Revert r137655. There is some question about whether the 'landingpad'

instruction should be marked as potentially reading and/or writing memory.

llvm-svn: 137863

3 files changed, 5 insertions, 3 deletions

diff --git a/llvm/lib/Analysis/LoopInfo.cpp b/llvm/lib/Analysis/LoopInfo.cpp
index 9a7c50d7fa4..36fd598d13c 100644
--- a/llvm/lib/Analysis/LoopInfo.cpp
+++ b/llvm/lib/Analysis/LoopInfo.cpp
@@ -99,6 +99,9 @@ bool Loop::makeLoopInvariant(Instruction *I, bool &Changed,
     return false;
   if (I->mayReadFromMemory())
     return false;
+  // The landingpad instruction is immobile.
+  if (isa<LandingPadInst>(I))
+    return false;
   // Determine the insertion point, unless one was given.
   if (!InsertPt) {
     BasicBlock *Preheader = getLoopPreheader();
diff --git a/llvm/lib/Transforms/InstCombine/InstructionCombining.cpp b/llvm/lib/Transforms/InstCombine/InstructionCombining.cpp
index 47e7dd4c220..838678b9fab 100644
--- a/llvm/lib/Transforms/InstCombine/InstructionCombining.cpp
+++ b/llvm/lib/Transforms/InstCombine/InstructionCombining.cpp
@@ -1418,7 +1418,8 @@ static bool TryToSinkInstruction(Instruction *I, BasicBlock *DestBlock) {
   assert(I->hasOneUse() && "Invariants didn't hold!");
 
   // Cannot move control-flow-involving, volatile loads, vaarg, etc.
-  if (isa<PHINode>(I) || I->mayHaveSideEffects() || isa<TerminatorInst>(I))
+  if (isa<PHINode>(I) || isa<LandingPadInst>(I) || I->mayHaveSideEffects() ||
+      isa<TerminatorInst>(I))
     return false;
 
   // Do not sink alloca instructions out of the entry block.
diff --git a/llvm/lib/VMCore/Instruction.cpp b/llvm/lib/VMCore/Instruction.cpp
index 863b098e8f8..f54cec11e2e 100644
--- a/llvm/lib/VMCore/Instruction.cpp
+++ b/llvm/lib/VMCore/Instruction.cpp
@@ -320,7 +320,6 @@ bool Instruction::mayReadFromMemory() const {
   case Instruction::Fence: // FIXME: refine definition of mayReadFromMemory
   case Instruction::AtomicCmpXchg:
   case Instruction::AtomicRMW:
-  case Instruction::LandingPad:
     return true;
   case Instruction::Call:
     return !cast<CallInst>(this)->doesNotAccessMemory();
@@ -341,7 +340,6 @@ bool Instruction::mayWriteToMemory() const {
   case Instruction::VAArg:
   case Instruction::AtomicCmpXchg:
   case Instruction::AtomicRMW:
-  case Instruction::LandingPad:
     return true;
   case Instruction::Call:
     return !cast<CallInst>(this)->onlyReadsMemory();