[Bug optimization/11162] new-ra bug

[Bug optimization/11162] new-ra bug

[tm@kloo.net]

PLEASE REPLY TO gcc-bugzilla@gcc.gnu.org ONLY, *NOT* gcc-bugs@gcc.gnu.org.

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=11162



------- Additional Comments From tm@kloo.net  2003-06-11 22:24 -------
Created an attachment (id=4205)
 --> (http://gcc.gnu.org/bugzilla/attachment.cgi?id=4205&action=view)
testcase

[Bug optimization/11162] New: new-ra bug

[tm@kloo.net]

PLEASE REPLY TO gcc-bugzilla@gcc.gnu.org ONLY, *NOT* gcc-bugs@gcc.gnu.org.

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=11162

           Summary: new-ra bug
           Product: gcc
           Version: 3.4
            Status: UNCONFIRMED
          Severity: normal
          Priority: P2
         Component: optimization
        AssignedTo: rth@gcc.gnu.org
        ReportedBy: tm@kloo.net
                CC: gcc-bugs@gcc.gnu.org
 GCC build triplet: i386-linux
  GCC host triplet: i386-linux
GCC target triplet: sh-elf

When channel.i from stress-1.17 is compiled with options:

-O2 -m4 -fnew-ra

the following error occurs:

/home/tm/stress-1.17/channel.i: In function `find_channel':
/home/tm/stress-1.17/channel.i:8226: internal compiler error: in pur
22
Please submit a full bug report,
with preprocessed source if appropriate.
See <URL:http://gcc.gnu.org/bugs.html> for instructions.

Program exited with code 01.

[Bug optimization/11162] new-ra bug

[tm@kloo.net]

PLEASE REPLY TO gcc-bugzilla@gcc.gnu.org ONLY, *NOT* gcc-bugs@gcc.gnu.org.

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=11162



------- Additional Comments From tm@kloo.net  2003-06-11 22:25 -------
GDB dump of basic blocks at abort point:

(gdb) print *bb
$2 = {head = 0x404aa898, end = 0x404aaa7c, head_tree = 0x0, end_tree
  succ = 0x0, local_set = 0x0, cond_local_set = 0x0, global_live_at_
  global_live_at_end = 0x843ca40, aux = 0x2, index = 0, prev_bb = 0x
  next_bb = 0x838a870, loop_depth = 0, loop_father = 0x8496dd8, coun
  flags = 5}
(gdb) print bb->succ
$3 = 0x0
(gdb) call debug_bb(bb)
;; Basic block 0, loop depth 0, count 0
;; Registers live at start: 4 [r4] 5 [r5] 14 [r14] 15 [r15] 145 [ap]
(note:HI 38 2 46 0 [bb 0] NOTE_INSN_BASIC_BLOCK)
(insn/f 46 38 47 0 (set (mem:SI (pre_dec:SI (reg/f:SI 15 r15)) [0 S4
        (reg/f:SI 14 r14)) -1 (nil)
    (expr_list:REG_INC (reg/f:SI 15 r15)
        (nil)))
(insn/f 47 46 48 0 (set (reg/f:SI 14 r14)
        (reg/f:SI 15 r15)) -1 (nil)
    (nil))
(note 48 47 3 0 NOTE_INSN_PROLOGUE_END)
(note:HI 3 48 4 0 NOTE_INSN_DELETED)
(note:HI 4 3 5 0 NOTE_INSN_DELETED)
(note:HI 5 4 12 0 NOTE_INSN_FUNCTION_BEG)
(note:HI 12 5 13 0 NOTE_INSN_DELETED)
(note:HI 13 12 16 0 NOTE_INSN_DELETED)
(insn:HI 16 13 17 0 (set (reg:SI 1 r1 [165])
        (symbol_ref:SI ("hash_find_channel") [flags 0x41] <function_
nnel>)) 123 {movsi_ie} (nil)
    (nil))
(call_insn/j:HI 17 16 44 0 (parallel [
            (call (mem:SI (reg:SI 1 r1 [165]) [0 S4 A32])
                (const_int 0 [0x0]))
            (use (reg:PSI 151 fpscr))
            (return)
        ]) 177 {sibcalli} (insn_list 16 (nil))
    (nil)
    (expr_list (use (reg:SI 5 r5 [ chptr ]))
        (expr_list (use (reg:SI 4 r4 [ chname ]))
            (nil))))
(insn 44 17 18 0 (use (reg/i:SI 0 r0 [ <result> ])) -1 (insn_list 17
    (nil))
;; Registers live at end: 0 [r0] 14 [r14] 15 [r15] 145 [ap] 151 []
;; Successors: 
(gdb)

[Bug optimization/11162] new-ra bug

[rth@gcc.gnu.org]

PLEASE REPLY TO gcc-bugzilla@gcc.gnu.org ONLY, *NOT* gcc-bugs@gcc.gnu.org.

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=11162


rth@gcc.gnu.org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
         AssignedTo|rth@gcc.gnu.org             |matz@suse.de
             Status|UNCONFIRMED                 |NEW
     Ever Confirmed|                            |1
   Last reconfirmed|0000-00-00 00:00:00         |2003-06-11 22:47:48
               date|                            |


------- Additional Comments From rth@gcc.gnu.org  2003-06-11 22:47 -------
The CFG code gets confused by the addition of a USE insn after a sibcall.
Sibcalls are supposed to end the block (and the function!), so the fact
that we have an instruction following one (even if its fake) is confusing.

Moreover, I can't figure out why the USE is being added at all.  There is
a non-explanation in ra.c, but if I change like so, the test case passes.


r~


Index: ra.c
===================================================================
RCS file: /cvs/gcc/gcc/gcc/ra.c,v
retrieving revision 1.8
diff -c -p -d -u -r1.8 ra.c
--- ra.c        7 Mar 2003 22:06:16 -0000       1.8
+++ ra.c        11 Jun 2003 22:43:10 -0000
@@ -677,7 +677,7 @@ reg_alloc ()
 
   /* We currently rely on the existence of the return value USE as
      one of the last insns.  Add it if it's not there anymore.  */
-  if (last)
+  if (0 && last)
     {
       edge e;
       for (e = EXIT_BLOCK_PTR->pred; e; e = e->pred_next)

[Bug optimization/11162] new-ra bug

[matz@suse.de]

PLEASE REPLY TO gcc-bugzilla@gcc.gnu.org ONLY, *NOT* gcc-bugs@gcc.gnu.org.

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=11162



------- Additional Comments From matz@suse.de  2003-06-12 06:08 -------
Subject: Re:  new-ra bug

On 11 Jun 2003, rth@gcc.gnu.org wrote:

> Moreover, I can't figure out why the USE is being added at all.

Crappy obsolete design ;-)  I didn't use mark_regs_live_at_end() to force
the return register live at the end, partly because I can basically only
deal with real register references (the flow.c code simply sets some bits
in the liveness bitmaps).  But it needs to be made live somehow, hence I
simply added such fake uses.  In the new-ra branch I added code to delete
these instructions after allocation again.  (Or rather I would have had,
had I committed ;( ).  Like the below patch.  It also fixes the testcase.

Somewhen I need to go over this again, to use something similar to the
mark_regs_live_at_end() function, because this method is bound to break
(for instance I only add the return value use, but not all the other regs
which that function might add).

Index: ra.c
===================================================================
RCS file: /cvs/gcc/gcc/gcc/ra.c,v
retrieving revision 1.8
diff -u -p -r1.8 ra.c
--- ra.c	7 Mar 2003 22:06:16 -0000	1.8
+++ ra.c	12 Jun 2003 06:06:03 -0000
@@ -669,6 +669,7 @@ reg_alloc ()
   int changed;
   FILE *ra_dump_file = rtl_dump_file;
   rtx last = get_last_insn ();
+  bitmap use_insns = BITMAP_XMALLOC ();

   if (! INSN_P (last))
     last = prev_real_insn (last);
@@ -686,11 +687,13 @@ reg_alloc ()
 	  last = bb->end;
 	  if (!INSN_P (last) || GET_CODE (PATTERN (last)) != USE)
 	    {
-	      rtx insns;
+	      rtx insn, insns;
 	      start_sequence ();
 	      use_return_register ();
 	      insns = get_insns ();
 	      end_sequence ();
+	      for (insn = insns; insn; insn = NEXT_INSN (insn))
+		bitmap_set_bit (use_insns, INSN_UID (insn));
 	      emit_insn_after (insns, last);
 	    }
 	}
@@ -868,6 +871,22 @@ reg_alloc ()
   no_new_pseudos = 1;
   rtl_dump_file = ra_dump_file;

+    {
+      edge e;
+      for (e = EXIT_BLOCK_PTR->pred; e; e = e->pred_next)
+	{
+	  basic_block bb = e->src;
+	  last = bb->end;
+	  for (last = bb->end; last; last = PREV_INSN (last))
+	    {
+	      if (last == bb->head)
+		break;
+	      if (bitmap_bit_p (use_insns, INSN_UID (last)))
+		delete_insn (last);
+	    }
+	}
+    }
+  BITMAP_XFREE (use_insns);
   /* Some spill insns could've been inserted after trapping calls, i.e.
      at the end of a basic block, which really ends at that call.
      Fixup that breakages by adjusting basic block boundaries.  */

[Bug optimization/11162] new-ra bug

[matz@suse.de]

PLEASE REPLY TO gcc-bugzilla@gcc.gnu.org ONLY, *NOT* gcc-bugs@gcc.gnu.org.

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=11162


matz@suse.de changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|NEW                         |ASSIGNED

[Bug optimization/11162] [-fnew-ra] ICE compiling channel.i on sh

[dank at kegel dot com]

PLEASE REPLY TO gcc-bugzilla@gcc.gnu.org ONLY, *NOT* gcc-bugs@gcc.gnu.org.

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=11162



------- Additional Comments From dank at kegel dot com  2003-09-14 18:37 -------
Here's a simpler testcase:

int foo(char *p1)
{
        return bar(p1);
}

I swear to god that's what it boiled down to.  This fails with 
/usr/gcc-3.4-20030903-glibc-2.3.2/bin/sh4-unknown-linux-gnu-gcc -O2 -m4 -fnew-ra
z.c 
z.c: In function `foo':

z.c:4: error: Abnormal edges for no purpose in bb 0
z.c:4: internal compiler error: verify_flow_info failed

[Bug optimization/11162] [-fnew-ra] ICE compiling channel.i on sh

[dank at kegel dot com]

PLEASE REPLY TO gcc-bugzilla@gcc.gnu.org ONLY, *NOT* gcc-bugs@gcc.gnu.org.

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=11162



------- Additional Comments From dank at kegel dot com  2003-09-14 20:08 -------
For completeness, here's a log using the original testcase:

/usr/gcc-3.4-20030903-glibc-2.3.2/bin/sh4-unknown-linux-gnu-gcc -m4 -O2 -fnew-ra
channel.i 
channel.i: In function `find_channel':
channel.i:8226: error: Abnormal edges for no purpose in bb 0
channel.i:8226: internal compiler error: verify_flow_info failed

This appears to be a dup of bug 9900

[Bug optimization/11162] [-fnew-ra] ICE compiling channel.i on sh

[pinskia at gcc dot gnu dot org]

PLEASE REPLY TO gcc-bugzilla@gcc.gnu.org ONLY, *NOT* gcc-bugs@gcc.gnu.org.

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=11162


pinskia at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |eezyy at gmx dot net


------- Additional Comments From pinskia at gcc dot gnu dot org  2003-09-14 20:24 -------
*** Bug 9900 has been marked as a duplicate of this bug. ***

[Bug optimization/11162] [3.4 Regression] [-fnew-ra] ICE compiling channel.i on sh

[pinskia at gcc dot gnu dot org]

PLEASE REPLY TO gcc-bugzilla@gcc.gnu.org ONLY, *NOT* gcc-bugs@gcc.gnu.org.

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=11162


pinskia at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
           Severity|normal                      |critical
            Summary|[-fnew-ra] ICE compiling    |[3.4 Regression] [-fnew-ra]
                   |channel.i on sh             |ICE compiling channel.i on
                   |                            |sh

[Bug optimization/11162] [3.4 Regression] [-fnew-ra] ICE compiling channel.i on sh

[dank at kegel dot com]

PLEASE REPLY TO gcc-bugzilla@gcc.gnu.org ONLY, *NOT* gcc-bugs@gcc.gnu.org.

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=11162



------- Additional Comments From dank at kegel dot com  2003-09-15 16:27 -------
This ICE seemed to go away when I apply the fix
for bug 11587.  Can someone else verify this?

[Bug optimization/11162] [3.4 Regression] [-fnew-ra] ICE compiling channel.i on sh

[dank at kegel dot com]

PLEASE REPLY TO gcc-bugzilla@gcc.gnu.org ONLY, *NOT* gcc-bugs@gcc.gnu.org.

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=11162


dank at kegel dot com changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |dank at kegel dot com


------- Additional Comments From dank at kegel dot com  2003-09-15 17:43 -------
I've prepared a patch to add a testcase for this PR to the testsuite; see
http://www.kegel.com/crosstool/current/patches/gcc-3.3.1/pr11162-1-test.patch
I'll submit it to gcc-patches in a couple days if nobody squawks.

[Bug optimization/11162] [3.4 Regression] [-fnew-ra] ICE compiling channel.i on sh

[pinskia at gcc dot gnu dot org]

-- 
           What    |Removed                     |Added
----------------------------------------------------------------------------
OtherBugsDependingO|                            |13246
              nThis|                            |


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=11162

[Bug optimization/11162] [3.4 Regression] [-fnew-ra] ICE compiling channel.i on sh

[pinskia at gcc dot gnu dot org]

-- 
           What    |Removed                     |Added
----------------------------------------------------------------------------
   Target Milestone|3.4                         |3.5


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=11162

[Bug optimization/11162] [new-ra] ICE compiling channel.i on sh

[dank at kegel dot com]

------- Additional Comments From dank at kegel dot com  2004-01-27 17:15 -------
I just verified it's not fixed in gcc-3.3-20040119 (didn't expect it to be).
I'll verify against a current gcc-3.4 snapshot next...

-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=11162

[Bug optimization/11162] [new-ra] ICE compiling channel.i on sh

[pinskia at gcc dot gnu dot org]

-- 
           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|WAITING                     |NEW
   Last reconfirmed|2003-06-11 22:47:48         |2004-03-02 01:36:11
               date|                            |


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=11162

[Bug optimization/11162] [new-ra] ICE compiling channel.i on sh

[dank at kegel dot com]

------- Additional Comments From dank at kegel dot com  2004-03-02 05:15 -------
Dang, lost my hardware before I could verify it.  
I can't test on sh4 anymore.

-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=11162

[Bug rtl-optimization/11162] [new-ra] ICE compiling channel.i on sh

[steven at gcc dot gnu dot org]

------- Additional Comments From steven at gcc dot gnu dot org  2005-01-03 12:08 -------
new-ra bug, so SUSPENDING.

-- 
           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|NEW                         |SUSPENDED


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=11162

[Bug rtl-optimization/11162] [new-ra] ICE compiling channel.i on sh

[pinskia at gcc dot gnu dot org]

------- Additional Comments From pinskia at gcc dot gnu dot org  2005-01-17 15:24 -------
Closing as wiill not fix as new-ra was removed from the mainline.

-- 
           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|SUSPENDED                   |RESOLVED
         Resolution|                            |WONTFIX
   Target Milestone|---                         |4.0.0


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=11162