From 2957f129a7390a068610e9af5a079c6fa1bead24 Mon Sep 17 00:00:00 2001
From: John Criswell <criswell@uiuc.edu>
Date: Wed, 13 Dec 2006 19:41:57 +0000
Subject: Remove DSA.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@32550 91177308-0d34-0410-b5e6-96231b3b80d8
---
 lib/Analysis/DataStructure/DataStructureOpt.cpp | 102 ------------------------
 1 file changed, 102 deletions(-)
 delete mode 100644 lib/Analysis/DataStructure/DataStructureOpt.cpp

(limited to 'lib/Analysis/DataStructure/DataStructureOpt.cpp')

diff --git a/lib/Analysis/DataStructure/DataStructureOpt.cpp b/lib/Analysis/DataStructure/DataStructureOpt.cpp
deleted file mode 100644
index 85da1763ac..0000000000
--- a/lib/Analysis/DataStructure/DataStructureOpt.cpp
+++ /dev/null
@@ -1,102 +0,0 @@
-//===- DataStructureOpt.cpp - Data Structure Analysis Based Optimizations -===//
-//
-//                     The LLVM Compiler Infrastructure
-//
-// This file was developed by the LLVM research group and is distributed under
-// the University of Illinois Open Source License. See LICENSE.TXT for details.
-//
-//===----------------------------------------------------------------------===//
-//
-// This pass uses DSA to a series of simple optimizations, like marking
-// unwritten global variables 'constant'.
-//
-//===----------------------------------------------------------------------===//
-
-#include "llvm/Analysis/DataStructure/DataStructure.h"
-#include "llvm/Analysis/DataStructure/DSGraph.h"
-#include "llvm/Analysis/Passes.h"
-#include "llvm/Module.h"
-#include "llvm/Constant.h"
-#include "llvm/Type.h"
-#include "llvm/ADT/Statistic.h"
-using namespace llvm;
-
-namespace {
-  Statistic
-  NumGlobalsConstanted("ds-opt", "Number of globals marked constant");
-  Statistic
-  NumGlobalsIsolated("ds-opt", "Number of globals with references dropped");
-
-  class DSOpt : public ModulePass {
-    TDDataStructures *TD;
-  public:
-    bool runOnModule(Module &M) {
-      TD = &getAnalysis<TDDataStructures>();
-      bool Changed = OptimizeGlobals(M);
-      return Changed;
-    }
-
-    virtual void getAnalysisUsage(AnalysisUsage &AU) const {
-      AU.addRequired<TDDataStructures>();      // Uses TD Datastructures
-      AU.addPreserved<LocalDataStructures>();  // Preserves local...
-      AU.addPreserved<TDDataStructures>();     // Preserves bu...
-      AU.addPreserved<BUDataStructures>();     // Preserves td...
-    }
-
-  private:
-    bool OptimizeGlobals(Module &M);
-  };
-
-  RegisterPass<DSOpt> X("ds-opt", "DSA-based simple optimizations");
-}
-
-ModulePass *llvm::createDSOptPass() { return new DSOpt(); }
-
-/// OptimizeGlobals - This method uses information taken from DSA to optimize
-/// global variables.
-///
-bool DSOpt::OptimizeGlobals(Module &M) {
-  DSGraph &GG = TD->getGlobalsGraph();
-  const DSGraph::ScalarMapTy &SM = GG.getScalarMap();
-  bool Changed = false;
-
-  for (Module::global_iterator I = M.global_begin(), E = M.global_end(); I != E; ++I)
-    if (!I->isExternal()) { // Loop over all of the non-external globals...
-      // Look up the node corresponding to this global, if it exists.
-      DSNode *GNode = 0;
-      DSGraph::ScalarMapTy::const_iterator SMI = SM.find(I);
-      if (SMI != SM.end()) GNode = SMI->second.getNode();
-
-      if (GNode == 0 && I->hasInternalLinkage()) {
-        // If there is no entry in the scalar map for this global, it was never
-        // referenced in the program.  If it has internal linkage, that means we
-        // can delete it.  We don't ACTUALLY want to delete the global, just
-        // remove anything that references the global: later passes will take
-        // care of nuking it.
-        if (!I->use_empty()) {
-          I->replaceAllUsesWith(Constant::getNullValue((Type*)I->getType()));
-          ++NumGlobalsIsolated;
-        }
-      } else if (GNode && GNode->isComplete()) {
-
-        // If the node has not been read or written, and it is not externally
-        // visible, kill any references to it so it can be DCE'd.
-        if (!GNode->isModified() && !GNode->isRead() &&I->hasInternalLinkage()){
-          if (!I->use_empty()) {
-            I->replaceAllUsesWith(Constant::getNullValue((Type*)I->getType()));
-            ++NumGlobalsIsolated;
-          }
-        }
-
-        // We expect that there will almost always be a node for this global.
-        // If there is, and the node doesn't have the M bit set, we can set the
-        // 'constant' bit on the global.
-        if (!GNode->isModified() && !I->isConstant()) {
-          I->setConstant(true);
-          ++NumGlobalsConstanted;
-          Changed = true;
-        }
-      }
-    }
-  return Changed;
-}
-- 
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