junrushao1994 commented on a change in pull request #10638:
URL: https://github.com/apache/tvm/pull/10638#discussion_r836832510



##########
File path: src/tir/schedule/primitive/reduction.cc
##########
@@ -284,7 +284,22 @@ StmtSRef DecomposeReduction(ScheduleState self, const 
StmtSRef& block_sref,
                /*body=*/body);
   }
   body = Substitute(body, loop_var_map);
-  // Step 6. Mutate IR
+  // Step 6. Add write regions back to read regions in update block.
+  Array<BufferRegion> new_reads;
+  std::unordered_set<const BufferNode*> read_bufs;
+  for (const BufferRegion& read_access : block->reads) {
+    read_bufs.insert(read_access->buffer.get());
+  }
+  for (const BufferRegion& write_access : block->writes) {
+    if (read_bufs.find(write_access->buffer.get()) == read_bufs.end()) {
+      new_reads.push_back(write_access);
+    }
+  }
+  for (const BufferRegion& read_access : block->reads) {
+    new_reads.push_back(read_access);
+  }
+  (const_cast<BlockNode*>(block))->reads = std::move(new_reads);

Review comment:
       @masahi thanks for reporting this! I'm not sure why the IRModule is 
mutated in place after decompose-reduction (not sure if i understand 
correctly), but would be great to have a minimal reproducible example after you 
returning from vacation :-)
   
   @yzh119 would you mind taking a look at the particular case Masa mentions 
and perhaps add a regression test? 




-- 
This is an automated message from the Apache Git Service.
To respond to the message, please log on to GitHub and use the
URL above to go to the specific comment.

To unsubscribe, e-mail: [email protected]

For queries about this service, please contact Infrastructure at:
[email protected]


Reply via email to