Hello,
(quoting myself from the PR audit trail)
We call sched_scan for preheader blocks from inner regions twice: first during
sel_add_loop_preheaders, and then during the subsequent call to sel_init_bbs
in setup_current_loop_nest. As a result, we also call remove_notes for those
blocks twice, and after the second call incorrectly record that the block has
no notes.
The solution is to call sel_add_loop_preheaders after sel_init_bbs. We need
to add new preheader blocks into 'bbs' vector in setup_current_loop_nest, so
we pass the pointer to the vector to sel_add_loop_preheaders.
PR rtl-optimization/48302
* sel-sched-ir.h (sel_add_loop_preheaders): Update prototype.
* sel-sched-ir.c (sel_add_loop_preheaders): Add 'bbs' argument. Use
it to record added preheader blocks.
(setup_current_loop_nest): Add 'bbs' argument. Pass it on to
sel_add_loop_preheaders.
(sel_region_init): Move call to setup_current_loop_nest after
sel_init_bbs.
testsuite:
g++.dg/opt/pr48302.C: New.