[llvm-commits] [llvm] r133255 - /llvm/trunk/lib/CodeGen/TailDuplication.cpp

[Rafael Espindola]

Author: rafael
Date: Fri Jun 17 08:59:43 2011
New Revision: 133255

URL: http://llvm.org/viewvc/llvm-project?rev=133255&view=rev
Log:
Two fixes relating to debug value:
* We should change the generated code because of a debug use.
* Avoid creating debug uses of undef, as they become a kill.
Test to follow.

Modified:
    llvm/trunk/lib/CodeGen/TailDuplication.cpp

Modified: llvm/trunk/lib/CodeGen/TailDuplication.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/CodeGen/TailDuplication.cpp?rev=133255&r1=133254&r2=133255&view=diff
==============================================================================
--- llvm/trunk/lib/CodeGen/TailDuplication.cpp (original)
+++ llvm/trunk/lib/CodeGen/TailDuplication.cpp Fri Jun 17 08:59:43 2011
@@ -242,6 +242,14 @@
             MachineOperand &UseMO = UI.getOperand();
             MachineInstr *UseMI = &*UI;
             ++UI;
+            if (UseMI->isDebugValue()) {
+              // SSAUpdate can replace the use with an undef. That creates
+              // a debug instruction that is a kill.
+              // FIXME: Should it SSAUpdate job to delete debug instructions
+              // instead of replacing the use with undef?
+              UseMI->eraseFromParent();
+              continue;
+            }
             if (UseMI->getParent() == DefBB && !UseMI->isPHI())
               continue;
             SSAUpdate.RewriteUse(UseMO);
@@ -283,6 +291,8 @@
   for (MachineRegisterInfo::use_iterator UI = MRI->use_begin(Reg),
          UE = MRI->use_end(); UI != UE; ++UI) {
     MachineInstr *UseMI = &*UI;
+    if (UseMI->isDebugValue())
+      continue;
     if (UseMI->getParent() != BB)
       return true;
   }