llvm-6502/include/llvm/Transforms/Utils/LoopUtils.h
Hal Finkel 73118c4128 Feeding isSafeToSpeculativelyExecute its DataLayout pointer
isSafeToSpeculativelyExecute can optionally take a DataLayout pointer. In the
past, this was mainly used to make better decisions regarding divisions known
not to trap, and so was not all that important for users concerned with "cheap"
instructions. However, now it also helps look through bitcasts for
dereferencable loads, and will also be important if/when we add a
dereferencable pointer attribute.

This is some initial work to feed a DataLayout pointer through to callers of
isSafeToSpeculativelyExecute, generally where one was already available.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@212720 91177308-0d34-0410-b5e6-96231b3b80d8
2014-07-10 14:41:31 +00:00

66 lines
2.2 KiB
C++

//===- llvm/Transforms/Utils/LoopUtils.h - Loop utilities -*- C++ -*-=========//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file defines some loop transformation utilities.
//
//===----------------------------------------------------------------------===//
#ifndef LLVM_TRANSFORMS_UTILS_LOOPUTILS_H
#define LLVM_TRANSFORMS_UTILS_LOOPUTILS_H
namespace llvm {
class AliasAnalysis;
class BasicBlock;
class DataLayout;
class DominatorTree;
class Loop;
class LoopInfo;
class Pass;
class ScalarEvolution;
BasicBlock *InsertPreheaderForLoop(Loop *L, Pass *P);
/// \brief Simplify each loop in a loop nest recursively.
///
/// This takes a potentially un-simplified loop L (and its children) and turns
/// it into a simplified loop nest with preheaders and single backedges. It
/// will optionally update \c AliasAnalysis and \c ScalarEvolution analyses if
/// passed into it.
bool simplifyLoop(Loop *L, DominatorTree *DT, LoopInfo *LI, Pass *PP,
AliasAnalysis *AA = nullptr, ScalarEvolution *SE = nullptr,
const DataLayout *DL = nullptr);
/// \brief Put loop into LCSSA form.
///
/// Looks at all instructions in the loop which have uses outside of the
/// current loop. For each, an LCSSA PHI node is inserted and the uses outside
/// the loop are rewritten to use this node.
///
/// LoopInfo and DominatorTree are required and preserved.
///
/// If ScalarEvolution is passed in, it will be preserved.
///
/// Returns true if any modifications are made to the loop.
bool formLCSSA(Loop &L, DominatorTree &DT, ScalarEvolution *SE = nullptr);
/// \brief Put a loop nest into LCSSA form.
///
/// This recursively forms LCSSA for a loop nest.
///
/// LoopInfo and DominatorTree are required and preserved.
///
/// If ScalarEvolution is passed in, it will be preserved.
///
/// Returns true if any modifications are made to the loop.
bool formLCSSARecursively(Loop &L, DominatorTree &DT,
ScalarEvolution *SE = nullptr);
}
#endif