Subtracting values to produce a -/0/+ comparison value only works when original values have limited range. Otherwise it leads to broken comparator that indicates 0 < 0x40000000 < 0x80000000 < 0.
Yuri posted an equivalent patch just a few hours ago: https://gcc.gnu.org/ml/gcc-patches/2017-07/msg00882.html * tree-vrp.c (compare_assert_loc): Properly compare hash values. --- gcc/tree-vrp.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/gcc/tree-vrp.c b/gcc/tree-vrp.c index 28205f1..d1888f6 100644 --- a/gcc/tree-vrp.c +++ b/gcc/tree-vrp.c @@ -6459,7 +6459,7 @@ compare_assert_loc (const void *pa, const void *pb) return (a->e != NULL ? 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 -- 1.8.3.1
