[Bug middle-end/53676] [4.7 regression] empty loop is not always removed now

[matt at use dot net]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=53676

--- Comment #16 from Matt Hargett <matt at use dot net> 2012-08-23 18:01:08 UTC ---
Back/forward-porting of the "trivial" restoration of the old behavior is
acceptable to me, as it would remove a major barrier to our adoption of 4.7.x.
That being said, if there's multi-platform testing I can do with a 'better' fix
based on trunk, I have SPARC and ARM qemu environments set up to regression
test on.

BTW, I realized that my initial analysis was wrong -- the int32_t and uint32_t
benchmarks are unaffected by this regression.

Let me know if there's an easy way to apply the restoration patch and I'll test
it locally on our amdfam10 and bdver2 hardware. If the testcase committed to
trunk would be applicable to a 4.7 fix as well, I can make a patch to integrate
that to ensure thie functionality doesn't regress again in future 4.7.x point
releases. I'm happy to do as much footwork as my expertise allows, just let me
know :)

Thanks!