CodeGen: Factor out code for tail call result compatibility check; NFC

llvm-svn: 264959

1 files changed, 36 insertions, 0 deletions

diff --git a/llvm/lib/CodeGen/CallingConvLower.cpp b/llvm/lib/CodeGen/CallingConvLower.cpp
index 2a8a9e793ab..7d67bcfe546 100644
--- a/llvm/lib/CodeGen/CallingConvLower.cpp
+++ b/llvm/lib/CodeGen/CallingConvLower.cpp
@@ -249,3 +249,39 @@ void CCState::analyzeMustTailForwardedRegisters(
     }
   }
 }
+
+bool CCState::resultsCompatible(CallingConv::ID CalleeCC,
+                                CallingConv::ID CallerCC, MachineFunction &MF,
+                                LLVMContext &C,
+                                const SmallVectorImpl<ISD::InputArg> &Ins,
+                                CCAssignFn CalleeFn, CCAssignFn CallerFn) {
+  if (CalleeCC == CallerCC)
+    return true;
+  SmallVector<CCValAssign, 4> RVLocs1;
+  CCState CCInfo1(CalleeCC, false, MF, RVLocs1, C);
+  CCInfo1.AnalyzeCallResult(Ins, CalleeFn);
+
+  SmallVector<CCValAssign, 4> RVLocs2;
+  CCState CCInfo2(CallerCC, false, MF, RVLocs2, C);
+  CCInfo2.AnalyzeCallResult(Ins, CallerFn);
+
+  if (RVLocs1.size() != RVLocs2.size())
+    return false;
+  for (unsigned I = 0, E = RVLocs1.size(); I != E; ++I) {
+    const CCValAssign &Loc1 = RVLocs1[I];
+    const CCValAssign &Loc2 = RVLocs2[I];
+    if (Loc1.getLocInfo() != Loc2.getLocInfo())
+      return false;
+    bool RegLoc1 = Loc1.isRegLoc();
+    if (RegLoc1 != Loc2.isRegLoc())
+      return false;
+    if (RegLoc1) {
+      if (Loc1.getLocReg() != Loc2.getLocReg())
+        return false;
+    } else {
+      if (Loc1.getLocMemOffset() != Loc2.getLocMemOffset())
+        return false;
+    }
+  }
+  return true;
+}