On 12/2/22 07:30, Richard Biener via Gcc-patches wrote:
The following fixes a wrong-code bug caused by loop invariant motion
hoisting an expression using an uninitialized value outside of its
controlling condition causing IVOPTs to use that to rewrite a defined
value. PR107839 is a similar case involving a bogus uninit diagnostic.
Bootstrapped and tested on x86_64-unknown-linux-gnu.
OK?
Thanks,
Richard.
PR tree-optimization/107833
PR tree-optimization/107839
* cfghooks.cc: Include tree.h.
* tree-ssa-loop-im.cc (movement_possibility): Wrap and
make stmts using any ssa_name_maybe_undef_p operand
to preserve execution.
(loop_invariant_motion_in_fun): Call mark_ssa_maybe_undefs
to init maybe-undefined status.
* tree-ssa-loop-ivopts.cc (ssa_name_maybe_undef_p,
ssa_name_set_maybe_undef, ssa_name_any_use_dominates_bb_p,
mark_ssa_maybe_undefs): Move ...
* tree-ssa.cc: ... here.
* tree-ssa.h (ssa_name_any_use_dominates_bb_p,
mark_ssa_maybe_undefs): Declare.
(ssa_name_maybe_undef_p, ssa_name_set_maybe_undef): Define.
* gcc.dg/torture/pr107833.c: New testcase.
* gcc.dg/uninit-pr107839.c: Likewise.
OK.
Jeff
