Merge pull request #6254 from pgavlin/RemoveRenameUpdatedVars

Remove RenameUpdatedVars.

2 files changed, 0 insertions, 157 deletions

diff --git a/src/jit/rationalize.cpp b/src/jit/rationalize.cpp
index ba81b87633..6c322fb88d 100644
--- a/src/jit/rationalize.cpp
+++ b/src/jit/rationalize.cpp
@@ -328,138 +328,6 @@ Compiler::fgInsertEmbeddedFormTemp(GenTree** ppTree, unsigned lclNum)
     return stmt;
 }
 
-//------------------------------------------------------------------------------
-// RenameUpdatedVars - detect trees that have internal assignments with preceding reads 
-//                     of the variables being written.
-//                     Replace the preceding reads with references to copies made in advance
-//                     in order to make breaking out the assignments legal
-//------------------------------------------------------------------------------
-
-void Rationalizer::RenameUpdatedVars(Location loc)
-{
-    // A variable which is assigned within the tree will have different 
-    // values at different points in the tree.  The rationalizer tries to
-    // break internal assignments out into their own tree and place those trees before
-    // the original tree.  This could result in changed meaning unless
-    // we have a way of differentiating between original and modified values
-
-    GenTree *statement = loc.tree;
-    assert(statement->IsStatement());
-
-    GenTree *tree = loc.tree->gtStmt.gtStmtExpr;
-
-    use->ZeroAll();
-    usedef->ZeroAll();
-    rename->ZeroAll();
-    unexp->ZeroAll();
-    
-    int *renameMap = (int *) alloca(sizeof(int) * comp->lvaCount);
-    var_types *renameTypeMap = (var_types *) alloca(sizeof(var_types) * comp->lvaCount);
-
-    // find locals that are redefined within the tree
-    foreach_treenode_execution_order(tree, statement)
-    {
-        if (tree->IsLocal())
-        {
-            int varIdx = tree->gtLclVarCommon.gtLclNum;
-            if (tree->gtFlags & GTF_VAR_DEF       // definition
-                || tree->gtFlags & GTF_VAR_USEDEF // this is a use/def as in x=x+y (only the lhs x is tagged)
-                || tree->gtFlags & GTF_VAR_USEASG)// this is a use/def for a x<op>=y
-            {
-                if (use->testBit(varIdx))
-                {
-                    usedef->setBit(varIdx);
-                }
-                else
-                {
-                    unexp->setBit(varIdx);
-                }
-            }
-            else
-            {
-                if (usedef->testBit(varIdx))
-                {
-                    rename->setBit(varIdx);
-                    renameTypeMap[varIdx] = tree->TypeGet();
-                }
-                else
-                {
-                    use->setBit(varIdx); // it's a plain use
-                }
-            }
-        }
-    }
-
-    if (!rename->anySet())
-        return;
-
-    indexType index;
-
-    // create the new variables and establish the mapping
-    // also insert copies before the statement
-    FOREACH_HBV_BIT_SET(index, rename)
-    {
-        JITDUMP("had to rename idx:%d in tree!\n", index);
-        DISPTREE(statement);
-
-        unsigned tmpIndex = 
-            renameMap[index] = 
-            comp->lvaGrabTemp(true DEBUGARG("rationalize renaming"));
-
-        LclVarDsc *newVar = &comp->lvaTable[tmpIndex];
-
-        newVar->lvType = renameTypeMap[index];
-
-        // Increment its lvRefCnt and lvRefCntWtd
-        comp->lvaTable[tmpIndex].incRefCnts(loc.block->getBBWeight(comp), comp);
-
-        // only need a copy for exposed uses, otherwise a def is the first occurence
-        if (!unexp->testBit(index))
-        {
-            GenTree *write = comp->gtNewAssignNode(comp->gtNewLclvNode(renameMap[index], newVar->TypeGet()), 
-                                                   comp->gtNewLclvNode((int)index, newVar->TypeGet()));
-
-            write = comp->fgNewStmtFromTree(write, statement->gtStmt.gtStmtILoffsx);
-            comp->fgInsertStmtBefore(loc.block, statement, write);
-
-            JITDUMP("New write tree:\n");
-            DISPTREE(write);
-        }
-    }
-    NEXT_HBV_BIT_SET;
-
-    hashBv *seenUse = hashBv::Create(this->comp);
-    hashBv *seenRedef = hashBv::Create(this->comp);
-
-    // we are looking for a def after use
-    // don't just start renaming if it kicks off with a def
-    foreach_treenode_execution_order(tree, statement)
-    {
-        if (tree->IsLocal())
-        {
-            int varIdx = tree->gtLclVarCommon.gtLclNum;
-            if (rename->testBit(varIdx))
-            {
-                if (tree->gtFlags & GTF_VAR_DEF
-                    //|| tree->gtFlags & GTF_VAR_USEDEF
-                    || tree->gtFlags & GTF_VAR_USEASG)
-                {
-                    if (seenUse->testBit(varIdx))
-                        seenRedef->setBit(varIdx);
-                }
-                else
-                {
-                    seenUse->setBit(varIdx);
-                }
-                if (!seenRedef->testBit(varIdx))
-                {
-                    tree->gtLclVarCommon.SetLclNum(renameMap[varIdx]);
-                }
-            }
-        }
-    }
-}
-
 // return op that is the store equivalent of the given load opcode
 genTreeOps storeForm(genTreeOps loadForm)
 {
@@ -1933,23 +1801,10 @@ void Rationalizer::DoPhase()
     comp->compCurBB = NULL;
     comp->fgOrder = Compiler::FGOrderLinear;
 
-    use     = hashBv::Create(this->comp); // is used
-    usedef  = hashBv::Create(this->comp); // is used and then defined
-    rename  = hashBv::Create(this->comp); // is used, defined and used again
-    unexp   = hashBv::Create(this->comp); // is unexposed - there is a def in this tree before any uses
-
     // break up the trees at side effects, etc
     Location loc(comp->fgFirstBB);
     while (loc.block)
     {
-        RenameUpdatedVars(loc);
-        loc = loc.Next();
-    }
-
-    loc.Reset(comp);
-
-    while (loc.block)
-    {
         loc = TreeTransformRationalization(loc);
         loc = loc.Next();
     }
diff --git a/src/jit/rationalize.h b/src/jit/rationalize.h
index b6f6ee752a..7d3b00b051 100644
--- a/src/jit/rationalize.h
+++ b/src/jit/rationalize.h
@@ -89,23 +89,11 @@ private:
 class Rationalizer : public Phase
 {
     //===============================================================================
-    // Data members
-
-    // used for renaming updated variables
-    hashBv *use;
-    hashBv *usedef;
-    hashBv *rename;
-    hashBv *unexp;
-
-
-    //===============================================================================
     // Methods
 public:
     Rationalizer(Compiler* comp);
     Location TreeTransformRationalization (Location loc);
 
-    void RenameUpdatedVars(Location loc);
-
 #ifdef DEBUG
 
     static void ValidateStatement(Location loc);