teach various passes about blockaddress. We no longer

crash on any clang tests.

llvm-svn: 85465

lib/Transforms/IPO/GlobalDCE.cpp

@@ -191,13 +191,13 @@ void GlobalDCE::GlobalIsNeeded(GlobalValue *G) {
 
 void GlobalDCE::MarkUsedGlobalsAsNeeded(Constant *C) {
   if (GlobalValue *GV = dyn_cast<GlobalValue>(C))
-    GlobalIsNeeded(GV);
-  else {
-    // Loop over all of the operands of the constant, adding any globals they
-    // use to the list of needed globals.
-    for (User::op_iterator I = C->op_begin(), E = C->op_end(); I != E; ++I)
-      MarkUsedGlobalsAsNeeded(cast<Constant>(*I));
-  }
+    return GlobalIsNeeded(GV);
+  
+  // Loop over all of the operands of the constant, adding any globals they
+  // use to the list of needed globals.
+  for (User::op_iterator I = C->op_begin(), E = C->op_end(); I != E; ++I)
+    if (Constant *OpC = dyn_cast<Constant>(*I))
+      MarkUsedGlobalsAsNeeded(OpC);
 }
 
 // RemoveUnusedGlobalValue - Loop over all of the uses of the specified

lib/Transforms/Scalar/SCCP.cpp

@@ -448,10 +448,16 @@ void SCCPSolver::getFeasibleSuccessors(TerminatorInst &TI,
         Succs[BCValue.getConstant() == ConstantInt::getFalse(*Context)] = true;
       }
     }
-  } else if (isa<InvokeInst>(&TI)) {
+    return;
+  }
+  
+  if (isa<InvokeInst>(&TI)) {
     // Invoke instructions successors are always executable.
     Succs[0] = Succs[1] = true;
-  } else if (SwitchInst *SI = dyn_cast<SwitchInst>(&TI)) {
+    return;
+  }
+  
+  if (SwitchInst *SI = dyn_cast<SwitchInst>(&TI)) {
     LatticeVal &SCValue = getValueState(SI->getCondition());
     if (SCValue.isOverdefined() ||   // Overdefined condition?
         (SCValue.isConstant() && !isa<ConstantInt>(SCValue.getConstant()))) {
@@ -459,9 +465,20 @@ void SCCPSolver::getFeasibleSuccessors(TerminatorInst &TI,
       Succs.assign(TI.getNumSuccessors(), true);
     } else if (SCValue.isConstant())
       Succs[SI->findCaseValue(cast<ConstantInt>(SCValue.getConstant()))] = true;
-  } else {
-    llvm_unreachable("SCCP: Don't know how to handle this terminator!");
+    return;
   }
+  
+  // TODO: This could be improved if the operand is a [cast of a] BlockAddress.
+  if (isa<IndirectBrInst>(&TI)) {
+    // Just mark all destinations executable!
+    Succs.assign(TI.getNumSuccessors(), true);
+    return;
+  }
+  
+#ifndef NDEBUG
+  errs() << "Unknown terminator instruction: " << TI << '\n';
+#endif
+  llvm_unreachable("SCCP: Don't know how to handle this terminator!");
 }
 
 
@@ -479,25 +496,27 @@ bool SCCPSolver::isEdgeFeasible(BasicBlock *From, BasicBlock *To) {
   if (BranchInst *BI = dyn_cast<BranchInst>(TI)) {
     if (BI->isUnconditional())
       return true;
-    else {
-      LatticeVal &BCValue = getValueState(BI->getCondition());
-      if (BCValue.isOverdefined()) {
-        // Overdefined condition variables mean the branch could go either way.
-        return true;
-      } else if (BCValue.isConstant()) {
-        // Not branching on an evaluatable constant?
-        if (!isa<ConstantInt>(BCValue.getConstant())) return true;
+    
+    LatticeVal &BCValue = getValueState(BI->getCondition());
+    if (BCValue.isOverdefined()) {
+      // Overdefined condition variables mean the branch could go either way.
+      return true;
+    } else if (BCValue.isConstant()) {
+      // Not branching on an evaluatable constant?
+      if (!isa<ConstantInt>(BCValue.getConstant())) return true;
 
-        // Constant condition variables mean the branch can only go a single way
-        return BI->getSuccessor(BCValue.getConstant() ==
-                                       ConstantInt::getFalse(*Context)) == To;
-      }
-      return false;
+      // Constant condition variables mean the branch can only go a single way
+      return BI->getSuccessor(BCValue.getConstant() ==
+                                     ConstantInt::getFalse(*Context)) == To;
     }
-  } else if (isa<InvokeInst>(TI)) {
-    // Invoke instructions successors are always executable.
+    return false;
+  }
+  
+  // Invoke instructions successors are always executable.
+  if (isa<InvokeInst>(TI))
     return true;
-  } else if (SwitchInst *SI = dyn_cast<SwitchInst>(TI)) {
+  
+  if (SwitchInst *SI = dyn_cast<SwitchInst>(TI)) {
     LatticeVal &SCValue = getValueState(SI->getCondition());
     if (SCValue.isOverdefined()) {  // Overdefined condition?
       // All destinations are executable!
@@ -517,12 +536,17 @@ bool SCCPSolver::isEdgeFeasible(BasicBlock *From, BasicBlock *To) {
       return SI->getDefaultDest() == To;
     }
     return false;
-  } else {
-#ifndef NDEBUG
-    errs() << "Unknown terminator instruction: " << *TI << '\n';
-#endif
-    llvm_unreachable(0);
   }
+  
+  // Just mark all destinations executable!
+  // TODO: This could be improved if the operand is a [cast of a] BlockAddress.
+  if (isa<IndirectBrInst>(&TI))
+    return true;
+  
+#ifndef NDEBUG
+  errs() << "Unknown terminator instruction: " << *TI << '\n';
+#endif
+  llvm_unreachable(0);
 }
 
 // visit Implementations - Something changed in this instruction... Either an

lib/Transforms/Utils/ValueMapper.cpp

@@ -113,8 +113,8 @@ Value *llvm::MapValue(const Value *V, ValueMapTy &VM) {
   
   if (BlockAddress *BA = dyn_cast<BlockAddress>(C)) {
     Function *F = cast<Function>(MapValue(BA->getFunction(), VM));
-    BasicBlock *BB = cast<BasicBlock>(MapValue(BA->getBasicBlock(), VM));
-    return VM[V] = BlockAddress::get(F, BB);
+    BasicBlock *BB = cast_or_null<BasicBlock>(MapValue(BA->getBasicBlock(),VM));
+    return VM[V] = BlockAddress::get(F, BB ? BB : BA->getBasicBlock());
   }
   
   llvm_unreachable("Unknown type of constant!");