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author | Shuxin Yang <shuxin.llvm@gmail.com> | 2013-03-06 17:48:48 +0000 |
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committer | Shuxin Yang <shuxin.llvm@gmail.com> | 2013-03-06 17:48:48 +0000 |
commit | 985dac65791b9f6f631bdd51c18fe66592a67469 (patch) | |
tree | 9265b2aa99cf3753755535652b74ad4683c4bcaf /include/llvm/Analysis/MemoryDependenceAnalysis.h | |
parent | 186d8a3d67ccd2b2401c5d7d4e2cc15c4d1fdeae (diff) | |
download | llvm-985dac65791b9f6f631bdd51c18fe66592a67469.tar.gz llvm-985dac65791b9f6f631bdd51c18fe66592a67469.tar.bz2 llvm-985dac65791b9f6f631bdd51c18fe66592a67469.tar.xz |
Memory Dependence Analysis (not mem-dep test) take advantage of "invariant.load" metadata.
The "invariant.load" metadata indicates the memory unit being accessed is immutable.
A load annotated with this metadata can be moved across any store.
As I am not sure if it is legal to move such loads across barrier/fence, this
change dose not allow such transformation.
rdar://11311484
Thank Arnold for code review.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@176562 91177308-0d34-0410-b5e6-96231b3b80d8
Diffstat (limited to 'include/llvm/Analysis/MemoryDependenceAnalysis.h')
-rw-r--r-- | include/llvm/Analysis/MemoryDependenceAnalysis.h | 7 |
1 files changed, 5 insertions, 2 deletions
diff --git a/include/llvm/Analysis/MemoryDependenceAnalysis.h b/include/llvm/Analysis/MemoryDependenceAnalysis.h index b87f886c00..47afd1b77b 100644 --- a/include/llvm/Analysis/MemoryDependenceAnalysis.h +++ b/include/llvm/Analysis/MemoryDependenceAnalysis.h @@ -391,14 +391,17 @@ namespace llvm { /// getPointerDependencyFrom - Return the instruction on which a memory /// location depends. If isLoad is true, this routine ignores may-aliases /// with read-only operations. If isLoad is false, this routine ignores - /// may-aliases with reads from read-only locations. + /// may-aliases with reads from read-only locations. If possible, pass + /// the query instruction as well; this function may take advantage of + /// the metadata annotated to the query instruction to refine the result. /// /// Note that this is an uncached query, and thus may be inefficient. /// MemDepResult getPointerDependencyFrom(const AliasAnalysis::Location &Loc, bool isLoad, BasicBlock::iterator ScanIt, - BasicBlock *BB); + BasicBlock *BB, + Instruction *QueryInst = 0); /// getLoadLoadClobberFullWidthSize - This is a little bit of analysis that |