[Verifier][AMDGPU] No store to const addrspace

Ensure store to const addrspace is not allowed by IR Verifier.

Author: jofrn

llvm/lib/IR/Verifier.cpp

@@ -4224,6 +4224,33 @@ void Verifier::visitLoadInst(LoadInst &LI) {
   visitInstruction(LI);
 }
 
+static bool isConstantAddressSpace(unsigned AS) {
+  switch (AS) {
+    using namespace AMDGPUAS;
+  case CONSTANT_ADDRESS:
+  case CONSTANT_ADDRESS_32BIT:
+  case CONSTANT_BUFFER_0:
+  case CONSTANT_BUFFER_1:
+  case CONSTANT_BUFFER_2:
+  case CONSTANT_BUFFER_3:
+  case CONSTANT_BUFFER_4:
+  case CONSTANT_BUFFER_5:
+  case CONSTANT_BUFFER_6:
+  case CONSTANT_BUFFER_7:
+  case CONSTANT_BUFFER_8:
+  case CONSTANT_BUFFER_9:
+  case CONSTANT_BUFFER_10:
+  case CONSTANT_BUFFER_11:
+  case CONSTANT_BUFFER_12:
+  case CONSTANT_BUFFER_13:
+  case CONSTANT_BUFFER_14:
+  case CONSTANT_BUFFER_15:
+    return true;
+  default:
+    return false;
+  }
+}
+
 void Verifier::visitStoreInst(StoreInst &SI) {
   PointerType *PTy = dyn_cast<PointerType>(SI.getOperand(1)->getType());
   Check(PTy, "Store operand must be a pointer.", &SI);
@@ -4246,6 +4273,10 @@ void Verifier::visitStoreInst(StoreInst &SI) {
     Check(SI.getSyncScopeID() == SyncScope::System,
           "Non-atomic store cannot have SynchronizationScope specified", &SI);
   }
+  if (TT.isAMDGPU()) {
+    Check(!isConstantAddressSpace(SI.getPointerAddressSpace()),
+          "Store cannot be to constant addrspace", &SI);
+  }
   visitInstruction(SI);
 }
 

llvm/test/CodeGen/AMDGPU/const-store.ll

@@ -0,0 +1,9 @@
+; RUN: not llc -mtriple=amdgcn < %s |& FileCheck %s
+
+define amdgpu_kernel void @store_const(ptr addrspace(4) %out, i32 %a, i32 %b) {
+; CHECK: Store cannot be to constant addrspace
+; CHECK-NEXT: store i32 %r, ptr addrspace(4) %out
+  %r = add i32 %a, %b
+  store i32 %r, ptr addrspace(4) %out
+  ret void
+}