From 50cb9b40c2b00bd538371363c714a02a65d0398e Mon Sep 17 00:00:00 2001 From: Chris Lattner Date: Thu, 17 Mar 2005 20:16:58 +0000 Subject: simplify this function a bit, allow DS-AA to build on/improve the mod/ref results returned by AA, not just use one or the other. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@20662 91177308-0d34-0410-b5e6-96231b3b80d8 --- lib/Analysis/DataStructure/DataStructureAA.cpp | 19 +++++++++++-------- 1 file changed, 11 insertions(+), 8 deletions(-) (limited to 'lib/Analysis/DataStructure/DataStructureAA.cpp') diff --git a/lib/Analysis/DataStructure/DataStructureAA.cpp b/lib/Analysis/DataStructure/DataStructureAA.cpp index 74fdb1f..2d62162 100644 --- a/lib/Analysis/DataStructure/DataStructureAA.cpp +++ b/lib/Analysis/DataStructure/DataStructureAA.cpp @@ -173,9 +173,11 @@ AliasAnalysis::AliasResult DSAA::alias(const Value *V1, unsigned V1Size, /// AliasAnalysis::ModRefResult DSAA::getModRefInfo(CallSite CS, Value *P, unsigned Size) { + AliasAnalysis::ModRefResult Result =AliasAnalysis::getModRefInfo(CS, P, Size); Function *F = CS.getCalledFunction(); - if (!F || F->isExternal()) - return AliasAnalysis::getModRefInfo(CS, P, Size); + + if (!F || F->isExternal() || Result == NoModRef) + return Result; // Clone the function TD graph, clearing off Mod/Ref flags const Function *csParent = CS.getInstruction()->getParent()->getParent(); @@ -189,12 +191,13 @@ DSAA::getModRefInfo(CallSite CS, Value *P, unsigned Size) { // Report the flags that have been added const DSNodeHandle &DSH = TDGraph.getNodeForValue(P); - if (const DSNode *N = DSH.getNode()) - if (N->isModified()) - return N->isRead() ? ModRef : Mod; - else - return N->isRead() ? Ref : NoModRef; - return NoModRef; + if (const DSNode *N = DSH.getNode()) { + if (!N->isModified()) // We proved it was not modified. + Result = ModRefResult(Result & ~Mod); + if (!N->isRead()) // We proved it was not read. + Result = ModRefResult(Result & ~Ref); + } + return Result; } -- cgit v1.1