//===-- BasicBlockPlacement.cpp - Basic Block Code Layout optimization ----===//
-//
+//
// The LLVM Compiler Infrastructure
//
-// This file was developed by the LLVM research group and is distributed under
-// the University of Illinois Open Source License. See LICENSE.TXT for details.
-//
+// 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
//
//===----------------------------------------------------------------------===//
+#define DEBUG_TYPE "block-placement"
#include "llvm/Analysis/ProfileInfo.h"
#include "llvm/Function.h"
#include "llvm/Pass.h"
#include "llvm/Support/CFG.h"
-#include "Support/Statistic.h"
+#include "llvm/ADT/Statistic.h"
+#include "llvm/Transforms/Scalar.h"
#include <set>
using namespace llvm;
+STATISTIC(NumMoved, "Number of basic blocks moved");
+
namespace {
- Statistic<> NumMoved("block-placement", "Number of basic blocks moved");
-
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 {
/// successors.
void PlaceBlocks(BasicBlock *BB);
};
-
- RegisterOpt<BlockPlacement> X("block-placement",
- "Profile Guided Basic Block Placement");
}
+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();
+ InsertPos = F.begin();
// Recursively place all blocks.
PlaceBlocks(F.begin());
-
- // If there are any unreachable blocks, move them to the end.
PlacedBlocks.clear();
NumMoved += NumMovedBlocks;
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.
-
- unsigned MaxExecutionCount = PI->getExecutionCount(*SI);
+
+ double MaxExecutionCount = PI->getExecutionCount(*SI);
BasicBlock *MaxSuccessor = *SI;
// Scan for more frequently executed successors
for (; SI != E; ++SI)
if (!PlacedBlocks.count(*SI)) {
- unsigned Count = PI->getExecutionCount(*SI);
+ double Count = PI->getExecutionCount(*SI);
if (Count > MaxExecutionCount ||
// Prefer to not disturb the code.
(Count == MaxExecutionCount && *SI == &*InsertPos)) {