Revert "[AliasSetTracker] Make AST smarter about intrinsics that don't actually affect memory."

This reverts commit r285191.

LICM appears to rely on the Alias Set Tracker hitting lifetime markers to prevent
code from being moved outside of the original scope.

llvm-svn: 285227

1 files changed, 0 insertions, 15 deletions

diff --git a/llvm/lib/Analysis/AliasSetTracker.cpp b/llvm/lib/Analysis/AliasSetTracker.cpp
index 0a947e175d4..954b22037ed 100644
--- a/llvm/lib/Analysis/AliasSetTracker.cpp
+++ b/llvm/lib/Analysis/AliasSetTracker.cpp
@@ -413,21 +413,6 @@ void AliasSetTracker::add(MemTransferInst *MTI) {
 void AliasSetTracker::addUnknown(Instruction *Inst) {
   if (isa<DbgInfoIntrinsic>(Inst))
     return; // Ignore DbgInfo Intrinsics.
-
-  if (auto *II = dyn_cast<IntrinsicInst>(Inst)) {
-    // These intrinsics will show up as affecting memory, but they are just
-    // markers.
-    switch (II->getIntrinsicID()) {
-    default:
-      break;
-    case Intrinsic::lifetime_start:
-    case Intrinsic::lifetime_end:
-    case Intrinsic::invariant_start:
-    case Intrinsic::invariant_end:
-    case Intrinsic::assume:
-      return;
-    }
-  }
   if (!Inst->mayReadOrWriteMemory())
     return; // doesn't alias anything