[SelectionDAG] Propagate scoped AA metadata when lowering mem intrinsics.

- When memory intrinsics, such as memcpy, the attached scoped AA
  metadata is not passed down to the backend. As a result, the backend
  cannot schedule relevant memory operations around them following that
  hint. In this patch, SelectionDAG is enhanced to propagate that
  metadata (scoped AA only) when they are lowered into loads and stores.

Differential Revision: https://reviews.llvm.org/D102215

1 files changed, 15 insertions, 5 deletions

diff --git a/llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp b/llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
index 0031b18..92d5213 100644
--- a/llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
+++ b/llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
@@ -5835,10 +5835,12 @@ void SelectionDAGBuilder::visitIntrinsicCall(const CallInst &I,
     // FIXME: Support passing different dest/src alignments to the memcpy DAG
     // node.
     SDValue Root = isVol ? getRoot() : getMemoryRoot();
+    AAMDNodes AAInfo;
+    I.getAAMetadata(AAInfo);
     SDValue MC = DAG.getMemcpy(Root, sdl, Op1, Op2, Op3, Alignment, isVol,
                                /* AlwaysInline */ false, isTC,
                                MachinePointerInfo(I.getArgOperand(0)),
-                               MachinePointerInfo(I.getArgOperand(1)));
+                               MachinePointerInfo(I.getArgOperand(1)), AAInfo);
     updateDAGForMaybeTailCall(MC);
     return;
   }
@@ -5856,10 +5858,12 @@ void SelectionDAGBuilder::visitIntrinsicCall(const CallInst &I,
     bool isTC = I.isTailCall() && isInTailCallPosition(I, DAG.getTarget());
     // FIXME: Support passing different dest/src alignments to the memcpy DAG
     // node.
+    AAMDNodes AAInfo;
+    I.getAAMetadata(AAInfo);
     SDValue MC = DAG.getMemcpy(getRoot(), sdl, Dst, Src, Size, Alignment, isVol,
                                /* AlwaysInline */ true, isTC,
                                MachinePointerInfo(I.getArgOperand(0)),
-                               MachinePointerInfo(I.getArgOperand(1)));
+                               MachinePointerInfo(I.getArgOperand(1)), AAInfo);
     updateDAGForMaybeTailCall(MC);
     return;
   }
@@ -5873,8 +5877,10 @@ void SelectionDAGBuilder::visitIntrinsicCall(const CallInst &I,
     bool isVol = MSI.isVolatile();
     bool isTC = I.isTailCall() && isInTailCallPosition(I, DAG.getTarget());
     SDValue Root = isVol ? getRoot() : getMemoryRoot();
+    AAMDNodes AAInfo;
+    I.getAAMetadata(AAInfo);
     SDValue MS = DAG.getMemset(Root, sdl, Op1, Op2, Op3, Alignment, isVol, isTC,
-                               MachinePointerInfo(I.getArgOperand(0)));
+                               MachinePointerInfo(I.getArgOperand(0)), AAInfo);
     updateDAGForMaybeTailCall(MS);
     return;
   }
@@ -5892,9 +5898,11 @@ void SelectionDAGBuilder::visitIntrinsicCall(const CallInst &I,
     // FIXME: Support passing different dest/src alignments to the memmove DAG
     // node.
     SDValue Root = isVol ? getRoot() : getMemoryRoot();
+    AAMDNodes AAInfo;
+    I.getAAMetadata(AAInfo);
     SDValue MM = DAG.getMemmove(Root, sdl, Op1, Op2, Op3, Alignment, isVol,
                                 isTC, MachinePointerInfo(I.getArgOperand(0)),
-                                MachinePointerInfo(I.getArgOperand(1)));
+                                MachinePointerInfo(I.getArgOperand(1)), AAInfo);
     updateDAGForMaybeTailCall(MM);
     return;
   }
@@ -7703,10 +7711,12 @@ bool SelectionDAGBuilder::visitMemPCpyCall(const CallInst &I) {
   // because the return pointer needs to be adjusted by the size of
   // the copied memory.
   SDValue Root = isVol ? getRoot() : getMemoryRoot();
+  AAMDNodes AAInfo;
+  I.getAAMetadata(AAInfo);
   SDValue MC = DAG.getMemcpy(Root, sdl, Dst, Src, Size, Alignment, isVol, false,
                              /*isTailCall=*/false,
                              MachinePointerInfo(I.getArgOperand(0)),
-                             MachinePointerInfo(I.getArgOperand(1)));
+                             MachinePointerInfo(I.getArgOperand(1)), AAInfo);
   assert(MC.getNode() != nullptr &&
          "** memcpy should not be lowered as TailCall in mempcpy context **");
   DAG.setRoot(MC);