diff options
Diffstat (limited to 'gcc/ada/gcc-interface/trans.c')
| -rw-r--r-- | gcc/ada/gcc-interface/trans.c | 37 |
1 files changed, 30 insertions, 7 deletions
diff --git a/gcc/ada/gcc-interface/trans.c b/gcc/ada/gcc-interface/trans.c index b658620..8a15c2d 100644 --- a/gcc/ada/gcc-interface/trans.c +++ b/gcc/ada/gcc-interface/trans.c @@ -2130,6 +2130,26 @@ can_equal_max_val_p (tree val, tree type, bool reverse) return can_equal_min_or_max_val_p (val, type, !reverse); } +/* Return true if VAL1 can be lower than VAL2. */ + +static bool +can_be_lower_p (tree val1, tree val2) +{ + if (TREE_CODE (val1) == NOP_EXPR) + val1 = TYPE_MIN_VALUE (TREE_TYPE (TREE_OPERAND (val1, 0))); + + if (TREE_CODE (val1) != INTEGER_CST) + return true; + + if (TREE_CODE (val2) == NOP_EXPR) + val2 = TYPE_MAX_VALUE (TREE_TYPE (TREE_OPERAND (val2, 0))); + + if (TREE_CODE (val2) != INTEGER_CST) + return true; + + return tree_int_cst_lt (val1, val2); +} + /* Subroutine of gnat_to_gnu to translate gnat_node, an N_Loop_Statement, to a GCC tree, which is returned. */ @@ -2297,16 +2317,19 @@ Loop_Statement_to_gnu (Node_Id gnat_node) LOOP_STMT_BOTTOM_COND_P (gnu_loop_stmt) = 1; /* If we use the BOTTOM_COND, we can turn the test into an inequality - test but we have to add an ENTRY_COND to protect the empty loop. */ + test but we may have to add ENTRY_COND to protect the empty loop. */ if (LOOP_STMT_BOTTOM_COND_P (gnu_loop_stmt)) { test_code = NE_EXPR; - gnu_cond_expr - = build3 (COND_EXPR, void_type_node, - build_binary_op (LE_EXPR, boolean_type_node, - gnu_low, gnu_high), - NULL_TREE, alloc_stmt_list ()); - set_expr_location_from_node (gnu_cond_expr, gnat_loop_spec); + if (can_be_lower_p (gnu_high, gnu_low)) + { + gnu_cond_expr + = build3 (COND_EXPR, void_type_node, + build_binary_op (LE_EXPR, boolean_type_node, + gnu_low, gnu_high), + NULL_TREE, alloc_stmt_list ()); + set_expr_location_from_node (gnu_cond_expr, gnat_loop_spec); + } } /* Open a new nesting level that will surround the loop to declare the |