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-rw-r--r--lib/Transforms/Utils/LoopExtractor.cpp69
1 files changed, 69 insertions, 0 deletions
diff --git a/lib/Transforms/Utils/LoopExtractor.cpp b/lib/Transforms/Utils/LoopExtractor.cpp
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+//===- LoopExtractor.cpp - Extract each loop into a new function ----------===//
+//
+// A pass wrapper around the ExtractLoop() scalar transformation to extract each
+// top-level loop into its own new function. If the loop is the ONLY loop in a
+// given function, it is not touched.
+//
+//===----------------------------------------------------------------------===//
+
+#include "llvm/Module.h"
+#include "llvm/Pass.h"
+#include "llvm/Analysis/LoopInfo.h"
+#include "llvm/Transforms/Scalar.h"
+#include "llvm/Transforms/Utils/FunctionUtils.h"
+#include <vector>
+using namespace llvm;
+
+namespace {
+
+// FIXME: PassManager should allow Module passes to require FunctionPasses
+struct LoopExtraction : public FunctionPass {
+
+public:
+ LoopExtractor() {}
+ virtual bool run(Module &M);
+ virtual bool runOnFunction(Function &F);
+
+ virtual void getAnalysisUsage(AnalysisUsage &AU) const {
+ AU.addRequired<LoopInfo>();
+ }
+
+};
+
+RegisterOpt<LoopExtractor>
+X("loop-extract", "Extract loops into new functions");
+
+bool LoopExtractor::run(Module &M) {
+ bool Changed = false;
+ for (Module::iterator i = M.begin(), e = M.end(); i != e; ++i)
+ Changed |= runOnFunction(*i);
+ return Changed;
+}
+
+bool LoopExtractor::runOnFunction(Function &F) {
+ std::cerr << F.getName() << "\n";
+
+ LoopInfo &LI = getAnalysis<LoopInfo>();
+
+ // We don't want to keep extracting the only loop of a function into a new one
+ if (LI.begin() == LI.end() || LI.begin() + 1 == LI.end())
+ return false;
+
+ bool Changed = false;
+
+ // Try to move each loop out of the code into separate function
+ for (LoopInfo::iterator i = LI.begin(), e = LI.end(); i != e; ++i)
+ Changed |= (ExtractLoop(*i) != 0);
+
+ return Changed;
+}
+
+
+
+} // End anonymous namespace
+
+/// createLoopExtractorPass
+///
+FunctionPass* llvm::createLoopExtractorPass() {
+ return new LoopExtractor;
+}