https://gcc.gnu.org/g:85621f98d245004a6c9787dde21e0acc17ab2c50
commit r14-9786-g85621f98d245004a6c9787dde21e0acc17ab2c50 Author: Richard Biener <rguent...@suse.de> Date: Thu Apr 4 10:00:51 2024 +0200 tree-optimization/114485 - neg induction with partial vectors We can't use vect_update_ivs_after_vectorizer for partial vectors, the following fixes vect_can_peel_nonlinear_iv_p accordingly. PR tree-optimization/114485 * tree-vect-loop-manip.cc (vect_can_peel_nonlinear_iv_p): vect_step_op_neg isn't OK for partial vectors but only for unknown niter. * gcc.dg/vect/pr114485.c: New testcase. Diff: --- gcc/testsuite/gcc.dg/vect/pr114485.c | 18 ++++++++++++++++++ gcc/tree-vect-loop-manip.cc | 14 +++++++------- 2 files changed, 25 insertions(+), 7 deletions(-) diff --git a/gcc/testsuite/gcc.dg/vect/pr114485.c b/gcc/testsuite/gcc.dg/vect/pr114485.c new file mode 100644 index 00000000000..6536806e350 --- /dev/null +++ b/gcc/testsuite/gcc.dg/vect/pr114485.c @@ -0,0 +1,18 @@ +#include "tree-vect.h" + +int b, c = 8, d; +int e[23]; +int main() +{ + check_vect (); + + int *h = e; + for (int i = 1; i < b + 21; i += 2) + { + c *= -1; + d = h[i] ? i : 0; + } + if (c != 8) + abort (); + return 0; +} diff --git a/gcc/tree-vect-loop-manip.cc b/gcc/tree-vect-loop-manip.cc index 56a6d8e4a8d..8d9b533d50f 100644 --- a/gcc/tree-vect-loop-manip.cc +++ b/gcc/tree-vect-loop-manip.cc @@ -2128,18 +2128,18 @@ vect_can_peel_nonlinear_iv_p (loop_vec_info loop_vinfo, For shift, when shift mount >= precision, there would be UD. For mult, don't known how to generate init_expr * pow (step, niters) for variable niters. - For neg, it should be ok, since niters of vectorized main loop + For neg unknown niters are ok, since niters of vectorized main loop will always be multiple of 2. - See also PR113163 and PR114196. */ - if ((!LOOP_VINFO_VECT_FACTOR (loop_vinfo).is_constant () - || LOOP_VINFO_USING_PARTIAL_VECTORS_P (loop_vinfo) - || !LOOP_VINFO_NITERS_KNOWN_P (loop_vinfo)) - && induction_type != vect_step_op_neg) + See also PR113163, PR114196 and PR114485. */ + if (!LOOP_VINFO_VECT_FACTOR (loop_vinfo).is_constant () + || LOOP_VINFO_USING_PARTIAL_VECTORS_P (loop_vinfo) + || (!LOOP_VINFO_NITERS_KNOWN_P (loop_vinfo) + && induction_type != vect_step_op_neg)) { if (dump_enabled_p ()) dump_printf_loc (MSG_MISSED_OPTIMIZATION, vect_location, "Peeling for epilogue is not supported" - " for nonlinear induction except neg" + " for this nonlinear induction" " when iteration count is unknown or" " when using partial vectorization.\n"); return false;