[PATCH] D79298: [NFC] Traverse function using dominator tree.

[Zoe Carver via Phabricator via llvm-commits]

zoecarver created this revision.
Herald added subscribers: llvm-commits, hiraditya.
Herald added a project: LLVM.

Iterate over the basic blocks in a function using a dominator tree instead of the function iterator.

This will be helpful when adding support for multiple blocks.


Repository:
  rG LLVM Github Monorepo

https://reviews.llvm.org/D79298

Files:
  llvm/lib/Transforms/Scalar/DeadStoreElimination.cpp


Index: llvm/lib/Transforms/Scalar/DeadStoreElimination.cpp
===================================================================
--- llvm/lib/Transforms/Scalar/DeadStoreElimination.cpp
+++ llvm/lib/Transforms/Scalar/DeadStoreElimination.cpp
@@ -9,9 +9,6 @@
 // This file implements a trivial dead store elimination that only considers
 // basic-block local redundant stores.
 //
-// FIXME: This should eventually be extended to be a post-dominator tree
-// traversal.  Doing so would be pretty trivial.
-//
 //===----------------------------------------------------------------------===//
 
 #include "llvm/Transforms/Scalar/DeadStoreElimination.h"
@@ -1388,12 +1385,14 @@
                                 MemoryDependenceResults *MD, DominatorTree *DT,
                                 const TargetLibraryInfo *TLI) {
   bool MadeChange = false;
-  for (BasicBlock &BB : F)
+  for (auto node = GraphTraits<DominatorTree *>::nodes_begin(DT);
+       node != GraphTraits<DominatorTree *>::nodes_end(DT); ++node) {
+    BasicBlock *BB = node->getBlock();
     // Only check non-dead blocks.  Dead blocks may have strange pointer
     // cycles that will confuse alias analysis.
-    if (DT->isReachableFromEntry(&BB))
-      MadeChange |= eliminateDeadStores(BB, AA, MD, DT, TLI);
-
+    if (DT->isReachableFromEntry(BB))
+      MadeChange |= eliminateDeadStores(*BB, AA, MD, DT, TLI);
+  }
   return MadeChange;
 }
 


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