More code cleanup [NFC]

[oota-llvm.git] / lib / Transforms / Scalar / LoopInterchange.cpp

diff --git a/lib/Transforms/Scalar/LoopInterchange.cpp b/lib/Transforms/Scalar/LoopInterchange.cpp
index f8c865b9c18be7642774579db4778cdf46e035e7..f7626c527c1604886fc275be9d3528be0c9841cd 100644 (file)
--- a/lib/Transforms/Scalar/LoopInterchange.cpp
+++ b/lib/Transforms/Scalar/LoopInterchange.cpp
@@ -28,18 +28,18 @@
 #include "llvm/Analysis/ScalarEvolutionExpressions.h"
 #include "llvm/Analysis/TargetTransformInfo.h"
 #include "llvm/Analysis/ValueTracking.h"
-#include "llvm/Transforms/Scalar.h"
+#include "llvm/IR/Dominators.h"
 #include "llvm/IR/Function.h"
 #include "llvm/IR/IRBuilder.h"
-#include "llvm/IR/IntrinsicInst.h"
 #include "llvm/IR/InstIterator.h"
-#include "llvm/IR/Dominators.h"
+#include "llvm/IR/IntrinsicInst.h"
 #include "llvm/Pass.h"
 #include "llvm/Support/Debug.h"
-#include "llvm/Transforms/Utils/SSAUpdater.h"
 #include "llvm/Support/raw_ostream.h"
-#include "llvm/Transforms/Utils/LoopUtils.h"
+#include "llvm/Transforms/Scalar.h"
 #include "llvm/Transforms/Utils/BasicBlockUtils.h"
+#include "llvm/Transforms/Utils/LoopUtils.h"
+#include "llvm/Transforms/Utils/SSAUpdater.h"
 using namespace llvm;
 
 #define DEBUG_TYPE "loop-interchange"
@@ -378,15 +378,12 @@ public:
                            LoopInfo *LI, DominatorTree *DT,
                            LoopInterchange *Pass, BasicBlock *LoopNestExit)
       : OuterLoop(Outer), InnerLoop(Inner), SE(SE), LI(LI), DT(DT),
-        LoopExit(LoopNestExit) {
-    initialize();
-  }
+        LoopExit(LoopNestExit) {}
 
   /// Interchange OuterLoop and InnerLoop.
   bool transform();
   void restructureLoops(Loop *InnerLoop, Loop *OuterLoop);
   void removeChildLoop(Loop *OuterLoop, Loop *InnerLoop);
-  void initialize();
 
 private:
   void splitInnerLoopLatch(Instruction *);
@@ -545,9 +542,7 @@ struct LoopInterchange : public FunctionPass {
       if (!Interchanged)
         return Changed;
       // Loops interchanged reflect the same in LoopList
-      Loop *OldOuterLoop = LoopList[i - 1];
-      LoopList[i - 1] = LoopList[i];
-      LoopList[i] = OldOuterLoop;
+      std::swap(LoopList[i - 1], LoopList[i]);
 
       // Update the DependencyMatrix
       interChangeDepedencies(DependencyMatrix, i, i - 1);
@@ -856,8 +851,9 @@ int LoopInterchangeProfitability::getInstrOrderCost() {
   return GoodOrder - BadOrder;
 }
 
-bool isProfitabileForVectorization(unsigned InnerLoopId, unsigned OuterLoopId,
-                                   CharMatrix &DepMatrix) {
+static bool isProfitabileForVectorization(unsigned InnerLoopId,
+                                          unsigned OuterLoopId,
+                                          CharMatrix &DepMatrix) {
   // TODO: Improve this heuristic to catch more cases.
   // If the inner loop is loop independent or doesn't carry any dependency it is
   // profitable to move this to outer position.
@@ -972,20 +968,10 @@ bool LoopInterchangeTransform::transform() {
   return true;
 }
 
-void LoopInterchangeTransform::initialize() {}
-
-void LoopInterchangeTransform::splitInnerLoopLatch(Instruction *inc) {
-
+void LoopInterchangeTransform::splitInnerLoopLatch(Instruction *Inc) {
   BasicBlock *InnerLoopLatch = InnerLoop->getLoopLatch();
-  BasicBlock::iterator I = InnerLoopLatch->begin();
-  BasicBlock::iterator E = InnerLoopLatch->end();
-  for (; I != E; ++I) {
-    if (inc == I)
-      break;
-  }
-
   BasicBlock *InnerLoopLatchPred = InnerLoopLatch;
-  InnerLoopLatch = SplitBlock(InnerLoopLatchPred, I, DT, LI);
+  InnerLoopLatch = SplitBlock(InnerLoopLatchPred, Inc, DT, LI);
 }
 
 void LoopInterchangeTransform::splitOuterLoopLatch() {
@@ -1005,38 +991,28 @@ void LoopInterchangeTransform::splitInnerLoopHeader() {
                   "InnerLoopHeader \n");
 }
 
+/// \brief Move all instructions except the terminator from FromBB right before
+/// InsertBefore
+static void moveBBContents(BasicBlock *FromBB, Instruction *InsertBefore) {
+  auto &ToList = InsertBefore->getParent()->getInstList();
+  auto &FromList = FromBB->getInstList();
+
+  ToList.splice(InsertBefore, FromList, FromList.begin(),
+                FromBB->getTerminator());
+}
+
 void LoopInterchangeTransform::adjustOuterLoopPreheader() {
   BasicBlock *OuterLoopPreHeader = OuterLoop->getLoopPreheader();
-  SmallVector<Instruction *, 8> Inst;
-  for (auto I = OuterLoopPreHeader->begin(), E = OuterLoopPreHeader->end();
-       I != E; ++I) {
-    if (isa<BranchInst>(*I))
-      break;
-    Inst.push_back(I);
-  }
-
   BasicBlock *InnerPreHeader = InnerLoop->getLoopPreheader();
-  for (auto I = Inst.begin(), E = Inst.end(); I != E; ++I) {
-    Instruction *Ins = cast<Instruction>(*I);
-    Ins->moveBefore(InnerPreHeader->getTerminator());
-  }
+
+  moveBBContents(OuterLoopPreHeader, InnerPreHeader->getTerminator());
 }
 
 void LoopInterchangeTransform::adjustInnerLoopPreheader() {
-
   BasicBlock *InnerLoopPreHeader = InnerLoop->getLoopPreheader();
-  SmallVector<Instruction *, 8> Inst;
-  for (auto I = InnerLoopPreHeader->begin(), E = InnerLoopPreHeader->end();
-       I != E; ++I) {
-    if (isa<BranchInst>(*I))
-      break;
-    Inst.push_back(I);
-  }
   BasicBlock *OuterHeader = OuterLoop->getHeader();
-  for (auto I = Inst.begin(), E = Inst.end(); I != E; ++I) {
-    Instruction *Ins = cast<Instruction>(*I);
-    Ins->moveBefore(OuterHeader->getTerminator());
-  }
+
+  moveBBContents(InnerLoopPreHeader, OuterHeader->getTerminator());
 }
 
 bool LoopInterchangeTransform::adjustLoopBranches() {
@@ -1141,32 +1117,15 @@ void LoopInterchangeTransform::adjustLoopPreheaders() {
   BranchInst *InnerTermBI =
       cast<BranchInst>(InnerLoopPreHeader->getTerminator());
 
-  SmallVector<Value *, 16> OuterPreheaderInstr;
-  SmallVector<Value *, 16> InnerPreheaderInstr;
-
-  for (auto I = OuterLoopPreHeader->begin(); !isa<BranchInst>(I); ++I)
-    OuterPreheaderInstr.push_back(I);
-
-  for (auto I = InnerLoopPreHeader->begin(); !isa<BranchInst>(I); ++I)
-    InnerPreheaderInstr.push_back(I);
-
   BasicBlock *HeaderSplit =
       SplitBlock(OuterLoopHeader, OuterLoopHeader->getTerminator(), DT, LI);
   Instruction *InsPoint = HeaderSplit->getFirstNonPHI();
   // These instructions should now be executed inside the loop.
   // Move instruction into a new block after outer header.
-  for (auto I = InnerPreheaderInstr.begin(), E = InnerPreheaderInstr.end();
-       I != E; ++I) {
-    Instruction *Ins = cast<Instruction>(*I);
-    Ins->moveBefore(InsPoint);
-  }
+  moveBBContents(InnerLoopPreHeader, InsPoint);
   // These instructions were not executed previously in the loop so move them to
   // the older inner loop preheader.
-  for (auto I = OuterPreheaderInstr.begin(), E = OuterPreheaderInstr.end();
-       I != E; ++I) {
-    Instruction *Ins = cast<Instruction>(*I);
-    Ins->moveBefore(InnerTermBI);
-  }
+  moveBBContents(OuterLoopPreHeader, InnerTermBI);
 }
 
 bool LoopInterchangeTransform::adjustLoopLinks() {