From: Jakob Stoklund Olesen <stoklund@2pi.dk>
Date: Thu, 3 Mar 2011 06:29:01 +0000 (+0000)
Subject: Renumber slot indexes uniformly instead of spacing according to the number of defs.
X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=2c11eb333c37edd5b15c1d05394861fdfc0eab90;p=oota-llvm.git

Renumber slot indexes uniformly instead of spacing according to the number of defs.

There are probably much larger speedups to be had by renumbering locally instead
of looping over the whole function. For now, the greedy register allocator is
25% faster.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@126926 91177308-0d34-0410-b5e6-96231b3b80d8
---

diff --git a/lib/CodeGen/SlotIndexes.cpp b/lib/CodeGen/SlotIndexes.cpp
index f18854be856..73adb92101d 100644
--- a/lib/CodeGen/SlotIndexes.cpp
+++ b/lib/CodeGen/SlotIndexes.cpp
@@ -129,26 +129,12 @@ void SlotIndexes::renumberIndexes() {
   // had been present.
   DEBUG(dbgs() << "\n*** Renumbering SlotIndexes ***\n");
 
-  functionSize = 0;
   unsigned index = 0;
 
   for (IndexListEntry *curEntry = front(); curEntry != getTail();
        curEntry = curEntry->getNext()) {
-
     curEntry->setIndex(index);
-
-    if (curEntry->getInstr() == 0) {
-      // MBB start entry. Just step index by 1.
-      index += SlotIndex::NUM;
-    }
-    else {
-      ++functionSize;
-      unsigned Slots = curEntry->getInstr()->getDesc().getNumDefs();
-      if (Slots == 0)
-        Slots = 1;
-
-      index += (Slots + 1) * SlotIndex::NUM;
-    }
+    index += 4*SlotIndex::NUM;
   }
 }