1 files changed, 78 insertions, 0 deletions
diff --git a/contrib/llvm/lib/Analysis/MemDerefPrinter.cpp b/contrib/llvm/lib/Analysis/MemDerefPrinter.cpp
new file mode 100644
index 000000000000..36f1424c8cf9
--- /dev/null
+++ b/contrib/llvm/lib/Analysis/MemDerefPrinter.cpp
@@ -0,0 +1,78 @@
+//===- MemDerefPrinter.cpp - Printer for isDereferenceablePointer ---------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#include "llvm/Analysis/Passes.h"
+#include "llvm/ADT/SetVector.h"
+#include "llvm/Analysis/MemoryDependenceAnalysis.h"
+#include "llvm/Analysis/ValueTracking.h"
+#include "llvm/IR/CallSite.h"
+#include "llvm/IR/DataLayout.h"
+#include "llvm/IR/InstIterator.h"
+#include "llvm/IR/LLVMContext.h"
+#include "llvm/IR/Module.h"
+#include "llvm/Support/ErrorHandling.h"
+#include "llvm/Support/raw_ostream.h"
+using namespace llvm;
+
+namespace {
+  struct MemDerefPrinter : public FunctionPass {
+    SmallVector<Value *, 4> Deref;
+    SmallPtrSet<Value *, 4> DerefAndAligned;
+
+    static char ID; // Pass identification, replacement for typeid
+    MemDerefPrinter() : FunctionPass(ID) {
+      initializeMemDerefPrinterPass(*PassRegistry::getPassRegistry());
+    }
+    void getAnalysisUsage(AnalysisUsage &AU) const override {
+      AU.setPreservesAll();
+    }
+    bool runOnFunction(Function &F) override;
+    void print(raw_ostream &OS, const Module * = nullptr) const override;
+    void releaseMemory() override {
+      Deref.clear();
+      DerefAndAligned.clear();
+    }
+  };
+}
+
+char MemDerefPrinter::ID = 0;
+INITIALIZE_PASS_BEGIN(MemDerefPrinter, "print-memderefs",
+                      "Memory Dereferenciblity of pointers in function", false, true)
+INITIALIZE_PASS_END(MemDerefPrinter, "print-memderefs",
+                    "Memory Dereferenciblity of pointers in function", false, true)
+
+FunctionPass *llvm::createMemDerefPrinter() {
+  return new MemDerefPrinter();
+}
+
+bool MemDerefPrinter::runOnFunction(Function &F) {
+  const DataLayout &DL = F.getParent()->getDataLayout();
+  for (auto &I: instructions(F)) {
+    if (LoadInst *LI = dyn_cast<LoadInst>(&I)) {
+      Value *PO = LI->getPointerOperand();
+      if (isDereferenceablePointer(PO, DL))
+        Deref.push_back(PO);
+      if (isDereferenceableAndAlignedPointer(PO, LI->getAlignment(), DL))
+        DerefAndAligned.insert(PO);
+    }
+  }
+  return false;
+}
+
+void MemDerefPrinter::print(raw_ostream &OS, const Module *M) const {
+  OS << "The following are dereferenceable:\n";
+  for (Value *V: Deref) {
+    V->print(OS);
+    if (DerefAndAligned.count(V))
+      OS << "\t(aligned)";
+    else
+      OS << "\t(unaligned)";
+    OS << "\n\n";
+  }
+}