Checkin headers for Utils library

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@2528 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 64 insertions, 0 deletions

diff --git a/include/llvm/Transforms/Utils/Local.h b/include/llvm/Transforms/Utils/Local.h
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+//===-- 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"
+#include "llvm/BasicBlock.h"
+
+//===----------------------------------------------------------------------===//
+//  Local constant propogation...
+//
+
+// doConstantPropogation - Constant prop a specific instruction.  Returns true
+// and potentially moves the iterator if constant propogation was performed.
+//
+bool doConstantPropogation(BasicBlock *BB, 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, BasicBlock::iterator &I,
+                            TerminatorInst *T);
+
+
+//===----------------------------------------------------------------------===//
+//  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::InstListType &BBIL, 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, and returns an 
+// iterator that designates the first element remaining after the block that
+// was deleted.
+//
+// WARNING:  The entry node of a method may not be simplified.
+//
+bool SimplifyCFG(Function::iterator &BBIt);
+
+#endif