Hi!
The following testcase FAILs with -fcompare-debug. The problem is that
create_iv behaves differently when inserting after into an empty bb (in that
case sets location to goto_locus), or when inserting before gsi_end_p (i.e.
at the end of bb; in that case it will not set location, otherwise it will
set it to the location of next stmt).
This isn't -fcompare-debug friendly, because if inserting after and the
bb contains only debug stmts, then the location will not be set with -g
and will be with -g0, or when inserting before, the location might either
be set from the following debug stmt rather than some non-debug stmt after
that, or might not be set with -g0 if it is to be inserted at the end of bb,
while with -g would be set to location of debug stmt.
The following patch should fix that, bootstrapped/regtested on x86_64-linux
and i686-linux, ok for trunk?
2020-03-24 Jakub Jelinek <ja...@redhat.com>
PR debug/94285
* tree-ssa-loop-manip.c (create_iv): If after, set stmt location to
e->goto_locus even if gsi_bb (*incr_pos) contains only debug stmts.
If not after and at *incr_pos is a debug stmt, set stmt location to
location of next non-debug stmt after it if any.
* gfortran.dg/pr94285.f90: New test.
--- gcc/tree-ssa-loop-manip.c.jj 2020-01-12 11:54:38.506381831 +0100
+++ gcc/tree-ssa-loop-manip.c 2020-03-23 23:57:41.395225047 +0100
@@ -129,7 +129,10 @@ create_iv (tree base, tree step, tree va
immediately after a statement whose location is known. */
if (after)
{
- if (gsi_end_p (*incr_pos))
+ if (gsi_end_p (*incr_pos)
+ || (is_gimple_debug (gsi_stmt (*incr_pos))
+ && gsi_bb (*incr_pos)
+ && gsi_end_p (gsi_last_nondebug_bb (gsi_bb (*incr_pos)))))
{
edge e = single_succ_edge (gsi_bb (*incr_pos));
gimple_set_location (stmt, e->goto_locus);
@@ -138,8 +141,11 @@ create_iv (tree base, tree step, tree va
}
else
{
- if (!gsi_end_p (*incr_pos))
- gimple_set_location (stmt, gimple_location (gsi_stmt (*incr_pos)));
+ gimple_stmt_iterator gsi = *incr_pos;
+ if (!gsi_end_p (gsi) && is_gimple_debug (gsi_stmt (gsi)))
+ gsi_next_nondebug (&gsi);
+ if (!gsi_end_p (gsi))
+ gimple_set_location (stmt, gimple_location (gsi_stmt (gsi)));
gsi_insert_before (incr_pos, stmt, GSI_NEW_STMT);
}
--- gcc/testsuite/gfortran.dg/pr94285.f90.jj 2020-03-23 18:55:19.677902869
+0100
+++ gcc/testsuite/gfortran.dg/pr94285.f90 2020-03-23 18:55:01.300172491
+0100
@@ -0,0 +1,5 @@
+! PR debug/94285
+! { dg-do compile }
+! { dg-options "-Os -fno-tree-dominator-opts -fno-tree-vrp -fcompare-debug" }
+
+include 'array_constructor_40.f90'
Jakub
