Simplify; no significant functionality change.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@133086 91177308-0d34-0410-b5e6-96231b3b80d8

lib/Transforms/Utils/Local.cpp

@@ -706,39 +706,15 @@ bool llvm::EliminateDuplicatePHINodes(BasicBlock *BB) {
 ///
 static unsigned enforceKnownAlignment(Value *V, unsigned Align,
                                       unsigned PrefAlign) {
+  V = V->stripPointerCasts();
 
-  User *U = dyn_cast<User>(V);
-  if (!U) return Align;
-
-  switch (Operator::getOpcode(U)) {
-  default: break;
-  case Instruction::BitCast:
-    return enforceKnownAlignment(U->getOperand(0), Align, PrefAlign);
-  case Instruction::GetElementPtr: {
-    // If all indexes are zero, it is just the alignment of the base pointer.
-    bool AllZeroOperands = true;
-    for (User::op_iterator i = U->op_begin() + 1, e = U->op_end(); i != e; ++i)
-      if (!isa<Constant>(*i) ||
-          !cast<Constant>(*i)->isNullValue()) {
-        AllZeroOperands = false;
-        break;
-      }
-
-    if (AllZeroOperands) {
-      // Treat this like a bitcast.
-      return enforceKnownAlignment(U->getOperand(0), Align, PrefAlign);
-    }
-    return Align;
-  }
-  case Instruction::Alloca: {
-    AllocaInst *AI = cast<AllocaInst>(V);
+  if (AllocaInst *AI = dyn_cast<AllocaInst>(V)) {
     // If there is a requested alignment and if this is an alloca, round up.
     if (AI->getAlignment() >= PrefAlign)
       return AI->getAlignment();
     AI->setAlignment(PrefAlign);
     return PrefAlign;
   }
-  }
 
   if (GlobalValue *GV = dyn_cast<GlobalValue>(V)) {
     // If there is a large requested alignment and we can, bump up the alignment