From dfe81ab87aa44e51635b60c964ff6a792dcbc9d3 Mon Sep 17 00:00:00 2001 From: Chris Lattner Date: Mon, 6 May 2002 17:27:57 +0000 Subject: [PATCH] Clean up ADCE by removing extraneous wrapper class git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@2494 91177308-0d34-0410-b5e6-96231b3b80d8 --- lib/Transforms/Scalar/ADCE.cpp | 85 +++++++++++++++++----------------- 1 file changed, 42 insertions(+), 43 deletions(-) diff --git a/lib/Transforms/Scalar/ADCE.cpp b/lib/Transforms/Scalar/ADCE.cpp index 4c322aa9d38..5a951078609 100644 --- a/lib/Transforms/Scalar/ADCE.cpp +++ b/lib/Transforms/Scalar/ADCE.cpp @@ -21,14 +21,16 @@ using std::cerr; #define DEBUG_ADCE 1 +namespace { + //===----------------------------------------------------------------------===// // ADCE Class // // This class does all of the work of Agressive Dead Code Elimination. // It's public interface consists of a constructor and a doADCE() method. // -class ADCE { - Function *M; // The function that we are working on +class ADCE : public FunctionPass { + Function *Func; // The function that we are working on std::vector WorkList; // Instructions that just became live std::set LiveSet; // The set of live instructions bool MadeChanges; @@ -37,17 +39,33 @@ class ADCE { // The public interface for this class // public: - // ADCE Ctor - Save the function to operate on... - inline ADCE(Function *f) : M(f), MadeChanges(false) {} + const char *getPassName() const { return "Aggressive Dead Code Elimination"; } + + // doADCE - Execute the Agressive Dead Code Elimination Algorithm + // + virtual bool runOnFunction(Function *F) { + Func = F; MadeChanges = false; + doADCE(getAnalysis(DominanceFrontier::PostDomID)); + assert(WorkList.empty()); + LiveSet.clear(); + return MadeChanges; + } + // getAnalysisUsage - We require post dominance frontiers (aka Control + // Dependence Graph) + virtual void getAnalysisUsage(AnalysisUsage &AU) const { + AU.addRequired(DominanceFrontier::PostDomID); + } - // doADCE() - Run the Agressive Dead Code Elimination algorithm, returning - // true if the function was modified. - bool doADCE(DominanceFrontier &CDG); //===--------------------------------------------------------------------===// // The implementation of this class // private: + // doADCE() - Run the Agressive Dead Code Elimination algorithm, returning + // true if the function was modified. + // + void doADCE(DominanceFrontier &CDG); + inline void markInstructionLive(Instruction *I) { if (LiveSet.count(I)) return; #ifdef DEBUG_ADCE @@ -71,14 +89,19 @@ private: const std::set &AliveBlocks); }; +} // End of anonymous namespace + +Pass *createAgressiveDCEPass() { + return new ADCE(); +} // doADCE() - Run the Agressive Dead Code Elimination algorithm, returning // true if the function was modified. // -bool ADCE::doADCE(DominanceFrontier &CDG) { +void ADCE::doADCE(DominanceFrontier &CDG) { #ifdef DEBUG_ADCE - cerr << "Function: " << M; + cerr << "Function: " << Func; #endif // Iterate over all of the instructions in the function, eliminating trivially @@ -87,8 +110,7 @@ bool ADCE::doADCE(DominanceFrontier &CDG) { // instructions live in basic blocks that are unreachable. These blocks will // be eliminated later, along with the instructions inside. // - for (df_iterator BBI = df_begin(M), - BBE = df_end(M); + for (df_iterator BBI = df_begin(Func), BBE = df_end(Func); BBI != BBE; ++BBI) { BasicBlock *BB = *BBI; for (BasicBlock::iterator II = BB->begin(), EI = BB->end(); II != EI; ) { @@ -156,7 +178,7 @@ bool ADCE::doADCE(DominanceFrontier &CDG) { #ifdef DEBUG_ADCE cerr << "Current Function: X = Live\n"; - for (Function::iterator I = M->begin(), E = M->end(); I != E; ++I) + for (Function::iterator I = Func->begin(), E = Func->end(); I != E; ++I) for (BasicBlock::iterator BI = (*I)->begin(), BE = (*I)->end(); BI != BE; ++BI) { if (LiveSet.count(*BI)) cerr << "X "; @@ -168,14 +190,14 @@ bool ADCE::doADCE(DominanceFrontier &CDG) { // order, patching up references to dead blocks... // std::set VisitedBlocks; - BasicBlock *EntryBlock = fixupCFG(M->front(), VisitedBlocks, AliveBlocks); - if (EntryBlock && EntryBlock != M->front()) { + BasicBlock *EntryBlock = fixupCFG(Func->front(), VisitedBlocks, AliveBlocks); + if (EntryBlock && EntryBlock != Func->front()) { if (isa(EntryBlock->front())) { // Cannot make the first block be a block with a PHI node in it! Instead, // strip the first basic block of the function to contain no instructions, // then add a simple branch to the "real" entry node... // - BasicBlock *E = M->front(); + BasicBlock *E = Func->front(); if (!isa(E->front()) || // Check for an actual change... cast(E->front())->getNumSuccessors() != 1 || cast(E->front())->getSuccessor(0) != EntryBlock) { @@ -191,8 +213,8 @@ bool ADCE::doADCE(DominanceFrontier &CDG) { } else { // We need to move the new entry block to be the first bb of the function - Function::iterator EBI = find(M->begin(), M->end(), EntryBlock); - std::swap(*EBI, *M->begin()); // Exchange old location with start of fn + Function::iterator EBI = find(Func->begin(), Func->end(), EntryBlock); + std::swap(*EBI, *Func->begin()); // Exchange old location with start of fn MadeChanges = true; } } @@ -200,7 +222,7 @@ bool ADCE::doADCE(DominanceFrontier &CDG) { // Now go through and tell dead blocks to drop all of their references so they // can be safely deleted. // - for (Function::iterator BI = M->begin(), BE = M->end(); BI != BE; ++BI) { + for (Function::iterator BI = Func->begin(), BE = Func->end(); BI != BE; ++BI){ BasicBlock *BB = *BI; if (!AliveBlocks.count(BB)) { BB->dropAllReferences(); @@ -211,16 +233,14 @@ bool ADCE::doADCE(DominanceFrontier &CDG) { // now because we know that there are no references to dead blocks (because // they have dropped all of their references... // - for (Function::iterator BI = M->begin(); BI != M->end();) { + for (Function::iterator BI = Func->begin(); BI != Func->end();) { if (!AliveBlocks.count(*BI)) { - delete M->getBasicBlocks().remove(BI); + delete Func->getBasicBlocks().remove(BI); MadeChanges = true; continue; // Don't increment iterator } ++BI; // Increment iterator... } - - return MadeChanges; } @@ -287,24 +307,3 @@ BasicBlock *ADCE::fixupCFG(BasicBlock *BB, std::set &VisitedBlocks, } } -namespace { - struct AgressiveDCE : public FunctionPass { - const char *getPassName() const {return "Aggressive Dead Code Elimination";} - - // doADCE - Execute the Agressive Dead Code Elimination Algorithm - // - virtual bool runOnFunction(Function *F) { - return ADCE(F).doADCE( - getAnalysis(DominanceFrontier::PostDomID)); - } - // getAnalysisUsage - We require post dominance frontiers (aka Control - // Dependence Graph) - virtual void getAnalysisUsage(AnalysisUsage &AU) const { - AU.addRequired(DominanceFrontier::PostDomID); - } - }; -} - -Pass *createAgressiveDCEPass() { - return new AgressiveDCE(); -}