Index: include/llvm/IR/Intrinsics.td
===================================================================
--- include/llvm/IR/Intrinsics.td
+++ include/llvm/IR/Intrinsics.td
@@ -67,6 +67,13 @@
   int ArgNo = argNo;
 }
 
+// IntrOnlyWriteMem - Despite writing to memory, this intrinsic neither reads
+// from memory nor does it have "additional" side effects. What this means is
+// target-dependent. The idea is that the intrinsic is lowered to a
+// target-dependent instruction which is store-like, but whose memory access
+// patterns cannot be properly modelled at the LLVM IR level.
+def IntrOnlyWriteMem : IntrinsicProperty;
+
 def IntrNoReturn : IntrinsicProperty;
 
 // IntrNoduplicate - Calls to this intrinsic cannot be duplicated.
Index: include/llvm/IR/IntrinsicsAMDGPU.td
===================================================================
--- include/llvm/IR/IntrinsicsAMDGPU.td
+++ include/llvm/IR/IntrinsicsAMDGPU.td
@@ -222,7 +222,7 @@
    llvm_i32_ty,       // offset(SGPR/VGPR/imm)
    llvm_i1_ty,        // glc(imm)
    llvm_i1_ty],       // slc(imm)
-  []>;
+  [IntrOnlyWriteMem]>;
 
 class AMDGPUBufferAtomic : Intrinsic <
   [llvm_i32_ty],
Index: lib/Target/AMDGPU/SIInstructions.td
===================================================================
--- lib/Target/AMDGPU/SIInstructions.td
+++ lib/Target/AMDGPU/SIInstructions.td
@@ -949,23 +949,18 @@
 defm BUFFER_LOAD_FORMAT_XYZW : MUBUF_Load_Helper <
   mubuf<0x03>, "buffer_load_format_xyzw", VReg_128
 >;
-// Without mayLoad and hasSideEffects, TableGen complains about the pattern
-// matching llvm.amdgcn.buffer.store.format. Eventually, we'll need a way
-// to express the effects of the intrinsic more precisely.
-let mayLoad = 1, hasSideEffects = 1 in {
-  defm BUFFER_STORE_FORMAT_X : MUBUF_Store_Helper <
-    mubuf<0x04>, "buffer_store_format_x", VGPR_32
-  >;
-  defm BUFFER_STORE_FORMAT_XY : MUBUF_Store_Helper <
-    mubuf<0x05>, "buffer_store_format_xy", VReg_64
-  >;
-  defm BUFFER_STORE_FORMAT_XYZ : MUBUF_Store_Helper <
-    mubuf<0x06>, "buffer_store_format_xyz", VReg_96
-  >;
-  defm BUFFER_STORE_FORMAT_XYZW : MUBUF_Store_Helper <
-    mubuf<0x07>, "buffer_store_format_xyzw", VReg_128
-  >;
-}
+defm BUFFER_STORE_FORMAT_X : MUBUF_Store_Helper <
+  mubuf<0x04>, "buffer_store_format_x", VGPR_32
+>;
+defm BUFFER_STORE_FORMAT_XY : MUBUF_Store_Helper <
+  mubuf<0x05>, "buffer_store_format_xy", VReg_64
+>;
+defm BUFFER_STORE_FORMAT_XYZ : MUBUF_Store_Helper <
+  mubuf<0x06>, "buffer_store_format_xyz", VReg_96
+>;
+defm BUFFER_STORE_FORMAT_XYZW : MUBUF_Store_Helper <
+  mubuf<0x07>, "buffer_store_format_xyzw", VReg_128
+>;
 defm BUFFER_LOAD_UBYTE : MUBUF_Load_Helper <
   mubuf<0x08, 0x10>, "buffer_load_ubyte", VGPR_32, i32, az_extloadi8_global
 >;
Index: utils/TableGen/CodeGenDAGPatterns.cpp
===================================================================
--- utils/TableGen/CodeGenDAGPatterns.cpp
+++ utils/TableGen/CodeGenDAGPatterns.cpp
@@ -2816,13 +2816,15 @@
 
     if (const CodeGenIntrinsic *IntInfo = N->getIntrinsicInfo(CDP)) {
       // If this is an intrinsic, analyze it.
-      if (IntInfo->ModRef >= CodeGenIntrinsic::ReadArgMem)
+      if (IntInfo->ModRef >= CodeGenIntrinsic::ReadArgMem &&
+          !IntInfo->onlyWriteMem)
         mayLoad = true;// These may load memory.
 
       if (IntInfo->ModRef >= CodeGenIntrinsic::ReadWriteArgMem)
         mayStore = true;// Intrinsics that can write to memory are 'mayStore'.
 
-      if (IntInfo->ModRef >= CodeGenIntrinsic::ReadWriteMem)
+      if (IntInfo->ModRef >= CodeGenIntrinsic::ReadWriteMem &&
+          !IntInfo->onlyWriteMem)
         // WriteMem intrinsics can have other strange effects.
         hasSideEffects = true;
     }
Index: utils/TableGen/CodeGenIntrinsics.h
===================================================================
--- utils/TableGen/CodeGenIntrinsics.h
+++ utils/TableGen/CodeGenIntrinsics.h
@@ -65,6 +65,12 @@
     };
     ModRefKind ModRef;
 
+    /// This is set to true if the intrinsic is explicitly marked as not loading
+    /// and not having side effects despite writing to memory. This is useful
+    /// for targets with special store intrinsics that do not write through
+    /// LLVM IR pointers.
+    bool onlyWriteMem;
+
     /// This is set to true if the intrinsic is overloaded by its argument
     /// types.
     bool isOverloaded;
Index: utils/TableGen/CodeGenTarget.cpp
===================================================================
--- utils/TableGen/CodeGenTarget.cpp
+++ utils/TableGen/CodeGenTarget.cpp
@@ -449,6 +449,7 @@
   TheDef = R;
   std::string DefName = R->getName();
   ModRef = ReadWriteMem;
+  onlyWriteMem = false;
   isOverloaded = false;
   isCommutative = false;
   canThrow = false;
@@ -589,6 +590,8 @@
       isConvergent = true;
     else if (Property->getName() == "IntrNoReturn")
       isNoReturn = true;
+    else if (Property->getName() == "IntrOnlyWriteMem")
+      onlyWriteMem = true;
     else if (Property->isSubClassOf("NoCapture")) {
       unsigned ArgNo = Property->getValueAsInt("ArgNo");
       ArgumentAttributes.push_back(std::make_pair(ArgNo, NoCapture));