https://gcc.gnu.org/bugzilla/show_bug.cgi?id=114396
Sam James <sjames at gcc dot gnu.org> changed:
What |Removed |Added
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CC| |liuhongt at gcc dot gnu.org
--- Comment #12 from Sam James <sjames at gcc dot gnu.org> ---
(In reply to Sam James from comment #11)
> Bisecting.
commit r13-7988-g82919cf4cb2321
Author: liuhongt <hongtao....@intel.com>
Date: Wed Oct 18 10:08:24 2023 +0800
Avoid compile time hog on vect_peel_nonlinear_iv_init for nonlinear
induction vec_step_op_mul when iteration count is too big.
There's loop in vect_peel_nonlinear_iv_init to get init_expr *
pow (step_expr, skip_niters). When skipn_iters is too big, compile time
hogs. To avoid that, optimize init_expr * pow (step_expr, skip_niters) to
init_expr << (exact_log2 (step_expr) * skip_niters) when step_expr is
pow of 2, otherwise give up vectorization when skip_niters >=
TYPE_PRECISION (TREE_TYPE (init_expr)).
