Teach FunctionAttrs about AccessesArgumentsReadonly.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@118617 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Transforms/IPO/FunctionAttrs.cpp b/lib/Transforms/IPO/FunctionAttrs.cpp
index a217393..71671d6 100644
--- a/lib/Transforms/IPO/FunctionAttrs.cpp
+++ b/lib/Transforms/IPO/FunctionAttrs.cpp
@@ -152,6 +152,25 @@
}
// Only reads and writes local memory.
continue;
+ case AliasAnalysis::AccessesArgumentsReadonly:
+ // Check whether all pointer arguments point to local memory, and
+ // ignore calls that only access local memory.
+ for (CallSite::arg_iterator CI = CS.arg_begin(), CE = CS.arg_end();
+ CI != CE; ++CI) {
+ Value *Arg = *CI;
+ if (Arg->getType()->isPointerTy()) {
+ AliasAnalysis::Location Loc(Arg,
+ AliasAnalysis::UnknownSize,
+ I->getMetadata(LLVMContext::MD_tbaa));
+ if (!AA->pointsToConstantMemory(Loc, /*OrLocal=*/true)) {
+ // Reads non-local memory.
+ ReadsMemory = true;
+ break;
+ }
+ }
+ }
+ // Only reads memory.
+ continue;
default:
// Otherwise, be conservative.
break;