[Bug tree-optimization/40585] New: [4.3/4.4/4.5 Regression] tracer duplicates blocks w/o adjusting EH tree

[Bug tree-optimization/40585] New: [4.3/4.4/4.5 Regression] tracer duplicates blocks w/o adjusting EH tree

[rguenth at gcc dot gnu dot org]

From

  if (__p_91 != 0B)
    goto <bb 39>;
  else
    goto <bb 40>;
  # SUCC: 39 [100.0%]  count:931 (true,exec) 40 (false,exec)

  # BLOCK 39 freq:4175 count:931
  # PRED: 38 [100.0%]  count:931 (true,exec)
  operator delete (__p_91);
  # SUCC: 40 [100.0%]  count:931 (fallthru,exec)

  # BLOCK 40 freq:4188 count:934
  # PRED: 38 (false,exec) 39 [100.0%]  count:931 (fallthru,exec)
  <<<exception object>>> = save_eptr.427_34;
  <<<filter object>>> = save_filt.428_33;
  resx 3;
  # SUCC:

it generates

  if (__p_91 != 0B)
    goto <bb 39>;
  else
    goto <bb 40>;
  # SUCC: 39 [100.0%]  count:931 (true,exec) 40 (false,exec)

  # BLOCK 39 freq:4175 count:931
  # PRED: 38 [100.0%]  count:931 (true,exec)
  operator delete (__p_91);
  # SUCC: 48 [100.0%]  count:931 (fallthru,exec)

  # BLOCK 48 freq:4175 count:931
  # PRED: 39 [100.0%]  count:931 (fallthru,exec)
  <<<exception object>>> = save_eptr.427_34;
  <<<filter object>>> = save_filt.428_33;
  resx 3;
  # SUCC:

  # BLOCK 40 freq:13 count:3
  # PRED: 38 (false,exec)
  <<<exception object>>> = save_eptr.427_34;
  <<<filter object>>> = save_filt.428_33;
  resx 3;
  # SUCC:

duplicating the tail.  This causes us to ICE later like

Loop.cpp:75: internal compiler error: in expand_resx_expr, at except.c:573
Please submit a full bug report,
with preprocessed source if appropriate.
See <http://bugs.opensuse.org/> for instructions.


-- 
           Summary: [4.3/4.4/4.5 Regression] tracer duplicates blocks w/o
                    adjusting EH tree
           Product: gcc
           Version: 4.5.0
            Status: UNCONFIRMED
          Keywords: ice-on-valid-code
          Severity: normal
          Priority: P3
         Component: tree-optimization
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: rguenth at gcc dot gnu dot org


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=40585

[Bug tree-optimization/40585] [4.3/4.4/4.5 Regression] tracer duplicates blocks w/o adjusting EH tree

[steven at gcc dot gnu dot org]

------- Comment #1 from steven at gcc dot gnu dot org  2009-06-29 12:00 -------
Ack. Honza, yours I would guess.


-- 

steven at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |hubicka at gcc dot gnu dot
                   |                            |org
             Status|UNCONFIRMED                 |NEW
     Ever Confirmed|0                           |1
   Last reconfirmed|0000-00-00 00:00:00         |2009-06-29 12:00:44
               date|                            |


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=40585

[Bug tree-optimization/40585] [4.3/4.4/4.5 Regression] tracer duplicates blocks w/o adjusting EH tree

[steven at gcc dot gnu dot org]

------- Comment #2 from steven at gcc dot gnu dot org  2009-06-29 12:02 -------
Richi, do you have a test case you can share?  I have seen this problem in code
I can't take public...


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=40585

[Bug tree-optimization/40585] [4.3/4.4/4.5 Regression] tracer duplicates blocks w/o adjusting EH tree

[rguenther at suse dot de]

------- Comment #3 from rguenther at suse dot de  2009-06-29 12:08 -------
Subject: Re:  [4.3/4.4/4.5 Regression] tracer
 duplicates blocks w/o adjusting EH tree

On Mon, 29 Jun 2009, steven at gcc dot gnu dot org wrote:

> ------- Comment #2 from steven at gcc dot gnu dot org  2009-06-29 12:02 -------
> Richi, do you have a test case you can share?  I have seen this problem in code
> I can't take public...

Likewise me, only reproducible with -fprofile-use and .gcda/.gcno
files from a customer...

Richard.


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=40585

[Bug tree-optimization/40585] [4.3/4.4/4.5 Regression] tracer duplicates blocks w/o adjusting EH tree

[rguenth at gcc dot gnu dot org]

-- 

rguenth at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Target Milestone|---                         |4.3.4


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=40585

[Bug tree-optimization/40585] [4.3/4.4/4.5 Regression] tracer duplicates blocks w/o adjusting EH tree

[hubicka at ucw dot cz]

------- Comment #4 from hubicka at ucw dot cz  2009-07-01 10:47 -------
Subject: Re:  [4.3/4.4/4.5 Regression] tracer duplicates blocks w/o adjusting
EH tree

Hi,
the following patch should prevent tracer from copying resx.  It is
remarkably ugly I need to unconstify all the copy_bb_p predicates, so
perhaps I will look into fixing the RTL expanders to allow multiple RESX
blocks instead.

Index: cfghooks.c
===================================================================
--- cfghooks.c  (revision 149102)
+++ cfghooks.c  (working copy)
@@ -874,7 +874,7 @@ tidy_fallthru_edges (void)
 /* Returns true if we can duplicate basic block BB.  */

 bool
-can_duplicate_block_p (const_basic_block bb)
+can_duplicate_block_p (basic_block bb)
 {
   if (!cfg_hooks->can_duplicate_block_p)
     internal_error ("%s does not support can_duplicate_block_p",
Index: cfghooks.h
===================================================================
--- cfghooks.h  (revision 149102)
+++ cfghooks.h  (working copy)
@@ -75,7 +75,7 @@ struct cfg_hooks
   bool (*predicted_by_p) (const_basic_block bb, enum br_predictor predictor);

   /* Return true when block A can be duplicated.  */
-  bool (*can_duplicate_block_p) (const_basic_block a);
+  bool (*can_duplicate_block_p) (basic_block a);

   /* Duplicate block A.  */
   basic_block (*duplicate_block) (basic_block a);
@@ -160,7 +160,7 @@ extern void tidy_fallthru_edge (edge);
 extern void tidy_fallthru_edges (void);
 extern void predict_edge (edge e, enum br_predictor predictor, int
probability);
 extern bool predicted_by_p (const_basic_block bb, enum br_predictor
predictor);
-extern bool can_duplicate_block_p (const_basic_block);
+extern bool can_duplicate_block_p (basic_block);
 extern basic_block duplicate_block (basic_block, edge, basic_block);
 extern bool block_ends_with_call_p (basic_block bb);
 extern bool block_ends_with_condjump_p (const_basic_block bb);
Index: bb-reorder.c
===================================================================
--- bb-reorder.c        (revision 149102)
+++ bb-reorder.c        (working copy)
@@ -176,7 +176,7 @@ static basic_block copy_bb (basic_block,
 static fibheapkey_t bb_to_key (basic_block);
 static bool better_edge_p (const_basic_block, const_edge, int, int, int, int,
const_edge);
 static void connect_traces (int, struct trace *);
-static bool copy_bb_p (const_basic_block, int);
+static bool copy_bb_p (basic_block, int);
 static int get_uncond_jump_length (void);
 static bool push_to_next_round_p (const_basic_block, int, int, int,
gcov_type);
 static void find_rarely_executed_basic_blocks_and_crossing_edges (edge **,
@@ -1157,7 +1157,7 @@ connect_traces (int n_traces, struct tra
    when code size is allowed to grow by duplication.  */

 static bool
-copy_bb_p (const_basic_block bb, int code_may_grow)
+copy_bb_p (basic_block bb, int code_may_grow)
 {
   int size = 0;
   int max_size = uncond_jump_length;
Index: tree-cfg.c
===================================================================
--- tree-cfg.c  (revision 149102)
+++ tree-cfg.c  (working copy)
@@ -5131,8 +5131,17 @@ gimple_move_block_after (basic_block bb,
 /* Return true if basic_block can be duplicated.  */

 static bool
-gimple_can_duplicate_bb_p (const_basic_block bb ATTRIBUTE_UNUSED)
+gimple_can_duplicate_bb_p (basic_block bb)
 {
+  gimple_stmt_iterator gsi = gsi_last_bb (bb);
+
+  /* RTL expander has quite artificial limitation to at most one RESX
instruction
+     per region.  It can be fixed by turning 1-1 map to 1-many map, but since
the
+     code needs to be rewritten to gimple level lowering and there is little
reason
+     for duplicating RESX instructions in order to optimize code performance,
we
+     just disallow it for the moment.  */
+  if (!gsi_end_p (gsi) && gimple_code (gsi_stmt (gsi)) == GIMPLE_RESX)
+    return false;
   return true;
 }

Index: cfgrtl.c
===================================================================
--- cfgrtl.c    (revision 149102)
+++ cfgrtl.c    (working copy)
@@ -3161,7 +3161,7 @@ struct cfg_hooks rtl_cfg_hooks = {
    should only be used through the cfghooks interface, and we do not want to
    move them here since it would require also moving quite a lot of related
    code.  They are in cfglayout.c.  */
-extern bool cfg_layout_can_duplicate_bb_p (const_basic_block);
+extern bool cfg_layout_can_duplicate_bb_p (basic_block);
 extern basic_block cfg_layout_duplicate_bb (basic_block);

 struct cfg_hooks cfg_layout_rtl_cfg_hooks = {


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=40585

[Bug tree-optimization/40585] [4.3/4.4/4.5 Regression] tracer duplicates blocks w/o adjusting EH tree

[rguenther at suse dot de]

------- Comment #5 from rguenther at suse dot de  2009-07-01 10:54 -------
Subject: Re:  [4.3/4.4/4.5 Regression] tracer
 duplicates blocks w/o adjusting EH tree

On Wed, 1 Jul 2009, hubicka at ucw dot cz wrote:

> ------- Comment #4 from hubicka at ucw dot cz  2009-07-01 10:47 -------
> Subject: Re:  [4.3/4.4/4.5 Regression] tracer duplicates blocks w/o adjusting
> EH tree
> 
> Hi,
> the following patch should prevent tracer from copying resx.  It is
> remarkably ugly I need to unconstify all the copy_bb_p predicates, so
> perhaps I will look into fixing the RTL expanders to allow multiple RESX
> blocks instead.

Less ugly would be to 'inline' gsi_last_bb by using

  gimple_seq seq = bb_seq (bb);
  gimple_seq_node last = gimple_seq_last (seq);
  if (last && gimple_code (last->stmt) == GIMPLE_RESX)
...

but yes, for trunk allowing mutliple RESX works for me as well.

Richard.


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=40585

[Bug tree-optimization/40585] [4.3/4.4/4.5 Regression] tracer duplicates blocks w/o adjusting EH tree

[rguenth at gcc dot gnu dot org]

------- Comment #6 from rguenth at gcc dot gnu dot org  2009-07-01 13:01 -------
I have a 4.3 backport along that line.


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=40585

[Bug tree-optimization/40585] [4.3/4.4/4.5 Regression] tracer duplicates blocks w/o adjusting EH tree

[rguenth at gcc dot gnu dot org]

------- Comment #7 from rguenth at gcc dot gnu dot org  2009-07-02 12:16 -------
Subject: Bug 40585

Author: rguenth
Date: Thu Jul  2 12:15:27 2009
New Revision: 149172

URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=149172
Log:
2009-07-02  Richard Guenther  <rguenther@suse.de>

        PR middle-end/40585
        * tree-cfg.c (tree_can_duplicate_bb_p): Disallow duplicating
        basic blocks with RESX_EXPR.

Modified:
    branches/gcc-4_3-branch/gcc/ChangeLog
    branches/gcc-4_3-branch/gcc/tree-cfg.c


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=40585

[Bug tree-optimization/40585] [4.5 Regression] tracer duplicates blocks w/o adjusting EH tree

[rguenth at gcc dot gnu dot org]

------- Comment #9 from rguenth at gcc dot gnu dot org  2009-07-02 12:17 -------
Fixed on the branches.


-- 

rguenth at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
      Known to fail|                            |4.3.3 4.4.0 4.5.0
      Known to work|                            |4.3.4 4.4.1
            Summary|[4.3/4.4/4.5 Regression]    |[4.5 Regression] tracer
                   |tracer duplicates blocks w/o|duplicates blocks w/o
                   |adjusting EH tree           |adjusting EH tree
   Target Milestone|4.3.4                       |4.5.0


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=40585

[Bug tree-optimization/40585] [4.5 Regression] tracer duplicates blocks w/o adjusting EH tree

[rguenth at gcc dot gnu dot org]

-- 

rguenth at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
         AssignedTo|unassigned at gcc dot gnu   |hubicka at gcc dot gnu dot
                   |dot org                     |org
             Status|NEW                         |ASSIGNED


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=40585

[Bug tree-optimization/40585] [4.3/4.4/4.5 Regression] tracer duplicates blocks w/o adjusting EH tree

[rguenth at gcc dot gnu dot org]

------- Comment #8 from rguenth at gcc dot gnu dot org  2009-07-02 12:16 -------
Subject: Bug 40585

Author: rguenth
Date: Thu Jul  2 12:16:39 2009
New Revision: 149173

URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=149173
Log:
2009-07-02  Richard Guenther  <rguenther@suse.de>

        PR middle-end/40585
        * tree-cfg.c (gimple_can_duplicate_bb_p): Disallow duplicating
        basic blocks with GIMPLE_RESX.

Modified:
    branches/gcc-4_4-branch/gcc/ChangeLog
    branches/gcc-4_4-branch/gcc/tree-cfg.c


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=40585

[Bug tree-optimization/40585] [4.5 Regression] tracer duplicates blocks w/o adjusting EH tree

[rguenth at gcc dot gnu dot org]

-- 

rguenth at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
           Priority|P3                          |P2


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=40585

[Bug tree-optimization/40585] [4.5 Regression] tracer duplicates blocks w/o adjusting EH tree

[hubicka at gcc dot gnu dot org]

------- Comment #10 from hubicka at gcc dot gnu dot org  2009-07-12 12:07 -------
Subject: Bug 40585

Author: hubicka
Date: Sun Jul 12 12:07:35 2009
New Revision: 149530

URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=149530
Log:

        PR tree-optimization/40585
        * except.c (expand_resx_expr): When there already is resume
        instruction, produce linked list.
        (build_post_landing_pads): Assert that resume is empty.
        (connect_post_landing_pads): Handle resume lists.
        (dump_eh_tree): Dump resume list.

Modified:
    trunk/gcc/ChangeLog
    trunk/gcc/except.c


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=40585

[Bug tree-optimization/40585] [4.5 Regression] tracer duplicates blocks w/o adjusting EH tree

[rguenth at gcc dot gnu dot org]

------- Comment #11 from rguenth at gcc dot gnu dot org  2009-08-24 13:12 -------
Fixed.


-- 

rguenth at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|ASSIGNED                    |RESOLVED
         Resolution|                            |FIXED


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=40585