fix(mgb/gopt): remove redundant reshape in nchw->nchw4 pass

GitOrigin-RevId: 0f5c7c3e485b4da0cdfe9b0db3e23945ac43ee16

src/gopt/impl/tensor_reformat.cpp

@@ -435,13 +435,10 @@ void TensorReformatPass::translate_pass(OptState& opt) const {
             return opr::IndexAt::make(xshp, {{0, cv(idx)}});
         };
         auto tshp0 = opr::Concat::make(
-                     {sub(0), sub(1) / 4, cv(4), sub(2), sub(3)}, 0),
-             tshp1 = opr::Concat::make(
-                     {sub(0), sub(1) / 4, sub(2), sub(3), cv(4)}, 0);
+                     {sub(0), sub(1) / 4, cv(4), sub(2), sub(3)}, 0);
         auto y0 = opr::Reshape::make(x, tshp0);
         auto y1 = opr::Dimshuffle::make(y0, {0, 1, 3, 4, 2});
-        auto y2 = opr::Reshape::make(y1, tshp1);
-        return y2.node();
+        return y1.node();
     };
     reformat[LayoutType::NCHW4_TO_NCHW] = [](VarNode* inp) -> VarNode* {
         auto x = SymbolVar(inp);
@@ -455,7 +452,8 @@ void TensorReformatPass::translate_pass(OptState& opt) const {
         auto y1 = opr::Reshape::make(y0, tshp0);
         return y1.node();
     };
-    reformat[LayoutType::WEIGHT_NCHW_TO_NCHW4_DENSE] = [](VarNode* inp) -> VarNode* {
+    reformat[LayoutType::WEIGHT_NCHW_TO_NCHW4_DENSE] =
+            [](VarNode* inp) -> VarNode* {
         auto x = SymbolVar(inp);
         auto xshp = opr::GetVarShape::make(x);
         auto cv = [&x](int v) { return x.make_scalar(v); };
@@ -471,7 +469,8 @@ void TensorReformatPass::translate_pass(OptState& opt) const {
         auto y2 = opr::Reshape::make(y1, tshp1);
         return y2.node();
     };
-    reformat[LayoutType::WEIGHT_NCHW_TO_NCHW4_GROUP] = [](VarNode* inp) -> VarNode* {
+    reformat[LayoutType::WEIGHT_NCHW_TO_NCHW4_GROUP] =
+            [](VarNode* inp) -> VarNode* {
         auto x = SymbolVar(inp);
         auto xshp = opr::GetVarShape::make(x);
         auto cv = [&x](int v) { return x.make_scalar(v); };

src/gopt/test/inference.cpp

@@ -2452,6 +2452,8 @@ TEST(TestGoptInference, ConvertFormatNCHW4GPU) {
 
     ASSERT_EQ(opr::ConvBias::Param::Format::NCHW4,
               find_opr<opr::ConvBias>(y_opt).param().format);
+    auto nr_reshape = find_opr_num<mgb::opr::Reshape>(y_opt);
+    ASSERT_EQ(2u, nr_reshape);
 
     graph->compile({{y_opt, {}}})
             ->to_json()