[StackVM] Updated CodeGenStackVM to handle DeclBuffer (apache#15036)

Part of changes being split out from
apache#14778 into independent
portions. This commit allows DeclBuffer to occur in the lowered TIR
passed to CodeGenStackVM.

src/target/stackvm/codegen_stackvm.cc

@@ -183,6 +183,8 @@ void CodeGenStackVM::VisitStmt_(const AllocateNode* op) {
   LOG(FATAL) << "Dynamic allocation not supported";
 }
 
+void CodeGenStackVM::VisitStmt_(const DeclBufferNode* op) { VisitStmt(op->body); }
+
 void CodeGenStackVM::VisitExpr_(const CallNode* op) {
   if (op->op.same_as(builtin::address_of())) {
     const BufferLoadNode* load = op->args[0].as<BufferLoadNode>();

src/target/stackvm/codegen_stackvm.h

@@ -139,6 +139,7 @@ class CodeGenStackVM : public ExprFunctor<void(const PrimExpr&)>,
   void VisitStmt_(const ForNode* op) final;
   void VisitStmt_(const IfThenElseNode* op) final;
   void VisitStmt_(const AllocateNode* op) final;
+  void VisitStmt_(const DeclBufferNode* op) final;
   void VisitStmt_(const AttrStmtNode* op) final;
   void VisitStmt_(const AssertStmtNode* op) final;
   void VisitStmt_(const EvaluateNode* op) final;

tests/python/unittest/test_target_codegen_vm_basic.py

@@ -17,6 +17,8 @@
 import tvm
 import tvm.testing
 from tvm import te
+from tvm.script import tir as T, ir as I
+
 import numpy as np
 
 
@@ -122,8 +124,20 @@ def check(f):
     run_jit(mod, check)
 
 
+def test_codegen_decl_buffer():
+    """The codegen should accept DeclBuffer nodes in its input"""
+
+    @I.ir_module
+    class mod:
+        @T.prim_func
+        def kernel(A_data: T.handle("float32")):
+            T.func_attr({"global_symbol": "kernel"})
+            A_buf = T.decl_buffer([256], dtype="float32", scope="global", data=A_data)
+
+    target = tvm.target.Target("stackvm")
+    stackvm_codegen = tvm.get_global_func("target.build.stackvm")
+    stackvm_codegen(mod, target)
+
+
 if __name__ == "__main__":
-    test_vm_parallel()
-    test_stack_vm_loop()
-    test_stack_vm_basic()
-    test_stack_vm_cond()
+    tvm.testing.main()