From f0608d829a7b8929108ac6718bd866adf710e936 Mon Sep 17 00:00:00 2001 From: Dan Gohman Date: Thu, 3 Sep 2009 16:10:48 +0000 Subject: [PATCH] Move getUniqueExitBlocks from LoopBase to Loop, since they depend on LoopSimplify form, which is currently only available on Loops (and not MachineLoops). Also, move the code out of the header file. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@80923 91177308-0d34-0410-b5e6-96231b3b80d8 --- include/llvm/Analysis/LoopInfo.h | 78 ++++---------------------------- lib/Analysis/LoopInfo.cpp | 68 ++++++++++++++++++++++++++++ 2 files changed, 78 insertions(+), 68 deletions(-) diff --git a/include/llvm/Analysis/LoopInfo.h b/include/llvm/Analysis/LoopInfo.h index b8617c134e4..b803176d889 100644 --- a/include/llvm/Analysis/LoopInfo.h +++ b/include/llvm/Analysis/LoopInfo.h @@ -230,74 +230,6 @@ public: ExitEdges.push_back(std::make_pair(*BI, *I)); } - /// getUniqueExitBlocks - Return all unique successor blocks of this loop. - /// These are the blocks _outside of the current loop_ which are branched to. - /// This assumes that loop is in canonical form. - /// - void getUniqueExitBlocks(SmallVectorImpl &ExitBlocks) const { - // Sort the blocks vector so that we can use binary search to do quick - // lookups. - SmallVector LoopBBs(block_begin(), block_end()); - std::sort(LoopBBs.begin(), LoopBBs.end()); - - std::vector switchExitBlocks; - - for (block_iterator BI = block_begin(), BE = block_end(); BI != BE; ++BI) { - - BlockT *current = *BI; - switchExitBlocks.clear(); - - typedef GraphTraits BlockTraits; - typedef GraphTraits > InvBlockTraits; - for (typename BlockTraits::ChildIteratorType I = - BlockTraits::child_begin(*BI), E = BlockTraits::child_end(*BI); - I != E; ++I) { - if (std::binary_search(LoopBBs.begin(), LoopBBs.end(), *I)) - // If block is inside the loop then it is not a exit block. - continue; - - typename InvBlockTraits::ChildIteratorType PI = - InvBlockTraits::child_begin(*I); - BlockT *firstPred = *PI; - - // If current basic block is this exit block's first predecessor - // then only insert exit block in to the output ExitBlocks vector. - // This ensures that same exit block is not inserted twice into - // ExitBlocks vector. - if (current != firstPred) - continue; - - // If a terminator has more then two successors, for example SwitchInst, - // then it is possible that there are multiple edges from current block - // to one exit block. - if (std::distance(BlockTraits::child_begin(current), - BlockTraits::child_end(current)) <= 2) { - ExitBlocks.push_back(*I); - continue; - } - - // In case of multiple edges from current block to exit block, collect - // only one edge in ExitBlocks. Use switchExitBlocks to keep track of - // duplicate edges. - if (std::find(switchExitBlocks.begin(), switchExitBlocks.end(), *I) - == switchExitBlocks.end()) { - switchExitBlocks.push_back(*I); - ExitBlocks.push_back(*I); - } - } - } - } - - /// getUniqueExitBlock - If getUniqueExitBlocks would return exactly one - /// block, return that block. Otherwise return null. - BlockT *getUniqueExitBlock() const { - SmallVector UniqueExitBlocks; - getUniqueExitBlocks(UniqueExitBlocks); - if (UniqueExitBlocks.size() == 1) - return UniqueExitBlocks[0]; - return 0; - } - /// getLoopPreheader - If there is a preheader for this loop, return it. A /// loop has a preheader if there is only one edge to the header of the loop /// from outside of the loop. If this is the case, the block branching to the @@ -569,6 +501,16 @@ public: /// normal form. bool isLoopSimplifyForm() const; + /// getUniqueExitBlocks - Return all unique successor blocks of this loop. + /// These are the blocks _outside of the current loop_ which are branched to. + /// This assumes that loop is in canonical form. + /// + void getUniqueExitBlocks(SmallVectorImpl &ExitBlocks) const; + + /// getUniqueExitBlock - If getUniqueExitBlocks would return exactly one + /// block, return that block. Otherwise return null. + BasicBlock *getUniqueExitBlock() const; + private: friend class LoopInfoBase; explicit Loop(BasicBlock *BB) : LoopBase(BB) {} diff --git a/lib/Analysis/LoopInfo.cpp b/lib/Analysis/LoopInfo.cpp index 25264801193..4245702ea10 100644 --- a/lib/Analysis/LoopInfo.cpp +++ b/lib/Analysis/LoopInfo.cpp @@ -294,6 +294,74 @@ bool Loop::isLoopSimplifyForm() const { return true; } +/// getUniqueExitBlocks - Return all unique successor blocks of this loop. +/// These are the blocks _outside of the current loop_ which are branched to. +/// This assumes that loop is in canonical form. +/// +void +Loop::getUniqueExitBlocks(SmallVectorImpl &ExitBlocks) const { + // Sort the blocks vector so that we can use binary search to do quick + // lookups. + SmallVector LoopBBs(block_begin(), block_end()); + std::sort(LoopBBs.begin(), LoopBBs.end()); + + std::vector switchExitBlocks; + + for (block_iterator BI = block_begin(), BE = block_end(); BI != BE; ++BI) { + + BasicBlock *current = *BI; + switchExitBlocks.clear(); + + typedef GraphTraits BlockTraits; + typedef GraphTraits > InvBlockTraits; + for (BlockTraits::ChildIteratorType I = + BlockTraits::child_begin(*BI), E = BlockTraits::child_end(*BI); + I != E; ++I) { + // If block is inside the loop then it is not a exit block. + if (std::binary_search(LoopBBs.begin(), LoopBBs.end(), *I)) + continue; + + InvBlockTraits::ChildIteratorType PI = InvBlockTraits::child_begin(*I); + BasicBlock *firstPred = *PI; + + // If current basic block is this exit block's first predecessor + // then only insert exit block in to the output ExitBlocks vector. + // This ensures that same exit block is not inserted twice into + // ExitBlocks vector. + if (current != firstPred) + continue; + + // If a terminator has more then two successors, for example SwitchInst, + // then it is possible that there are multiple edges from current block + // to one exit block. + if (std::distance(BlockTraits::child_begin(current), + BlockTraits::child_end(current)) <= 2) { + ExitBlocks.push_back(*I); + continue; + } + + // In case of multiple edges from current block to exit block, collect + // only one edge in ExitBlocks. Use switchExitBlocks to keep track of + // duplicate edges. + if (std::find(switchExitBlocks.begin(), switchExitBlocks.end(), *I) + == switchExitBlocks.end()) { + switchExitBlocks.push_back(*I); + ExitBlocks.push_back(*I); + } + } + } +} + +/// getUniqueExitBlock - If getUniqueExitBlocks would return exactly one +/// block, return that block. Otherwise return null. +BasicBlock *Loop::getUniqueExitBlock() const { + SmallVector UniqueExitBlocks; + getUniqueExitBlocks(UniqueExitBlocks); + if (UniqueExitBlocks.size() == 1) + return UniqueExitBlocks[0]; + return 0; +} + //===----------------------------------------------------------------------===// // LoopInfo implementation // -- 2.34.1