[PATCH] Fix PR43255

[Richard Guenther]

This fixes ICEs in VRP that occur because we have some unfolded
trees.

Bootstrapped and tested on x86_64-unknown-linux-gnu, applied to trunk.

Richard.

2010-03-11  Richard Guenther  <rguenther@suse.de>

	PR tree-optimization/43255
	* tree-vrp.c (process_assert_insertions_for): Do not insert
	asserts for trivial conditions.

	* gcc.c-torture/compile/pr43255.c: New testcase.

Index: gcc/tree-vrp.c
===================================================================
*** gcc/tree-vrp.c	(revision 157384)
--- gcc/tree-vrp.c	(working copy)
*************** process_assert_insertions_for (tree name
*** 4836,4841 ****
--- 4836,4845 ----
    edge_iterator ei;
    edge e;
  
+   /* If we have X <=> X do not insert an assert expr for that.  */
+   if (loc->expr == loc->val)
+     return false;
+ 
    cond = build2 (loc->comp_code, boolean_type_node, loc->expr, loc->val);
    assert_stmt = build_assert_expr_for (cond, name);
    if (loc->e)
Index: gcc/testsuite/gcc.c-torture/compile/pr43255.c
===================================================================
*** gcc/testsuite/gcc.c-torture/compile/pr43255.c	(revision 0)
--- gcc/testsuite/gcc.c-torture/compile/pr43255.c	(revision 0)
***************
*** 0 ****
--- 1,33 ----
+ int safe (int);
+ 
+ static unsigned foo (unsigned ui1, unsigned ui2)
+ {
+   return ui1 + ui2;
+ }
+ 
+ int g_22;
+ int *volatile g_23 = &g_22;
+ int **g_282[8][10][1];
+ int *g_330 = &g_22;
+ volatile unsigned g_348;
+ int g_397;
+ 
+ void int32func (const unsigned char p_10)
+ {
+   if (foo
+       (~
+        (p_10 |
+ 	(*g_282[(unsigned long) g_397 % 8][(unsigned) g_22 % 10][g_348 % 1]) ==
+ 	(*g_282[(unsigned long) g_397 % 8][(unsigned) g_22 % 10][g_348 % 1])),
+        1))
+     {
+     }
+   else if (*g_330 >=
+ 	   safe (*g_23 ^
+ 		 (**g_282[(unsigned long) g_397 % 8][(unsigned) g_22 % 10]
+ 		  [g_348 % 1])) & **g_282[8][10][1], 1)
+     {
+     }
+ }
+ 
+