789     case lir_log10: {

   790       // log and log10 need one temporary fpu stack slot, so

   791       // there is one temporary registers stored in temp of the

   792       // operation. the stack allocator must guarantee that the stack

   793       // slots are really free, otherwise there might be a stack

   794       // overflow.

   795       assert(right->is_illegal(), "must be");

   796       assert(left->is_fpu_register(), "must be");

   797       assert(res->is_fpu_register(), "must be");

   798       assert(op2->tmp1_opr()->is_fpu_register(), "must be");

   799 

   800       insert_free_if_dead(op2->tmp1_opr());

   801       insert_free_if_dead(res, left);

   802       insert_exchange(left);

   803       do_rename(left, res);

   804 

   805       new_left = to_fpu_stack_top(res);

   806       new_res = new_left;

   807 

   808       op2->set_fpu_stack_size(sim()->stack_size());

   809       assert(sim()->stack_size() <= 7, "at least one stack slot must be free");

   810       break;

   811     }

   812 

   813 

   814     case lir_tan: {

   815       // sin, cos and exp need two temporary fpu stack slots, so there are two temporary

   816       // registers (stored in right and temp of the operation).

   817       // the stack allocator must guarantee that the stack slots are really free,

   818       // otherwise there might be a stack overflow.

   819       assert(left->is_fpu_register(), "must be");

   820       assert(res->is_fpu_register(), "must be");

   821       // assert(left->is_last_use(), "old value gets destroyed");

   822       assert(right->is_fpu_register(), "right is used as the first temporary register");

   823       assert(op2->tmp1_opr()->is_fpu_register(), "temp is used as the second temporary register");

   824       assert(fpu_num(left) != fpu_num(right) && fpu_num(right) != fpu_num(op2->tmp1_opr()) && fpu_num(op2->tmp1_opr()) != fpu_num(res), "need distinct temp registers");

   825 

   826       insert_free_if_dead(right);

   827       insert_free_if_dead(op2->tmp1_opr());

   828 

   829       insert_free_if_dead(res, left);

   830       insert_exchange(left);

   831       do_rename(left, res);

   832 

   833       new_left = to_fpu_stack_top(res);

   834       new_res = new_left;

   835 

   836       op2->set_fpu_stack_size(sim()->stack_size());

   837       assert(sim()->stack_size() <= 6, "at least two stack slots must be free");

   838       break;

   839     }

   840