Index: lib/Target/AMDGPU/SIInsertWaits.cpp
===================================================================
--- lib/Target/AMDGPU/SIInsertWaits.cpp
+++ lib/Target/AMDGPU/SIInsertWaits.cpp
@@ -231,15 +231,17 @@
     return false;
 
   // Check if this operand is the value being stored.
-  // Special case for DS instructions, since the address
+  // Special case for DS/FLAT instructions, since the address
   // operand comes before the value operand and it may have
   // multiple data operands.
 
-  if (TII->isDS(MI)) {
+  if (TII->isDS(MI) || TII->isFLAT(MI)) {
     MachineOperand *Data = TII->getNamedOperand(MI, AMDGPU::OpName::data);
     if (Data && Op.isIdenticalTo(*Data))
       return true;
+  }
 
+  if (TII->isDS(MI)) {
     MachineOperand *Data0 = TII->getNamedOperand(MI, AMDGPU::OpName::data0);
     if (Data0 && Op.isIdenticalTo(*Data0))
       return true;