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* Expose new pass DeadInstElimination
* Add comments that describe the differences between the DCE passes git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@1553 91177308-0d34-0410-b5e6-96231b3b80d8
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@ -11,6 +11,26 @@
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#include "llvm/Pass.h"
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#include "llvm/BasicBlock.h"
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//===----------------------------------------------------------------------===//
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// DeadInstElimination - This pass quickly removes trivially dead instructions
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// without modifying the CFG of the function. It is a BasicBlockPass, so it
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// runs efficiently when queued next to other BasicBlockPass's.
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//
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struct DeadInstElimination : public BasicBlockPass {
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virtual bool runOnBasicBlock(BasicBlock *BB);
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};
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//===----------------------------------------------------------------------===//
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// DeadCodeElimination - This pass is more powerful than DeadInstElimination,
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// because it will remove dead basic blocks as well as all of the instructions
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// contained within them. This pass is useful to run after another pass has
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// reorganized the CFG and possibly modified control flow.
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//
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// TODO: In addition to DCE stuff, this also merges basic blocks together and
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// otherwise simplifies control flow. This should be factored out of this pass
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// eventually into it's own pass.
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//
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struct DeadCodeElimination : public MethodPass {
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// External Interface:
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//
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@ -42,6 +62,11 @@ struct DeadCodeElimination : public MethodPass {
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//===----------------------------------------------------------------------===//
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// AgressiveDCE - This pass uses the SSA based Agressive DCE algorithm. This
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// algorithm assumes instructions are dead until proven otherwise, which makes
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// it more successful are removing non-obviously dead instructions.
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//
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struct AgressiveDCE : public MethodPass {
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// DoADCE - Execute the Agressive Dead Code Elimination Algorithm
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//
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