https://gcc.gnu.org/g:bcf8cec0e8f11a9de0b435688cb82dcf8810686b
commit r14-12076-gbcf8cec0e8f11a9de0b435688cb82dcf8810686b Author: Richard Biener <[email protected]> Date: Fri May 30 14:11:47 2025 +0200 tree-optimization/120357 - ICE with early break vectorization When doing early break vectorization of a loop with a conditional reduction the epilog creation code is confused as to before which exit to insert the conditional reduction induction IV update. The following make sure this is done before the main IV exit. PR tree-optimization/120357 * tree-vect-loop.cc (vect_create_epilog_for_reduction): Create the conditional reduction induction IV increment before the main IV exit. * gcc.dg/vect/vect-early-break_136-pr120357.c: New testcase. (cherry picked from commit dce4da51ab66c3abb84448326910cd42f6fe2499) Diff: --- gcc/testsuite/gcc.dg/vect/vect-early-break_136-pr120357.c | 13 +++++++++++++ gcc/tree-vect-loop.cc | 3 ++- 2 files changed, 15 insertions(+), 1 deletion(-) diff --git a/gcc/testsuite/gcc.dg/vect/vect-early-break_136-pr120357.c b/gcc/testsuite/gcc.dg/vect/vect-early-break_136-pr120357.c new file mode 100644 index 000000000000..8a51cfc46a5d --- /dev/null +++ b/gcc/testsuite/gcc.dg/vect/vect-early-break_136-pr120357.c @@ -0,0 +1,13 @@ +/* { dg-do compile } */ +/* { dg-add-options vect_early_break } */ +/* { dg-additional-options "-O3" } */ + +char a; +unsigned long long t[2][22]; +int u[22]; +void f(void) +{ + for (int v = 0; v < 22; v++) + for (_Bool w = 0; w < (u[v] < 0) + 1; w = 1) + a *= 0 != t[w][v]; +} diff --git a/gcc/tree-vect-loop.cc b/gcc/tree-vect-loop.cc index 75fbcdf46d09..37548d03edb4 100644 --- a/gcc/tree-vect-loop.cc +++ b/gcc/tree-vect-loop.cc @@ -6134,7 +6134,8 @@ vect_create_epilog_for_reduction (loop_vec_info loop_vinfo, /* Create an induction variable. */ gimple_stmt_iterator incr_gsi; bool insert_after; - vect_iv_increment_position (loop_exit, &incr_gsi, &insert_after); + vect_iv_increment_position (LOOP_VINFO_IV_EXIT (loop_vinfo), + &incr_gsi, &insert_after); create_iv (series_vect, PLUS_EXPR, vec_step, NULL_TREE, loop, &incr_gsi, insert_after, &indx_before_incr, &indx_after_incr);
