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AA metadata refactoring (introduce AAMDNodes)

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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
This commit is contained in:
Hal Finkel
2014-07-24 12:16:19 +00:00
parent a4abc43a56
commit 2c7c54c86c
50 changed files with 521 additions and 389 deletions
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20
lib/Transforms/Scalar/JumpThreading.cpp
View File

@ -26,6 +26,7 @@
#include "llvm/IR/DataLayout.h"
#include "llvm/IR/IntrinsicInst.h"
#include "llvm/IR/LLVMContext.h"
#include "llvm/IR/Metadata.h"
#include "llvm/IR/ValueHandle.h"
#include "llvm/Pass.h"
#include "llvm/Support/CommandLine.h"
@ -888,9 +889,10 @@ bool JumpThreading::SimplifyPartiallyRedundantLoad(LoadInst *LI) {
if (BBIt != LoadBB->begin())
return false;
// If all of the loads and stores that feed the value have the same TBAA tag,
// then we can propagate it onto any newly inserted loads.
MDNode *TBAATag = LI->getMetadata(LLVMContext::MD_tbaa);
// If all of the loads and stores that feed the value have the same AA tags,
// then we can propagate them onto any newly inserted loads.
AAMDNodes AATags;
LI->getAAMetadata(AATags);
SmallPtrSet<BasicBlock*, 8> PredsScanned;
typedef SmallVector<std::pair<BasicBlock*, Value*>, 8> AvailablePredsTy;
@ -909,16 +911,16 @@ bool JumpThreading::SimplifyPartiallyRedundantLoad(LoadInst *LI) {
// Scan the predecessor to see if the value is available in the pred.
BBIt = PredBB->end();
MDNode *ThisTBAATag = nullptr;
AAMDNodes ThisAATags;
Value *PredAvailable = FindAvailableLoadedValue(LoadedPtr, PredBB, BBIt, 6,
nullptr, &ThisTBAATag);
nullptr, &ThisAATags);
if (!PredAvailable) {
OneUnavailablePred = PredBB;
continue;
}
// If tbaa tags disagree or are not present, forget about them.
if (TBAATag != ThisTBAATag) TBAATag = nullptr;
// If AA tags disagree or are not present, forget about them.
if (AATags != ThisAATags) AATags = AAMDNodes();
// If so, this load is partially redundant. Remember this info so that we
// can create a PHI node.
@ -978,8 +980,8 @@ bool JumpThreading::SimplifyPartiallyRedundantLoad(LoadInst *LI) {
LI->getAlignment(),
UnavailablePred->getTerminator());
NewVal->setDebugLoc(LI->getDebugLoc());
if (TBAATag)
NewVal->setMetadata(LLVMContext::MD_tbaa, TBAATag);
if (AATags)
NewVal->setAAMetadata(AATags);
AvailablePreds.push_back(std::make_pair(UnavailablePred, NewVal));
}