Limit the number of times we recurse through this algorithm. All of the

intructions are processed. So there's no need to look at them if they're used as
operands of other instructions.

llvm-svn: 155327

llvm/lib/VMCore/Module.cpp

@@ -505,22 +505,30 @@ namespace {
           incorporateValue(Aliasee);
       }
       
-      SmallVector<std::pair<unsigned, MDNode*>, 4> MDForInst;
-
       // Get types from functions.
+      SmallVector<std::pair<unsigned, MDNode*>, 4> MDForInst;
       for (Module::const_iterator FI = M.begin(), E = M.end(); FI != E; ++FI) {
         incorporateType(FI->getType());
         
+        // First incorporate the arguments.
+        for (Function::const_arg_iterator AI = FI->arg_begin(),
+               AE = FI->arg_end(); AI != AE; ++AI)
+          incorporateValue(AI);
+
         for (Function::const_iterator BB = FI->begin(), E = FI->end();
              BB != E;++BB)
           for (BasicBlock::const_iterator II = BB->begin(),
                E = BB->end(); II != E; ++II) {
             const Instruction &I = *II;
-            // Incorporate the type of the instruction and all its operands.
+            // Incorporate the type of the instruction.
             incorporateType(I.getType());
+
+            // Incorporate non-instruction operand types. (We are incorporating
+            // all instructions with this loop.)
             for (User::const_op_iterator OI = I.op_begin(), OE = I.op_end();
                  OI != OE; ++OI)
-              incorporateValue(*OI);
+              if (!isa<Instruction>(OI))
+                incorporateValue(*OI);
             
             // Incorporate types hiding in metadata.
             I.getAllMetadataOtherThanDebugLoc(MDForInst);
@@ -570,7 +578,11 @@ namespace {
       
       // Check this type.
       incorporateType(V->getType());
-      
+
+      // If this is an instruction, we incorporate it separately.
+      if (isa<Instruction>(V))
+        return;
+
       // Look in operands for types.
       const User *U = cast<User>(V);
       for (Constant::const_op_iterator I = U->op_begin(),