From 2bcc808cf9eb24d7ed58c8913947d2f30fce76fe Mon Sep 17 00:00:00 2001 From: Ramkumar Ramachandra Date: Tue, 13 Jan 2015 03:46:47 +0000 Subject: [PATCH] Standardize {pred,succ,use,user}_empty() The functions {pred,succ,use,user}_{begin,end} exist, but many users have to check *_begin() with *_end() by hand to determine if the BasicBlock or User is empty. Fix this with a standard *_empty(), demonstrating a few usecases. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@225760 91177308-0d34-0410-b5e6-96231b3b80d8 --- include/llvm/IR/CFG.h | 6 ++++++ include/llvm/IR/Value.h | 2 ++ lib/Analysis/CFG.cpp | 2 +- lib/IR/Verifier.cpp | 2 +- lib/Transforms/IPO/PruneEH.cpp | 4 ++-- lib/Transforms/Scalar/JumpThreading.cpp | 4 ++-- lib/Transforms/Scalar/Reg2Mem.cpp | 2 +- lib/Transforms/Utils/SimplifyCFG.cpp | 6 +++--- 8 files changed, 18 insertions(+), 10 deletions(-) diff --git a/include/llvm/IR/CFG.h b/include/llvm/IR/CFG.h index c8be8bd1f2a..5400d238486 100644 --- a/include/llvm/IR/CFG.h +++ b/include/llvm/IR/CFG.h @@ -93,6 +93,9 @@ inline pred_iterator pred_end(BasicBlock *BB) { return pred_iterator(BB, true);} inline const_pred_iterator pred_end(const BasicBlock *BB) { return const_pred_iterator(BB, true); } +inline bool pred_empty(const BasicBlock *BB) { + return pred_begin(BB) == pred_end(BB); +} @@ -257,6 +260,9 @@ inline succ_iterator succ_end(BasicBlock *BB) { inline succ_const_iterator succ_end(const BasicBlock *BB) { return succ_const_iterator(BB->getTerminator(), true); } +inline bool succ_empty(const BasicBlock *BB) { + return succ_begin(BB) == succ_end(BB); +} template struct isPodLike > { static const bool value = isPodLike::value; diff --git a/include/llvm/IR/Value.h b/include/llvm/IR/Value.h index 92070210f2c..705fc0f52d5 100644 --- a/include/llvm/IR/Value.h +++ b/include/llvm/IR/Value.h @@ -286,6 +286,8 @@ public: return iterator_range(use_begin(), use_end()); } + bool user_empty() const { return UseList == nullptr; } + typedef user_iterator_impl user_iterator; typedef user_iterator_impl const_user_iterator; user_iterator user_begin() { return user_iterator(UseList); } diff --git a/lib/Analysis/CFG.cpp b/lib/Analysis/CFG.cpp index 25e7bc0fc40..8ecd70b5d71 100644 --- a/lib/Analysis/CFG.cpp +++ b/lib/Analysis/CFG.cpp @@ -27,7 +27,7 @@ using namespace llvm; void llvm::FindFunctionBackedges(const Function &F, SmallVectorImpl > &Result) { const BasicBlock *BB = &F.getEntryBlock(); - if (succ_begin(BB) == succ_end(BB)) + if (succ_empty(BB)) return; SmallPtrSet Visited; diff --git a/lib/IR/Verifier.cpp b/lib/IR/Verifier.cpp index e02b9e34fa6..4bf2d1a6dc6 100644 --- a/lib/IR/Verifier.cpp +++ b/lib/IR/Verifier.cpp @@ -1128,7 +1128,7 @@ void Verifier::visitFunction(const Function &F) { // Check the entry node const BasicBlock *Entry = &F.getEntryBlock(); - Assert1(pred_begin(Entry) == pred_end(Entry), + Assert1(pred_empty(Entry), "Entry block to function must not have predecessors!", Entry); // The address of the entry block cannot be taken, unless it is dead. diff --git a/lib/Transforms/IPO/PruneEH.cpp b/lib/Transforms/IPO/PruneEH.cpp index b2c4a099b02..7bd4ce12860 100644 --- a/lib/Transforms/IPO/PruneEH.cpp +++ b/lib/Transforms/IPO/PruneEH.cpp @@ -200,7 +200,7 @@ bool PruneEH::SimplifyFunction(Function *F) { BB->getInstList().pop_back(); // If the unwind block is now dead, nuke it. - if (pred_begin(UnwindBlock) == pred_end(UnwindBlock)) + if (pred_empty(UnwindBlock)) DeleteBasicBlock(UnwindBlock); // Delete the new BB. ++NumRemoved; @@ -234,7 +234,7 @@ bool PruneEH::SimplifyFunction(Function *F) { /// updating the callgraph to reflect any now-obsolete edges due to calls that /// exist in the BB. void PruneEH::DeleteBasicBlock(BasicBlock *BB) { - assert(pred_begin(BB) == pred_end(BB) && "BB is not dead!"); + assert(pred_empty(BB) && "BB is not dead!"); CallGraph &CG = getAnalysis().getCallGraph(); CallGraphNode *CGN = CG[BB->getParent()]; diff --git a/lib/Transforms/Scalar/JumpThreading.cpp b/lib/Transforms/Scalar/JumpThreading.cpp index 96bb2c8d191..78beb3f98dc 100644 --- a/lib/Transforms/Scalar/JumpThreading.cpp +++ b/lib/Transforms/Scalar/JumpThreading.cpp @@ -188,7 +188,7 @@ bool JumpThreading::runOnFunction(Function &F) { // If the block is trivially dead, zap it. This eliminates the successor // edges which simplifies the CFG. - if (pred_begin(BB) == pred_end(BB) && + if (pred_empty(BB) && BB != &BB->getParent()->getEntryBlock()) { DEBUG(dbgs() << " JT: Deleting dead block '" << BB->getName() << "' with terminator: " << *BB->getTerminator() << '\n'); @@ -662,7 +662,7 @@ static bool hasAddressTakenAndUsed(BasicBlock *BB) { bool JumpThreading::ProcessBlock(BasicBlock *BB) { // If the block is trivially dead, just return and let the caller nuke it. // This simplifies other transformations. - if (pred_begin(BB) == pred_end(BB) && + if (pred_empty(BB) && BB != &BB->getParent()->getEntryBlock()) return false; diff --git a/lib/Transforms/Scalar/Reg2Mem.cpp b/lib/Transforms/Scalar/Reg2Mem.cpp index b6023e2ce78..1b46727c17b 100644 --- a/lib/Transforms/Scalar/Reg2Mem.cpp +++ b/lib/Transforms/Scalar/Reg2Mem.cpp @@ -73,7 +73,7 @@ bool RegToMem::runOnFunction(Function &F) { // Insert all new allocas into entry block. BasicBlock *BBEntry = &F.getEntryBlock(); - assert(pred_begin(BBEntry) == pred_end(BBEntry) && + assert(pred_empty(BBEntry) && "Entry block to function must not have predecessors!"); // Find first non-alloca instruction and create insertion point. This is diff --git a/lib/Transforms/Utils/SimplifyCFG.cpp b/lib/Transforms/Utils/SimplifyCFG.cpp index 50ebdb77158..c8b6705ab5e 100644 --- a/lib/Transforms/Utils/SimplifyCFG.cpp +++ b/lib/Transforms/Utils/SimplifyCFG.cpp @@ -3020,7 +3020,7 @@ bool SimplifyCFGOpt::SimplifyReturn(ReturnInst *RI, IRBuilder<> &Builder) { } // If we eliminated all predecessors of the block, delete the block now. - if (pred_begin(BB) == pred_end(BB)) + if (pred_empty(BB)) // We know there are no successors, so just nuke the block. BB->eraseFromParent(); @@ -3193,7 +3193,7 @@ bool SimplifyCFGOpt::SimplifyUnreachable(UnreachableInst *UI) { } // If this block is now dead, remove it. - if (pred_begin(BB) == pred_end(BB) && + if (pred_empty(BB) && BB != &BB->getParent()->getEntryBlock()) { // We know there are no successors, so just nuke the block. BB->eraseFromParent(); @@ -4587,7 +4587,7 @@ bool SimplifyCFGOpt::run(BasicBlock *BB) { // Remove basic blocks that have no predecessors (except the entry block)... // or that just have themself as a predecessor. These are unreachable. - if ((pred_begin(BB) == pred_end(BB) && + if ((pred_emtpy(BB) && BB != &BB->getParent()->getEntryBlock()) || BB->getSinglePredecessor() == BB) { DEBUG(dbgs() << "Removing BB: \n" << *BB);