On Tue, 11 Mar 2025, Jakub Jelinek wrote:
> Hi!
>
> The PR116463 r15-3128 change regressed the following testcase at -O0.
> While for -O1+ we can do -fvar-tracking-assignments, for -O0 we don't
> (partly because it is compile time expensive and partly because at -O0
> most of the vars live most of their lifetime in memory slots), so if we
> DCE some statements, it can mean that DW_AT_location for some vars won't
> be available or even it won't be possible to put a breakpoint at some
> particular line in the source.
> We normally perform dce just in the subpasses of
> pass_local_optimization_passes or pass_all_optimizations or
> pass_all_optimizations_g, so don't do that at all for -O0. So the complex
> change is an exception. And it was described as a way to help forwprop and
> reassoc, neither applies to -O0.
>
> This regresses PR119120 again though, I'll post a patch for that momentarily.
>
> Bootstrapped/regtested on x86_64-linux and i686-linux, ok for trunk?
OK.
> 2025-03-11 Jakub Jelinek <ja...@redhat.com>
>
> PR debug/119190
> * tree-complex.cc (update_complex_assignment, tree_lower_complex):
> Perform simple dce on dce_worklist only if optimize.
>
> * gfortran.dg/guality/pr119190.f90: New test.
>
> --- gcc/tree-complex.cc.jj 2025-01-02 11:23:34.810261473 +0100
> +++ gcc/tree-complex.cc 2025-03-10 13:18:42.655209216 +0100
> @@ -735,7 +735,8 @@ update_complex_assignment (gimple_stmt_i
> update_stmt (stmt);
> if (maybe_clean_or_replace_eh_stmt (old_stmt, stmt))
> bitmap_set_bit (need_eh_cleanup, gimple_bb (stmt)->index);
> - bitmap_set_bit (dce_worklist, SSA_NAME_VERSION (gimple_assign_lhs (stmt)));
> + if (optimize)
> + bitmap_set_bit (dce_worklist, SSA_NAME_VERSION (gimple_assign_lhs
> (stmt)));
>
> update_complex_components (gsi, gsi_stmt (*gsi), r, i);
> }
> @@ -1967,7 +1968,8 @@ tree_lower_complex (void)
> complex_propagate.ssa_propagate ();
>
> need_eh_cleanup = BITMAP_ALLOC (NULL);
> - dce_worklist = BITMAP_ALLOC (NULL);
> + if (optimize)
> + dce_worklist = BITMAP_ALLOC (NULL);
>
> complex_variable_components = new int_tree_htab_type (10);
>
> @@ -2014,8 +2016,11 @@ tree_lower_complex (void)
>
> gsi_commit_edge_inserts ();
>
> - simple_dce_from_worklist (dce_worklist, need_eh_cleanup);
> - BITMAP_FREE (dce_worklist);
> + if (optimize)
> + {
> + simple_dce_from_worklist (dce_worklist, need_eh_cleanup);
> + BITMAP_FREE (dce_worklist);
> + }
>
> unsigned todo
> = gimple_purge_all_dead_eh_edges (need_eh_cleanup) ? TODO_cleanup_cfg :
> 0;
> --- gcc/testsuite/gfortran.dg/guality/pr119190.f90.jj 2025-03-10
> 13:19:34.375502530 +0100
> +++ gcc/testsuite/gfortran.dg/guality/pr119190.f90 2025-03-10
> 13:24:13.394683486 +0100
> @@ -0,0 +1,13 @@
> +! PR debug/119190
> +! { dg-do run }
> +! { dg-options "-g" }
> +
> +program foo
> + integer :: ia, ib
> + complex :: ci
> + ia = 1
> + ib = 2
> + ci = cmplx(ia, ib)
> + print *, ia
> + print *, ib ! { dg-final { gdb-test 12 "ci" "(1,2)" } }
> +end program
>
> Jakub
>
>
--
Richard Biener <rguent...@suse.de>
SUSE Software Solutions Germany GmbH,
Frankenstrasse 146, 90461 Nuernberg, Germany;
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