diff options
Diffstat (limited to 'gcc/tree-vrp.c')
| -rw-r--r-- | gcc/tree-vrp.c | 21 |
1 files changed, 21 insertions, 0 deletions
diff --git a/gcc/tree-vrp.c b/gcc/tree-vrp.c index b5654c5..bbdf9ce 100644 --- a/gcc/tree-vrp.c +++ b/gcc/tree-vrp.c @@ -5310,6 +5310,27 @@ register_edge_assert_for_2 (tree name, edge e, gimple_stmt_iterator bsi, if (is_gimple_assign (def_stmt)) rhs_code = gimple_assign_rhs_code (def_stmt); + /* In the case of NAME != CST1 where NAME = A +- CST2 we can + assert that A != CST1 -+ CST2. */ + if ((comp_code == EQ_EXPR || comp_code == NE_EXPR) + && (rhs_code == PLUS_EXPR || rhs_code == MINUS_EXPR)) + { + tree op0 = gimple_assign_rhs1 (def_stmt); + tree op1 = gimple_assign_rhs2 (def_stmt); + if (TREE_CODE (op0) == SSA_NAME + && TREE_CODE (op1) == INTEGER_CST + && live_on_edge (e, op0) + && !has_single_use (op0)) + { + enum tree_code reverse_op = (rhs_code == PLUS_EXPR + ? MINUS_EXPR : PLUS_EXPR); + op1 = int_const_binop (reverse_op, val, op1); + if (TREE_OVERFLOW (op1)) + op1 = drop_tree_overflow (op1); + register_new_assert_for (op0, op0, comp_code, op1, NULL, e, bsi); + } + } + /* Add asserts for NAME cmp CST and NAME being defined as NAME = (int) NAME2. */ if (!TYPE_UNSIGNED (TREE_TYPE (val)) |