[AMDGPU] Don't create MachinePointerInfos with an UndefValue pointer

Summary:
The only useful information the UndefValue conveys is the address space,
which MachinePointerInfo can represent directly without referring to an
IR value.

Reviewers: arsenm, rampitec

Subscribers: kzhuravl, jvesely, wdng, nhaehnle, yaxunl, dstuttard, tpr, t-tye, hiraditya, Petar.Avramovic, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D71838

1 files changed, 3 insertions, 9 deletions

diff --git a/llvm/lib/Target/AMDGPU/R600ISelLowering.cpp b/llvm/lib/Target/AMDGPU/R600ISelLowering.cpp
index b02c4609cef..dbc9afaa33c 100644
--- a/llvm/lib/Target/AMDGPU/R600ISelLowering.cpp
+++ b/llvm/lib/Target/AMDGPU/R600ISelLowering.cpp
@@ -1175,8 +1175,7 @@ SDValue R600TargetLowering::lowerPrivateTruncStore(StoreSDNode *Store,
 
   // Load dword
   // TODO: can we be smarter about machine pointer info?
-  MachinePointerInfo PtrInfo(UndefValue::get(
-      Type::getInt32PtrTy(*DAG.getContext(), AMDGPUAS::PRIVATE_ADDRESS)));
+  MachinePointerInfo PtrInfo(AMDGPUAS::PRIVATE_ADDRESS);
   SDValue Dst = DAG.getLoad(MVT::i32, DL, Chain, Ptr, PtrInfo);
 
   Chain = Dst.getValue(1);
@@ -1406,8 +1405,7 @@ SDValue R600TargetLowering::lowerPrivateExtLoad(SDValue Op,
 
   // Load dword
   // TODO: can we be smarter about machine pointer info?
-  MachinePointerInfo PtrInfo(UndefValue::get(
-      Type::getInt32PtrTy(*DAG.getContext(), AMDGPUAS::PRIVATE_ADDRESS)));
+  MachinePointerInfo PtrInfo(AMDGPUAS::PRIVATE_ADDRESS);
   SDValue Read = DAG.getLoad(MVT::i32, DL, Chain, Ptr, PtrInfo);
 
   // Get offset within the register.
@@ -1608,9 +1606,6 @@ SDValue R600TargetLowering::LowerFormalArguments(
       continue;
     }
 
-    PointerType *PtrTy = PointerType::get(VT.getTypeForEVT(*DAG.getContext()),
-                                          AMDGPUAS::PARAM_I_ADDRESS);
-
     // i64 isn't a legal type, so the register type used ends up as i32, which
     // isn't expected here. It attempts to create this sextload, but it ends up
     // being invalid. Somehow this seems to work with i64 arguments, but breaks
@@ -1631,11 +1626,10 @@ SDValue R600TargetLowering::LowerFormalArguments(
     // XXX - I think PartOffset should give you this, but it seems to give the
     // size of the register which isn't useful.
 
-    unsigned ValBase = ArgLocs[In.getOrigArgIndex()].getLocMemOffset();
     unsigned PartOffset = VA.getLocMemOffset();
     unsigned Alignment = MinAlign(VT.getStoreSize(), PartOffset);
 
-    MachinePointerInfo PtrInfo(UndefValue::get(PtrTy), PartOffset - ValBase);
+    MachinePointerInfo PtrInfo(AMDGPUAS::PARAM_I_ADDRESS);
     SDValue Arg = DAG.getLoad(
         ISD::UNINDEXED, Ext, VT, DL, Chain,
         DAG.getConstant(PartOffset, DL, MVT::i32), DAG.getUNDEF(MVT::i32),