[Bug rtl-optimization/48302] ICE: SIGSEGV in reposition_prologue_and_epilogue_notes (function.c:5662) with -fcrossjumping -fselective-scheduling2

[amonakov at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=48302

Alexander Monakov <amonakov at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |ASSIGNED
   Last reconfirmed|                            |2011.04.06 16:08:13
                 CC|                            |amonakov at gcc dot gnu.org
         AssignedTo|unassigned at gcc dot       |amonakov at gcc dot gnu.org
                   |gnu.org                     |
     Ever Confirmed|0                           |1

--- Comment #1 from Alexander Monakov <amonakov at gcc dot gnu.org> 2011-04-06 16:08:13 UTC ---
Confirmed.  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.

diff --git a/gcc/sel-sched-ir.c b/gcc/sel-sched-ir.c
index 95c1431..a6daa58 100644
--- a/gcc/sel-sched-ir.c
+++ b/gcc/sel-sched-ir.c
@@ -6094,11 +6094,11 @@ sel_find_rgns (void)
   bbs_in_loop_rgns = NULL;
 }

-/* Adds the preheader blocks from previous loop to current region taking
-   it from LOOP_PREHEADER_BLOCKS (current_loop_nest).
+/* Add the preheader blocks from previous loop to current region taking
+   it from LOOP_PREHEADER_BLOCKS (current_loop_nest) and record them in *BBS.
    This function is only used with -fsel-sched-pipelining-outer-loops.  */
 void
-sel_add_loop_preheaders (void)
+sel_add_loop_preheaders (bb_vec_t *bbs)
 {
   int i;
   basic_block bb;
@@ -6109,6 +6109,7 @@ sel_add_loop_preheaders (void)
        VEC_iterate (basic_block, preheader_blocks, i, bb);
        i++)
     {
+      VEC_safe_push (basic_block, heap, *bbs, bb);
       VEC_safe_push (basic_block, heap, last_added_blocks, bb);
       sel_add_bb (bb);
     }
diff --git a/gcc/sel-sched-ir.h b/gcc/sel-sched-ir.h
index 5516da9..b0c52eb 100644
--- a/gcc/sel-sched-ir.h
+++ b/gcc/sel-sched-ir.h
@@ -1628,7 +1628,7 @@ extern void sel_sched_region (int);
 extern loop_p get_loop_nest_for_rgn (unsigned int);
 extern bool considered_for_pipelining_p (struct loop *);
 extern void make_region_from_loop_preheader (VEC(basic_block, heap) **);
-extern void sel_add_loop_preheaders (void);
+extern void sel_add_loop_preheaders (bb_vec_t *);
 extern bool sel_is_loop_preheader_p (basic_block);
 extern void clear_outdated_rtx_info (basic_block);
 extern void free_data_sets (basic_block);
diff --git a/gcc/sel-sched.c b/gcc/sel-sched.c
index 415eaa4..42a2cde 100644
--- a/gcc/sel-sched.c
+++ b/gcc/sel-sched.c
@@ -6802,7 +6802,7 @@ current_region_empty_p (void)

 /* Prepare and verify loop nest for pipelining.  */
 static void
-setup_current_loop_nest (int rgn)
+setup_current_loop_nest (int rgn, bb_vec_t *bbs)
 {
   current_loop_nest = get_loop_nest_for_rgn (rgn);

@@ -6811,7 +6811,7 @@ setup_current_loop_nest (int rgn)

   /* If this loop has any saved loop preheaders from nested loops,
      add these basic blocks to the current region.  */
-  sel_add_loop_preheaders ();
+  sel_add_loop_preheaders (bbs);

   /* Check that we're starting with a valid information.  */
   gcc_assert (loop_latch_edge (current_loop_nest));
@@ -6850,9 +6850,6 @@ sel_region_init (int rgn)
   if (current_region_empty_p ())
     return true;

-  if (flag_sel_sched_pipelining)
-    setup_current_loop_nest (rgn);
-
   sel_setup_region_sched_flags ();

   bbs = VEC_alloc (basic_block, heap, current_nr_blocks);
@@ -6862,6 +6859,9 @@ sel_region_init (int rgn)

   sel_init_bbs (bbs, NULL);

+  if (flag_sel_sched_pipelining)
+    setup_current_loop_nest (rgn, &bbs);
+
   /* Initialize luids and dependence analysis which both sel-sched and haifa
      need.  */
   sched_init_luids (bbs, NULL, NULL, NULL);