https://gcc.gnu.org/bugzilla/show_bug.cgi?id=68083
--- Comment #7 from Alexandre Oliva <aoliva at gcc dot gnu.org> --- Author: aoliva Date: Tue Nov 3 00:30:07 2015 New Revision: 229690 URL: https://gcc.gnu.org/viewcvs?rev=229690&root=gcc&view=rev Log: [PR68083] don't introduce undefined behavior in ifcombine The ifcombine pass may move a conditional access to an uninitialized value before the condition that ensures it is always well-defined, thus introducing undefined behavior. Stop it from doing so. for gcc/ChangeLog PR tree-optimization/68083 * tree-ssa-ifcombine.c: Include tree-ssa.h. (bb_no_side_effects_p): Test for undefined uses too. * tree-ssa.c (gimple_uses_undefined_value_p): New. * tree-ssa.h (gimple_uses_undefined_value_p): Declare. for gcc/testsuite/ChangeLog PR tree-optimization/68083 * gcc.dg/torture/pr68083.c: New. From Zhendong Su. Added: trunk/gcc/testsuite/gcc.dg/torture/pr68083.c Modified: trunk/ChangeLog trunk/gcc/ChangeLog trunk/gcc/testsuite/ChangeLog trunk/gcc/tree-ssa-ifcombine.c trunk/gcc/tree-ssa.c trunk/gcc/tree-ssa.h
