[PATCH][PR tree-optimization/64823] Handle threading through blocks with PHIs, but no statements

[Jack Howarth]

This also breaks the bootstrap on x86_64-apple-darwin14 due to a
similar stage 2/3 comparison failure.

On Fri, Feb 13, 2015 at 6:01 PM, H.J. Lu <hjl.tools@gmail.com> wrote:
> On Fri, Feb 13, 2015 at 1:11 PM, Jeff Law <law@redhat.com> wrote:
>> This time with the right patch file.
>>
>> commit 48087ce0b383457b5919cbcc2ce1a5e1aaa264c3
>> Author: Jeff Law <law@redhat.com>
>> Date:   Fri Feb 13 14:08:06 2015 -0700
>>
>>         PR tree-optimization/64823
>>         * tree-vrp.c (identify_jump_threads): Handle blocks with no
>> statements.
>>         * tree-ssa-threadedge.c (potentially_threadable_block): Allow
>>         threading through blocks with PHIs, but no statements.
>>         (thread_through_normal_block): Distinguish between blocks where
>>         we did not process all the statements and blocks with no statements.
>>
>>         PR tree-optimization/64823
>>         gcc.dg/uninit-20.c: New test.
>>
>
> This caused:
>
> https://gcc.gnu.org/bugzilla/show_bug.cgi?id=65060
>
>
> --
> H.J.