[C++] Use 'nullptr'. Transforms edition.

[oota-llvm.git] / lib / Analysis / LoopPass.cpp

diff --git a/lib/Analysis/LoopPass.cpp b/lib/Analysis/LoopPass.cpp
index 1540112fe10cfda4aa659f771b946e485ad717be..683d6d74ab42949b14ef5bc7c45cf11b408c855a 100644 (file)
--- a/lib/Analysis/LoopPass.cpp
+++ b/lib/Analysis/LoopPass.cpp
@@ -14,11 +14,13 @@
 //===----------------------------------------------------------------------===//
 
 #include "llvm/Analysis/LoopPass.h"
-#include "llvm/Assembly/PrintModulePass.h"
+#include "llvm/IR/IRPrintingPasses.h"
 #include "llvm/Support/Debug.h"
 #include "llvm/Support/Timer.h"
 using namespace llvm;
 
+#define DEBUG_TYPE "loop-pass-manager"
+
 namespace {
 
 /// PrintLoopPass - Print a Function corresponding to a Loop.
@@ -33,11 +35,11 @@ public:
   PrintLoopPass(const std::string &B, raw_ostream &o)
       : LoopPass(ID), Banner(B), Out(o) {}
 
-  virtual void getAnalysisUsage(AnalysisUsage &AU) const {
+  void getAnalysisUsage(AnalysisUsage &AU) const override {
     AU.setPreservesAll();
   }
 
-  bool runOnLoop(Loop *L, LPPassManager &) {
+  bool runOnLoop(Loop *L, LPPassManager &) override {
     Out << Banner;
     for (Loop::block_iterator b = L->block_begin(), be = L->block_end();
          b != be;
@@ -61,8 +63,8 @@ LPPassManager::LPPassManager()
   : FunctionPass(ID), PMDataManager() {
   skipThisLoop = false;
   redoThisLoop = false;
-  LI = NULL;
-  CurrentLoop = NULL;
+  LI = nullptr;
+  CurrentLoop = nullptr;
 }
 
 /// Delete loop from the loop queue and loop hierarchy (LoopInfo).
@@ -188,6 +190,10 @@ bool LPPassManager::runOnFunction(Function &F) {
   // advantage in deleting uses in a later loop before optimizing the
   // definitions in an earlier loop. If we find a clear reason to process in
   // forward order, then a forward variant of LoopPassManager should be created.
+  //
+  // Note that LoopInfo::iterator visits loops in reverse program
+  // order. Here, reverse_iterator gives us a forward order, and the LoopQueue
+  // reverses the order a third time by popping from the back.
   for (LoopInfo::reverse_iterator I = LI->rbegin(), E = LI->rend(); I != E; ++I)
     addLoopIntoQueue(*I, LQ);
 
@@ -361,3 +367,17 @@ void LoopPass::assignPassManager(PMStack &PMS,
 
   LPPM->add(this);
 }
+
+// Containing function has Attribute::OptimizeNone and transformation
+// passes should skip it.
+bool LoopPass::skipOptnoneFunction(const Loop *L) const {
+  const Function *F = L->getHeader()->getParent();
+  if (F && F->hasFnAttribute(Attribute::OptimizeNone)) {
+    // FIXME: Report this to dbgs() only once per function.
+    DEBUG(dbgs() << "Skipping pass '" << getPassName()
+          << "' in function " << F->getName() << "\n");
+    // FIXME: Delete loop from pass manager's queue?
+    return true;
+  }
+  return false;
+}