Allocate the contents of DwarfDebug's StringMaps in a single big BumpPtrAllocator.

[oota-llvm.git] / lib / CodeGen / LiveRangeEdit.cpp

diff --git a/lib/CodeGen/LiveRangeEdit.cpp b/lib/CodeGen/LiveRangeEdit.cpp
index 0c679c8215938baa6e3440be067894373d8cd596..434388b94efee9997d6eb4d2347ab96a2c619a5d 100644 (file)
--- a/lib/CodeGen/LiveRangeEdit.cpp
+++ b/lib/CodeGen/LiveRangeEdit.cpp
@@ -54,8 +54,8 @@ bool LiveRangeEdit::checkRematerializable(VNInfo *VNI,
 }
 
 void LiveRangeEdit::scanRemattable(AliasAnalysis *aa) {
-  for (LiveInterval::vni_iterator I = Parent.vni_begin(),
-       E = Parent.vni_end(); I != E; ++I) {
+  for (LiveInterval::vni_iterator I = getParent().vni_begin(),
+       E = getParent().vni_end(); I != E; ++I) {
     VNInfo *VNI = *I;
     if (VNI->isUnused())
       continue;
@@ -220,6 +220,9 @@ void LiveRangeEdit::eliminateDeadDefs(SmallVectorImpl<MachineInstr*> &Dead,
 
       DEBUG(dbgs() << "Deleting dead def " << Idx << '\t' << *MI);
 
+      // Collect virtual registers to be erased after MI is gone.
+      SmallVector<unsigned, 8> RegsToErase;
+
       // Check for live intervals that may shrink
       for (MachineInstr::mop_iterator MOI = MI->operands_begin(),
              MOE = MI->operands_end(); MOI != MOE; ++MOI) {
@@ -245,10 +248,8 @@ void LiveRangeEdit::eliminateDeadDefs(SmallVectorImpl<MachineInstr*> &Dead,
             if (TheDelegate)
               TheDelegate->LRE_WillShrinkVirtReg(LI.reg);
             LI.removeValNo(VNI);
-            if (LI.empty()) {
-              ToShrink.remove(&LI);
-              eraseVirtReg(Reg);
-            }
+            if (LI.empty())
+              RegsToErase.push_back(Reg);
           }
         }
       }
@@ -258,6 +259,16 @@ void LiveRangeEdit::eliminateDeadDefs(SmallVectorImpl<MachineInstr*> &Dead,
       LIS.RemoveMachineInstrFromMaps(MI);
       MI->eraseFromParent();
       ++NumDCEDeleted;
+
+      // Erase any virtregs that are now empty and unused. There may be <undef>
+      // uses around. Keep the empty live range in that case.
+      for (unsigned i = 0, e = RegsToErase.size(); i != e; ++i) {
+        unsigned Reg = RegsToErase[i];
+        if (LIS.hasInterval(Reg) && MRI.reg_nodbg_empty(Reg)) {
+          ToShrink.remove(&LIS.getInterval(Reg));
+          eraseVirtReg(Reg);
+        }
+      }
     }
 
     if (ToShrink.empty())
@@ -308,6 +319,10 @@ void LiveRangeEdit::eliminateDeadDefs(SmallVectorImpl<MachineInstr*> &Dead,
         TheDelegate->LRE_DidCloneVirtReg(Dups.back()->reg, LI->reg);
     }
     ConEQ.Distribute(&Dups[0], MRI);
+    DEBUG({
+      for (unsigned i = 0; i != NumComp; ++i)
+        dbgs() << '\t' << *Dups[i] << '\n';
+    });
   }
 }