Re: ICE on ARM due to recent patch

[Richard Earnshaw <rearnsha at gcc dot gnu dot org>]

On Fri, 2005-07-29 at 01:09, Steven Bosscher wrote:
> On Friday 29 July 2005 02:07, Josh Conner wrote:
> > I see an ICE during scheduling when trying to build for arm-none-
> > elf.  I tracked the failures back to two issues in the following code
> > (from add_branch_dependences):
> 
> See http://gcc.gnu.org/PR23117 and the patch therein.
> 
> Gr.
> Steven

I've checked in the attached patch:

2005-07-29  Richard Earnshaw  <richard.earnshaw@arm.com>
	    Steven Bosscher  <stevenb@suse.de>

	PR rtl-optimization/23117
	* sched-rgn.c (add_branch_dependences): Handle COND_EXEC correctly
	when head == tail.  Tidy comment.

Index: sched-rgn.c
===================================================================
RCS file: /cvs/gcc/gcc/gcc/sched-rgn.c,v
retrieving revision 1.99
diff -p -r1.99 sched-rgn.c
*** sched-rgn.c	27 Jul 2005 16:28:34 -0000	1.99
--- sched-rgn.c	29 Jul 2005 09:27:51 -0000
*************** add_branch_dependences (rtx head, rtx ta
*** 1954,1962 ****
  
  		T = [addr]
  	C  ?	addr += 4
! 	!C  ?	X += 12
  	C  ?	T += 1
! 	C ?	jump foo
  
       On a target with a one cycle stall on a memory access the optimal
       sequence would be:
--- 1954,1962 ----
  
  		T = [addr]
  	C  ?	addr += 4
! 	!C ?	X += 12
  	C  ?	T += 1
! 	C  ?	jump foo
  
       On a target with a one cycle stall on a memory access the optimal
       sequence would be:
*************** add_branch_dependences (rtx head, rtx ta
*** 1977,1993 ****
    if (!reload_completed || ! JUMP_P (tail))
      return;
  
!   insn = PREV_INSN (tail);
    while (insn != head)
      {
        /* Note that we want to add this dependency even when
  	 sched_insns_conditions_mutex_p returns true.  The whole point
  	 is that we _want_ this dependency, even if these insns really
  	 are independent.  */
        if (INSN_P (insn) && GET_CODE (PATTERN (insn)) == COND_EXEC)
  	add_dependence (tail, insn, REG_DEP_ANTI);
- 
-       insn = PREV_INSN (insn);
      }
  #endif
  }
--- 1977,1993 ----
    if (!reload_completed || ! JUMP_P (tail))
      return;
  
!   insn = tail;
    while (insn != head)
      {
+       insn = PREV_INSN (insn);
+ 
        /* Note that we want to add this dependency even when
  	 sched_insns_conditions_mutex_p returns true.  The whole point
  	 is that we _want_ this dependency, even if these insns really
  	 are independent.  */
        if (INSN_P (insn) && GET_CODE (PATTERN (insn)) == COND_EXEC)
  	add_dependence (tail, insn, REG_DEP_ANTI);
      }
  #endif
  }