On Fri, Sep 10, 2010 at 5:51 PM, Ian Lance Taylor <i...@google.com> wrote:
> Richard Guenther <richard.guent...@gmail.com> writes:
>
>> On Fri, Sep 10, 2010 at 5:39 PM, Paulo J. Matos <pocma...@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?
I doubt that anbody tested this on the tree-level, so I doubt it'll work
correctly.
Richard.
> Ian
>
