Scaffolding for LDA pass.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@74120 91177308-0d34-0410-b5e6-96231b3b80d8

include/llvm/Analysis/LoopDependenceAnalysis.h

@@ -0,0 +1,52 @@
+//===- llvm/Analysis/LoopDependenceAnalysis.h --------------- -*- C++ -*---===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// LoopDependenceAnalysis is an LLVM pass that analyses dependences in memory
+// accesses in loops.
+//
+// Please note that this is work in progress and the interface is subject to
+// change.
+//
+// TODO: adapt as interface progresses
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_ANALYSIS_LOOP_DEPENDENCE_ANALYSIS_H
+#define LLVM_ANALYSIS_LOOP_DEPENDENCE_ANALYSIS_H
+
+#include "llvm/Analysis/LoopPass.h"
+
+namespace llvm {
+
+  class AnalysisUsage;
+  class LoopPass;
+  class ScalarEvolution;
+
+  class LoopDependenceAnalysis : public LoopPass {
+    Loop *L;
+    ScalarEvolution *SE;
+
+  public:
+    static char ID; // Class identification, replacement for typeinfo
+    LoopDependenceAnalysis() : LoopPass(&ID) {}
+
+    bool runOnLoop(Loop*, LPPassManager&);
+
+    virtual void getAnalysisUsage(AnalysisUsage&) const;
+  }; // class LoopDependenceAnalysis
+
+
+  // createLoopDependenceAnalysisPass - This creates an instance of the
+  // LoopDependenceAnalysis pass.
+  //
+  LoopPass *createLoopDependenceAnalysisPass();
+
+} // namespace llvm
+
+#endif /* LLVM_ANALYSIS_LOOP_DEPENDENCE_ANALYSIS_H */

include/llvm/Analysis/Passes.h

@@ -18,6 +18,7 @@
 namespace llvm {
   class FunctionPass;
   class ImmutablePass;
+  class LoopPass;
   class ModulePass;
   class Pass;
   class LibCallInfo;
@@ -116,6 +117,13 @@ namespace llvm {
   // createLiveValuesPass - This creates an instance of the LiveValues pass.
   //
   FunctionPass *createLiveValuesPass();
+
+  //===--------------------------------------------------------------------===//
+  //
+  // createLoopDependenceAnalysisPass - This creates an instance of the
+  // LoopDependenceAnalysis pass.
+  //
+  LoopPass *createLoopDependenceAnalysisPass();
   
   // Minor pass prototypes, allowing us to expose them through bugpoint and
   // analyze.

include/llvm/LinkAllPasses.h

@@ -77,6 +77,7 @@ namespace {
       (void) llvm::createLCSSAPass();
       (void) llvm::createLICMPass();
       (void) llvm::createLiveValuesPass();
+      (void) llvm::createLoopDependenceAnalysisPass();
       (void) llvm::createLoopExtractorPass();
       (void) llvm::createLoopSimplifyPass();
       (void) llvm::createLoopStrengthReducePass();

lib/Analysis/CMakeLists.txt

@@ -18,6 +18,7 @@ add_llvm_library(LLVMAnalysis
   LibCallAliasAnalysis.cpp
   LibCallSemantics.cpp
   LiveValues.cpp
+  LoopDependenceAnalysis.cpp
   LoopInfo.cpp
   LoopPass.cpp
   LoopVR.cpp

lib/Analysis/LoopDependenceAnalysis.cpp

@@ -0,0 +1,47 @@
+//===- LoopDependenceAnalysis.cpp - LDA Implementation ----------*- C++ -*-===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This is the (beginning) of an implementation of a loop dependence analysis
+// framework, which is used to detect dependences in memory accesses in loops.
+//
+// Please note that this is work in progress and the interface is subject to
+// change.
+//
+// TODO: adapt as implementation progresses.
+//
+//===----------------------------------------------------------------------===//
+
+#define DEBUG_TYPE "lda"
+#include "llvm/Analysis/LoopDependenceAnalysis.h"
+#include "llvm/Analysis/LoopPass.h"
+#include "llvm/Analysis/ScalarEvolution.h"
+using namespace llvm;
+
+LoopPass *llvm::createLoopDependenceAnalysisPass() {
+  return new LoopDependenceAnalysis();
+}
+
+static RegisterPass<LoopDependenceAnalysis>
+R("lda", "Loop Dependence Analysis", false, true);
+char LoopDependenceAnalysis::ID = 0;
+
+//===----------------------------------------------------------------------===//
+//                   LoopDependenceAnalysis Implementation
+//===----------------------------------------------------------------------===//
+
+bool LoopDependenceAnalysis::runOnLoop(Loop *L, LPPassManager &) {
+  this->L = L;
+  SE = &getAnalysis<ScalarEvolution>();
+  return false;
+}
+
+void LoopDependenceAnalysis::getAnalysisUsage(AnalysisUsage &AU) const {
+  AU.setPreservesAll();
+  AU.addRequired<ScalarEvolution>();
+}