diff options
Diffstat (limited to 'llvm/lib/Analysis/AliasAnalysis.cpp')
| -rw-r--r-- | llvm/lib/Analysis/AliasAnalysis.cpp | 15 |
1 files changed, 11 insertions, 4 deletions
diff --git a/llvm/lib/Analysis/AliasAnalysis.cpp b/llvm/lib/Analysis/AliasAnalysis.cpp index 3454ce0be2b..054930c0e19 100644 --- a/llvm/lib/Analysis/AliasAnalysis.cpp +++ b/llvm/lib/Analysis/AliasAnalysis.cpp @@ -450,6 +450,7 @@ AliasAnalysis::callCapturesBefore(const Instruction *I, return AliasAnalysis::ModRef; unsigned ArgNo = 0; + AliasAnalysis::ModRefResult R = AliasAnalysis::NoModRef; for (ImmutableCallSite::arg_iterator CI = CS.arg_begin(), CE = CS.arg_end(); CI != CE; ++CI, ++ArgNo) { // Only look at the no-capture or byval pointer arguments. If this @@ -463,12 +464,18 @@ AliasAnalysis::callCapturesBefore(const Instruction *I, // is impossible to alias the pointer we're checking. If not, we have to // assume that the call could touch the pointer, even though it doesn't // escape. - if (!isNoAlias(AliasAnalysis::Location(*CI), - AliasAnalysis::Location(Object))) { - return AliasAnalysis::ModRef; + if (isNoAlias(AliasAnalysis::Location(*CI), + AliasAnalysis::Location(Object))) + continue; + if (CS.doesNotAccessMemory(ArgNo)) + continue; + if (CS.onlyReadsMemory(ArgNo)) { + R = AliasAnalysis::Ref; + continue; } + return AliasAnalysis::ModRef; } - return AliasAnalysis::NoModRef; + return R; } // AliasAnalysis destructor: DO NOT move this to the header file for |
