[Relax] Fix FuseOpsByPattern dropping bound constants on duplicate-structure functions

src/relax/ir/block_builder.cc

@@ -429,14 +429,28 @@ class BlockBuilderImpl : public BlockBuilderNode {
     }
   };
 
+  /*!
+   * \brief Structural equality that DOES compare tensor (constant) data content. The hash above
+   * intentionally ignores tensor content for speed, but the equality must stay exact: otherwise two
+   * grouped functions that differ only in their bound constants (e.g. two conv layers with
+   * different weights) would be incorrectly treated as duplicates and merged.
+   */
+  class StructuralEqualConsiderNDarray {
+   public:
+    bool operator()(const ffi::ObjectRef& lhs, const ffi::ObjectRef& rhs) const {
+      return ffi::StructuralEqual::Equal(lhs, rhs, /*map_free_vars=*/false,
+                                         /*skip_tensor_content=*/false);
+    }
+  };
+
   /*!
    * \brief A hashmap to store the mapping of Relax functions and TIR PrimFuncs
    * in context_mod to their GlobalVar to avoid generating duplicated functions.
    * We use a custom hash to avoid hashing constants that may be bound to each BaseFunc.
    */
   std::unique_ptr<std::unordered_map<
       BaseFunc, std::unordered_set<GlobalVar, ffi::ObjectPtrHash, ffi::ObjectPtrEqual>,
-      StructuralHashIgnoreNDarray, ffi::StructuralEqual>>
+      StructuralHashIgnoreNDarray, StructuralEqualConsiderNDarray>>
       ctx_func_dedup_map_ = nullptr;
 
   /*!
@@ -446,7 +460,7 @@ class BlockBuilderImpl : public BlockBuilderNode {
     if (ctx_func_dedup_map_ != nullptr) return;
     ctx_func_dedup_map_ = std::make_unique<std::unordered_map<
         BaseFunc, std::unordered_set<GlobalVar, ffi::ObjectPtrHash, ffi::ObjectPtrEqual>,
-        StructuralHashIgnoreNDarray, ffi::StructuralEqual>>();
+        StructuralHashIgnoreNDarray, StructuralEqualConsiderNDarray>>();
     for (const auto& kv : context_mod_->functions) {
       const GlobalVar gv = kv.first;
       const BaseFunc func = kv.second;