> I noticed while debugging why my "A?CST1:CST0" patch was broken for
> Ada, I noticed the following ranges for boolean types:
> # RANGE [0, 1] NONZERO 1
> _14 = checks__saved_checks_tos.482_2 > 0;
> # RANGE [0, 255] NONZERO 1
> _18 = _14 == 0;
> _19 = ~_18;
The '~' looks problematic if this is for Ada code, it ought to be:
_19 = _18 ^ 1;
See below.
> Should TYPE_UNSIGNED be always set for boolean types?
>
> I am testing the below patch to see if it fixes the problem, if we
> should assume TYPE_UNSIGNED is true for boolean types. If we should
> not assume that, then there is a problem with conversion between
> boolean types that have TYPE_UNSIGNED mismatched.
The patch is a nop, boolean types are always unsigned in Ada, see cstand.adb:
Set_Is_Unsigned_Type (Standard_Boolean);
but they have 8-bit precision instead of 1-bit precision so must be handled
with care, in particular BIT_NOT_EXPR should be avoided for them, see e.g. the
gimplifier:
if (TYPE_PRECISION (TREE_TYPE (*expr_p)) == 1)
*expr_p = build1_loc (input_location, BIT_NOT_EXPR,
TREE_TYPE (*expr_p),
TREE_OPERAND (*expr_p, 0));
else
*expr_p = build2_loc (input_location, BIT_XOR_EXPR,
TREE_TYPE (*expr_p),
TREE_OPERAND (*expr_p, 0),
build_int_cst (TREE_TYPE
(*expr_p), 1));
--
Eric Botcazou
