[llvm-commits] [llvm] r127922 - /llvm/trunk/lib/Transforms/Utils/Local.cpp

[Devang Patel]

Author: dpatel
Date: Fri Mar 18 18:28:02 2011
New Revision: 127922

URL: http://llvm.org/viewvc/llvm-project?rev=127922&view=rev
Log:
Consider debug info intrinsics pointing to null value as dead instructions.

Modified:
    llvm/trunk/lib/Transforms/Utils/Local.cpp

Modified: llvm/trunk/lib/Transforms/Utils/Local.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/Utils/Local.cpp?rev=127922&r1=127921&r2=127922&view=diff
==============================================================================
--- llvm/trunk/lib/Transforms/Utils/Local.cpp (original)
+++ llvm/trunk/lib/Transforms/Utils/Local.cpp Fri Mar 18 18:28:02 2011
@@ -211,7 +211,20 @@
 bool llvm::isInstructionTriviallyDead(Instruction *I) {
   if (!I->use_empty() || isa<TerminatorInst>(I)) return false;
 
-  // We don't want debug info removed by anything this general.
+  // We don't want debug info removed by anything this general, unless
+  // debug info is empty.
+  if (DbgDeclareInst *DDI = dyn_cast<DbgDeclareInst>(I)) {
+    if (DDI->getAddress()) 
+      return false;
+    else
+      return true;
+  } else if (DbgValueInst *DVI = dyn_cast<DbgValueInst>(I)) {
+    if (DVI->getValue())
+      return false;
+    else
+      return true;
+  }
+
   if (isa<DbgInfoIntrinsic>(I)) return false;
 
   if (!I->mayHaveSideEffects()) return true;