[PATCH PR71503/PR71683]Fix ICE in tree-if-conv.c

[Jeff Law]

On 07/19/2016 07:39 AM, Bin.Cheng wrote:
> On Thu, Jul 14, 2016 at 6:49 PM, Jeff Law <law@redhat.com> wrote:
>> On 07/14/2016 10:12 AM, Bin Cheng wrote:
>>>
>>> Hi,
>>> This is a simple patch fixing ICE in tree-if-conv.c.  Existing code does
>>> not setup a variable (cond) when predicate of basic block is true and it
>>> asserts on the variable.  Interesting thing is dead code is not cleaned up
>>> before ifcvt, but that's another story.
>>> Bootstrap and test on x86_64.  Is it OK?
>>>
>>> Thanks,
>>> bin
>>>
>>> 2016-07-13  Bin Cheng  <bin.cheng@arm.com>
>>>
>>>         PR tree-optimization/71503
>>>         PR tree-optimization/71683
>>>         * tree-if-conv.c (gen_phi_arg_condition): Set cond when predicate
>>>         is true.
>>
>> Maybe I'm missing something, but in the case where we COND is already set
>> and we encounter a true predicate later, shouldn't that make the result true
>> as well?
>>
>> I don't think the code will though -- we just throw away the true condition.
>> ISTM that the right thing to do is
>>
>> if (is_true_predicate (c))
>>   {
>>     cond = c;
>>     continue;
>>   }
>>
>> Can you see if you can trigger a case where we have an existing cond, then
>> later find a true condition to verify the right thing happens?
> Hi,
> Attachment is the updated patch, it breaks the loop once TRUE
> predicate is found.  I also built spec2k6/spec2k and your case is not
> found.  Is it OK?
This version is OK.  Thanks,
jeff