diff options
Diffstat (limited to 'lib/Transforms/IPO/AddReadAttrs.cpp')
| -rw-r--r-- | lib/Transforms/IPO/AddReadAttrs.cpp | 10 |
1 files changed, 6 insertions, 4 deletions
diff --git a/lib/Transforms/IPO/AddReadAttrs.cpp b/lib/Transforms/IPO/AddReadAttrs.cpp index 3e7d860d1d..b70bdaf763 100644 --- a/lib/Transforms/IPO/AddReadAttrs.cpp +++ b/lib/Transforms/IPO/AddReadAttrs.cpp @@ -47,14 +47,14 @@ Pass *llvm::createAddReadAttrsPass() { return new AddReadAttrs(); } bool AddReadAttrs::runOnSCC(const std::vector<CallGraphNode *> &SCC) { CallGraph &CG = getAnalysis<CallGraph>(); - // Check if any of the functions in the SCC read or write memory. - // If they write memory then just give up. + // Check if any of the functions in the SCC read or write memory. If they + // write memory then they can't be marked readnone or readonly. bool ReadsMemory = false; for (unsigned i = 0, e = SCC.size(); i != e; ++i) { Function *F = SCC[i]->getFunction(); if (F == 0) - // External node - may write memory. + // External node - may write memory. Just give up. return false; if (F->doesNotAccessMemory()) @@ -65,7 +65,7 @@ bool AddReadAttrs::runOnSCC(const std::vector<CallGraphNode *> &SCC) { // something that writes memory, so treat them like declarations. if (F->isDeclaration() || F->mayBeOverridden()) { if (!F->onlyReadsMemory()) - // May write memory. + // May write memory. Just give up. return false; ReadsMemory = true; @@ -83,7 +83,9 @@ bool AddReadAttrs::runOnSCC(const std::vector<CallGraphNode *> &SCC) { continue; if (II->mayWriteToMemory()) + // Writes memory. Just give up. return false; + ReadsMemory |= II->mayReadFromMemory(); } } |