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git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@2777 91177308-0d34-0410-b5e6-96231b3b80d8
63 lines
2.2 KiB
C++
63 lines
2.2 KiB
C++
//===-- Local.h - Functions to perform local transformations -----*- C++ -*--=//
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//
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// This family of functions perform various local transformations to the
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// program.
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//
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//===----------------------------------------------------------------------===//
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#ifndef LLVM_TRANSFORMS_UTILS_LOCAL_H
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#define LLVM_TRANSFORMS_UTILS_LOCAL_H
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#include "llvm/Function.h"
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#include "llvm/BasicBlock.h"
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//===----------------------------------------------------------------------===//
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// Local constant propogation...
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//
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// doConstantPropogation - Constant prop a specific instruction. Returns true
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// and potentially moves the iterator if constant propogation was performed.
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//
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bool doConstantPropogation(BasicBlock::iterator &I);
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// ConstantFoldTerminator - If a terminator instruction is predicated on a
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// constant value, convert it into an unconditional branch to the constant
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// destination. This is a nontrivial operation because the successors of this
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// basic block must have their PHI nodes updated.
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//
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bool ConstantFoldTerminator(BasicBlock *BB);
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//===----------------------------------------------------------------------===//
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// Local dead code elimination...
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//
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// isInstructionTriviallyDead - Return true if the result produced by the
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// instruction is not used, and the instruction has no side effects.
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//
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bool isInstructionTriviallyDead(Instruction *I);
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// dceInstruction - Inspect the instruction at *BBI and figure out if it
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// isTriviallyDead. If so, remove the instruction and update the iterator to
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// point to the instruction that immediately succeeded the original instruction.
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//
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bool dceInstruction(BasicBlock::iterator &BBI);
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//===----------------------------------------------------------------------===//
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// Control Flow Graph Restructuring...
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//
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// SimplifyCFG - This function is used to do simplification of a CFG. For
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// example, it adjusts branches to branches to eliminate the extra hop, it
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// eliminates unreachable basic blocks, and does other "peephole" optimization
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// of the CFG. It returns true if a modification was made, possibly deleting
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// the basic block that was pointed to.
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//
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// WARNING: The entry node of a method may not be simplified.
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//
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bool SimplifyCFG(BasicBlock *BB);
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#endif
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