[TargetLowering] Add MachineMemOperand::Flags to allowsMemoryAccess tests (PR42123)

As discussed on D62910, we need to check whether particular types of memory access are allowed, not just their alignment/address-space.

This NFC patch adds a MachineMemOperand::Flags argument to allowsMemoryAccess and allowsMisalignedMemoryAccesses, and wires up calls to pass the relevant flags to them.

If people are happy with this approach I can then update X86TargetLowering::allowsMisalignedMemoryAccesses to handle misaligned NT load/stores.

Differential Revision: https://reviews.llvm.org/D63075

llvm-svn: 363179

2 files changed, 12 insertions, 9 deletions

diff --git a/llvm/lib/Target/AArch64/AArch64ISelLowering.cpp b/llvm/lib/Target/AArch64/AArch64ISelLowering.cpp
index ba8bbd25159..60032cd797a 100644
--- a/llvm/lib/Target/AArch64/AArch64ISelLowering.cpp
+++ b/llvm/lib/Target/AArch64/AArch64ISelLowering.cpp
@@ -1074,10 +1074,9 @@ MVT AArch64TargetLowering::getScalarShiftAmountTy(const DataLayout &DL,
   return MVT::i64;
 }
 
-bool AArch64TargetLowering::allowsMisalignedMemoryAccesses(EVT VT,
-                                                           unsigned AddrSpace,
-                                                           unsigned Align,
-                                                           bool *Fast) const {
+bool AArch64TargetLowering::allowsMisalignedMemoryAccesses(
+    EVT VT, unsigned AddrSpace, unsigned Align, MachineMemOperand::Flags Flags,
+    bool *Fast) const {
   if (Subtarget->requiresStrictAlign())
     return false;
 
@@ -2843,7 +2842,8 @@ SDValue AArch64TargetLowering::LowerSTORE(SDValue Op,
   unsigned AS = StoreNode->getAddressSpace();
   unsigned Align = StoreNode->getAlignment();
   if (Align < MemVT.getStoreSize() &&
-      !allowsMisalignedMemoryAccesses(MemVT, AS, Align, nullptr)) {
+      !allowsMisalignedMemoryAccesses(
+          MemVT, AS, Align, StoreNode->getMemOperand()->getFlags(), nullptr)) {
     return scalarizeVectorStore(StoreNode, DAG);
   }
 
@@ -8716,7 +8716,9 @@ EVT AArch64TargetLowering::getOptimalMemOpType(
     if (memOpAlign(SrcAlign, DstAlign, AlignCheck))
       return true;
     bool Fast;
-    return allowsMisalignedMemoryAccesses(VT, 0, 1, &Fast) && Fast;
+    return allowsMisalignedMemoryAccesses(VT, 0, 1, MachineMemOperand::MONone,
+                                          &Fast) &&
+           Fast;
   };
 
   if (CanUseNEON && IsMemset && !IsSmallMemset &&
diff --git a/llvm/lib/Target/AArch64/AArch64ISelLowering.h b/llvm/lib/Target/AArch64/AArch64ISelLowering.h
index c6aab742ab4..94793c678ae 100644
--- a/llvm/lib/Target/AArch64/AArch64ISelLowering.h
+++ b/llvm/lib/Target/AArch64/AArch64ISelLowering.h
@@ -262,9 +262,10 @@ public:
 
   /// Returns true if the target allows unaligned memory accesses of the
   /// specified type.
-  bool allowsMisalignedMemoryAccesses(EVT VT, unsigned AddrSpace = 0,
-                                      unsigned Align = 1,
-                                      bool *Fast = nullptr) const override;
+  bool allowsMisalignedMemoryAccesses(
+      EVT VT, unsigned AddrSpace = 0, unsigned Align = 1,
+      MachineMemOperand::Flags Flags = MachineMemOperand::MONone,
+      bool *Fast = nullptr) const override;
 
   /// Provide custom lowering hooks for some operations.
   SDValue LowerOperation(SDValue Op, SelectionDAG &DAG) const override;