[llvm-commits] CVS: llvm/lib/Transforms/Utils/LoopExtractor.cpp

[Misha Brukman]

Changes in directory llvm/lib/Transforms/Utils:

LoopExtractor.cpp added (r1.1)

---
Log message:

A pass that uses the generic CodeExtractor to rip out *every* loop in every
function, as long as the loop isn't the only one in that function. This should
help debugging passes easier with BugPoint.


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Diffs of the changes:  (+69 -0)

Index: llvm/lib/Transforms/Utils/LoopExtractor.cpp
diff -c /dev/null llvm/lib/Transforms/Utils/LoopExtractor.cpp:1.1
*** /dev/null	Fri Feb 27 21:33:11 2004
--- llvm/lib/Transforms/Utils/LoopExtractor.cpp	Fri Feb 27 21:33:01 2004
***************
*** 0 ****
--- 1,69 ----
+ //===- 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;
+ }