[vta] get ia64 to pass bootstrap-debug and bootstrap4-debug(-g0)

[Alexandre Oliva <aoliva at redhat dot com>]

This is the only ia64-specific patch I needed for ia64-linux-gnu to
generate the same code for host and target directories in a full
bootstrap with all languages.  An additional patch for gas is needed
for target libraries to compare identical, because of uninitialized
assembler memory that would hold the unwind personality address.  I
posted the fix to the binutils list the other day.

It is possible that, in this patch, the hunks in variable_issue and
dfa_new_cycle are obviated by the debug-always-ready patch I've
recently installed, but I guess it's safer to keep them.

I'm checking it in the vta branch, closing tonight's (oops,
toomorning's :-) session of posting and installing last year's
patches.


Now I'm going to focus on implementing the last bit of functionality
(turning debug insns into var location notes, in var-tracking), and
then I'll do another merge and see what breaks.  Bug reports of
differences that compare-debug detects between objects for other
targets or different BOOT_CFLAGS options are welcome.

for  gcc/ChangeLog.vta
from  Alexandre Oliva  <aoliva@redhat.com>

	* config/ia64/ia64.c (ia64_safe_itanium_class): Ignore debug insns.
	(group_barrier_needed): Not for debug insns.
	(ia64_variable_issue): Always accept debug insns.
	(ia64_dfa_new_cycle): Not because of debug insns.
	(final_emit_insn_group_barriers): Don't emit a barrier after a
	call just because of debug insns.

Index: gcc/config/ia64/ia64.c
===================================================================
--- gcc/config/ia64/ia64.c.orig	2007-12-23 04:27:15.000000000 -0200
+++ gcc/config/ia64/ia64.c	2007-12-28 15:24:36.000000000 -0200
@@ -5231,6 +5231,8 @@ ia64_safe_itanium_class (rtx insn)
 {
   if (recog_memoized (insn) >= 0)
     return get_attr_itanium_class (insn);
+  else if (DEBUG_INSN_P (insn))
+    return ITANIUM_CLASS_IGNORE;
   else
     return ITANIUM_CLASS_UNKNOWN;
 }
@@ -5940,6 +5942,7 @@ group_barrier_needed (rtx insn)
   switch (GET_CODE (insn))
     {
     case NOTE:
+    case DEBUG_INSN:
       break;
 
     case BARRIER:
@@ -6564,6 +6570,9 @@ ia64_variable_issue (FILE *dump ATTRIBUT
 	pending_data_specs--;
     }
 
+  if (DEBUG_INSN_P (insn))
+    return 1;
+
   last_scheduled_insn = insn;
   memcpy (prev_cycle_state, curr_state, dfa_state_size);
   if (reload_completed)
@@ -6621,6 +6630,9 @@ ia64_dfa_new_cycle (FILE *dump, int verb
   int setup_clocks_p = FALSE;
 
   gcc_assert (insn && INSN_P (insn));
+  if (DEBUG_INSN_P (insn))
+    return 0;
+
   if ((reload_completed && safe_group_barrier_needed (insn))
       || (last_scheduled_insn
 	  && (GET_CODE (last_scheduled_insn) == CALL_INSN
@@ -8289,6 +8301,21 @@ final_emit_insn_group_barriers (FILE *du
 	    }
 	  else if (need_barrier_p || group_barrier_needed (insn))
 	    {
+	      if (DEBUG_INSN_P (insn))
+		{
+		  rtx next = NEXT_INSN (insn);
+
+		  while (next != current_sched_info->next_tail
+			 && DEBUG_INSN_P (next))
+		    next = NEXT_INSN (next);
+
+		  /* If everything after the barrier-needing insn is
+		     debug insns, we wouldn't emit the barrier if they
+		     weren't there.  */
+		  if (next == current_sched_info->next_tail)
+		    continue;
+		}
+
 	      if (TARGET_EARLY_STOP_BITS)
 		{
 		  rtx last;

-- 
Alexandre Oliva         http://www.lsd.ic.unicamp.br/~oliva/
FSF Latin America Board Member         http://www.fsfla.org/
Red Hat Compiler Engineer   aoliva@{redhat.com, gcc.gnu.org}
Free Software Evangelist  oliva@{lsd.ic.unicamp.br, gnu.org}