Added destructors and comments.
Added correct spill candidate selection logic.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@1493 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/RegAlloc/LiveRangeInfo.cpp b/lib/CodeGen/RegAlloc/LiveRangeInfo.cpp
index 00385d9..7fb688f 100644
--- a/lib/CodeGen/RegAlloc/LiveRangeInfo.cpp
+++ b/lib/CodeGen/RegAlloc/LiveRangeInfo.cpp
@@ -1,5 +1,8 @@
#include "llvm/CodeGen/LiveRangeInfo.h"
+//---------------------------------------------------------------------------
+// Constructor
+//---------------------------------------------------------------------------
LiveRangeInfo::LiveRangeInfo(const Method *const M,
const TargetMachine& tm,
vector<RegClass *> &RCL)
@@ -10,22 +13,58 @@
{ }
+//---------------------------------------------------------------------------
+// Destructor: Deletes all LiveRanges in the LiveRangeMap
+//---------------------------------------------------------------------------
+LiveRangeInfo::~LiveRangeInfo() {
+
+ LiveRangeMapType::iterator MI = LiveRangeMap.begin();
+
+ for( ; MI != LiveRangeMap.end() ; ++MI) {
+ if( (*MI).first ) {
+
+ LiveRange *LR = (*MI).second;
+
+ if( LR ) {
+
+ // we need to be careful in deleting LiveRanges in LiveRangeMap
+ // since two/more Values in the live range map can point to the same
+ // live range. We have to make the other entries NULL when we delete
+ // a live range.
+
+ LiveRange::iterator LI = LR->begin();
+
+ for( ; LI != LR->end() ; ++LI) {
+ LiveRangeMap[*LI] = NULL;
+ }
+
+ delete LR;
+
+ }
+ }
+ }
+
+}
+
+
+//---------------------------------------------------------------------------
// union two live ranges into one. The 2nd LR is deleted. Used for coalescing.
// Note: the caller must make sure that L1 and L2 are distinct and both
// LRs don't have suggested colors
-
+//---------------------------------------------------------------------------
void LiveRangeInfo::unionAndUpdateLRs(LiveRange *const L1, LiveRange *L2)
{
assert( L1 != L2);
- L1->setUnion( L2 ); // add elements of L2 to L1
+ L1->setUnion( L2 ); // add elements of L2 to L1
ValueSet::iterator L2It;
for( L2It = L2->begin() ; L2It != L2->end(); ++L2It) {
//assert(( L1->getTypeID() == L2->getTypeID()) && "Merge:Different types");
- L1->add( *L2It ); // add the var in L2 to L1
- LiveRangeMap[ *L2It ] = L1; // now the elements in L2 should map to L1
+ L1->add( *L2It ); // add the var in L2 to L1
+ LiveRangeMap[ *L2It ] = L1; // now the elements in L2 should map
+ //to L1
}
@@ -40,13 +79,19 @@
if( L2->isCallInterference() )
L1->setCallInterference();
+
+ L1->addSpillCost( L2->getSpillCost() ); // add the spill costs
- delete ( L2 ); // delete L2 as it is no longer needed
+ delete ( L2 ); // delete L2 as it is no longer needed
}
-
+//---------------------------------------------------------------------------
+// Method for constructing all live ranges in a method. It creates live
+// ranges for all values defined in the instruction stream. Also, it
+// creates live ranges for all incoming arguments of the method.
+//---------------------------------------------------------------------------
void LiveRangeInfo::constructLiveRanges()
{
@@ -216,10 +261,14 @@
}
-
-// Suggest colors for call and return args.
-// Also create new LRs for implicit defs
-
+//---------------------------------------------------------------------------
+// If some live ranges must be colored with specific hardware registers
+// (e.g., for outgoing call args), suggesting of colors for such live
+// ranges is done using target specific method. Those methods are called
+// from this function. The target specific methods must:
+// 1) suggest colors for call and return args.
+// 2) create new LRs for implicit defs in machine instructions
+//---------------------------------------------------------------------------
void LiveRangeInfo::suggestRegs4CallRets()
{
@@ -243,11 +292,11 @@
}
+//--------------------------------------------------------------------------
+// The following method coalesces live ranges when possible. This method
+// must be called after the interference graph has been constructed.
-void LiveRangeInfo::coalesceLRs()
-{
-
/* Algorithm:
for each BB in method
for each machine instruction (inst)
@@ -260,6 +309,11 @@
merge2IGNodes(def, op) // i.e., merge 2 LRs
*/
+//---------------------------------------------------------------------------
+void LiveRangeInfo::coalesceLRs()
+{
+
+
if( DEBUG_RA)
cout << endl << "Coalscing LRs ..." << endl;