Revert "calculate builtin_object_size if argument is a removable poin…

…ter"

Revert r262337 as "check-llvm ubsan" step failed on
sanitizer-x86_64-linux-fast buildbot.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@262349 91177308-0d34-0410-b5e6-96231b3b80d8

lib/Transforms/InstCombine/InstructionCombining.cpp

@@ -1941,25 +1941,6 @@ Instruction *InstCombiner::visitAllocSite(Instruction &MI) {
   // true or false as appropriate.
   SmallVector<WeakVH, 64> Users;
   if (isAllocSiteRemovable(&MI, Users, TLI)) {
-    for (unsigned i = 0, e = Users.size(); i != e; ++i) {
-      // Lowering all @llvm.objectsize calls first because they may
-      // use a bitcast/GEP of the alloca we are removing.
-      Instruction *I = cast_or_null<Instruction>(&*Users[i]);
-      if (!I) continue;
-
-      if (IntrinsicInst *II = dyn_cast<IntrinsicInst>(I)) {
-        if (II->getIntrinsicID() == Intrinsic::objectsize) {
-          uint64_t Size;
-          if (!getObjectSize(II->getArgOperand(0), Size, DL, TLI)) {
-            ConstantInt *CI = cast<ConstantInt>(II->getArgOperand(1));
-            Size = CI->isZero() ? -1ULL : 0;
-          }
-          replaceInstUsesWith(*I, ConstantInt::get(I->getType(), Size));
-          eraseInstFromFunction(*I);
-          Users[i] = nullptr; // Skip examining in the next loop.
-        }
-      }
-    }
     for (unsigned i = 0, e = Users.size(); i != e; ++i) {
       Instruction *I = cast_or_null<Instruction>(&*Users[i]);
       if (!I) continue;
@@ -1970,6 +1951,12 @@ Instruction *InstCombiner::visitAllocSite(Instruction &MI) {
                                              C->isFalseWhenEqual()));
       } else if (isa<BitCastInst>(I) || isa<GetElementPtrInst>(I)) {
         replaceInstUsesWith(*I, UndefValue::get(I->getType()));
+      } else if (IntrinsicInst *II = dyn_cast<IntrinsicInst>(I)) {
+        if (II->getIntrinsicID() == Intrinsic::objectsize) {
+          ConstantInt *CI = cast<ConstantInt>(II->getArgOperand(1));
+          uint64_t DontKnow = CI->isZero() ? -1ULL : 0;
+          replaceInstUsesWith(*I, ConstantInt::get(I->getType(), DontKnow));
+        }
       }
       eraseInstFromFunction(*I);
     }