llvm-6502/include/llvm/Transforms/Utils/Local.h
Chris Lattner 04d8dc31f6 - Do not expose Critical Edge breaking mechanics outside the BCE pass, thus
removing it from Transforms/Local.h and from Transforms/Utils/*


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@3909 91177308-0d34-0410-b5e6-96231b3b80d8
2002-09-24 15:51:54 +00:00

64 lines
2.2 KiB
C++

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