add pass to eliminate depend value

mindspore/ccsrc/optimizer/irpass.cc

@@ -70,6 +70,7 @@ OptimizeIRPassLib::OptimizeIRPassLib() {
   same_eliminate_ = MakeSubstitution(SameEliminater(), "same_eliminate", prim::kPrimSameTypeShape);
   check_bprop_eliminate_ = MakeSubstitution(CheckBpropEliminater(), "check_bprop_eliminate", prim::kPrimCheckBprop);
   reset_defer_inline_ = MakeSubstitution(ResetDeferInline(), "reset_defer_inline", IsValueNode<FuncGraph>);
+  depend_value_elim_ = MakeSubstitution(DependValueElim(), "depend_value_elim", prim::kPrimDepend);
 
   // Env Item Eliminate
   env_get_item_eliminate_ = MakeSubstitution(EnvGetItemEliminater(), "env_get_item_eliminate", prim::kPrimEnvGetItem);

mindspore/ccsrc/optimizer/irpass.h

@@ -48,6 +48,7 @@ class OptimizeIRPassLib {
   SubstitutionPtr same_eliminate_;
   SubstitutionPtr check_bprop_eliminate_;
   SubstitutionPtr reset_defer_inline_;
+  SubstitutionPtr depend_value_elim_;
 
   // Env Item Eliminate
   SubstitutionPtr env_get_item_eliminate_;

mindspore/ccsrc/optimizer/irpass/special_op_eliminate.h

@@ -24,9 +24,11 @@
 
 #include "optimizer/optimizer.h"
 #include "optimizer/irpass.h"
+#include "ir/optimizer_caller.h"
 #include "optimizer/irpass/prim_eliminate.h"
 #include "ir/visitor.h"
 #include "operator/ops.h"
+#include "ir/pattern_matcher.h"
 
 namespace mindspore {
 namespace opt {
@@ -191,6 +193,17 @@ class ZeroLikeFillZero : public AnfVisitor {
   AnfNodePtr y_{nullptr};
   PrimitivePtr PrimFill_, PrimShape_, PrimDType_;
 };
+
+// {prim::kPrimDepend, X, ValueCond}->X
+class DependValueElim : public OptimizerCaller {
+ public:
+  AnfNodePtr operator()(const OptimizerPtr &, const AnfNodePtr &node) override {
+    PatternNode<AnfNodePtr> x, cond;
+    MATCH_REPLACE_IF(node, PPrimitive(prim::kPrimDepend, x, cond), x, IsVNode(cond.GetNode(node)));
+    return nullptr;
+  }
+};
+
 }  // namespace irpass
 }  // namespace opt
 }  // namespace mindspore

mindspore/ccsrc/pipeline/pass.cc

@@ -108,6 +108,7 @@ OptPassGroupMap GetOptPassesA(const opt::irpass::OptimizeIRPassLib &irpass) {
     irpass.incorporate_env_getitem_,
     irpass.incorporate_env_getitem_switch_,
     irpass.new_env_get_item_,
+    irpass.depend_value_elim_,
   });
   opt::OptPassConfig a_3 = opt::OptPassConfig({
     irpass.same_eliminate_,

tests/ut/cpp/optimizer/lib_test.cc

@@ -257,6 +257,14 @@ TEST_F(TestOptLib, test_elim_transpose) {
   ASSERT_TRUE(CheckOpt(before, after, patterns));
 }
 
+TEST_F(TestOptLib, test_elim_depend_value) {
+  FuncGraphPtr before = getPyFun.CallAndParseRet("test_elim_depend_value", "before");
+  FuncGraphPtr after = getPyFun.CallAndParseRet("test_elim_depend_value", "after");
+
+  auto patterns = std::vector<SubstitutionPtr>({irpass.depend_value_elim_});
+  ASSERT_TRUE(CheckOpt(before, after, patterns));
+}
+
 TEST_F(TestOptLib, test_elim_tile_multiply_one) {
   FuncGraphPtr before = getPyFun.CallAndParseRet("test_elim_tile_multiply_one", "before");
   FuncGraphPtr after = getPyFun.CallAndParseRet("test_elim_tile_multiply_one", "after");

tests/ut/cpp/python_input/gtest_input/optimizer/opt_test.py

@@ -494,6 +494,21 @@ def test_elim_transpose(tag):
 
     return fns[tag]
 
+def test_elim_depend_value(tag):
+    """ test_elim_depend_value """
+    fns = FnDict()
+    depend = P.Depend()
+
+    @fns
+    def before(x):
+        return depend(x, None)
+
+    @fns
+    def after(x):
+        return x
+
+    return fns[tag]
+
 
 def test_elim_tile_multiply_one(tag):
     """ test_elim_tile_multiply_one """