2010-05-28 16:19:17 +00:00
|
|
|
//===- Loads.h - Local load analysis --------------------------------------===//
|
|
|
|
//
|
|
|
|
// The LLVM Compiler Infrastructure
|
|
|
|
//
|
|
|
|
// This file is distributed under the University of Illinois Open Source
|
|
|
|
// License. See LICENSE.TXT for details.
|
|
|
|
//
|
|
|
|
//===----------------------------------------------------------------------===//
|
|
|
|
//
|
|
|
|
// This file declares simple local analyses for load instructions.
|
|
|
|
//
|
|
|
|
//===----------------------------------------------------------------------===//
|
|
|
|
|
|
|
|
#ifndef LLVM_ANALYSIS_LOADS_H
|
|
|
|
#define LLVM_ANALYSIS_LOADS_H
|
|
|
|
|
2013-01-02 11:36:10 +00:00
|
|
|
#include "llvm/IR/BasicBlock.h"
|
2010-05-28 16:19:17 +00:00
|
|
|
|
|
|
|
namespace llvm {
|
|
|
|
|
|
|
|
class AliasAnalysis;
|
2012-10-08 16:38:25 +00:00
|
|
|
class DataLayout;
|
2012-03-13 18:07:41 +00:00
|
|
|
class MDNode;
|
2010-05-28 16:19:17 +00:00
|
|
|
|
|
|
|
/// isSafeToLoadUnconditionally - Return true if we know that executing a load
|
|
|
|
/// from this value cannot trap. If it is not obviously safe to load from the
|
|
|
|
/// specified pointer, we do a quick local scan of the basic block containing
|
|
|
|
/// ScanFrom, to determine if the address is already accessed.
|
|
|
|
bool isSafeToLoadUnconditionally(Value *V, Instruction *ScanFrom,
|
2015-03-10 02:37:25 +00:00
|
|
|
unsigned Align);
|
2010-05-28 16:19:17 +00:00
|
|
|
|
|
|
|
/// FindAvailableLoadedValue - Scan the ScanBB block backwards (starting at
|
|
|
|
/// the instruction before ScanFrom) checking to see if we have the value at
|
|
|
|
/// the memory address *Ptr locally available within a small number of
|
|
|
|
/// instructions. If the value is available, return it.
|
|
|
|
///
|
|
|
|
/// If not, return the iterator for the last validated instruction that the
|
|
|
|
/// value would be live through. If we scanned the entire block and didn't
|
|
|
|
/// find something that invalidates *Ptr or provides it, ScanFrom would be
|
|
|
|
/// left at begin() and this returns null. ScanFrom could also be left
|
|
|
|
///
|
|
|
|
/// MaxInstsToScan specifies the maximum instructions to scan in the block.
|
|
|
|
/// If it is set to 0, it will scan the whole block. You can also optionally
|
|
|
|
/// specify an alias analysis implementation, which makes this more precise.
|
2012-03-13 18:07:41 +00:00
|
|
|
///
|
2014-07-24 12:16:19 +00:00
|
|
|
/// If AATags is non-null and a load or store is found, the AA tags from the
|
|
|
|
/// load or store are recorded there. If there are no AA tags or if no access
|
2012-03-13 18:07:41 +00:00
|
|
|
/// is found, it is left unmodified.
|
2010-05-28 16:19:17 +00:00
|
|
|
Value *FindAvailableLoadedValue(Value *Ptr, BasicBlock *ScanBB,
|
|
|
|
BasicBlock::iterator &ScanFrom,
|
|
|
|
unsigned MaxInstsToScan = 6,
|
2014-04-15 04:59:12 +00:00
|
|
|
AliasAnalysis *AA = nullptr,
|
2014-07-24 12:16:19 +00:00
|
|
|
AAMDNodes *AATags = nullptr);
|
2010-05-28 16:19:17 +00:00
|
|
|
|
2015-06-23 09:49:53 +00:00
|
|
|
}
|
2010-05-28 16:19:17 +00:00
|
|
|
|
|
|
|
#endif
|