From 9942ba9c0ed45c77298cdeb7a9326f04745d5709 Mon Sep 17 00:00:00 2001
From: Jakob Stoklund Olesen <stoklund@2pi.dk>
Date: Thu, 11 Aug 2011 21:18:34 +0000
Subject: [PATCH] Remove more dead code.

collectInterferingVRegs will be the primary function for interference
checks.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@137354 91177308-0d34-0410-b5e6-96231b3b80d8
---
 lib/CodeGen/LiveIntervalUnion.cpp | 28 ++--------------------------
 lib/CodeGen/LiveIntervalUnion.h   | 12 +-----------
 2 files changed, 3 insertions(+), 37 deletions(-)

diff --git a/lib/CodeGen/LiveIntervalUnion.cpp b/lib/CodeGen/LiveIntervalUnion.cpp
index b30e169ee0f..cf5fb6a09f1 100644
--- a/lib/CodeGen/LiveIntervalUnion.cpp
+++ b/lib/CodeGen/LiveIntervalUnion.cpp
@@ -181,32 +181,6 @@ LiveIntervalUnion::Query::firstInterference() {
   return FirstInterference;
 }
 
-// Treat the result as an iterator and advance to the next interfering pair
-// of segments. This is a plain iterator with no filter.
-bool LiveIntervalUnion::Query::nextInterference(InterferenceResult &IR) const {
-  assert(isInterference(IR) && "iteration past end of interferences");
-
-  // Advance either the VirtReg or LiveUnion segment to ensure that we visit all
-  // unique overlapping pairs.
-  if (IR.VirtRegI->end < IR.LiveUnionI.stop()) {
-    if (++IR.VirtRegI == VirtReg->end())
-      return false;
-  }
-  else {
-    if (!(++IR.LiveUnionI).valid()) {
-      IR.VirtRegI = VirtReg->end();
-      return false;
-    }
-  }
-  // Short-circuit findIntersection() if possible.
-  if (overlap(*IR.VirtRegI, IR.LiveUnionI))
-    return true;
-
-  // Find the next intersection.
-  findIntersection(IR);
-  return isInterference(IR);
-}
-
 // Scan the vector of interfering virtual registers in this union. Assume it's
 // quite small.
 bool LiveIntervalUnion::Query::isSeenInterference(LiveInterval *VirtReg) const {
@@ -226,6 +200,8 @@ bool LiveIntervalUnion::Query::isSeenInterference(LiveInterval *VirtReg) const {
 // For comments on how to speed it up, see Query::findIntersection().
 unsigned LiveIntervalUnion::Query::
 collectInterferingVRegs(unsigned MaxInterferingRegs) {
+  if (InterferingVRegs.size() >= MaxInterferingRegs)
+    return InterferingVRegs.size();
   InterferenceResult IR = firstInterference();
   LiveInterval::iterator VirtRegEnd = VirtReg->end();
   LiveInterval *RecentInterferingVReg = NULL;
diff --git a/lib/CodeGen/LiveIntervalUnion.h b/lib/CodeGen/LiveIntervalUnion.h
index 7f494474f99..570ad94b77e 100644
--- a/lib/CodeGen/LiveIntervalUnion.h
+++ b/lib/CodeGen/LiveIntervalUnion.h
@@ -188,7 +188,7 @@ public:
     }
 
     // Does this live virtual register interfere with the union?
-    bool checkInterference() { return isInterference(firstInterference()); }
+    bool checkInterference() { return collectInterferingVRegs(1); }
 
     // Count the virtual registers in this union that interfere with this
     // query's live virtual register, up to maxInterferingRegs.
@@ -218,17 +218,7 @@ public:
 
     // Private interface for queries
     const InterferenceResult &firstInterference();
-    bool nextInterference(InterferenceResult &IR) const;
     void findIntersection(InterferenceResult &IR) const;
-
-    bool isInterference(const InterferenceResult &IR) const {
-      if (IR.VirtRegI != VirtReg->end()) {
-        assert(overlap(*IR.VirtRegI, IR.LiveUnionI) &&
-               "invalid segment iterators");
-        return true;
-      }
-      return false;
-    }
   };
 };