Prep for merging 3.4: Undo changes from 3.3 branch

lib/Transforms/Scalar/CodeGenPrepare.cpp

 //===- CodeGenPrepare.cpp - Prepare a function for code generation --------===//
 //
 //                     The LLVM Compiler Infrastructure
 //
 // This file is distributed under the University of Illinois Open Source
 // License. See LICENSE.TXT for details.
 //
 //===----------------------------------------------------------------------===//
 //
 // This pass munges the code in the input function to better prepare it for
 // SelectionDAG-based code generation. This works around limitations in it's
 // basic-block-at-a-time approach. It should eventually be removed.
 //
 //===----------------------------------------------------------------------===//
 
 #define DEBUG_TYPE "codegenprepare"
 #include "llvm/Transforms/Scalar.h"
 #include "llvm/ADT/DenseMap.h"
 #include "llvm/ADT/SmallSet.h"
 #include "llvm/ADT/Statistic.h"
-#include "llvm/ADT/ValueMap.h"
 #include "llvm/Analysis/DominatorInternals.h"
 #include "llvm/Analysis/Dominators.h"
 #include "llvm/Analysis/InstructionSimplify.h"
 #include "llvm/Analysis/ProfileInfo.h"
 #include "llvm/Assembly/Writer.h"
 #include "llvm/IR/Constants.h"
 #include "llvm/IR/DataLayout.h"
 #include "llvm/IR/DerivedTypes.h"
 #include "llvm/IR/Function.h"
 #include "llvm/IR/IRBuilder.h"
@@ skipping 50 matching lines @@
     ProfileInfo *PFI;
 
     /// CurInstIterator - As we scan instructions optimizing them, this is the
     /// next instruction to optimize.  Xforms that can invalidate this should
     /// update it.
     BasicBlock::iterator CurInstIterator;
 
     /// Keeps track of non-local addresses that have been sunk into a block.
     /// This allows us to avoid inserting duplicate code for blocks with
     /// multiple load/stores of the same address.
-    ValueMap<Value*, Value*> SunkAddrs;
+    DenseMap<Value*, Value*> SunkAddrs;
 
     /// ModifiedDT - If CFG is modified in anyway, dominator tree may need to
     /// be updated.
     bool ModifiedDT;
 
     /// OptSize - True if optimizing for size.
     bool OptSize;
 
   public:
     static char ID; // Pass identification, replacement for typeid
@@ skipping 1544 matching lines @@
     WeakVH IterHandle(CurInstIterator);
     BasicBlock *BB = CurInstIterator->getParent();
 
     RecursivelyDeleteTriviallyDeadInstructions(Repl, TLInfo);
 
     if (IterHandle != CurInstIterator) {
       // If the iterator instruction was recursively deleted, start over at the
       // start of the block.
       CurInstIterator = BB->begin();
       SunkAddrs.clear();
+    } else {
+      // This address is now available for reassignment, so erase the table
+      // entry; we don't want to match some completely different instruction.
+      SunkAddrs[Addr] = 0;
     }
   }
   ++NumMemoryInsts;
   return true;
 }
 
 /// OptimizeInlineAsmInst - If there are any memory operands, use
 /// OptimizeMemoryInst to sink their address computing into the block when
 /// possible / profitable.
 bool CodeGenPrepare::OptimizeInlineAsmInst(CallInst *CS) {
@@ skipping 333 matching lines @@
           DVI->insertBefore(VI->getParent()->getFirstInsertionPt());
         else
           DVI->insertAfter(VI);
         MadeChange = true;
         ++NumDbgValueMoved;
       }
     }
   }
   return MadeChange;
 }