Two coalescer fixes in one.
1. Use the same value# to represent unknown values being merged into sub-registers.
2. When coalescer commute an instruction and the destination is a physical register, update its sub-registers by merging in the extended ranges.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@66610 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/LiveInterval.cpp b/lib/CodeGen/LiveInterval.cpp
index 40f8cd4..75cd36d 100644
--- a/lib/CodeGen/LiveInterval.cpp
+++ b/lib/CodeGen/LiveInterval.cpp
@@ -551,6 +551,20 @@
}
}
+VNInfo *LiveInterval::getUnknownValNo(BumpPtrAllocator &VNInfoAllocator) {
+ unsigned i = getNumValNums();
+ if (i) {
+ do {
+ --i;
+ VNInfo *VNI = getValNumInfo(i);
+ if (VNI->def == ~0U && !VNI->copy &&
+ !VNI->hasPHIKill && !VNI->redefByEC && VNI->kills.empty())
+ return VNI;
+ } while (i != 0);
+ }
+ return getNextValue(~0U, 0, VNInfoAllocator);
+}
+
/// MergeInClobberRanges - For any live ranges that are not defined in the
/// current interval, but are defined in the Clobbers interval, mark them
@@ -561,8 +575,7 @@
// Find a value # to use for the clobber ranges. If there is already a value#
// for unknown values, use it.
- // FIXME: Use a single sentinal number for these!
- VNInfo *ClobberValNo = getNextValue(~0U, 0, VNInfoAllocator);
+ VNInfo *ClobberValNo = getUnknownValNo(VNInfoAllocator);
iterator IP = begin();
for (const_iterator I = Clobbers.begin(), E = Clobbers.end(); I != E; ++I) {
@@ -587,6 +600,32 @@
}
}
+void LiveInterval::MergeInClobberRange(unsigned Start, unsigned End,
+ BumpPtrAllocator &VNInfoAllocator) {
+ // Find a value # to use for the clobber ranges. If there is already a value#
+ // for unknown values, use it.
+ VNInfo *ClobberValNo = getUnknownValNo(VNInfoAllocator);
+
+ iterator IP = begin();
+ IP = std::upper_bound(IP, end(), Start);
+
+ // If the start of this range overlaps with an existing liverange, trim it.
+ if (IP != begin() && IP[-1].end > Start) {
+ Start = IP[-1].end;
+ // Trimmed away the whole range?
+ if (Start >= End) return;
+ }
+ // If the end of this range overlaps with an existing liverange, trim it.
+ if (IP != end() && End > IP->start) {
+ End = IP->start;
+ // If this trimmed away the whole range, ignore it.
+ if (Start == End) return;
+ }
+
+ // Insert the clobber interval.
+ addRangeFrom(LiveRange(Start, End, ClobberValNo), IP);
+}
+
/// MergeValueNumberInto - This method is called when two value nubmers
/// are found to be equivalent. This eliminates V1, replacing all
/// LiveRanges with the V1 value number with the V2 value number. This can
diff --git a/lib/CodeGen/SimpleRegisterCoalescing.cpp b/lib/CodeGen/SimpleRegisterCoalescing.cpp
index 942d8d9..c29ee62 100644
--- a/lib/CodeGen/SimpleRegisterCoalescing.cpp
+++ b/lib/CodeGen/SimpleRegisterCoalescing.cpp
@@ -193,13 +193,12 @@
IntB.addRange(LiveRange(FillerStart, FillerEnd, BValNo));
// If the IntB live range is assigned to a physical register, and if that
- // physreg has aliases,
+ // physreg has sub-registers, update their live intervals as well.
if (TargetRegisterInfo::isPhysicalRegister(IntB.reg)) {
- // Update the liveintervals of sub-registers.
- for (const unsigned *AS = tri_->getSubRegisters(IntB.reg); *AS; ++AS) {
- LiveInterval &AliasLI = li_->getInterval(*AS);
- AliasLI.addRange(LiveRange(FillerStart, FillerEnd,
- AliasLI.getNextValue(FillerStart, 0, li_->getVNInfoAllocator())));
+ for (const unsigned *SR = tri_->getSubRegisters(IntB.reg); *SR; ++SR) {
+ LiveInterval &SRLI = li_->getInterval(*SR);
+ SRLI.addRange(LiveRange(FillerStart, FillerEnd,
+ SRLI.getNextValue(FillerStart, 0, li_->getVNInfoAllocator())));
}
}
@@ -367,6 +366,9 @@
BExtend[ALR->end] = BLR->end;
// Update uses of IntA of the specific Val# with IntB.
+ bool BHasSubRegs = false;
+ if (TargetRegisterInfo::isPhysicalRegister(IntB.reg))
+ BHasSubRegs = *tri_->getSubRegisters(IntB.reg);
for (MachineRegisterInfo::use_iterator UI = mri_->use_begin(IntA.reg),
UE = mri_->use_end(); UI != UE;) {
MachineOperand &UseMO = UI.getOperand();
@@ -398,6 +400,9 @@
const LiveRange *DLR = IntB.getLiveRangeContaining(DefIdx);
BHasPHIKill |= DLR->valno->hasPHIKill;
assert(DLR->valno->def == DefIdx);
+ if (BHasSubRegs)
+ // Don't know how to update sub-register live intervals.
+ return false;
BDeadValNos.push_back(DLR->valno);
BExtend[DLR->start] = DLR->end;
JoinedCopies.insert(UseMI);
@@ -435,6 +440,15 @@
if (EI != BExtend.end())
End = EI->second;
IntB.addRange(LiveRange(AI->start, End, ValNo));
+
+ // If the IntB live range is assigned to a physical register, and if that
+ // physreg has sub-registers, update their live intervals as well.
+ if (TargetRegisterInfo::isPhysicalRegister(IntB.reg)) {
+ for (const unsigned *SR = tri_->getSubRegisters(IntB.reg); *SR; ++SR) {
+ LiveInterval &SRLI = li_->getInterval(*SR);
+ SRLI.MergeInClobberRange(AI->start, End, li_->getVNInfoAllocator());
+ }
+ }
}
IntB.addKills(ValNo, BKills);
ValNo->hasPHIKill = BHasPHIKill;