[Refactor] Improve layout equality checks and error messaging (#471)

* [Refactor] Simplify buffer_region_to_tile_region function in copy.py

* Removed redundant logic for handling region extents in the buffer_region_to_tile_region function, streamlining the code for better readability and maintainability.
* Enhanced error handling by focusing on essential checks while eliminating unnecessary complexity related to variable extents.

* [Refactor] Improve layout equality checks and error messaging

* Updated the `IsEqual` method in `FragmentNode` to ensure consistent evaluation of thread ranges.
* Enhanced error messaging in `ParallelOp::InferLayout` to include source buffer information for better debugging.
* Adjusted `ReduceOp::InferLayout` to set thread range during layout condensation, improving layout inference accuracy.

* lintfix

* [Refactor] Rename SetThreadRange to BindThreadRange for clarity

* Updated the `SetThreadRange` method in `FragmentNode` and related classes to `BindThreadRange`, improving method naming consistency and clarity.
* Adjusted all references to the renamed method across the codebase, ensuring proper functionality and maintaining existing behavior.
* Enhanced layout equality checks to handle thread ranges more robustly in `IsEqual` method.
* Updated layout inference methods in `Gemm`, `ParallelOp`, and `ReduceOp` to utilize the new method name, ensuring seamless integration with the updated API.

* [Refactor] Update BindThreadRange usage across layout inference methods

* Modified the implementation of `BindThreadRange` in `FragmentNode` to create a new object instance, enhancing thread range binding functionality.
* Updated all references to `BindThreadRange` in layout inference methods across `Gemm`, `ParallelOp`, and `ReduceOp` to ensure consistency with the new implementation.
* Adjusted the return statements in various layout inference functions to utilize the updated method, maintaining existing behavior while improving clarity.

* lint fix

src/layout/layout.cc

@@ -201,9 +201,10 @@ Fragment FragmentNode::DeReplicate() const {
                   int(*rep_size) / factor, NullOpt);
 }
 
-Fragment FragmentNode::SetThreadRange(Range thread_range) {
-  thread_range_ = thread_range;
-  return GetRef<Fragment>(this);
+Fragment FragmentNode::BindThreadRange(Range thread_range) const {
+  auto n = make_object<FragmentNode>(*this);
+  n->thread_range_ = thread_range;
+  return Fragment(n);
 }
 
 Layout LayoutNode::Inverse() const {
@@ -415,11 +416,13 @@ bool FragmentNode::IsEqual(const FragmentNode *other, bool skip_index) const {
   // a[i, j] = b[j, i] in register level.
 
   bool ret = StructuralEqual()(this->InputShape(), other->InputShape());
-  ret &= StructuralEqual()(this->ThreadRange(), other->ThreadRange());
   if (!ret) {
     // may be broadcast case
     return true;
   }
+  if (this->thread_range_.defined() && other->thread_range_.defined()) {
+    ret &= StructuralEqual()(this->thread_range_, other->thread_range_);
+  }
   ret &= StructuralEqual()(this->OutputShape(), other->OutputShape());
   ret &= StructuralEqual()(this->ReplicateExtent(), other->ReplicateExtent());
   ret &= StructuralEqual()(this->ThreadExtent(), other->ThreadExtent());

src/layout/layout.h

@@ -95,7 +95,7 @@ public:
 
   std::string DebugOutput() const final;
 
-  Fragment SetThreadRange(Range thread_range);
+  Fragment BindThreadRange(Range thread_range) const;
 
   Range ThreadRange() const { return thread_range_; }
 
@@ -127,12 +127,6 @@ public:
                    Optional<Var> replicate_var);
 
   TVM_DEFINE_OBJECT_REF_METHODS(Fragment, Layout, FragmentNode);
-
-  Fragment SetThreadRange(Range thread_range) {
-    auto node = make_object<FragmentNode>(*this->get());
-    node->SetThreadRange(thread_range);
-    return Fragment(node);
-  }
 };
 
 Var InputPlaceholder(size_t idx);

src/op/gemm.cc

@@ -172,7 +172,7 @@ LayoutMap Gemm::InferLayout(const LayoutInferArgs &T, InferLevel level) {
         ComputeWarpPartition(block_size / warp_size, T.target);
     auto fragment =
         makeGemmVoltaFragmentC(M, N, M / warp_m, N / warp_n, C->dtype.bits());
-    results.Set(C, fragment.SetThreadRange(thread_range));
+    results.Set(C, fragment->BindThreadRange(thread_range));
     if (A.scope() == "shared" || A.scope() == "shared.dyn") {
       int dim_A = A->shape.size();
       results.Set(A, makeGemmVoltaABLayout(*as_const_int(A->shape[dim_A - 2]),
@@ -181,7 +181,7 @@ LayoutMap Gemm::InferLayout(const LayoutInferArgs &T, InferLevel level) {
     } else if (A.scope() == "local.fragment") {
       ICHECK(trans_A == false);
       auto fragment = makeGemmVoltaFragmentA(M, N, K, M / warp_m, N / warp_n);
-      results.Set(A, fragment.SetThreadRange(thread_range));
+      results.Set(A, fragment->BindThreadRange(thread_range));
     } else {
       ICHECK(0);
     }
@@ -197,7 +197,7 @@ LayoutMap Gemm::InferLayout(const LayoutInferArgs &T, InferLevel level) {
         ComputeWarpPartition(block_size / warp_size, T.target);
     auto fragment =
         makeGemmFragmentC(M, N, M / warp_m, N / warp_n, C->dtype.bits());
-    results.Set(C, fragment.SetThreadRange(thread_range));
+    results.Set(C, fragment->BindThreadRange(thread_range));
 
     if (A.scope() == "shared" || A.scope() == "shared.dyn") {
       int dim_A = A->shape.size();
@@ -210,7 +210,7 @@ LayoutMap Gemm::InferLayout(const LayoutInferArgs &T, InferLevel level) {
       ICHECK(trans_A == false);
       auto fragment =
           makeGemmFragmentA(M, N, K, M / warp_m, N / warp_n, A->dtype.bits());
-      results.Set(A, fragment.SetThreadRange(thread_range));
+      results.Set(A, fragment->BindThreadRange(thread_range));
     } else {
       ICHECK(0);
     }
@@ -225,7 +225,7 @@ LayoutMap Gemm::InferLayout(const LayoutInferArgs &T, InferLevel level) {
       ICHECK(trans_B == false) << "B is local.fragment, trans_B must be false, "
                                   "please raise an issue if you see this";
       auto fragment = makeGemmFragmentB(M, N, K, M / warp_m, N / warp_n);
-      results.Set(B, fragment.SetThreadRange(thread_range));
+      results.Set(B, fragment->BindThreadRange(thread_range));
     } else {
       ICHECK(0);
     }
@@ -239,7 +239,7 @@ LayoutMap Gemm::InferLayout(const LayoutInferArgs &T, InferLevel level) {
             ? makeGemmFragmentCHopper(M, N, M / warp_m, N / warp_n,
                                       C->dtype.bits())
             : makeGemmFragmentC(M, N, M / warp_m, N / warp_n, C->dtype.bits());
-    results.Set(C, fragment.SetThreadRange(thread_range));
+    results.Set(C, fragment->BindThreadRange(thread_range));
     if (A.scope() == "shared" || A.scope() == "shared.dyn") {
       int dim_A = A->shape.size();
       const int64_t mat_stride = *as_const_int(A->shape[dim_A - 2]);
@@ -252,7 +252,7 @@ LayoutMap Gemm::InferLayout(const LayoutInferArgs &T, InferLevel level) {
       ICHECK(trans_A == false);
       auto fragment =
           makeGemmFragmentA(M, N, K, M / warp_m, N / warp_n, A->dtype.bits());
-      results.Set(A, fragment.SetThreadRange(thread_range));
+      results.Set(A, fragment->BindThreadRange(thread_range));
     }
     if (B.scope() == "shared" || B.scope() == "shared.dyn") {
       int dim_B = B->shape.size();
@@ -272,7 +272,7 @@ LayoutMap Gemm::InferLayout(const LayoutInferArgs &T, InferLevel level) {
 
     auto fragment =
         makeGemmFragmentCCDNA(M, N, M / warp_m, N / warp_n, C->dtype.bits());
-    results.Set(C, fragment.SetThreadRange(thread_range));
+    results.Set(C, fragment->BindThreadRange(thread_range));
 
     if (A.scope() == "shared" || A.scope() == "shared.dyn") {
       int dim_A = A->shape.size();
@@ -283,7 +283,7 @@ LayoutMap Gemm::InferLayout(const LayoutInferArgs &T, InferLevel level) {
     } else if (A.scope() == "local.fragment") {
       auto fragment = makeGemmFragmentACDNA(M, N, K, M / warp_m, N / warp_n,
                                             A->dtype.bits(), trans_A);
-      results.Set(A, fragment.SetThreadRange(thread_range));
+      results.Set(A, fragment->BindThreadRange(thread_range));
     } else {
       ICHECK(0);
     }
@@ -296,7 +296,7 @@ LayoutMap Gemm::InferLayout(const LayoutInferArgs &T, InferLevel level) {
       results.Set(B, shared_layout);
     } else if (B.scope() == "local.fragment") {
       auto fragment = makeGemmFragmentB(M, N, K, M / warp_m, N / warp_n);
-      results.Set(B, fragment.SetThreadRange(thread_range));
+      results.Set(B, fragment->BindThreadRange(thread_range));
     } else {
       ICHECK(0);
     }

src/op/parallel.cc

@@ -181,7 +181,7 @@ LayoutMap ParallelOp::InferLayout(const LayoutInferArgs &T, InferLevel level) {
       PrimExpr loop_var_to_thread =
           src_layout->ForwardThread(indice_map_[buffer], rep);
       return Fragment(loop_vars_, {}, loop_var_to_thread, rep_iter)
-          .SetThreadRange(T.thread_bounds);
+          ->BindThreadRange(T.thread_bounds);
     }
   };
   if (source_buffer.defined()) {
@@ -272,7 +272,7 @@ LayoutMap ParallelOp::InferLayout(const LayoutInferArgs &T, InferLevel level) {
   LayoutMap results;
   for (const auto &[buffer, _] : indice_map_) {
     if (!T.layout_map.count(buffer)) {
-      results.Set(buffer, CompleteBufferFragment(buffer).SetThreadRange(
+      results.Set(buffer, CompleteBufferFragment(buffer)->BindThreadRange(
                               T.thread_bounds));
     }
     // Though they may exist some conflicts, but it's fine.
@@ -285,13 +285,13 @@ LayoutMap ParallelOp::InferLayout(const LayoutInferArgs &T, InferLevel level) {
         const FragmentNode *src_layout =
             T.layout_map[buffer].as<Fragment>().get();
         Fragment dst_layout_fragment =
-            CompleteBufferFragment(buffer).SetThreadRange(T.thread_bounds);
+            CompleteBufferFragment(buffer)->BindThreadRange(T.thread_bounds);
         const FragmentNode *dst_layout =
             dst_layout_fragment.as<Fragment>().get();
         if (src_layout && dst_layout) {
           ICHECK(src_layout->IsEqual(dst_layout, true))
               << "Layout may conflict with ParallelOp for buffer " << buffer
-              << "\nError body begin:\n"
+              << " vs. " << source_buffer << "\nError body begin:\n"
               << GetRoot()->body << "\nError body end"
               << "\nLHS = " << src_layout->DebugOutput()
               << "\nRHS = " << dst_layout->DebugOutput()

src/op/reduce.cc

@@ -272,7 +272,8 @@ LayoutMap ReduceOp::InferLayout(const LayoutInferArgs &T, InferLevel level) {
         fwd, FloorDiv(ReplicationPlaceholder(), indice_rep_extent));
     Fragment dst_layout =
         Fragment(dst->shape, {}, thd, dest_buffer_rep_extent, NullOpt)
-            ->CondenseReplicateVar();
+            ->CondenseReplicateVar()
+            ->BindThreadRange(T.thread_bounds);
     return {{dst, dst_layout}};
   }
   return {};

src/transform/loop_partition.cc

@@ -191,7 +191,7 @@ Fragment PlanLoopPartition(For op, int vectorize_size, Range thread_range) {
   size_t num_thread = *as_const_int(thread_range->extent);
   LoopPartitioner partitioner;
   Fragment fragment = partitioner.Partition(op, num_thread, vectorize_size);
-  return fragment.SetThreadRange(thread_range);
+  return fragment->BindThreadRange(thread_range);
 }
 
 For LoopPragmaUnroll(For stmt) {