[TVMScript] T.allocate with T.decl_buffer syntax sugar for TVMScr…

…ipt printer (#13813)

This PR implements the syntax sugar of `T.allocate` with `T.decl_buffer` for new TVMScript printer. This syntax sugar will skip the `T.allocate`, when its body is a matched `T.decl_buffer`, and the `Var` defined in `T.allocate` is only used in that `T.decl_buffer`. For example, it will change

```python
buffer_data = T.allocate([128, 128])
buffer = T.decl_buffer([128, 128], data=buffer_data)
```
into

```python
buffer = T.decl_buffer([128, 128])
```
but keep the following `T.allocate` unchanged:
```python
buffer_data = T.allocate([128, 128])
buffer_0 = T.decl_buffer([128, 128], data=buffer_data)
buffer_1 = T.decl_buffer([128, 128], data=buffer_data)
```
and
```python
buffer_data = T.allocate([128, 128])
buffer = T.decl_buffer([256, 256], data=buffer_data)
```

src/script/printer/tir/function.cc

@@ -17,7 +17,6 @@
  * under the License.
  */
 #include <tvm/runtime/device_api.h>
-#include <tvm/tir/stmt_functor.h>
 
 #include "./utils.h"
 
@@ -65,47 +64,7 @@ bool IsSimpleBuffer(const tir::Buffer& buf) {
 }
 
 int CountVarOccurrence(const tir::PrimFunc& f, const tir::Var& v) {
-  class OccurrenceCounter : public tir::StmtExprVisitor {
-   public:
-    int count = 0;
-    const tir::VarNode* v = nullptr;
-
-    void VisitExpr_(const tir::VarNode* op) final {
-      if (op == v) {
-        ++count;
-      }
-      tir::StmtExprVisitor::VisitExpr_(op);
-    }
-
-    void VisitStmt_(const tir::BufferStoreNode* op) final {
-      VisitBuffer(op->buffer.get());
-      tir::StmtExprVisitor::VisitStmt_(op);
-    }
-
-    void VisitExpr_(const tir::BufferLoadNode* op) final {
-      VisitBuffer(op->buffer.get());
-      tir::StmtExprVisitor::VisitExpr_(op);
-    }
-
-    void VisitStmt_(const tir::DeclBufferNode* op) final {
-      VisitBuffer(op->buffer.get());
-      tir::StmtExprVisitor::VisitStmt_(op);
-    }
-
-    void VisitBuffer(const tir::BufferNode* buffer) {
-      VisitExpr(buffer->data);
-      for (const PrimExpr& shape_i : buffer->shape) {
-        VisitExpr(shape_i);
-      }
-      for (const PrimExpr& stride_i : buffer->strides) {
-        VisitExpr(stride_i);
-      }
-      VisitExpr(buffer->elem_offset);
-    }
-  };
-
-  OccurrenceCounter counter;
-  counter.v = v.get();
+  OccurrenceCounter counter(v.get());
   counter(f->body);
   for (const tir::Var& v : f->params) {
     counter(v);

src/script/printer/tir/stmt.cc

@@ -152,10 +152,34 @@ TVM_STATIC_IR_FUNCTOR(IRDocsifier, vtable)
                                  }));
         });
 
+bool IsAllocateDeclBufferPattern(const tir::AllocateNode* allocate) {
+  const tir::Var& buffer_var = allocate->buffer_var;
+  if (const tir::DeclBufferNode* decl_buffer = allocate->body.as<tir::DeclBufferNode>()) {
+    const tir::Buffer& buffer = decl_buffer->buffer;
+    if (buffer_var.same_as(buffer->data) && allocate->dtype == buffer->dtype &&
+        tir::is_one(allocate->condition) && !allocate->annotations.size() &&
+        allocate->extents.size() == buffer->shape.size()) {
+      tir::ExprDeepEqual expr_equal;
+      for (size_t i = 0, n = allocate->extents.size(); i < n; ++i) {
+        if (!expr_equal(allocate->extents[i], buffer->shape[i])) {
+          return false;
+        }
+      }
+      return true;
+    }
+  }
+  return false;
+}
+
 TVM_STATIC_IR_FUNCTOR(IRDocsifier, vtable)
     .set_dispatch<tir::Allocate>(  //
         "", [](tir::Allocate stmt, ObjectPath p, IRDocsifier d) -> Doc {
           bool concise = AllowConciseScoping(d);
+          OccurrenceCounter counter(stmt->buffer_var.get());
+          counter(stmt->body);
+          if (counter.count == 1 && IsAllocateDeclBufferPattern(stmt.get())) {
+            return d->AsDoc(stmt->body, p->Attr("body"));
+          }
           String storage_scope = tir::GetPtrStorageScope(stmt->buffer_var);
           Array<ExprDoc> args;
           Array<String> kwargs_keys;

src/script/printer/tir/utils.h

@@ -27,6 +27,7 @@
 #include <tvm/tir/function.h>
 #include <tvm/tir/op.h>
 #include <tvm/tir/stmt.h>
+#include <tvm/tir/stmt_functor.h>
 
 #include <string>
 #include <unordered_map>
@@ -220,6 +221,50 @@ ExprDoc BufferDecl(const tir::Buffer& buffer, const String& method, const Array<
 ExprDoc BufferAttn(const tir::Buffer& buffer, const ObjectPath& p, const Frame& frame,
                    const IRDocsifier& d);
 
+/*! \brief A Var occurrence counter visitor */
+class OccurrenceCounter : public tir::StmtExprVisitor {
+ public:
+  /*! \brief The occurrence counter */
+  int count = 0;
+  /*! \brief The Var to count occurrence */
+  const tir::VarNode* v = nullptr;
+
+  void VisitExpr_(const tir::VarNode* op) final {
+    if (op == v) {
+      ++count;
+    }
+    tir::StmtExprVisitor::VisitExpr_(op);
+  }
+
+  void VisitStmt_(const tir::BufferStoreNode* op) final {
+    VisitBuffer(op->buffer.get());
+    tir::StmtExprVisitor::VisitStmt_(op);
+  }
+
+  void VisitExpr_(const tir::BufferLoadNode* op) final {
+    VisitBuffer(op->buffer.get());
+    tir::StmtExprVisitor::VisitExpr_(op);
+  }
+
+  void VisitStmt_(const tir::DeclBufferNode* op) final {
+    VisitBuffer(op->buffer.get());
+    tir::StmtExprVisitor::VisitStmt_(op);
+  }
+
+  void VisitBuffer(const tir::BufferNode* buffer) {
+    VisitExpr(buffer->data);
+    for (const PrimExpr& shape_i : buffer->shape) {
+      VisitExpr(shape_i);
+    }
+    for (const PrimExpr& stride_i : buffer->strides) {
+      VisitExpr(stride_i);
+    }
+    VisitExpr(buffer->elem_offset);
+  }
+
+  explicit OccurrenceCounter(const tir::VarNode* var) { v = var; }
+};
+
 }  // namespace printer
 }  // namespace script
 }  // namespace tvm

tests/python/unittest/test_tvmscript_printer_tir.py

@@ -22,6 +22,7 @@
 from tvm.script.ir_builder import IRBuilder
 from tvm.script.ir_builder import tir as T
 from tvm.script.printer import default
+import tvm.testing
 
 
 @contextmanager
@@ -327,6 +328,53 @@ def test_allocate():
     )
 
 
+def test_allocate_with_decl_buffer_sugar():
+    with IRBuilder() as ib:
+        with T.allocate([128, 128], "float32") as buffer_data:
+            with T.decl_buffer([128, 128], "float32", data=buffer_data) as buffer:
+                T.evaluate(0)
+    obj = ib.get()
+    _assert_print(
+        obj,
+        """
+with T.decl_buffer((128, 128)) as buffer:
+    T.evaluate(0)
+""",
+    )
+
+
+def test_allocate_with_decl_buffer_no_sugar_multi_usage():
+    with IRBuilder() as ib:
+        with T.allocate([128, 128], "float32") as buffer_data:
+            with T.decl_buffer([128, 128], "float32", data=buffer_data) as buffer:
+                T.evaluate(buffer_data)
+    obj = ib.get()
+    _assert_print(
+        obj,
+        """
+with T.allocate([128, 128], "float32", "global") as v:
+    buffer = T.decl_buffer((128, 128), data=v)
+    T.evaluate(v)
+""",
+    )
+
+
+def test_allocate_with_decl_buffer_no_sugar_mismatch():
+    with IRBuilder() as ib:
+        with T.allocate([128, 128], "float32") as buffer_data:
+            with T.decl_buffer([256, 256], "float32", data=buffer_data) as buffer:
+                T.evaluate(buffer_data)
+    obj = ib.get()
+    _assert_print(
+        obj,
+        """
+with T.allocate([128, 128], "float32", "global") as v:
+    buffer = T.decl_buffer((256, 256), data=v)
+    T.evaluate(v)
+""",
+    )
+
+
 def test_decl_buffer():
     with IRBuilder() as ib:
         with T.decl_buffer((10, 10), data=T.ptr("float32")):
@@ -686,46 +734,4 @@ def main():
 
 
 if __name__ == "__main__":
-    test_prim_func()
-    test_prim_func_no_sugar_inlined_buffer()
-    test_prim_func_no_sugar_shared_buffer_data()
-    test_block_realize()
-    test_block()
-    test_buffer()
-    test_buffer_region()
-    test_buffer_load()
-    test_buffer_store()
-    test_match_buffer_region()
-    test_for()
-    test_let_stmt()
-    test_attr_stmt()
-    test_assert_stmt()
-    test_while()
-    test_allocate()
-    test_decl_buffer()
-    test_prefetch()
-    test_seq_stmt()
-    test_if_then_else()
-    test_evaluate()
-    test_buffer_realize()
-    test_var()
-    test_size_var()
-    test_iter_var()
-    test_string_imm()
-    test_cast()
-    test_binary_arith()
-    test_logical()
-    test_select()
-    test_ramp()
-    test_broadcast()
-    test_let_expr()
-    test_call()
-    test_comm_reducer()
-    test_any()
-    test_int_imm()
-    test_float_imm()
-    test_range()
-    test_prim_type()
-    test_pointer_type()
-    test_tuple_type()
-    test_remap()
+    tvm.testing.main()