Added code to PhyRegAlloc to mark unusable suggested regs

Added initialization to AdjList to IGNode constructor - major bug fix

llvm-svn: 920

2 files changed, 57 insertions, 6 deletions

diff --git a/llvm/lib/CodeGen/RegAlloc/IGNode.cpp b/llvm/lib/CodeGen/RegAlloc/IGNode.cpp
index 0e8a124cd3d..75007a0898b 100644
--- a/llvm/lib/CodeGen/RegAlloc/IGNode.cpp
+++ b/llvm/lib/CodeGen/RegAlloc/IGNode.cpp
@@ -2,6 +2,7 @@
 
 
 IGNode::IGNode(LiveRange *const PLR, unsigned int Ind): Index(Ind),
+							AdjList(),
                                                         ParentLR(PLR)
 {
   OnStack = false;
diff --git a/llvm/lib/CodeGen/RegAlloc/PhyRegAlloc.cpp b/llvm/lib/CodeGen/RegAlloc/PhyRegAlloc.cpp
index 98300499b15..b36e8e44437 100644
--- a/llvm/lib/CodeGen/RegAlloc/PhyRegAlloc.cpp
+++ b/llvm/lib/CodeGen/RegAlloc/PhyRegAlloc.cpp
@@ -665,11 +665,7 @@ void PhyRegAlloc::printMachineCode()
 	    // else it must be a register value
 	    const int RegNum = Op.getAllocatedRegNum();
 
-	    //if( RegNum != 1000)
-
-	      cout << "\t" << "%" << MRI.getUnifiedRegName( RegNum );
-	    // else cout << "\t<*NoReg*>";
-
+	    cout << "\t" << "%" << MRI.getUnifiedRegName( RegNum );
 	  }
 
 	} 
@@ -740,6 +736,8 @@ void PhyRegAlloc::colorCallRetArgs()
 
 }
 
+
+
 //----------------------------------------------------------------------------
 
 //----------------------------------------------------------------------------
@@ -772,6 +770,52 @@ void PhyRegAlloc::printLabel(const Value *const Val)
 
 
 //----------------------------------------------------------------------------
+// This method calls setSugColorUsable method of each live range. This
+// will determine whether the suggested color of LR is  really usable.
+// A suggested color is not usable when the suggested color is volatile
+// AND when there are call interferences
+//----------------------------------------------------------------------------
+
+void PhyRegAlloc::markUnusableSugColors()
+{
+  if(DEBUG_RA ) cout << "Creating LR lists ..." << endl;
+
+  // hash map iterator
+  LiveRangeMapType::const_iterator HMI = (LRI.getLiveRangeMap())->begin();   
+  LiveRangeMapType::const_iterator HMIEnd = (LRI.getLiveRangeMap())->end();   
+
+    for(  ; HMI != HMIEnd ; ++HMI ) {
+      
+      if( (*HMI).first ) { 
+
+	LiveRange *L = (*HMI).second;      // get the LiveRange
+
+	if(L) { 
+	  if( L->hasSuggestedColor() ) {
+
+	    int RCID = (L->getRegClass())->getID();
+	    if( MRI.isRegVolatile( RCID,  L->getSuggestedColor()) &&
+		L->isCallInterference() )
+	      L->setSuggestedColorUsable( false );
+	    else
+	      L->setSuggestedColorUsable( true );
+	  }
+	} // if L->hasSuggestedColor()
+      }
+    } // for all LR's in hash map
+}
+
+
+
+
+
+
+
+
+
+
+
+//----------------------------------------------------------------------------
 // The entry pont to Register Allocation
 //----------------------------------------------------------------------------
 
@@ -814,7 +858,13 @@ void PhyRegAlloc::allocateRegisters()
       RegClassList[ rc ]->printIG();       
   }
 
-  // color all register classes
+
+  // mark un-usable suggested color before graph coloring algorithm.
+  // When this is done, the graph coloring algo will not reserve
+  // suggested color unnecessarily - they can be used by another LR
+  markUnusableSugColors(); 
+
+  // color all register classes using the graph coloring algo
   for( unsigned int rc=0; rc < NumOfRegClasses ; rc++)  
     RegClassList[ rc ]->colorAllRegs();