Rebuilding the cfg

[Ian Lance Taylor]

Richard Guenther <richard.guenther@gmail.com> writes:

> On Fri, Sep 10, 2010 at 5:39 PM, Paulo J. Matos <pocmatos@gmail.com> wrote:
>> Hello,
>>
>> On my frontend pass, I am dealing with basic blocks and I am for:
>> ,----
>> | int f(int n)
>> | {
>> |   switch(n)
>> |   {
>> |     case 0: f1("0"); break;
>> |     case 500: f2("500"); break;
>> |     case 1000: f3("1000"); break;
>> |     default: d(); break;
>> |   }
>> | }
>> `----
>>
>> transforming it into:
>> ,----
>> | int f(int n)
>> | {
>> |   if(n < 500)
>> |     if(n == 0)
>> |       f1("0");
>> |     else
>> |       goto def;
>> |   else
>> |     if(n == 500)
>> |       f2("500");
>> |     else
>> |       if(n == 1000)
>> |         f3("1000");
>> |       else
>> |         goto def;
>> |
>> |   return;
>> |
>> | def:
>> |   d();
>> |   return;
>> | }
>> `----
>>
>> The problem with this is that it contains nested ifs.
>> Is there a way for me to insert this tree and ask GCC to rebuild the CFG
>> or I need to build the correct CFG manually?
>
> You need to build it manually.

Can't he just call find_many_sub_basic_blocks?

Ian