From 228ebd0f4cf9207d32d61ef4b11b81736895dc09 Mon Sep 17 00:00:00 2001
From: Devang Patel <dpatel@apple.com>
Date: Tue, 13 Oct 2009 22:56:32 +0000
Subject: [PATCH] Check void type before using RAUWd.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@84049 91177308-0d34-0410-b5e6-96231b3b80d8
---
 .../Scalar/InstructionCombining.cpp           | 19 +++++++++++++++----
 lib/Transforms/Scalar/LICM.cpp                | 10 ++++++++--
 lib/Transforms/Scalar/LoopUnswitch.cpp        |  5 ++++-
 3 files changed, 27 insertions(+), 7 deletions(-)

diff --git a/lib/Transforms/Scalar/InstructionCombining.cpp b/lib/Transforms/Scalar/InstructionCombining.cpp
index 5cb58e8d61d..88421db8267 100644
--- a/lib/Transforms/Scalar/InstructionCombining.cpp
+++ b/lib/Transforms/Scalar/InstructionCombining.cpp
@@ -9979,7 +9979,10 @@ Instruction *InstCombiner::visitCallSite(CallSite CS) {
       new StoreInst(ConstantInt::getTrue(*Context),
                 UndefValue::get(Type::getInt1PtrTy(*Context)), 
                                   OldCall);
-      OldCall->replaceAllUsesWith(UndefValue::get(OldCall->getType()));
+      // If OldCall dues not return void then replaceAllUsesWith undef.
+      // This allows ValueHandlers and custom metadata to adjust itself.
+      if (OldCall->getType() != Type::getVoidTy(*Context))
+        OldCall->replaceAllUsesWith(UndefValue::get(OldCall->getType()));
       if (isa<CallInst>(OldCall))   // Not worth removing an invoke here.
         return EraseInstFromFunction(*OldCall);
       return 0;
@@ -9993,8 +9996,11 @@ Instruction *InstCombiner::visitCallSite(CallSite CS) {
                UndefValue::get(Type::getInt1PtrTy(*Context)),
                   CS.getInstruction());
 
-    CS.getInstruction()->
-      replaceAllUsesWith(UndefValue::get(CS.getInstruction()->getType()));
+    // If CS dues not return void then replaceAllUsesWith undef.
+    // This allows ValueHandlers and custom metadata to adjust itself.
+    if (CS.getInstruction()->getType() != Type::getVoidTy(*Context))
+      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.
@@ -12779,7 +12785,12 @@ bool InstCombiner::DoOneIteration(Function &F, unsigned Iteration) {
             ++NumDeadInst;
             MadeIRChange = true;
           }
-          I->replaceAllUsesWith(UndefValue::get(I->getType()));
+
+
+          // If I is not void type then replaceAllUsesWith undef.
+          // This allows ValueHandlers and custom metadata to adjust itself.
+          if (I->getType() != Type::getVoidTy(*Context))
+            I->replaceAllUsesWith(UndefValue::get(I->getType()));
           I->eraseFromParent();
         }
       }
diff --git a/lib/Transforms/Scalar/LICM.cpp b/lib/Transforms/Scalar/LICM.cpp
index 89120a6fb0c..1574115aa6c 100644
--- a/lib/Transforms/Scalar/LICM.cpp
+++ b/lib/Transforms/Scalar/LICM.cpp
@@ -487,7 +487,10 @@ void LICM::sink(Instruction &I) {
       // Instruction is not used, just delete it.
       CurAST->deleteValue(&I);
       // If I has users in unreachable blocks, eliminate.
-      I.replaceAllUsesWith(UndefValue::get(I.getType()));
+      // If I is not void type then replaceAllUsesWith undef.
+      // This allows ValueHandlers and custom metadata to adjust itself.
+      if (I.getType() != Type::getVoidTy(I.getContext()))
+        I.replaceAllUsesWith(UndefValue::get(I.getType()));
       I.eraseFromParent();
     } else {
       // Move the instruction to the start of the exit block, after any PHI
@@ -500,7 +503,10 @@ void LICM::sink(Instruction &I) {
     // The instruction is actually dead if there ARE NO exit blocks.
     CurAST->deleteValue(&I);
     // If I has users in unreachable blocks, eliminate.
-    I.replaceAllUsesWith(UndefValue::get(I.getType()));
+    // If I is not void type then replaceAllUsesWith undef.
+    // This allows ValueHandlers and custom metadata to adjust itself.
+    if (I.getType() != Type::getVoidTy(I.getContext()))
+      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 07ee071d00f..a217a32db00 100644
--- a/lib/Transforms/Scalar/LoopUnswitch.cpp
+++ b/lib/Transforms/Scalar/LoopUnswitch.cpp
@@ -781,7 +781,10 @@ void LoopUnswitch::RemoveBlockIfDead(BasicBlock *BB,
     
     // Anything that uses the instructions in this basic block should have their
     // uses replaced with undefs.
-    I->replaceAllUsesWith(UndefValue::get(I->getType()));
+    // If I is not void type then replaceAllUsesWith undef.
+    // This allows ValueHandlers and custom metadata to adjust itself.
+    if (I->getType() != Type::getVoidTy(I->getContext()))
+      I->replaceAllUsesWith(UndefValue::get(I->getType()));
   }
   
   // If this is the edge to the header block for a loop, remove the loop and