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Diffstat (limited to 'lib/Transforms/Scalar/MarkModRef.cpp')
-rw-r--r-- | lib/Transforms/Scalar/MarkModRef.cpp | 69 |
1 files changed, 0 insertions, 69 deletions
diff --git a/lib/Transforms/Scalar/MarkModRef.cpp b/lib/Transforms/Scalar/MarkModRef.cpp deleted file mode 100644 index 5e83ee9310..0000000000 --- a/lib/Transforms/Scalar/MarkModRef.cpp +++ /dev/null @@ -1,69 +0,0 @@ -//===--------- MarkModRef.cpp - Mark functions readnone/readonly ----------===// -// -// The LLVM Compiler Infrastructure -// -// This file is distributed under the University of Illinois Open Source -// License. See LICENSE.TXT for details. -// -//===----------------------------------------------------------------------===// -// -// This pass marks functions readnone/readonly based on the results of alias -// analysis. This requires a sufficiently powerful alias analysis, such as -// GlobalsModRef (invoke as "opt ... -globalsmodref-aa -markmodref ..."). -// -//===----------------------------------------------------------------------===// - -#define DEBUG_TYPE "markmodref" -#include "llvm/ADT/Statistic.h" -#include "llvm/Analysis/AliasAnalysis.h" -#include "llvm/Support/Compiler.h" -#include "llvm/Transforms/Scalar.h" -#include "llvm/Function.h" -#include "llvm/Pass.h" -using namespace llvm; - -STATISTIC(NumReadNone, "Number of functions marked readnone"); -STATISTIC(NumReadOnly, "Number of functions marked readonly"); - -namespace { - struct VISIBILITY_HIDDEN MarkModRef : public FunctionPass { - static char ID; // Pass identification, replacement for typeid - MarkModRef() : FunctionPass(&ID) {} - - bool runOnFunction(Function &F); - - virtual void getAnalysisUsage(AnalysisUsage &AU) const { - AU.setPreservesCFG(); - AU.addRequired<AliasAnalysis>(); - AU.addPreserved<AliasAnalysis>(); - } - }; -} - -char MarkModRef::ID = 0; -static RegisterPass<MarkModRef> -X("markmodref", "Mark functions readnone/readonly"); - -bool MarkModRef::runOnFunction(Function &F) { - // FIXME: Wrong for functions with weak linkage. - if (F.doesNotAccessMemory()) - // Cannot do better. - return false; - - AliasAnalysis &AA = getAnalysis<AliasAnalysis>(); - AliasAnalysis::ModRefBehavior ModRef = AA.getModRefBehavior(&F); - if (ModRef == AliasAnalysis::DoesNotAccessMemory) { - F.setDoesNotAccessMemory(); - NumReadNone++; - return true; - } else if (ModRef == AliasAnalysis::OnlyReadsMemory && !F.onlyReadsMemory()) { - F.setOnlyReadsMemory(); - NumReadOnly++; - return true; - } - return false; -} - -FunctionPass *llvm::createMarkModRefPass() { - return new MarkModRef(); -} |