Constant propagation after hitting assume(cmp) bugfix

Last time code run into assertion `BBE.isSingleEdge()` in
lib/IR/Dominators.cpp:200.

http://reviews.llvm.org/D12170

llvm-svn: 246244

1 files changed, 20 insertions, 0 deletions

diff --git a/llvm/lib/Transforms/Utils/Local.cpp b/llvm/lib/Transforms/Utils/Local.cpp
index 8c29ed50b45..364651bda3c 100644
--- a/llvm/lib/Transforms/Utils/Local.cpp
+++ b/llvm/lib/Transforms/Utils/Local.cpp
@@ -1349,3 +1349,23 @@ unsigned llvm::replaceDominatedUsesWith(Value *From, Value *To,
   }
   return Count;
 }
+
+unsigned llvm::replaceDominatedUsesWith(Value *From, Value *To,
+                                        DominatorTree &DT,
+                                        const BasicBlock *BB) {
+  assert(From->getType() == To->getType());
+
+  unsigned Count = 0;
+  for (Value::use_iterator UI = From->use_begin(), UE = From->use_end();
+       UI != UE;) {
+    Use &U = *UI++;
+    auto *I = cast<Instruction>(U.getUser());
+    if (DT.dominates(BB, I->getParent())) {
+      U.set(To);
+      DEBUG(dbgs() << "Replace dominated use of '" << From->getName() << "' as "
+                   << *To << " in " << *U << "\n");
+      ++Count;
+    }
+  }
+  return Count;
+}