re PR middle-end/64491 (incorrect warning: loop exit may only be reached after undefi...

re PR middle-end/64491 (incorrect warning: loop exit may only be reached after undefined behavior)

Fix PR64491

2015-03-18  Andrew Stubbs  <ams@codesourcery.com>

	PR middle-end/64491
	Revert:
	2014-11-20  Andrew Stubbs  <ams@codesourcery.com>

	* tree-ssa-loop-niter.c (maybe_lower_iteration_bound): Warn if a loop
	condition would be removed due to undefined behaviour.

2015-03-18  Andrew Stubbs  <ams@codesourcery.com>

	PR middle-end/64491
	Revert:
	2014-11-20  Andrew Stubbs  <ams@codesourcery.com>

	* gcc.dg/undefined-loop-1.c: New file.
	* gcc.dg/undefined-loop-2.c: New file.

	2014-12-24  Andrew Stubbs  <ams@codesourcery.com>

	PR testsuite/64032
	* gcc.dg/undefined-loop-2.c: Don't allow GCC to optimize away the
	loop exits too early.

From-SVN: r221492