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author | Chris Lattner <sabre@nondot.org> | 2004-01-30 22:15:41 +0000 |
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committer | Chris Lattner <sabre@nondot.org> | 2004-01-30 22:15:41 +0000 |
commit | 762e8e846f0ad50ffea56216c5ea20db1c95b756 (patch) | |
tree | a01d89abaf096bc80c30f2a6063c620af2a046ae /include | |
parent | cf93cdde567c2fd4a5e5539a736836cdfe935c66 (diff) | |
download | llvm-762e8e846f0ad50ffea56216c5ea20db1c95b756.tar.gz llvm-762e8e846f0ad50ffea56216c5ea20db1c95b756.tar.bz2 llvm-762e8e846f0ad50ffea56216c5ea20db1c95b756.tar.xz |
Add a new pointsToConstantMemory method to the AliasAnalysis interface
which can be implemented to improve the quality of mod-ref information.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@11020 91177308-0d34-0410-b5e6-96231b3b80d8
Diffstat (limited to 'include')
-rw-r--r-- | include/llvm/Analysis/AliasAnalysis.h | 9 |
1 files changed, 8 insertions, 1 deletions
diff --git a/include/llvm/Analysis/AliasAnalysis.h b/include/llvm/Analysis/AliasAnalysis.h index b0e9b23ab1..9b5d8ff037 100644 --- a/include/llvm/Analysis/AliasAnalysis.h +++ b/include/llvm/Analysis/AliasAnalysis.h @@ -95,6 +95,11 @@ public: /// virtual void getMustAliases(Value *P, std::vector<Value*> &RetVals) {} + /// pointsToConstantMemory - If the specified pointer is known to point into + /// constant global memory, return true. This allows disambiguation of store + /// instructions from constant pointers. + /// + virtual bool pointsToConstantMemory(const Value *P) { return false; } //===--------------------------------------------------------------------===// /// Simple mod/ref information... @@ -114,7 +119,9 @@ public: /// pointer. /// virtual ModRefResult getModRefInfo(CallSite CS, Value *P, unsigned Size) { - return ModRef; + // If P points to a constant memory location, the call definitely could not + // modify the memory location. + return pointsToConstantMemory(P) ? Ref : ModRef; } /// getModRefInfo - Return information about whether two call sites may refer |