[llvm-commits] [llvm] r139780 - in /llvm/trunk: include/llvm/CodeGen/LiveInterval.h lib/CodeGen/LiveInterval.cpp

[Jakob Stoklund Olesen]

Author: stoklund
Date: Wed Sep 14 23:37:18 2011
New Revision: 139780

URL: http://llvm.org/viewvc/llvm-project?rev=139780&view=rev
Log:
Leave hasPHIKill flags alone in LiveInterval::RenumberValues.

It is conservatively correct to keep the hasPHIKill flags, even after
deleting PHI-defs.

The calculation can be very expensive after taildup has created a
quadratic number of indirectbr edges in the CFG, and the hasPHIKill flag
isn't used for anything after RenumberValues().

Modified:
    llvm/trunk/include/llvm/CodeGen/LiveInterval.h
    llvm/trunk/lib/CodeGen/LiveInterval.cpp

Modified: llvm/trunk/include/llvm/CodeGen/LiveInterval.h
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/include/llvm/CodeGen/LiveInterval.h?rev=139780&r1=139779&r2=139780&view=diff
==============================================================================
--- llvm/trunk/include/llvm/CodeGen/LiveInterval.h (original)
+++ llvm/trunk/include/llvm/CodeGen/LiveInterval.h Wed Sep 14 23:37:18 2011
@@ -313,7 +313,6 @@
 
     /// RenumberValues - Renumber all values in order of appearance and remove
     /// unused values.
-    /// Recalculate phi-kill flags in case any phi-def values were removed.
     void RenumberValues(LiveIntervals &lis);
 
     /// isOnlyLROfValNo - Return true if the specified live range is the only

Modified: llvm/trunk/lib/CodeGen/LiveInterval.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/CodeGen/LiveInterval.cpp?rev=139780&r1=139779&r2=139780&view=diff
==============================================================================
--- llvm/trunk/lib/CodeGen/LiveInterval.cpp (original)
+++ llvm/trunk/lib/CodeGen/LiveInterval.cpp Wed Sep 14 23:37:18 2011
@@ -148,7 +148,6 @@
 /// remaining unused values.
 void LiveInterval::RenumberValues(LiveIntervals &lis) {
   SmallPtrSet<VNInfo*, 8> Seen;
-  bool seenPHIDef = false;
   valnos.clear();
   for (const_iterator I = begin(), E = end(); I != E; ++I) {
     VNInfo *VNI = I->valno;
@@ -157,26 +156,6 @@
     assert(!VNI->isUnused() && "Unused valno used by live range");
     VNI->id = (unsigned)valnos.size();
     valnos.push_back(VNI);
-    VNI->setHasPHIKill(false);
-    if (VNI->isPHIDef())
-      seenPHIDef = true;
-  }
-
-  // Recompute phi kill flags.
-  if (!seenPHIDef)
-    return;
-  for (const_vni_iterator I = vni_begin(), E = vni_end(); I != E; ++I) {
-    VNInfo *VNI = *I;
-    if (!VNI->isPHIDef())
-      continue;
-    const MachineBasicBlock *PHIBB = lis.getMBBFromIndex(VNI->def);
-    assert(PHIBB && "No basic block for phi-def");
-    for (MachineBasicBlock::const_pred_iterator PI = PHIBB->pred_begin(),
-         PE = PHIBB->pred_end(); PI != PE; ++PI) {
-      VNInfo *KVNI = getVNInfoAt(lis.getMBBEndIdx(*PI).getPrevSlot());
-      if (KVNI)
-        KVNI->setHasPHIKill(true);
-    }
   }
 }