Add code to check at SelectionDAGISel::LowerArguments time to see if return values can be lowered to registers. Coming soon, code to perform sret-demotion if return values cannot be lowered to registers
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@86324 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/SelectionDAG/CallingConvLower.cpp b/lib/CodeGen/SelectionDAG/CallingConvLower.cpp
index fbe40b6..38839c4 100644
--- a/lib/CodeGen/SelectionDAG/CallingConvLower.cpp
+++ b/lib/CodeGen/SelectionDAG/CallingConvLower.cpp
@@ -77,6 +77,21 @@
}
}
+/// CheckReturn - Analyze the return values of a function, returning true if
+/// the return can be performed without sret-demotion, and false otherwise.
+bool CCState::CheckReturn(const SmallVectorImpl<EVT> &OutTys,
+ const SmallVectorImpl<ISD::ArgFlagsTy> &ArgsFlags,
+ CCAssignFn Fn) {
+ // Determine which register each value should be copied into.
+ for (unsigned i = 0, e = OutTys.size(); i != e; ++i) {
+ EVT VT = OutTys[i];
+ ISD::ArgFlagsTy ArgFlags = ArgsFlags[i];
+ if (Fn(i, VT, VT, CCValAssign::Full, ArgFlags, *this))
+ return false;
+ }
+ return true;
+}
+
/// AnalyzeReturn - Analyze the returned values of a return,
/// incorporating info about the result values into this state.
void CCState::AnalyzeReturn(const SmallVectorImpl<ISD::OutputArg> &Outs,