re PR rtl-optimization/57268 (c nested loops hang compiler in sched-deps.c)

2013-05-31  Dinar Temirbulatov  <dinar@kugelworks.com>

        PR rtl-optimization/57268
        * sched-deps.c (sched_analyze_2): Flush dependence lists if
        the sum of the read and write lists exceeds MAX_PENDING_LIST_LENGTH.

From-SVN: r199564

gcc/ChangeLog

+2013-05-31  Dinar Temirbulatov  <dinar@kugelworks.com>
+
+	PR rtl-optimization/57268
+	* sched-deps.c (sched_analyze_2): Flush dependence lists if
+	the sum of the read and write lists exceeds MAX_PENDING_LIST_LENGTH.
+
 2013-05-31  Eric Botcazou  <ebotcazou@adacore.com>
 
 	* config/rs6000/predicates.md (rs6000_cbranch_operator): Accept some

gcc/sched-deps.c

@@ -2690,8 +2690,14 @@ sched_analyze_2 (struct deps_desc *deps, rtx x, rtx insn)
 
 	/* Always add these dependencies to pending_reads, since
 	   this insn may be followed by a write.  */
-        if (!deps->readonly)
-          add_insn_mem_dependence (deps, true, insn, x);
+	if (!deps->readonly)
+	  {
+	    if ((deps->pending_read_list_length
+		 + deps->pending_write_list_length)
+		> MAX_PENDING_LIST_LENGTH)
+	      flush_pending_lists (deps, insn, true, true);
+	    add_insn_mem_dependence (deps, true, insn, x);
+	}
 
 	sched_analyze_2 (deps, XEXP (x, 0), insn);