Do not check use_empty() before replaceAllUsesWith(). This gives ValueHandles a chanc...

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@84033 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/lib/Transforms/Scalar/InstructionCombining.cpp b/lib/Transforms/Scalar/InstructionCombining.cpp
index b67bc050bd7d70c239bfbc794c9c3327d9e0c7ca..5cb58e8d61d5a638e22e6b306a81eba87344b707 100644 (file)
--- a/lib/Transforms/Scalar/InstructionCombining.cpp
+++ b/lib/Transforms/Scalar/InstructionCombining.cpp
@@ -9979,8 +9979,7 @@ Instruction *InstCombiner::visitCallSite(CallSite CS) {
       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 @@ Instruction *InstCombiner::visitCallSite(CallSite CS) {
                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 @@ bool InstCombiner::transformConstExprCastCall(CallSite CS) {
     }
   }
 
-  
+
   if (!Caller->use_empty())
     Caller->replaceAllUsesWith(NV);
   
@@ -10398,7 +10396,7 @@ Instruction *InstCombiner::transformCallThroughTrampoline(CallSite CS) {
           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 @@ bool InstCombiner::DoOneIteration(Function &F, unsigned Iteration) {
             ++NumDeadInst;
             MadeIRChange = true;
           }
-          if (!I->use_empty())
-            I->replaceAllUsesWith(UndefValue::get(I->getType()));
+          I->replaceAllUsesWith(UndefValue::get(I->getType()));
           I->eraseFromParent();
         }
       }

diff --git a/lib/Transforms/Scalar/LICM.cpp b/lib/Transforms/Scalar/LICM.cpp
index aac842ddca73707bd363573fff742aa72c5d235f..89120a6fb0c1722b6d6ecf107e48fc7b58adb639 100644 (file)
--- a/lib/Transforms/Scalar/LICM.cpp
+++ b/lib/Transforms/Scalar/LICM.cpp
@@ -486,8 +486,8 @@ void LICM::sink(Instruction &I) {
     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 @@ void LICM::sink(Instruction &I) {
   } 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

diff --git a/lib/Transforms/Scalar/LoopUnswitch.cpp b/lib/Transforms/Scalar/LoopUnswitch.cpp
index 624f2400fb1c54ac8fd9c4e03cad300104f78989..07ee071d00fb449a8a0f6f5f8941e27ff7fb9e4d 100644 (file)
--- a/lib/Transforms/Scalar/LoopUnswitch.cpp
+++ b/lib/Transforms/Scalar/LoopUnswitch.cpp
@@ -781,8 +781,7 @@ void LoopUnswitch::RemoveBlockIfDead(BasicBlock *BB,
     
     // 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