[llvm] r307879 - [TargetLowering] Add hook for adding target MMO flags when doing ISel.

[Geoff Berry via llvm-commits]

Author: gberry
Date: Wed Jul 12 20:49:42 2017
New Revision: 307879

URL: http://llvm.org/viewvc/llvm-project?rev=307879&view=rev
Log:
[TargetLowering] Add hook for adding target MMO flags when doing ISel.

Summary: Add TargetLowering hook getMMOFlags() to add target specific
MMO flags to load/store instructions created by ISel.

Reviewers: bogner, hfinkel, qcolombet, MatzeB

Subscribers: mcrosier, javed.absar, llvm-commits

Differential Revision: https://reviews.llvm.org/D34962

Modified:
    llvm/trunk/include/llvm/Target/TargetLowering.h
    llvm/trunk/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp

Modified: llvm/trunk/include/llvm/Target/TargetLowering.h
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/include/llvm/Target/TargetLowering.h?rev=307879&r1=307878&r2=307879&view=diff
==============================================================================
--- llvm/trunk/include/llvm/Target/TargetLowering.h (original)
+++ llvm/trunk/include/llvm/Target/TargetLowering.h Wed Jul 12 20:49:42 2017
@@ -3076,6 +3076,13 @@ public:
     return Chain;
   }
 
+  /// This callback is used to inspect load/store instructions and add
+  /// target-specific MachineMemOperand flags to them.  The default
+  /// implementation does nothing.
+  virtual MachineMemOperand::Flags getMMOFlags(const Instruction &I) const {
+    return MachineMemOperand::MONone;
+  }
+
   /// This callback is invoked by the type legalizer to legalize nodes with an
   /// illegal operand type but legal result types.  It replaces the
   /// LowerOperation callback in the type Legalizer.  The reason we can not do

Modified: llvm/trunk/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp?rev=307879&r1=307878&r2=307879&view=diff
==============================================================================
--- llvm/trunk/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp (original)
+++ llvm/trunk/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp Wed Jul 12 20:49:42 2017
@@ -3571,6 +3571,7 @@ void SelectionDAGBuilder::visitLoad(cons
       MMOFlags |= MachineMemOperand::MOInvariant;
     if (isDereferenceable)
       MMOFlags |= MachineMemOperand::MODereferenceable;
+    MMOFlags |= TLI.getMMOFlags(I);
 
     SDValue L = DAG.getLoad(ValueVTs[i], dl, Root, A,
                             MachinePointerInfo(SV, Offsets[i]), Alignment,
@@ -3700,6 +3701,7 @@ void SelectionDAGBuilder::visitStore(con
     MMOFlags |= MachineMemOperand::MOVolatile;
   if (I.getMetadata(LLVMContext::MD_nontemporal) != nullptr)
     MMOFlags |= MachineMemOperand::MONonTemporal;
+  MMOFlags |= TLI.getMMOFlags(I);
 
   // An aggregate load cannot wrap around the address space, so offsets to its
   // parts don't wrap either.