[PATCH] D107534: Add a pass to garbage-collect empty basic blocks after code generation.

[Sriraman Tallam via Phabricator via llvm-commits]

tmsriram added inline comments.


================
Comment at: llvm/lib/CodeGen/GCEmptyBasicBlocks.cpp:53
+    if (HasAnyRealCode)
+      continue;
+
----------------
If the block has no real instructions but debug instructions, is it correct to nuke it?


================
Comment at: llvm/lib/CodeGen/GCEmptyBasicBlocks.cpp:58
+    // predecessors. Although this shouldn't happen in valid code.
+    if (NextMBB == E && !Preds.empty())
+      continue;
----------------
If it is the last block it must have predecessors or you couldn't get to it, so !Preds.empty() is redundant.


================
Comment at: llvm/lib/CodeGen/GCEmptyBasicBlocks.cpp:70
+      if (JTI)
+        JTI->ReplaceMBBInJumpTables(&*MBB, &*NextMBB);
+    }
----------------
Should we add the non-real instructions in this block to the beginning of the next block too?


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D107534/new/

https://reviews.llvm.org/D107534