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DeadCodeElimination: clang-format and comment 

llvm-svn: 177782
This commit is contained in:
Tobias Grosser 2013-03-23 00:16:05 +00:00
parent 33bc2e93be
commit c30d9cc678
1 changed files with 22 additions and 23 deletions
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45
polly/lib/DeadCodeElimination.cpp
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@ -7,8 +7,16 @@
//
//===----------------------------------------------------------------------===//
//
// If values calculated within an iteration are not used later on the iteration
// can be removed entirely. This pass removes such iterations.
// This is a skeleton that is meant to contain a dead code elimination pass
// later on.
//
// The idea of this pass is to loop over all statements and to remove statement
// iterations that do not calculate any value that is read later on. We need to
// make sure to forward RAR and WAR dependences.
//
// A case where this pass might be useful is
// http://llvm.org/bugs/show_bug.cgi?id=5117
//
//===----------------------------------------------------------------------===//
#include "polly/Dependences.h"
@ -26,8 +34,7 @@ class DeadCodeElim : public ScopPass {
public:
static char ID;
explicit DeadCodeElim() : ScopPass(ID) {
}
explicit DeadCodeElim() : ScopPass(ID) {}
virtual bool runOnScop(Scop &S);
void printScop(llvm::raw_ostream &OS) const;
@ -40,36 +47,28 @@ char DeadCodeElim::ID = 0;
bool DeadCodeElim::runOnScop(Scop &S) {
Dependences *D = &getAnalysis<Dependences>();
int Kinds = Dependences::TYPE_RAW | Dependences::TYPE_WAR |
Dependences::TYPE_WAW;
int Kinds =
Dependences::TYPE_RAW | Dependences::TYPE_WAR | Dependences::TYPE_WAW;
isl_union_map *Deps = D->getDependences(Kinds);
// The idea of this pass is to loop over all statments and remove statement
// iterations that do not calculate any value that is read later on. We need
// to make sure to forward RAR and WAR dependences.
//
// A case where this pass might be useful is
// http://llvm.org/bugs/show_bug.cgi?id=5117
isl_union_map_free(Deps);
return false;
}
void DeadCodeElim::printScop(raw_ostream &OS) const {
}
void DeadCodeElim::printScop(raw_ostream &OS) const {}
void DeadCodeElim::getAnalysisUsage(AnalysisUsage &AU) const {
ScopPass::getAnalysisUsage(AU);
AU.addRequired<Dependences>();
}
INITIALIZE_PASS_BEGIN(DeadCodeElim, "polly-dce",
"Polly - Remove dead iterations", false, false)
INITIALIZE_PASS_DEPENDENCY(Dependences)
INITIALIZE_PASS_DEPENDENCY(ScopInfo)
INITIALIZE_PASS_END(DeadCodeElim, "polly-dce",
"Polly - Remove dead iterations", false, false)
Pass *polly::createDeadCodeElimPass() { return new DeadCodeElim(); }
INITIALIZE_PASS_BEGIN(DeadCodeElim, "polly-dce",
"Polly - Remove dead iterations", false, false);
INITIALIZE_PASS_DEPENDENCY(Dependences);
INITIALIZE_PASS_DEPENDENCY(ScopInfo);
INITIALIZE_PASS_END(DeadCodeElim, "polly-dce", "Polly - Remove dead iterations",
false, false)
Pass* polly::createDeadCodeElimPass() {
return new DeadCodeElim();
}