RegisterPressure: Unify the sparse sets in LiveRegsSet; NFC

Also do some cleanups comment improvements.

llvm-svn: 250598

1 files changed, 19 insertions, 12 deletions

diff --git a/llvm/lib/CodeGen/RegisterPressure.cpp b/llvm/lib/CodeGen/RegisterPressure.cpp
index 8172c558ac7..2ef23c7541d 100644
--- a/llvm/lib/CodeGen/RegisterPressure.cpp
+++ b/llvm/lib/CodeGen/RegisterPressure.cpp
@@ -157,6 +157,18 @@ void RegionPressure::openBottom(MachineBasicBlock::const_iterator PrevBottom) {
   LiveInRegs.clear();
 }
 
+void LiveRegSet::init(const MachineRegisterInfo &MRI) {
+  const TargetRegisterInfo &TRI = *MRI.getTargetRegisterInfo();
+  unsigned NumRegUnits = TRI.getNumRegs();
+  unsigned NumVirtRegs = MRI.getNumVirtRegs();
+  Regs.setUniverse(NumRegUnits + NumVirtRegs);
+  this->NumRegUnits = NumRegUnits;
+}
+
+void LiveRegSet::clear() {
+  Regs.clear();
+}
+
 const LiveRange *RegPressureTracker::getLiveRange(unsigned Reg) const {
   if (TargetRegisterInfo::isVirtualRegister(Reg))
     return &LIS->getInterval(Reg);
@@ -176,8 +188,7 @@ void RegPressureTracker::reset() {
   else
     static_cast<RegionPressure&>(P).reset();
 
-  LiveRegs.PhysRegs.clear();
-  LiveRegs.VirtRegs.clear();
+  LiveRegs.clear();
   UntiedDefs.clear();
 }
 
@@ -210,8 +221,7 @@ void RegPressureTracker::init(const MachineFunction *mf,
 
   P.MaxSetPressure = CurrSetPressure;
 
-  LiveRegs.PhysRegs.setUniverse(TRI->getNumRegUnits());
-  LiveRegs.VirtRegs.setUniverse(MRI->getNumVirtRegs());
+  LiveRegs.init(*MRI);
   if (TrackUntiedDefs)
     UntiedDefs.setUniverse(MRI->getNumVirtRegs());
 }
@@ -250,9 +260,8 @@ void RegPressureTracker::closeTop() {
     static_cast<RegionPressure&>(P).TopPos = CurrPos;
 
   assert(P.LiveInRegs.empty() && "inconsistent max pressure result");
-  P.LiveInRegs.reserve(LiveRegs.PhysRegs.size() + LiveRegs.VirtRegs.size());
-  P.LiveInRegs.append(LiveRegs.PhysRegs.begin(), LiveRegs.PhysRegs.end());
-  P.LiveInRegs.append(LiveRegs.VirtRegs.begin(), LiveRegs.VirtRegs.end());
+  P.LiveInRegs.reserve(LiveRegs.size());
+  LiveRegs.appendTo(P.LiveInRegs);
 }
 
 /// Set the boundary for the bottom of the region and summarize live outs.
@@ -263,16 +272,14 @@ void RegPressureTracker::closeBottom() {
     static_cast<RegionPressure&>(P).BottomPos = CurrPos;
 
   assert(P.LiveOutRegs.empty() && "inconsistent max pressure result");
-  P.LiveOutRegs.reserve(LiveRegs.PhysRegs.size() + LiveRegs.VirtRegs.size());
-  P.LiveOutRegs.append(LiveRegs.PhysRegs.begin(), LiveRegs.PhysRegs.end());
-  P.LiveOutRegs.append(LiveRegs.VirtRegs.begin(), LiveRegs.VirtRegs.end());
+  P.LiveOutRegs.reserve(LiveRegs.size());
+  LiveRegs.appendTo(P.LiveOutRegs);
 }
 
 /// Finalize the region boundaries and record live ins and live outs.
 void RegPressureTracker::closeRegion() {
   if (!isTopClosed() && !isBottomClosed()) {
-    assert(LiveRegs.PhysRegs.empty() && LiveRegs.VirtRegs.empty() &&
-           "no region boundary");
+    assert(LiveRegs.size() == 0 && "no region boundary");
     return;
   }
   if (!isBottomClosed())