6502/llvm-6502
1
0
Fork 0
mirror of https://github.com/c64scene-ar/llvm-6502.git synced 2025-06-12 13:38:21 +00:00
Code Issues Projects Releases Wiki Activity

Also compute MBB live-in lists in the new rewriter pass.

Browse Source 
This deduplicates some code from the optimizing register allocators, and
it means that it is now possible to change the register allocators'
solutions simply by editing the VirtRegMap between the register
allocator pass and the rewriter.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@158249 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Jakob Stoklund Olesen
2012-06-09 00:14:47 +00:00
parent 77592fe39c
commit fe17bdbb50
6 changed files with 32 additions and 89 deletions
Download Patch File Download Diff File Expand all files Collapse all files

32
lib/CodeGen/VirtRegMap.cpp
View File

@ -203,6 +203,9 @@ bool VirtRegRewriter::runOnMachineFunction(MachineFunction &fn) {
// Add kill flags while we still have virtual registers.
LIS->addKillFlags();
// Live-in lists on basic blocks are required for physregs.
addMBBLiveIns();
// Rewrite virtual registers.
rewrite();
@ -216,6 +219,35 @@ bool VirtRegRewriter::runOnMachineFunction(MachineFunction &fn) {
return true;
}
// Compute MBB live-in lists from virtual register live ranges and their
// assignments.
void VirtRegRewriter::addMBBLiveIns() {
SmallVector<MachineBasicBlock*, 16> LiveIn;
for (unsigned Idx = 0, IdxE = MRI->getNumVirtRegs(); Idx != IdxE; ++Idx) {
unsigned VirtReg = TargetRegisterInfo::index2VirtReg(Idx);
if (MRI->reg_nodbg_empty(VirtReg))
continue;
LiveInterval &LI = LIS->getInterval(VirtReg);
if (LI.empty() || LIS->intervalIsInOneMBB(LI))
continue;
// This is a virtual register that is live across basic blocks. Its
// assigned PhysReg must be marked as live-in to those blocks.
unsigned PhysReg = VRM->getPhys(VirtReg);
assert(PhysReg != VirtRegMap::NO_PHYS_REG && "Unmapped virtual register.");
// Scan the segments of LI.
for (LiveInterval::const_iterator I = LI.begin(), E = LI.end(); I != E;
++I) {
if (!Indexes->findLiveInMBBs(I->start, I->end, LiveIn))
continue;
for (unsigned i = 0, e = LiveIn.size(); i != e; ++i)
if (!LiveIn[i]->isLiveIn(PhysReg))
LiveIn[i]->addLiveIn(PhysReg);
LiveIn.clear();
}
}
}
void VirtRegRewriter::rewrite() {
SmallVector<unsigned, 8> SuperDeads;
SmallVector<unsigned, 8> SuperDefs;