From 2d50a58da7f1d7b70f39069de6a8a9c29033c26a Mon Sep 17 00:00:00 2001
From: guruhegde <guruhegde1308@gmail.com>
Date: Mon, 7 Oct 2019 10:10:18 +0200
Subject: [PATCH] Add helper methods

---
 src/Util.cpp | 32 ++++++++++++++++++++++++++++++++
 src/Util.h   |  9 +++++++++
 2 files changed, 41 insertions(+)

diff --git a/src/Util.cpp b/src/Util.cpp
index dfa5306..72abf56 100644
--- a/src/Util.cpp
+++ b/src/Util.cpp
@@ -421,4 +421,36 @@ pair<BasicBlock *, BasicBlock *> unifyFunctionExitNodes(Function &F) {
   return make_pair(NewRetBlock, UnreachableBlock);
 }
 
+template <typename InstType>
+auto findFirstUseOfValueInInstType(Value * V) {
+  auto FU = find_if(V->users(),
+                    [&] (const auto * U) { return isa<InstType>(U)?true:false; });
+  return cast<InstType>(FU);
+}
+
+template <typename InstType>
+auto findLastUseOfValueInInstType(Value * V) {
+  InstType * LU = nullptr;
+  for_each(V->users(),
+          [&] (const auto * U) { if (isa<InstType>(U)) LU = cast<InstType>(U); });
+  return LU;
+}
+
+AllocaInst * getLoopIndexVar(Loop * L) {
+  AllocaInst * Index = nullptr;
+  auto LatchBB = L->getLoopLatch();
+  assert(LatchBB && "Latch block can't be null!");
+
+  // Find index increment instruction.
+  // XXX Assume latch block contains only one add instruction, verify it.
+  auto It = find_if(*LatchBB,
+          [&] (const Instruction & I) {
+          return (isa<BinaryOperator>(I) &&
+                  I.getOpcode() == Instruction::Add &&
+                  cast<ConstantInt>(I.getOperand(1))->equalsInt(1)) ? true : false; });
+
+  Index = cast<AllocaInst>(cast<LoadInst>(It->getOperand(0))->getOperand(0));
+  return Index;
+}
+
 } // namespace tas
diff --git a/src/Util.h b/src/Util.h
index 8f0308f..2d153ec 100644
--- a/src/Util.h
+++ b/src/Util.h
@@ -78,6 +78,15 @@ llvm::Value * addIncrementIndexOp(llvm::AllocaInst * IdxPtr,
 void printRegeionInfo(llvm::Function * F);
 
 std::pair<llvm::BasicBlock *, llvm::BasicBlock *> unifyFunctionExitNodes(llvm::Function & F);
+
+template <typename InstType>
+auto findFirstUseOfValueInInstType(llvm::Value * V);
+
+template <typename InstType>
+auto findLastUseOfValueInInstType(llvm::Value * V);
+
+llvm::AllocaInst * getLoopIndexVar(llvm::Loop * L);
+
 } // namespace tas
 
 #endif
-- 
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