DAG: propagate whether an arg is a pointer for CallingConv decisions.

The arm64_32 ABI specifies that pointers (despite being 32-bits) should be
zero-extended to 64-bits when passed in registers for efficiency reasons. This
means that the SelectionDAG needs to be able to tell the backend that an
argument was originally a pointer, which is implmented here.

Additionally, some memory intrinsics need to be declared as taking an i8*
instead of an iPTR.

There should be no CodeGen change yet, but it will be triggered when AArch64
backend support for ILP32 is added.

llvm-svn: 358398

1 files changed, 22 insertions, 0 deletions

diff --git a/llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp b/llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
index 2bf68ac81c9..4391acd6ea6 100644
--- a/llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
+++ b/llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
@@ -1846,6 +1846,12 @@ void SelectionDAGBuilder::visitRet(const ReturnInst &I) {
         if (RetInReg)
           Flags.setInReg();
 
+        if (I.getOperand(0)->getType()->isPointerTy()) {
+          Flags.setPointer();
+          Flags.setPointerAddrSpace(
+              cast<PointerType>(I.getOperand(0)->getType())->getAddressSpace());
+        }
+
         // Propagate extension type if any
         if (ExtendKind == ISD::SIGN_EXTEND)
           Flags.setSExt();
@@ -8834,9 +8840,15 @@ TargetLowering::LowerCallTo(TargetLowering::CallLoweringInfo &CLI) const {
                                                        CLI.CallConv, VT);
       for (unsigned i = 0; i != NumRegs; ++i) {
         ISD::InputArg MyFlags;
+        MyFlags.Flags = Flags;
         MyFlags.VT = RegisterVT;
         MyFlags.ArgVT = VT;
         MyFlags.Used = CLI.IsReturnValueUsed;
+        if (CLI.RetTy->isPointerTy()) {
+          MyFlags.Flags.setPointer();
+          MyFlags.Flags.setPointerAddrSpace(
+              cast<PointerType>(CLI.RetTy)->getAddressSpace());
+        }
         if (CLI.RetSExt)
           MyFlags.Flags.setSExt();
         if (CLI.RetZExt)
@@ -8887,6 +8899,11 @@ TargetLowering::LowerCallTo(TargetLowering::CallLoweringInfo &CLI) const {
       // specify the alignment it wants.
       unsigned OriginalAlignment = getABIAlignmentForCallingConv(ArgTy, DL);
 
+      if (Args[i].Ty->isPointerTy()) {
+        Flags.setPointer();
+        Flags.setPointerAddrSpace(
+            cast<PointerType>(Args[i].Ty)->getAddressSpace());
+      }
       if (Args[i].IsZExt)
         Flags.setZExt();
       if (Args[i].IsSExt)
@@ -9375,6 +9392,11 @@ void SelectionDAGISel::LowerArguments(const Function &F) {
       unsigned OriginalAlignment =
           TLI->getABIAlignmentForCallingConv(ArgTy, DL);
 
+      if (Arg.getType()->isPointerTy()) {
+        Flags.setPointer();
+        Flags.setPointerAddrSpace(
+            cast<PointerType>(Arg.getType())->getAddressSpace());
+      }
       if (Arg.hasAttribute(Attribute::ZExt))
         Flags.setZExt();
       if (Arg.hasAttribute(Attribute::SExt))