6502/llvm-6502
1
0
Fork 0
mirror of https://github.com/c64scene-ar/llvm-6502.git synced 2025-01-21 19:32:16 +00:00
Code Issues Projects Releases Wiki Activity

Correctly construct live intervals for the copies we inserted into the predecessors of a block containing a PHI.

Browse Source 
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@51950 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Owen Anderson 2008-06-04 17:55:58 +00:00
parent 7a315e865a
commit 38b425020b
1 changed files with 38 additions and 1 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

39
lib/CodeGen/StrongPHIElimination.cpp
View File

@ -467,6 +467,8 @@ void StrongPHIElimination::processBlock(MachineBasicBlock* MBB) {
} else {
// Otherwise, add it to the renaming set
LiveInterval& I = LI.getOrCreateInterval(SrcReg);
// We need to subtract one from the index because live ranges are open
// at the end.
unsigned idx = LI.getMBBEndIdx(P->getOperand(i).getMBB()) - 1;
VNInfo* VN = I.getLiveRangeContaining(idx)->valno;
@ -632,7 +634,7 @@ void StrongPHIElimination::processPHIUnion(MachineInstr* Inst,
/// of Static Single Assignment Form" by Briggs, et al.
void StrongPHIElimination::ScheduleCopies(MachineBasicBlock* MBB,
std::set<unsigned>& pushed) {
// FIXME: This function needs to update LiveVariables
// FIXME: This function needs to update LiveIntervals
std::map<unsigned, unsigned>& copy_set= Waiting[MBB];
std::map<unsigned, unsigned> worklist;
@ -661,6 +663,8 @@ void StrongPHIElimination::ScheduleCopies(MachineBasicBlock* MBB,
MachineRegisterInfo& MRI = MF->getRegInfo();
const TargetInstrInfo *TII = MF->getTarget().getInstrInfo();
SmallVector<std::pair<unsigned, MachineInstr*>, 4> InsertedPHIDests;
// Iterate over the worklist, inserting copies
while (!worklist.empty() || !copy_set.empty()) {
while (!worklist.empty()) {
@ -691,6 +695,11 @@ void StrongPHIElimination::ScheduleCopies(MachineBasicBlock* MBB,
map[curr.first], RC, RC);
map[curr.first] = curr.second;
// Push this copy onto InsertedPHICopies so we can
// update LiveIntervals with it.
MachineBasicBlock::iterator MI = MBB->getFirstTerminator();
InsertedPHIDests.push_back(std::make_pair(curr.second, --MI));
// If curr.first is a destination in copy_set...
for (std::map<unsigned, unsigned>::iterator I = copy_set.begin(),
E = copy_set.end(); I != E; )
@ -723,6 +732,34 @@ void StrongPHIElimination::ScheduleCopies(MachineBasicBlock* MBB,
worklist.insert(curr);
}
}
// Renumber the instructions so that we can perform the index computations
// needed to create new live intervals.
LI.computeNumbering();
// For copies that we inserted at the ends of predecessors, we construct
// live intervals. This is pretty easy, since we know that the destination
// register cannot have be in live at that point previously. We just have
// to make sure that, for registers that serve as inputs to more than one
// PHI, we don't create multiple overlapping live intervals.
std::set<unsigned> RegHandled;
for (SmallVector<std::pair<unsigned, MachineInstr*>, 4>::iterator I =
InsertedPHIDests.begin(), E = InsertedPHIDests.end(); I != E; ++I) {
if (!RegHandled.count(I->first)) {
LiveInterval& Interval = LI.getOrCreateInterval(I->first);
VNInfo* VN = Interval.getNextValue(
LI.getInstructionIndex(I->second) + LiveIntervals::InstrSlots::DEF,
I->second, LI.getVNInfoAllocator());
VN->hasPHIKill = true;
VN->kills.push_back(LI.getMBBEndIdx(I->second->getParent()));
LiveRange LR(LI.getInstructionIndex(I->second) +
LiveIntervals::InstrSlots::DEF,
LI.getMBBEndIdx(I->second->getParent()) + 1, VN);
Interval.addRange(LR);
RegHandled.insert(I->first);
}
}
}
/// InsertCopies - insert copies into MBB and all of its successors