On Aug 25, 2011, at 1:35 PM, Michael Meissner wrote:
> The alternative is something like what Kenney and Mike are doing in their
> private port, where they have new syntax in the MD file for builtins.
I think the issue is actually largely orthogonal. In our code, we generate
which code is used by a description for the built-in, picking a simple one:
(define_builtin "port_add" "port_add_<type>"
[
(define_outputs [(var_operand:T_ALL_DI 0)])
(define_inputs [(var_operand:T_ALL_DI 1)
(var_operand:T_ALL_DI 2)
(var_operand:T_ALL_DI 3)])
(define_rtl_pattern "port_add_<m_mode>" [0 1 2 3])
(attributes [pure])
]
)
from this, we generate everything needed. Way under the hood, there is a set
of enum values, but, you wouldn't ever see them. There isn't a one-to-one
correspondence as we permit overloading. We start as 0 and increase, but, we
could just as easily start at LAST_MI_BUILTIN+1. Things like T_ALL_DI as
iterators which describe the front-end type to use and how it relates to modes
in rtl-land. T_DI might be long, and T_UDI might be unsigned long, the mode
for both is DImode.
