https://gcc.gnu.org/bugzilla/show_bug.cgi?id=112774
--- Comment #2 from GCC Commits <cvs-commit at gcc dot gnu.org> --- The master branch has been updated by Hao Liu <h...@gcc.gnu.org>: https://gcc.gnu.org/g:2efe3a7de0107618397264017fb045f237764cc7 commit r14-6299-g2efe3a7de0107618397264017fb045f237764cc7 Author: Hao Liu <h...@os.amperecomputing.com> Date: Wed Dec 6 14:52:19 2023 +0800 tree-optimization/112774: extend the SCEV CHREC tree with a nonwrapping flag The flag is defined as CHREC_NOWRAP(tree), and will be dumped from "{offset, +, 1}_1" to "{offset, +, 1}<nw>_1" (nw is short for nonwrapping). Two SCEV interfaces record_nonwrapping_chrec and nonwrapping_chrec_p are added to set and check the flag respectively. As resetting the SCEV cache (i.e., the chrec trees) may not reset the loop->estimate_state, free_numbers_of_iterations_estimates is called explicitly in loop vectorization to make sure the flag can be calculated propriately by niter. gcc/ChangeLog: PR tree-optimization/112774 * tree-pretty-print.cc: if nonwrapping flag is set, chrec will be printed with additional <nw> info. * tree-scalar-evolution.cc: add record_nonwrapping_chrec and nonwrapping_chrec_p to set and check the new flag respectively. * tree-scalar-evolution.h: Likewise. * tree-ssa-loop-niter.cc (idx_infer_loop_bounds, infer_loop_bounds_from_pointer_arith, infer_loop_bounds_from_signedness, scev_probably_wraps_p): call record_nonwrapping_chrec before record_nonwrapping_iv, call nonwrapping_chrec_p to check the flag is set and return false from scev_probably_wraps_p. * tree-vect-loop.cc (vect_analyze_loop): call free_numbers_of_iterations_estimates explicitly. * tree-core.h: document the nothrow_flag usage in CHREC_NOWRAP * tree.h: add CHREC_NOWRAP(NODE), base.nothrow_flag is used to represent the nonwrapping info. gcc/testsuite/ChangeLog: * gcc.dg/tree-ssa/scev-16.c: New test.
