1 files changed, 0 insertions, 152 deletions
diff --git a/lib/Transforms/Scalar/BasicBlockPlacement.cpp b/lib/Transforms/Scalar/BasicBlockPlacement.cpp
deleted file mode 100644
index e755008..0000000
--- a/lib/Transforms/Scalar/BasicBlockPlacement.cpp
+++ /dev/null
@@ -1,152 +0,0 @@
-//===-- BasicBlockPlacement.cpp - Basic Block Code Layout optimization ----===//
-//
-//                     The LLVM Compiler Infrastructure
-//
-// This file is distributed under the University of Illinois Open Source
-// License. See LICENSE.TXT for details.
-//
-//===----------------------------------------------------------------------===//
-//
-// This file implements a very simple profile guided basic block placement
-// algorithm.  The idea is to put frequently executed blocks together at the
-// start of the function, and hopefully increase the number of fall-through
-// conditional branches.  If there is no profile information for a particular
-// function, this pass basically orders blocks in depth-first order
-//
-// The algorithm implemented here is basically "Algo1" from "Profile Guided Code
-// Positioning" by Pettis and Hansen, except that it uses basic block counts
-// instead of edge counts.  This should be improved in many ways, but is very
-// simple for now.
-//
-// Basically we "place" the entry block, then loop over all successors in a DFO,
-// placing the most frequently executed successor until we run out of blocks.  I
-// told you this was _extremely_ simplistic. :) This is also much slower than it
-// could be.  When it becomes important, this pass will be rewritten to use a
-// better algorithm, and then we can worry about efficiency.
-//
-//===----------------------------------------------------------------------===//
-
-#define DEBUG_TYPE "block-placement"
-#include "llvm/Transforms/Scalar.h"
-#include "llvm/ADT/Statistic.h"
-#include "llvm/Analysis/ProfileInfo.h"
-#include "llvm/IR/Function.h"
-#include "llvm/Pass.h"
-#include "llvm/Support/CFG.h"
-#include <set>
-using namespace llvm;
-
-STATISTIC(NumMoved, "Number of basic blocks moved");
-
-namespace {
-  struct BlockPlacement : public FunctionPass {
-    static char ID; // Pass identification, replacement for typeid
-    BlockPlacement() : FunctionPass(ID) {
-      initializeBlockPlacementPass(*PassRegistry::getPassRegistry());
-    }
-
-    virtual bool runOnFunction(Function &F);
-
-    virtual void getAnalysisUsage(AnalysisUsage &AU) const {
-      AU.setPreservesCFG();
-      AU.addRequired<ProfileInfo>();
-      //AU.addPreserved<ProfileInfo>();  // Does this work?
-    }
-  private:
-    /// PI - The profile information that is guiding us.
-    ///
-    ProfileInfo *PI;
-
-    /// NumMovedBlocks - Every time we move a block, increment this counter.
-    ///
-    unsigned NumMovedBlocks;
-
-    /// PlacedBlocks - Every time we place a block, remember it so we don't get
-    /// into infinite loops.
-    std::set<BasicBlock*> PlacedBlocks;
-
-    /// InsertPos - This an iterator to the next place we want to insert a
-    /// block.
-    Function::iterator InsertPos;
-
-    /// PlaceBlocks - Recursively place the specified blocks and any unplaced
-    /// successors.
-    void PlaceBlocks(BasicBlock *BB);
-  };
-}
-
-char BlockPlacement::ID = 0;
-INITIALIZE_PASS_BEGIN(BlockPlacement, "block-placement",
-                "Profile Guided Basic Block Placement", false, false)
-INITIALIZE_AG_DEPENDENCY(ProfileInfo)
-INITIALIZE_PASS_END(BlockPlacement, "block-placement",
-                "Profile Guided Basic Block Placement", false, false)
-
-FunctionPass *llvm::createBlockPlacementPass() { return new BlockPlacement(); }
-
-bool BlockPlacement::runOnFunction(Function &F) {
-  PI = &getAnalysis<ProfileInfo>();
-
-  NumMovedBlocks = 0;
-  InsertPos = F.begin();
-
-  // Recursively place all blocks.
-  PlaceBlocks(F.begin());
-
-  PlacedBlocks.clear();
-  NumMoved += NumMovedBlocks;
-  return NumMovedBlocks != 0;
-}
-
-
-/// PlaceBlocks - Recursively place the specified blocks and any unplaced
-/// successors.
-void BlockPlacement::PlaceBlocks(BasicBlock *BB) {
-  assert(!PlacedBlocks.count(BB) && "Already placed this block!");
-  PlacedBlocks.insert(BB);
-
-  // Place the specified block.
-  if (&*InsertPos != BB) {
-    // Use splice to move the block into the right place.  This avoids having to
-    // remove the block from the function then readd it, which causes a bunch of
-    // symbol table traffic that is entirely pointless.
-    Function::BasicBlockListType &Blocks = BB->getParent()->getBasicBlockList();
-    Blocks.splice(InsertPos, Blocks, BB);
-
-    ++NumMovedBlocks;
-  } else {
-    // This block is already in the right place, we don't have to do anything.
-    ++InsertPos;
-  }
-
-  // Keep placing successors until we run out of ones to place.  Note that this
-  // loop is very inefficient (N^2) for blocks with many successors, like switch
-  // statements.  FIXME!
-  while (1) {
-    // Okay, now place any unplaced successors.
-    succ_iterator SI = succ_begin(BB), E = succ_end(BB);
-
-    // Scan for the first unplaced successor.
-    for (; SI != E && PlacedBlocks.count(*SI); ++SI)
-      /*empty*/;
-    if (SI == E) return;  // No more successors to place.
-
-    double MaxExecutionCount = PI->getExecutionCount(*SI);
-    BasicBlock *MaxSuccessor = *SI;
-
-    // Scan for more frequently executed successors
-    for (; SI != E; ++SI)
-      if (!PlacedBlocks.count(*SI)) {
-        double Count = PI->getExecutionCount(*SI);
-        if (Count > MaxExecutionCount ||
-            // Prefer to not disturb the code.
-            (Count == MaxExecutionCount && *SI == &*InsertPos)) {
-          MaxExecutionCount = Count;
-          MaxSuccessor = *SI;
-        }
-      }
-
-    // Now that we picked the maximally executed successor, place it.
-    PlaceBlocks(MaxSuccessor);
-  }
-}