r255635 - in /trunk/gcc: ChangeLog testsuite/Ch...

[rguenth@gcc.gnu.org]

Author: rguenth
Date: Thu Dec 14 14:32:24 2017
New Revision: 255635

URL: https://gcc.gnu.org/viewcvs?rev=255635&root=gcc&view=rev
Log:
2017-12-14  Richard Biener  <rguenther@suse.de>

	PR tree-optimization/83326
	* tree-ssa-loop-ivcanon.c (try_unroll_loop_completely): Add
	may_be_zero parameter and handle it by not marking the first
	peeled copy as not exiting the loop.
	(try_peel_loop): Likewise.
	(canonicalize_loop_induction_variables): Use number_of_iterations_exit
	to handle the case of constant or zero iterations and perform
	loop header copying on-the-fly.

	* gcc.dg/tree-ssa/pr81388-2.c: Adjust.

Modified:
    trunk/gcc/ChangeLog
    trunk/gcc/testsuite/ChangeLog
    trunk/gcc/testsuite/gcc.dg/tree-ssa/pr81388-2.c
    trunk/gcc/tree-ssa-loop-ivcanon.c