From patchwork Fri Feb 22 16:33:47 2013
Content-Type: text/plain; charset="utf-8"
MIME-Version: 1.0
Content-Transfer-Encoding: 7bit
Subject: patch for PR56148
From: Vladimir Makarov <vmakarov@redhat.com>
X-Patchwork-Id: 222554
Message-Id: <51279DEB.8020903@redhat.com>
To: GCC Patches <gcc-patches@gcc.gnu.org>
Date: Fri, 22 Feb 2013 11:33:47 -0500

The following patch fixes ppc64/ia64 bootstrap problem occurred after 
submitting patch for PR56148.  The problem might occur for x86/x86-64 
therefore I am submitting this patch for trunk too.

The patch was successfully bootstrapped on x86/x86-64, ppc64, ia64.

Committed as rev. 196223.

2013-02-22  Vladimir Makarov  <vmakarov@redhat.com>

         PR inline-asm/56148
         * lra-constraints.c (process_alt_operands): Reload operand
         conflicting with earlier clobber only if no more other conflicting
         operands.


Index: lra-constraints.c
===================================================================
--- lra-constraints.c	(revision 196081)
+++ lra-constraints.c	(working copy)
@@ -2052,7 +2052,7 @@ process_alt_operands (int only_alternati
       curr_alt_dont_inherit_ops_num = 0;
       for (nop = 0; nop < early_clobbered_regs_num; nop++)
 	{
-	  int i, j, clobbered_hard_regno;
+	  int i, j, clobbered_hard_regno, first_conflict_j, last_conflict_j;
 	  HARD_REG_SET temp_set;
 
 	  i = early_clobbered_nops[nop];
@@ -2063,6 +2063,7 @@ process_alt_operands (int only_alternati
 	  clobbered_hard_regno = hard_regno[i];
 	  CLEAR_HARD_REG_SET (temp_set);
 	  add_to_hard_reg_set (&temp_set, biggest_mode[i], clobbered_hard_regno);
+	  first_conflict_j = last_conflict_j = -1;
 	  for (j = 0; j < n_operands; j++)
 	    if (j == i
 		/* We don't want process insides of match_operator and
@@ -2077,19 +2078,26 @@ process_alt_operands (int only_alternati
 	    /* If we don't reload j-th operand, check conflicts.  */
 	    else if ((curr_alt_win[j] || curr_alt_match_win[j])
 		     && uses_hard_regs_p (*curr_id->operand_loc[j], temp_set))
-	      break;
-	  if (j >= n_operands)
+	      {
+		if (first_conflict_j < 0)
+		  first_conflict_j = j;
+		last_conflict_j = j;
+	      }
+	  if (last_conflict_j < 0)
 	    continue;
 	  /* If earlyclobber operand conflicts with another
 	     non-matching operand which is actually the same register
 	     as the earlyclobber operand, it is better to reload the
 	     another operand as an operand matching the earlyclobber
 	     operand can be also the same.  */
-	  if (operand_reg[j] != NULL_RTX && ! curr_alt_match_win[j]
-	      && REGNO (operand_reg[i]) == REGNO (operand_reg[j]))
+	  if (first_conflict_j == last_conflict_j
+	      && operand_reg[last_conflict_j]
+	      != NULL_RTX && ! curr_alt_match_win[last_conflict_j]
+	      && REGNO (operand_reg[i]) == REGNO (operand_reg[last_conflict_j]))
 	    {
-	      curr_alt_win[j] = false;
-	      curr_alt_dont_inherit_ops[curr_alt_dont_inherit_ops_num++] = j;
+	      curr_alt_win[last_conflict_j] = false;
+	      curr_alt_dont_inherit_ops[curr_alt_dont_inherit_ops_num++]
+		= last_conflict_j;
 	      losers++;
 	      overall += LRA_LOSER_COST_FACTOR;
 	    }