Number SlotIndexes uniformly without looking at the number of defs on each instruction.

You can't really predict how many indexes will be needed from the number of
defs, so let's keep it simple.

Also remove an extra empty index that was inserted after each basic block. It
was intended for live-out ranges, but it was never used that way.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@127014 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/lib/CodeGen/SlotIndexes.cpp b/lib/CodeGen/SlotIndexes.cpp
index a495d1fd832cbd05cdda55e3a0276c96e2bfb528..28e3fb5c159d1d1c288891ab307af1bf8dcf2c59 100644 (file)
--- a/lib/CodeGen/SlotIndexes.cpp
+++ b/lib/CodeGen/SlotIndexes.cpp
@@ -75,8 +75,6 @@ bool SlotIndexes::runOnMachineFunction(MachineFunction &fn) {
     // Insert an index for the MBB start.
     SlotIndex blockStartIndex(back(), SlotIndex::LOAD);
 
-    index += SlotIndex::NUM;
-
     for (MachineBasicBlock::iterator miItr = mbb->begin(), miEnd = mbb->end();
          miItr != miEnd; ++miItr) {
       MachineInstr *mi = miItr;
@@ -84,27 +82,16 @@ bool SlotIndexes::runOnMachineFunction(MachineFunction &fn) {
         continue;
 
       // Insert a store index for the instr.
-      push_back(createEntry(mi, index));
+      push_back(createEntry(mi, index += SlotIndex::InstrDist));
 
       // Save this base index in the maps.
-      mi2iMap.insert(
-        std::make_pair(mi, SlotIndex(back(), SlotIndex::LOAD)));
+      mi2iMap.insert(std::make_pair(mi, SlotIndex(back(), SlotIndex::LOAD)));
  
       ++functionSize;
-
-      unsigned Slots = mi->getDesc().getNumDefs();
-      if (Slots == 0)
-        Slots = 1;
-
-      index += (Slots + 1) * SlotIndex::NUM;
     }
 
-    // We insert two blank instructions between basic blocks.
-    // One to represent live-out registers and one to represent live-ins.
-    push_back(createEntry(0, index));
-    index += SlotIndex::NUM;
-
-    push_back(createEntry(0, index));
+    // We insert one blank instructions between basic blocks.
+    push_back(createEntry(0, index += SlotIndex::InstrDist));
 
     SlotIndex blockEndIndex(back(), SlotIndex::LOAD);
     mbb2IdxMap.insert(
@@ -123,13 +110,7 @@ bool SlotIndexes::runOnMachineFunction(MachineFunction &fn) {
 }
 
 void SlotIndexes::renumberIndexes() {
-
   // Renumber updates the index of every element of the index list.
-  // If all instrs in the function have been allocated an index (which has been
-  // placed in the index list in the order of instruction iteration) then the
-  // resulting numbering will match what would have been generated by the
-  // pass during the initial numbering of the function if the new instructions
-  // had been present.
   DEBUG(dbgs() << "\n*** Renumbering SlotIndexes ***\n");
   ++NumRenumPasses;
 
@@ -138,7 +119,7 @@ void SlotIndexes::renumberIndexes() {
   for (IndexListEntry *curEntry = front(); curEntry != getTail();
        curEntry = curEntry->getNext()) {
     curEntry->setIndex(index);
-    index += 4*SlotIndex::NUM;
+    index += SlotIndex::InstrDist;
   }
 }