re PR tree-optimization/31911 (Short function (md4) takes very long to compile)

2007-05-13  Daniel Berlin  <dberlin@dberlin.org>

	Fix PR tree-optimization/31911
	* tree-ssa-pre.c (phi_translate): Make sure to cache results even
	if they didn't change the expression.

From-SVN: r124657

gcc/ChangeLog

+2007-05-13  Daniel Berlin  <dberlin@dberlin.org>
+
+	Fix PR tree-optimization/31911
+	* tree-ssa-pre.c (phi_translate): Make sure to cache results even
+	if they didn't change the expression.
+
 2007-05-13  Zdenek Dvorak  <dvorakz@suse.cz>
 
 	* tree-scalar-evolution.c (resolve_mixers): Exported.

gcc/tree-ssa-pre.c

@@ -1075,8 +1075,8 @@ phi_translate (tree expr, bitmap_set_t set1, bitmap_set_t set2,
 		newexpr->base.ann = NULL;
 		vn_lookup_or_add_with_vuses (newexpr, tvuses);
 		expr = newexpr;
-		phi_trans_add (oldexpr, newexpr, pred, tvuses);
 	      }
+	    phi_trans_add (oldexpr, expr, pred, tvuses);
 	  }
       }
       return expr;
@@ -1188,8 +1188,8 @@ phi_translate (tree expr, bitmap_set_t set1, bitmap_set_t set2,
 		vn_lookup_or_add_with_vuses (newexpr, newvuses);
 	      }
 	    expr = newexpr;
-	    phi_trans_add (oldexpr, newexpr, pred, newvuses);
 	  }
+	phi_trans_add (oldexpr, expr, pred, newvuses);
       }
       return expr;
       break;
@@ -1233,8 +1233,8 @@ phi_translate (tree expr, bitmap_set_t set1, bitmap_set_t set2,
 		vn_lookup_or_add (newexpr, NULL);
 	      }
 	    expr = newexpr;
-	    phi_trans_add (oldexpr, newexpr, pred, NULL);
 	  }
+	phi_trans_add (oldexpr, expr, pred, NULL);
       }
       return expr;
 
@@ -1266,8 +1266,8 @@ phi_translate (tree expr, bitmap_set_t set1, bitmap_set_t set2,
 		vn_lookup_or_add (newexpr, NULL);
 	      }
 	    expr = newexpr;
-	    phi_trans_add (oldexpr, newexpr, pred, NULL);
 	  }
+	phi_trans_add (oldexpr, expr, pred, NULL);
       }
       return expr;