RegisterPressure: Hide non-const iterators of PressureDiff

[oota-llvm.git] / lib / CodeGen / MachineBlockPlacement.cpp

diff --git a/lib/CodeGen/MachineBlockPlacement.cpp b/lib/CodeGen/MachineBlockPlacement.cpp
index ecc50c916b0b425f0570a0de5335c336c188a941..84cc9bcdb60db08d95aefeec12a993589b45d61d 100644 (file)
--- a/lib/CodeGen/MachineBlockPlacement.cpp
+++ b/lib/CodeGen/MachineBlockPlacement.cpp
@@ -51,7 +51,7 @@ using namespace llvm;
 #define DEBUG_TYPE "block-placement"
 
 STATISTIC(NumCondBranches, "Number of conditional branches");
-STATISTIC(NumUncondBranches, "Number of uncondittional branches");
+STATISTIC(NumUncondBranches, "Number of unconditional branches");
 STATISTIC(CondBranchTakenFreq,
           "Potential frequency of taking conditional branches");
 STATISTIC(UncondBranchTakenFreq,
@@ -505,14 +505,14 @@ MachineBasicBlock *MachineBlockPlacement::getFirstUnplacedBlock(
     const BlockFilterSet *BlockFilter) {
   for (MachineFunction::iterator I = PrevUnplacedBlockIt, E = F.end(); I != E;
        ++I) {
-    if (BlockFilter && !BlockFilter->count(I))
+    if (BlockFilter && !BlockFilter->count(&*I))
       continue;
-    if (BlockToChain[I] != &PlacedChain) {
+    if (BlockToChain[&*I] != &PlacedChain) {
       PrevUnplacedBlockIt = I;
       // Now select the head of the chain to which the unplaced block belongs
       // as the block to place. This will force the entire chain to be placed,
       // and satisfies the requirements of merging chains.
-      return *BlockToChain[I]->begin();
+      return *BlockToChain[&*I]->begin();
     }
   }
   return nullptr;
@@ -661,7 +661,7 @@ MachineBlockPlacement::findBestLoopExit(MachineFunction &F, MachineLoop &L,
   for (MachineBasicBlock *MBB : L.getBlocks()) {
     BlockChain &Chain = *BlockToChain[MBB];
     // Ensure that this block is at the end of a chain; otherwise it could be
-    // mid-way through an inner loop or a successor of an analyzable branch.
+    // mid-way through an inner loop or a successor of an unanalyzable branch.
     if (MBB != *std::prev(Chain.end()))
       continue;
 
@@ -678,7 +678,7 @@ MachineBlockPlacement::findBestLoopExit(MachineFunction &F, MachineLoop &L,
     uint32_t WeightScale = 0;
     uint32_t SumWeight = MBPI->getSumForBlock(MBB, WeightScale);
     for (MachineBasicBlock *Succ : MBB->successors()) {
-      if (Succ->isLandingPad())
+      if (Succ->isEHPad())
         continue;
       if (Succ == MBB)
         continue;
@@ -715,7 +715,7 @@ MachineBlockPlacement::findBestLoopExit(MachineFunction &F, MachineLoop &L,
       // a frequency higher than the current exit before we consider breaking
       // the layout.
       BranchProbability Bias(100 - ExitBlockBias, 100);
-      if (!ExitingBB || BestExitLoopDepth < SuccLoopDepth ||
+      if (!ExitingBB || SuccLoopDepth > BestExitLoopDepth ||
           ExitEdgeFreq > BestExitEdgeFreq ||
           (MBB->isLayoutSuccessor(Succ) &&
            !(ExitEdgeFreq < BestExitEdgeFreq * Bias))) {
@@ -724,8 +724,8 @@ MachineBlockPlacement::findBestLoopExit(MachineFunction &F, MachineLoop &L,
       }
     }
 
-    // Restore the old exiting state, no viable looping successor was found.
     if (!HasLoopingSucc) {
+      // Restore the old exiting state, no viable looping successor was found.
       ExitingBB = OldExitingBB;
       BestExitEdgeFreq = OldBestExitEdgeFreq;
       continue;
@@ -889,7 +889,7 @@ void MachineBlockPlacement::buildCFGChains(MachineFunction &F) {
   // the assumptions of the remaining algorithm.
   SmallVector<MachineOperand, 4> Cond; // For AnalyzeBranch.
   for (MachineFunction::iterator FI = F.begin(), FE = F.end(); FI != FE; ++FI) {
-    MachineBasicBlock *BB = FI;
+    MachineBasicBlock *BB = &*FI;
     BlockChain *Chain =
         new (ChainAllocator.Allocate()) BlockChain(BlockToChain, BB);
     // Also, merge any blocks which we cannot reason about and must preserve
@@ -900,8 +900,8 @@ void MachineBlockPlacement::buildCFGChains(MachineFunction &F) {
       if (!TII->AnalyzeBranch(*BB, TBB, FBB, Cond) || !FI->canFallThrough())
         break;
 
-      MachineFunction::iterator NextFI(std::next(FI));
-      MachineBasicBlock *NextBB = NextFI;
+      MachineFunction::iterator NextFI = std::next(FI);
+      MachineBasicBlock *NextBB = &*NextFI;
       // Ensure that the layout successor is a viable block, as we know that
       // fallthrough is a possibility.
       assert(NextFI != FE && "Can't fallthrough past the last block.");
@@ -1004,7 +1004,7 @@ void MachineBlockPlacement::buildCFGChains(MachineFunction &F) {
     // Update the terminator of the previous block.
     if (ChainBB == *FunctionChain.begin())
       continue;
-    MachineBasicBlock *PrevBB = std::prev(MachineFunction::iterator(ChainBB));
+    MachineBasicBlock *PrevBB = &*std::prev(MachineFunction::iterator(ChainBB));
 
     // FIXME: It would be awesome of updateTerminator would just return rather
     // than assert when the branch cannot be analyzed in order to remove this
@@ -1064,13 +1064,14 @@ void MachineBlockPlacement::buildCFGChains(MachineFunction &F) {
   // exclusively on the loop info here so that we can align backedges in
   // unnatural CFGs and backedges that were introduced purely because of the
   // loop rotations done during this layout pass.
+  // FIXME: Use Function::optForSize().
   if (F.getFunction()->hasFnAttribute(Attribute::OptimizeForSize))
     return;
   if (FunctionChain.begin() == FunctionChain.end())
     return; // Empty chain.
 
   const BranchProbability ColdProb(1, 5); // 20%
-  BlockFrequency EntryFreq = MBFI->getBlockFreq(F.begin());
+  BlockFrequency EntryFreq = MBFI->getBlockFreq(&F.front());
   BlockFrequency WeightedEntryFreq = EntryFreq * ColdProb;
   for (MachineBasicBlock *ChainBB : FunctionChain) {
     if (ChainBB == *FunctionChain.begin())
@@ -1224,4 +1225,3 @@ bool MachineBlockPlacementStats::runOnMachineFunction(MachineFunction &F) {
 
   return false;
 }
-