re PR debug/45656 (gfortran.dg/forall_4.f90 -O3, wrong code with -g)

PR debug/45656
* cse.c (cse_extended_basic_block): Preserve cc0 info across
debug isnsn.  Skip them when searching for cc0 setter.
(set_live_p): Skip debug insns when searching for cc0 user.

From-SVN: r165150

gcc/ChangeLog

 2010-10-08  Alexandre Oliva  <aoliva@redhat.com>
 
+	PR debug/45656
+	* cse.c (cse_extended_basic_block): Preserve cc0 info across
+	debug isnsn.  Skip them when searching for cc0 setter.
+	(set_live_p): Skip debug insns when searching for cc0 user.
+
+2010-10-08  Alexandre Oliva  <aoliva@redhat.com>
+
 	PR debug/45673
 	PR debug/45604
 	PR debug/45419

gcc/cse.c

@@ -6348,30 +6348,32 @@ cse_extended_basic_block (struct cse_basic_block_data *ebb_data)
 		recorded_label_ref = true;
 
 #ifdef HAVE_cc0
-	      /* If the previous insn set CC0 and this insn no longer
-		 references CC0, delete the previous insn.  Here we use
-		 fact that nothing expects CC0 to be valid over an insn,
-		 which is true until the final pass.  */
+	      if (NONDEBUG_INSN_P (insn))
 		{
+		  /* If the previous insn sets CC0 and this insn no
+		     longer references CC0, delete the previous insn.
+		     Here we use fact that nothing expects CC0 to be
+		     valid over an insn, which is true until the final
+		     pass.  */
 		  rtx prev_insn, tem;
 
-		prev_insn = PREV_INSN (insn);
+		  prev_insn = prev_nonnote_nondebug_insn (insn);
 		  if (prev_insn && NONJUMP_INSN_P (prev_insn)
-		    && (tem = single_set (prev_insn)) != 0
+		      && (tem = single_set (prev_insn)) != NULL_RTX
 		      && SET_DEST (tem) == cc0_rtx
 		      && ! reg_mentioned_p (cc0_rtx, PATTERN (insn)))
 		    delete_insn (prev_insn);
-	      }
 
-	      /* If this insn is not the last insn in the basic block,
-		 it will be PREV_INSN(insn) in the next iteration.  If
-		 we recorded any CC0-related information for this insn,
-		 remember it.  */
+		  /* If this insn is not the last insn in the basic
+		     block, it will be PREV_INSN(insn) in the next
+		     iteration.  If we recorded any CC0-related
+		     information for this insn, remember it.  */
 		  if (insn != BB_END (bb))
 		    {
 		      prev_insn_cc0 = this_insn_cc0;
 		      prev_insn_cc0_mode = this_insn_cc0_mode;
 		    }
+		}
 #endif
 	    }
 	}
@@ -6713,7 +6715,7 @@ set_live_p (rtx set, rtx insn ATTRIBUTE_UNUSED, /* Only used with HAVE_cc0.  */
 #ifdef HAVE_cc0
   else if (GET_CODE (SET_DEST (set)) == CC0
 	   && !side_effects_p (SET_SRC (set))
-	   && ((tem = next_nonnote_insn (insn)) == 0
+	   && ((tem = next_nonnote_nondebug_insn (insn)) == NULL_RTX
 	       || !INSN_P (tem)
 	       || !reg_referenced_p (cc0_rtx, PATTERN (tem))))
     return false;