[llvm-commits] [llvm] r84033 - in /llvm/trunk/lib/Transforms/Scalar: InstructionCombining.cpp LICM.cpp LoopUnswitch.cpp

[Devang Patel]

Author: dpatel
Date: Tue Oct 13 16:41:20 2009
New Revision: 84033

URL: http://llvm.org/viewvc/llvm-project?rev=84033&view=rev
Log:
Do not check use_empty() before replaceAllUsesWith(). This gives ValueHandles a chance to get properly updated.


Modified:
    llvm/trunk/lib/Transforms/Scalar/InstructionCombining.cpp
    llvm/trunk/lib/Transforms/Scalar/LICM.cpp
    llvm/trunk/lib/Transforms/Scalar/LoopUnswitch.cpp

Modified: llvm/trunk/lib/Transforms/Scalar/InstructionCombining.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/Scalar/InstructionCombining.cpp?rev=84033&r1=84032&r2=84033&view=diff

==============================================================================
--- llvm/trunk/lib/Transforms/Scalar/InstructionCombining.cpp (original)
+++ llvm/trunk/lib/Transforms/Scalar/InstructionCombining.cpp Tue Oct 13 16:41:20 2009
@@ -9979,8 +9979,7 @@
       new StoreInst(ConstantInt::getTrue(*Context),
                 UndefValue::get(Type::getInt1PtrTy(*Context)), 
                                   OldCall);
-      if (!OldCall->use_empty())
-        OldCall->replaceAllUsesWith(UndefValue::get(OldCall->getType()));
+      OldCall->replaceAllUsesWith(UndefValue::get(OldCall->getType()));
       if (isa<CallInst>(OldCall))   // Not worth removing an invoke here.
         return EraseInstFromFunction(*OldCall);
       return 0;
@@ -9994,9 +9993,8 @@
                UndefValue::get(Type::getInt1PtrTy(*Context)),
                   CS.getInstruction());
 
-    if (!CS.getInstruction()->use_empty())
-      CS.getInstruction()->
-        replaceAllUsesWith(UndefValue::get(CS.getInstruction()->getType()));
+    CS.getInstruction()->
+      replaceAllUsesWith(UndefValue::get(CS.getInstruction()->getType()));
 
     if (InvokeInst *II = dyn_cast<InvokeInst>(CS.getInstruction())) {
       // Don't break the CFG, insert a dummy cond branch.
@@ -10251,7 +10249,7 @@
     }
   }
 
-  
+
   if (!Caller->use_empty())
     Caller->replaceAllUsesWith(NV);
   
@@ -10398,7 +10396,7 @@
           setCallingConv(cast<CallInst>(Caller)->getCallingConv());
         cast<CallInst>(NewCaller)->setAttributes(NewPAL);
       }
-      if (Caller->getType() != Type::getVoidTy(*Context) && !Caller->use_empty())
+      if (Caller->getType() != Type::getVoidTy(*Context))
         Caller->replaceAllUsesWith(NewCaller);
       Caller->eraseFromParent();
       Worklist.Remove(Caller);
@@ -12781,8 +12779,7 @@
             ++NumDeadInst;
             MadeIRChange = true;
           }
-          if (!I->use_empty())
-            I->replaceAllUsesWith(UndefValue::get(I->getType()));
+          I->replaceAllUsesWith(UndefValue::get(I->getType()));
           I->eraseFromParent();
         }
       }

Modified: llvm/trunk/lib/Transforms/Scalar/LICM.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/Scalar/LICM.cpp?rev=84033&r1=84032&r2=84033&view=diff

==============================================================================
--- llvm/trunk/lib/Transforms/Scalar/LICM.cpp (original)
+++ llvm/trunk/lib/Transforms/Scalar/LICM.cpp Tue Oct 13 16:41:20 2009
@@ -486,8 +486,8 @@
     if (!isExitBlockDominatedByBlockInLoop(ExitBlocks[0], I.getParent())) {
       // Instruction is not used, just delete it.
       CurAST->deleteValue(&I);
-      if (!I.use_empty())  // If I has users in unreachable blocks, eliminate.
-        I.replaceAllUsesWith(UndefValue::get(I.getType()));
+      // If I has users in unreachable blocks, eliminate.
+      I.replaceAllUsesWith(UndefValue::get(I.getType()));
       I.eraseFromParent();
     } else {
       // Move the instruction to the start of the exit block, after any PHI
@@ -499,8 +499,8 @@
   } else if (ExitBlocks.empty()) {
     // The instruction is actually dead if there ARE NO exit blocks.
     CurAST->deleteValue(&I);
-    if (!I.use_empty())  // If I has users in unreachable blocks, eliminate.
-      I.replaceAllUsesWith(UndefValue::get(I.getType()));
+    // If I has users in unreachable blocks, eliminate.
+    I.replaceAllUsesWith(UndefValue::get(I.getType()));
     I.eraseFromParent();
   } else {
     // Otherwise, if we have multiple exits, use the PromoteMem2Reg function to

Modified: llvm/trunk/lib/Transforms/Scalar/LoopUnswitch.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/Scalar/LoopUnswitch.cpp?rev=84033&r1=84032&r2=84033&view=diff

==============================================================================
--- llvm/trunk/lib/Transforms/Scalar/LoopUnswitch.cpp (original)
+++ llvm/trunk/lib/Transforms/Scalar/LoopUnswitch.cpp Tue Oct 13 16:41:20 2009
@@ -781,8 +781,7 @@
     
     // Anything that uses the instructions in this basic block should have their
     // uses replaced with undefs.
-    if (!I->use_empty())
-      I->replaceAllUsesWith(UndefValue::get(I->getType()));
+    I->replaceAllUsesWith(UndefValue::get(I->getType()));
   }
   
   // If this is the edge to the header block for a loop, remove the loop and