2017-07-15  Yury Gribov  <tetra2005@gmail.com>

gcc/
        * tree-vrp.c (compare_assert_loc): Fix comparison function
	to return predictable results.

diff -rupN gcc/gcc/tree-vrp.c gcc-qsort/gcc/tree-vrp.c
--- gcc/gcc/tree-vrp.c	2017-07-14 08:20:48.000000000 +0200
+++ gcc-qsort/gcc/tree-vrp.c	2017-07-14 10:04:06.000000000 +0200
@@ -6426,7 +6426,7 @@ compare_assert_loc (const void *pa, cons
     return (a->e && b->e
 	    ? a->e->src->index - b->e->src->index
 	    : a->bb->index - b->bb->index);
-  return ha - hb;
+  return ha > hb ? 1 : -1;
 }
 
 /* Process all the insertions registered for every name N_i registered