DAG: propagate ConsecutiveRegs flags to returns too.

Arguments already have a flag to inform backends when they have been split up.
The AArch64 arm64_32 ABI makes use of these on return types too, so that code
emitted for armv7k can be ABI-compliant.

There should be no CodeGen changes yet, just making more information available.

llvm-svn: 358399

1 files changed, 18 insertions, 0 deletions

diff --git a/llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp b/llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
index 4391acd6ea6..818f1ada04b 100644
--- a/llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
+++ b/llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
@@ -1814,6 +1814,10 @@ void SelectionDAGBuilder::visitRet(const ReturnInst &I) {
 
       const Function *F = I.getParent()->getParent();
 
+      bool NeedsRegBlock = TLI.functionArgumentNeedsConsecutiveRegisters(
+          I.getOperand(0)->getType(), F->getCallingConv(),
+          /*IsVarArg*/ false);
+
       ISD::NodeType ExtendKind = ISD::ANY_EXTEND;
       if (F->getAttributes().hasAttribute(AttributeList::ReturnIndex,
                                           Attribute::SExt))
@@ -1852,6 +1856,12 @@ void SelectionDAGBuilder::visitRet(const ReturnInst &I) {
               cast<PointerType>(I.getOperand(0)->getType())->getAddressSpace());
         }
 
+        if (NeedsRegBlock) {
+          Flags.setInConsecutiveRegs();
+          if (j == NumValues - 1)
+            Flags.setInConsecutiveRegsLast();
+        }
+
         // Propagate extension type if any
         if (ExtendKind == ISD::SIGN_EXTEND)
           Flags.setSExt();
@@ -8832,7 +8842,15 @@ TargetLowering::LowerCallTo(TargetLowering::CallLoweringInfo &CLI) const {
     // points into the callers stack frame.
     CLI.IsTailCall = false;
   } else {
+    bool NeedsRegBlock = functionArgumentNeedsConsecutiveRegisters(
+        CLI.RetTy, CLI.CallConv, CLI.IsVarArg);
     for (unsigned I = 0, E = RetTys.size(); I != E; ++I) {
+      ISD::ArgFlagsTy Flags;
+      if (NeedsRegBlock) {
+        Flags.setInConsecutiveRegs();
+        if (I == RetTys.size() - 1)
+          Flags.setInConsecutiveRegsLast();
+      }
       EVT VT = RetTys[I];
       MVT RegisterVT = getRegisterTypeForCallingConv(CLI.RetTy->getContext(),
                                                      CLI.CallConv, VT);