mirror of
https://github.com/c64scene-ar/llvm-6502.git
synced 2024-11-01 15:11:24 +00:00
2c7c54c86c
In order to enable the preservation of noalias function parameter information after inlining, and the representation of block-level __restrict__ pointer information (etc.), additional kinds of aliasing metadata will be introduced. This metadata needs to be carried around in AliasAnalysis::Location objects (and MMOs at the SDAG level), and so we need to generalize the current scheme (which is hard-coded to just one TBAA MDNode*). This commit introduces only the necessary refactoring to allow for the introduction of other aliasing metadata types, but does not actually introduce any (that will come in a follow-up commit). What it does introduce is a new AAMDNodes structure to hold all of the aliasing metadata nodes associated with a particular memory-accessing instruction, and uses that structure instead of the raw MDNode* in AliasAnalysis::Location, etc. No functionality change intended. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@213859 91177308-0d34-0410-b5e6-96231b3b80d8
59 lines
2.4 KiB
C++
59 lines
2.4 KiB
C++
//===- 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
|
|
|
|
#include "llvm/IR/BasicBlock.h"
|
|
|
|
namespace llvm {
|
|
|
|
class AliasAnalysis;
|
|
class DataLayout;
|
|
class MDNode;
|
|
|
|
/// 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,
|
|
unsigned Align,
|
|
const DataLayout *TD = nullptr);
|
|
|
|
/// 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.
|
|
///
|
|
/// 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
|
|
/// is found, it is left unmodified.
|
|
Value *FindAvailableLoadedValue(Value *Ptr, BasicBlock *ScanBB,
|
|
BasicBlock::iterator &ScanFrom,
|
|
unsigned MaxInstsToScan = 6,
|
|
AliasAnalysis *AA = nullptr,
|
|
AAMDNodes *AATags = nullptr);
|
|
|
|
}
|
|
|
|
#endif
|