From a857fe115b9f4d64b17dee48664dad364dd23a18 Mon Sep 17 00:00:00 2001
From: Benjamin Kramer <benny.kra@googlemail.com>
Date: Fri, 7 Jun 2013 16:13:49 +0000
Subject: [PATCH] R600: Fix a potential iterator invalidation issue.

As a bonus this reduces the loop from O(n^2) to O(n).

llvm-svn: 183532
---
 llvm/lib/Target/R600/R600OptimizeVectorRegisters.cpp | 8 +++-----
 1 file changed, 3 insertions(+), 5 deletions(-)

diff --git a/llvm/lib/Target/R600/R600OptimizeVectorRegisters.cpp b/llvm/lib/Target/R600/R600OptimizeVectorRegisters.cpp
index 9d237bb7a049..0c123a101e7b 100644
--- a/llvm/lib/Target/R600/R600OptimizeVectorRegisters.cpp
+++ b/llvm/lib/Target/R600/R600OptimizeVectorRegisters.cpp
@@ -198,11 +198,9 @@ MachineInstr *R600VectorRegMerger::RebuildVector(
         .addReg(SubReg)
         .addImm(Chan);
     UpdatedRegToChan[SubReg] = Chan;
-    for (std::vector<unsigned>::iterator RemoveIt = UpdatedUndef.begin(),
-        RemoveE = UpdatedUndef.end(); RemoveIt != RemoveE; ++ RemoveIt) {
-      if (*RemoveIt == Chan)
-        UpdatedUndef.erase(RemoveIt);
-    }
+    UpdatedUndef.erase(
+        std::remove(UpdatedUndef.begin(), UpdatedUndef.end(), Chan),
+        UpdatedUndef.end());
     DEBUG(dbgs() << "    ->"; Tmp->dump(););
     (void)Tmp;
     SrcVec = DstReg;