (PredLVBB->getPOId() <= POID)
|
|
needAnotherIt = true;
|
|
}
|
|
} // for
|
|
|
|
return needAnotherIt;
|
|
}
|
|
|
|
|
|
|
|
// ----------------- Methods For Debugging (Printing) -----------------
|
|
|
|
void BBLiveVar::printAllSets() const {
|
|
std::cerr << " Defs: "; printSet(DefSet); std::cerr << "\n";
|
|
std::cerr << " In: "; printSet(InSet); std::cerr << "\n";
|
|
std::cerr << " Out: "; printSet(OutSet); std::cerr << "\n";
|
|
}
|
|
|
|
void BBLiveVar::printInOutSets() const {
|
|
std::cerr << " In: "; printSet(InSet); std::cerr << "\n";
|
|
std::cerr << " Out: "; printSet(OutSet); std::cerr << "\n";
|
|
}
|
|
|
|
} // End llvm namespace
|