diff options
| -rw-r--r-- | include/llvm/Analysis/AliasAnalysis.h | 13 | ||||
| -rw-r--r-- | lib/Transforms/IPO/FunctionAttrs.cpp | 5 |
2 files changed, 12 insertions, 6 deletions
diff --git a/include/llvm/Analysis/AliasAnalysis.h b/include/llvm/Analysis/AliasAnalysis.h index 6b716ddee9..12b2090b17 100644 --- a/include/llvm/Analysis/AliasAnalysis.h +++ b/include/llvm/Analysis/AliasAnalysis.h @@ -268,14 +268,21 @@ public: return onlyReadsMemory(getModRefBehavior(F)); } - /// onlyReadsMemory - If the functions with the specified behavior are known - /// to only read from non-volatile memory (or not access memory at all), return - /// true. For use when the call site is not known. + /// onlyReadsMemory - Return true if functions with the specified behavior are + /// known to only read from non-volatile memory (or not access memory at all). /// static bool onlyReadsMemory(ModRefBehavior MRB) { return !(MRB & Mod); } + /// onlyAccessesArgPointees - Return true if functions with the specified + /// behavior are known to read at most from objects pointed to by their + /// pointer-typed arguments (with arbitrary offsets). + /// + static bool onlyAccessesArgPointees(ModRefBehavior MRB) { + return !(MRB & Anywhere & ~ArgumentPointees); + } + /// getModRefInfo - Return information about whether or not an instruction may /// read or write the specified memory location. An instruction /// that doesn't read or write memory may be trivially LICM'd for example. diff --git a/lib/Transforms/IPO/FunctionAttrs.cpp b/lib/Transforms/IPO/FunctionAttrs.cpp index 3b1b13d378..2e3440066e 100644 --- a/lib/Transforms/IPO/FunctionAttrs.cpp +++ b/lib/Transforms/IPO/FunctionAttrs.cpp @@ -131,9 +131,8 @@ bool FunctionAttrs::AddReadAttrs(const CallGraphSCC &SCC) { AliasAnalysis::ModRefBehavior MRB = AA->getModRefBehavior(CS); // If the call doesn't access arbitrary memory, we may be able to // figure out something. - if (!(MRB & AliasAnalysis::Anywhere & - ~AliasAnalysis::ArgumentPointees)) { - // If the call accesses argument pointees, check each argument. + if (AliasAnalysis::onlyAccessesArgPointees(MRB)) { + // If the call does access argument pointees, check each argument. if (MRB & AliasAnalysis::AccessesArguments) // Check whether all pointer arguments point to local memory, and // ignore calls that only access local memory. |