[PATCH] Minor changes in tree-vrp.c

[Patrick Palka <patrick at parcs dot ath dot cx>]

1. When dumping assert details, print loc->expr instead of the bare SSA
name.  loc->expr is not always equal to the SSA name.  For example we
sometimes insert an ASSERT_EXPR like

  x_7 = ASSERT_EXPR <x_4(D), (unsigned int) x_4(D) + 4294967295 > 8>;

The diff of the new dump output looks like:

Assertions to be inserted for x_4(D)
        if (_4 <= 8)

        BB #3
        EDGE 2->3 2 [39.0%]  (FALSE_VALUE,EXECUTABLE)
 -      PREDICATE: x_4(D) gt_expr 8
 +      PREDICATE: (unsigned int) x_4(D) + 4294967295 gt_expr 8

2. In extract_code_and_val_from_cond_with_ops verify that name is equal to
either cond_op0 or cond_op1.  If name is not equal to one of these
operands then its caller register_edge_assert_for will malfunction and
the wrong assertion will get inserted.

Is this OK to commit after bootstrap + regtesting?

gcc/ChangeLog:

	* tree-vrp.c (dump_asserts_for): Print loc->expr instead of
	name.
	(extract_code_and_val_from_cond_with_ops): Verify that name is
	either cond_op0 or cond_op1.
---
 gcc/tree-vrp.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/gcc/tree-vrp.c b/gcc/tree-vrp.c
index a3068ec..5072370 100644
--- a/gcc/tree-vrp.c
+++ b/gcc/tree-vrp.c
@@ -4827,7 +4827,7 @@ dump_asserts_for (FILE *file, tree name)
 	  dump_edge_info (file, loc->e, dump_flags, 0);
 	}
       fprintf (file, "\n\tPREDICATE: ");
-      print_generic_expr (file, name, 0);
+      print_generic_expr (file, loc->expr, 0);
       fprintf (file, " %s ", get_tree_code_name (loc->comp_code));
       print_generic_expr (file, loc->val, 0);
       fprintf (file, "\n\n");
@@ -5009,13 +5009,15 @@ extract_code_and_val_from_cond_with_ops (tree name, enum tree_code cond_code,
       comp_code = swap_tree_comparison (cond_code);
       val = cond_op0;
     }
-  else
+  else if (name == cond_op0)
     {
       /* The comparison is of the form NAME COMP VAL, so the
 	 comparison code remains unchanged.  */
       comp_code = cond_code;
       val = cond_op1;
     }
+  else
+    gcc_unreachable ();
 
   /* Invert the comparison code as necessary.  */
   if (invert)
-- 
2.9.2.413.g76d2a70