fmt.Fprintf(&buf, "%v", i.Op)
	sep := " "
	for _, v := range i.Args {
		if v == nil {
			break
		}
		fmt.Fprintf(&buf, "%s%v", sep, v)
		sep = ", "
	}
	return buf.String()
}

func isReg(a Arg) bool {
	_, ok := a.(Reg)
	return ok
}

func isSegReg(a Arg) bool {
	r, ok := a.(Reg)
	return ok && ES <= r && r <= GS
}

func isMem(a Arg) bool {
	_, ok := a.(Mem)
	return ok

	if args != nil {
		text += " "
		// Indirect call/jmp gets a star to distinguish from direct jump address.
		if (inst.Op == CALL || inst.Op == JMP || inst.Op == LJMP || inst.Op == LCALL) && (isMem(inst.Args[0]) || isReg(inst.Args[0])) {
			text += "*"
		}
		text += strings.Join(args, ",")
	}
	return text
}

// gnuArg returns the GNU syntax for the argument x from the instruction inst.

		r := e.findRegFor(c.Type)
		if e.s.f.pass.debug > regDebug {
			fmt.Printf("breaking cycle with v%d in %s:%s\n", vid, loc, c)
		}
		e.erase(r)
		pos := d.pos.WithNotStmt()
		if _, isReg := loc.(*Register); isReg {
			c = e.p.NewValue1(pos, OpCopy, c.Type, c)
		} else {
			c = e.p.NewValue1(pos, OpLoadReg, c.Type, c)
		}
		e.set(r, vid, c, false, pos)

bool IsPlaceholder(const tensorflow::NodeDef& node_def);

bool IsScalarConst(const tensorflow::NodeDef& node_def, int v);

bool IsAddN(const tensorflow::NodeDef& node_def, int n);

bool IsNeg(const tensorflow::NodeDef& node_def, const string& input);

bool GetGraphDef(TF_Graph* graph, tensorflow::GraphDef* graph_def);

bool GetNodeDef(TF_Operation* oper, tensorflow::NodeDef* node_def);

    } else if (attr.first == "N") {
      if (attr.second.i() == n) {
        found_n = true;
      } else {
        return false;
      }
    }
  }
  return found_t && found_n;
}

bool IsNeg(const tensorflow::NodeDef& node_def, const string& input) {
  return node_def.op() == "Neg" && node_def.name() == "neg" &&
         node_def.input_size() == 1 && node_def.input(0) == input;
}

  ASSERT_EQ(TF_OK, TF_GetCode(s)) << TF_Message(s);

  // Serialize to NodeDef.
  NodeDef node_def;
  ASSERT_TRUE(GetNodeDef(neg, &node_def));

  // Validate NodeDef is what we expect.
  EXPECT_TRUE(IsNeg(node_def, "add"));

  // Serialize to GraphDef.
  GraphDef graph_def2;
  ASSERT_TRUE(GetGraphDef(graph, &graph_def2));

  // Compare with first GraphDef + added NodeDef.

t=2/(2+x);ty=4*t-2;for(;j>0;j--){tmp=d;d=ty*d-dd+cof[j];dd=tmp;}
res=t*Math.exp(-x*x+0.5*(cof[0]+ty*d)-dd);return isneg?res-1:1-res;};var dnorm=function(x,mean,std){return 0.5*(1+erf((x-mean)/Math.sqrt(2*std*std)));}