PATCH: mips16 machine_dependent_reorg

[Andrew Haley <aph@pasanda.cygnus.co.uk>]

This MIPS16 patch forces the output of the local constant pool if no
barrier has been found before a relative load instruction has gone out
of range.  This can happen if a function is, for example, a very long
list of	assignments.

Andrew.

Fri Aug 20 13:43:41 1999  Andrew Haley  <aph@cygnus.com>

	* config/mips/mips.c (machine_dependent_reorg): Force a
	barrier to output the local constant pool if a barrier hasn't
	been found at a natural point in the instruction stream.  
	
Index: mips.c
===================================================================
RCS file: /cvs/egcs/egcs/gcc/config/mips/mips.c,v
retrieving revision 1.62
diff -p -2 -c -r1.62 mips.c
*** mips.c	1999/08/09 14:00:07	1.62
--- mips.c	1999/08/20 14:24:58
*************** machine_dependent_reorg (first)
*** 8373,8377 ****
       rtx first;
  {
!   int insns_len, max_internal_pool_size, pool_size, addr;
    rtx insn;
    struct constant *constants;
--- 8373,8377 ----
       rtx first;
  {
!   int insns_len, max_internal_pool_size, pool_size, addr, first_constant_ref;
    rtx insn;
    struct constant *constants;
*************** machine_dependent_reorg (first)
*** 8441,8444 ****
--- 8441,8445 ----
    constants = NULL;
    addr = 0;
+   first_constant_ref = -1;
  
    for (insn = first; insn; insn = NEXT_INSN (insn))
*************** machine_dependent_reorg (first)
*** 8499,8502 ****
--- 8500,8506 ----
  					newsrc);
  	      INSN_CODE (insn) = -1;
+ 
+ 	      if (first_constant_ref < 0)
+ 		first_constant_ref = addr;
  	    }
  	}
*************** machine_dependent_reorg (first)
*** 8530,8554 ****
  	    dump_constants (constants, insn);
  	  constants = NULL;
  	}
! 
!       /* ??? If we don't find a barrier within 0x8000 bytes of
!          instructions and constants in CONSTANTS, we need to invent
!          one.  This seems sufficiently unlikely that I am not going to
!          worry about it.  */
!     }
! 
!   if (constants != NULL)
!     {
!       rtx label, jump, barrier;
! 
!       label = gen_label_rtx ();
!       jump = emit_jump_insn_after (gen_jump (label), get_last_insn ());
!       JUMP_LABEL (jump) = label;
!       LABEL_NUSES (label) = 1;
!       barrier = emit_barrier_after (jump);
!       emit_label_after (label, barrier);
!       dump_constants (constants, barrier);
!       constants = NULL;
!     }
  
    /* ??? If we output all references to a constant in internal
--- 8534,8564 ----
  	    dump_constants (constants, insn);
  	  constants = NULL;
+ 	  first_constant_ref = -1;
  	}
!       
!       if (constants != NULL
! 	       && (NEXT_INSN (insn) == NULL 
! 		   || (first_constant_ref >= 0 
! 		       && (((addr - first_constant_ref)
! 			    + 2 /* for alignment */
! 			    + 2 /* for a short jump insn */
! 			    + pool_size)
! 			   >= 0x8000))))
! 	{
! 	  /* If we haven't had a barrier within 0x8000 bytes of a
!              constant reference or we are at the end of the function,
!              emit a barrier now. */
! 
! 	  rtx label, jump, barrier;
! 	      
! 	  label = gen_label_rtx ();
! 	  jump = emit_jump_insn_after (gen_jump (label), insn);
! 	  JUMP_LABEL (jump) = label;
! 	  LABEL_NUSES (label) = 1;
! 	  barrier = emit_barrier_after (jump);
! 	  emit_label_after (label, barrier);
! 	  first_constant_ref = -1;
! 	}
!      }
  
    /* ??? If we output all references to a constant in internal