[Bug] [ir] Fix a bug in "offload" (#1224)

taichi/transforms/offload.cpp

@@ -247,26 +247,6 @@ class IdentifyValuesUsedInOtherOffloads : public BasicStmtVisitor {
     }
   }
 
-  void visit(LocalLoadStmt *stmt) override {
-    TI_ASSERT(current_offloaded);
-    TI_ASSERT(stmt->width() == 1);
-    test_and_allocate(stmt->ptr[0].var);
-  }
-
-  void visit(LocalStoreStmt *stmt) override {
-    TI_ASSERT(current_offloaded);
-    TI_ASSERT(stmt->width() == 1);
-    test_and_allocate(stmt->ptr);
-  }
-
-  void visit(AtomicOpStmt *stmt) override {
-    TI_ASSERT(current_offloaded);
-    TI_ASSERT(stmt->width() == 1);
-    if (stmt->dest->is<AllocaStmt>()) {
-      test_and_allocate(stmt->dest);
-    }
-  }
-
   void visit(Stmt *stmt) override {
     int n_op = stmt->num_operands();
     for (int i = 0; i < n_op; i++) {

tests/python/test_loops.py

@@ -151,3 +151,23 @@ def test(b: ti.i32, e: ti.i32):
         test(b, e)
         for i in range(b, e):
             assert x[i - b] == i
+
+
+@ti.all_archs
+def test_assignment_in_nested_loops():
+    # https://github.com/taichi-dev/taichi/issues/1109
+    m = ti.var(ti.f32, 3)
+    x = ti.var(ti.f32, ())
+
+    @ti.kernel
+    def func():
+        a = x[None]
+        for i in m:
+            b = a
+            for j in range(1):
+                b = b
+            x[None] = b
+
+    x[None] = 1
+    func()
+    assert x[None] == 1